11 files changed, 3286 insertions, 3 deletions

diff --git a/llvm/test/CodeGen/AArch64/O3-pipeline.ll b/llvm/test/CodeGen/AArch64/O3-pipeline.ll
index f2babdfb869..03815481ef5 100644
--- a/llvm/test/CodeGen/AArch64/O3-pipeline.ll
+++ b/llvm/test/CodeGen/AArch64/O3-pipeline.ll
@@ -32,6 +32,10 @@
 ; CHECK-NEXT:       Loop Pass Manager
 ; CHECK-NEXT:         Induction Variable Users
 ; CHECK-NEXT:         Loop Strength Reduction
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:         Function Alias Analysis Results
+; CHECK-NEXT:       Merge contiguous icmps into a memcmp
+; CHECK-NEXT:       Expand memcmp() to load/stores
 ; CHECK-NEXT:       Lower Garbage Collection Instructions
 ; CHECK-NEXT:       Shadow Stack GC Lowering
 ; CHECK-NEXT:       Remove unreachable blocks from the CFG
diff --git a/llvm/test/CodeGen/ARM/O3-pipeline.ll b/llvm/test/CodeGen/ARM/O3-pipeline.ll
index 6e1e5922caa..f81f8ce51d1 100644
--- a/llvm/test/CodeGen/ARM/O3-pipeline.ll
+++ b/llvm/test/CodeGen/ARM/O3-pipeline.ll
@@ -16,6 +16,10 @@
 ; CHECK-NEXT:      Loop Pass Manager
 ; CHECK-NEXT:        Induction Variable Users
 ; CHECK-NEXT:        Loop Strength Reduction
+; CHECK-NEXT:      Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:      Function Alias Analysis Results
+; CHECK-NEXT:      Merge contiguous icmps into a memcmp
+; CHECK-NEXT:      Expand memcmp() to load/stores
 ; CHECK-NEXT:      Lower Garbage Collection Instructions
 ; CHECK-NEXT:      Shadow Stack GC Lowering
 ; CHECK-NEXT:      Remove unreachable blocks from the CFG
diff --git a/llvm/test/CodeGen/Generic/llc-start-stop.ll b/llvm/test/CodeGen/Generic/llc-start-stop.ll
index 1fc01533d35..fa34838a411 100644
--- a/llvm/test/CodeGen/Generic/llc-start-stop.ll
+++ b/llvm/test/CodeGen/Generic/llc-start-stop.ll
@@ -13,15 +13,15 @@
 ; STOP-BEFORE-NOT: Loop Strength Reduction
 
 ; RUN: llc < %s -debug-pass=Structure -start-after=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=START-AFTER
-; START-AFTER: -gc-lowering
+; START-AFTER: -aa -mergeicmps
 ; START-AFTER: FunctionPass Manager
-; START-AFTER-NEXT: Lower Garbage Collection Instructions
+; START-AFTER-NEXT: Dominator Tree Construction
 
 ; RUN: llc < %s -debug-pass=Structure -start-before=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=START-BEFORE
 ; START-BEFORE: -machine-branch-prob -domtree
 ; START-BEFORE: FunctionPass Manager
 ; START-BEFORE: Loop Strength Reduction
-; START-BEFORE-NEXT: Lower Garbage Collection Instructions
+; START-BEFORE-NEXT: Basic Alias Analysis (stateless AA impl)
 
 ; RUN: not llc < %s -start-before=nonexistent -o /dev/null 2>&1 | FileCheck %s -check-prefix=NONEXISTENT-START-BEFORE
 ; RUN: not llc < %s -stop-before=nonexistent -o /dev/null 2>&1 | FileCheck %s -check-prefix=NONEXISTENT-STOP-BEFORE
diff --git a/llvm/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll b/llvm/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll
new file mode 100644
index 00000000000..30aff0e32b8
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/memCmpUsedInZeroEqualityComparison.ll
@@ -0,0 +1,220 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -ppc-gpr-icmps=all -verify-machineinstrs -mcpu=pwr8 < %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-unknown-linux-gnu"
+
+@zeroEqualityTest01.buffer1 = private unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 4], align 4
+@zeroEqualityTest01.buffer2 = private unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 3], align 4
+@zeroEqualityTest02.buffer1 = private unnamed_addr constant [4 x i32] [i32 4, i32 0, i32 0, i32 0], align 4
+@zeroEqualityTest02.buffer2 = private unnamed_addr constant [4 x i32] [i32 3, i32 0, i32 0, i32 0], align 4
+@zeroEqualityTest03.buffer1 = private unnamed_addr constant [4 x i32] [i32 0, i32 0, i32 0, i32 3], align 4
+@zeroEqualityTest03.buffer2 = private unnamed_addr constant [4 x i32] [i32 0, i32 0, i32 0, i32 4], align 4
+@zeroEqualityTest04.buffer1 = private unnamed_addr constant [15 x i32] [i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14], align 4
+@zeroEqualityTest04.buffer2 = private unnamed_addr constant [15 x i32] [i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 13], align 4
+
+declare signext i32 @memcmp(i8* nocapture, i8* nocapture, i64) local_unnamed_addr #1
+
+; Check 4 bytes - requires 1 load for each param.
+define signext i32 @zeroEqualityTest02(i8* %x, i8* %y) {
+; CHECK-LABEL: zeroEqualityTest02:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lwz 3, 0(3)
+; CHECK-NEXT:    lwz 4, 0(4)
+; CHECK-NEXT:    xor 3, 3, 4
+; CHECK-NEXT:    cntlzw 3, 3
+; CHECK-NEXT:    srwi 3, 3, 5
+; CHECK-NEXT:    xori 3, 3, 1
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* %x, i8* %y, i64 4)
+  %not.cmp = icmp ne i32 %call, 0
+  %. = zext i1 %not.cmp to i32
+  ret i32 %.
+}
+
+; Check 16 bytes - requires 2 loads for each param (or use vectors?).
+define signext i32 @zeroEqualityTest01(i8* %x, i8* %y) {
+; CHECK-LABEL: zeroEqualityTest01:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    ld 5, 0(3)
+; CHECK-NEXT:    ld 6, 0(4)
+; CHECK-NEXT:    cmpld 5, 6
+; CHECK-NEXT:    bne 0, .LBB1_2
+; CHECK-NEXT:  # %bb.1: # %loadbb1
+; CHECK-NEXT:    ld 3, 8(3)
+; CHECK-NEXT:    ld 4, 8(4)
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    li 3, 0
+; CHECK-NEXT:    beq 0, .LBB1_3
+; CHECK-NEXT:  .LBB1_2: # %res_block
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:  .LBB1_3: # %endblock
+; CHECK-NEXT:    clrldi 3, 3, 32
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* %x, i8* %y, i64 16)
+  %not.tobool = icmp ne i32 %call, 0
+  %. = zext i1 %not.tobool to i32
+  ret i32 %.
+}
+
+; Check 7 bytes - requires 3 loads for each param.
+define signext i32 @zeroEqualityTest03(i8* %x, i8* %y) {
+; CHECK-LABEL: zeroEqualityTest03:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lwz 5, 0(3)
+; CHECK-NEXT:    lwz 6, 0(4)
+; CHECK-NEXT:    cmplw 5, 6
+; CHECK-NEXT:    bne 0, .LBB2_3
+; CHECK-NEXT:  # %bb.1: # %loadbb1
+; CHECK-NEXT:    lhz 5, 4(3)
+; CHECK-NEXT:    lhz 6, 4(4)
+; CHECK-NEXT:    cmplw 5, 6
+; CHECK-NEXT:    bne 0, .LBB2_3
+; CHECK-NEXT:  # %bb.2: # %loadbb2
+; CHECK-NEXT:    lbz 3, 6(3)
+; CHECK-NEXT:    lbz 4, 6(4)
+; CHECK-NEXT:    cmplw 3, 4
+; CHECK-NEXT:    li 3, 0
+; CHECK-NEXT:    beq 0, .LBB2_4
+; CHECK-NEXT:  .LBB2_3: # %res_block
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:  .LBB2_4: # %endblock
+; CHECK-NEXT:    clrldi 3, 3, 32
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* %x, i8* %y, i64 7)
+  %not.lnot = icmp ne i32 %call, 0
+  %cond = zext i1 %not.lnot to i32
+  ret i32 %cond
+}
+
+; Validate with > 0
+define signext i32 @zeroEqualityTest04() {
+; CHECK-LABEL: zeroEqualityTest04:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addis 3, 2, .LzeroEqualityTest02.buffer1@toc@ha
+; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest02.buffer2@toc@ha
+; CHECK-NEXT:    addi 6, 3, .LzeroEqualityTest02.buffer1@toc@l
+; CHECK-NEXT:    addi 5, 4, .LzeroEqualityTest02.buffer2@toc@l
+; CHECK-NEXT:    ldbrx 3, 0, 6
+; CHECK-NEXT:    ldbrx 4, 0, 5
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    bne 0, .LBB3_2
+; CHECK-NEXT:  # %bb.1: # %loadbb1
+; CHECK-NEXT:    li 4, 8
+; CHECK-NEXT:    ldbrx 3, 6, 4
+; CHECK-NEXT:    ldbrx 4, 5, 4
+; CHECK-NEXT:    li 5, 0
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    beq 0, .LBB3_3
+; CHECK-NEXT:  .LBB3_2: # %res_block
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:    li 4, -1
+; CHECK-NEXT:    isel 5, 4, 3, 0
+; CHECK-NEXT:  .LBB3_3: # %endblock
+; CHECK-NEXT:    extsw 3, 5
+; CHECK-NEXT:    neg 3, 3
+; CHECK-NEXT:    rldicl 3, 3, 1, 63
+; CHECK-NEXT:    xori 3, 3, 1
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* bitcast ([4 x i32]* @zeroEqualityTest02.buffer1 to i8*), i8* bitcast ([4 x i32]* @zeroEqualityTest02.buffer2 to i8*), i64 16)
+  %not.cmp = icmp slt i32 %call, 1
+  %. = zext i1 %not.cmp to i32
+  ret i32 %.
+}
+
+; Validate with < 0
+define signext i32 @zeroEqualityTest05() {
+; CHECK-LABEL: zeroEqualityTest05:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addis 3, 2, .LzeroEqualityTest03.buffer1@toc@ha
+; CHECK-NEXT:    addis 4, 2, .LzeroEqualityTest03.buffer2@toc@ha
+; CHECK-NEXT:    addi 6, 3, .LzeroEqualityTest03.buffer1@toc@l
+; CHECK-NEXT:    addi 5, 4, .LzeroEqualityTest03.buffer2@toc@l
+; CHECK-NEXT:    ldbrx 3, 0, 6
+; CHECK-NEXT:    ldbrx 4, 0, 5
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    bne 0, .LBB4_2
+; CHECK-NEXT:  # %bb.1: # %loadbb1
+; CHECK-NEXT:    li 4, 8
+; CHECK-NEXT:    ldbrx 3, 6, 4
+; CHECK-NEXT:    ldbrx 4, 5, 4
+; CHECK-NEXT:    li 5, 0
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    beq 0, .LBB4_3
+; CHECK-NEXT:  .LBB4_2: # %res_block
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:    li 4, -1
+; CHECK-NEXT:    isel 5, 4, 3, 0
+; CHECK-NEXT:  .LBB4_3: # %endblock
+; CHECK-NEXT:    nor 3, 5, 5
+; CHECK-NEXT:    rlwinm 3, 3, 1, 31, 31
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* bitcast ([4 x i32]* @zeroEqualityTest03.buffer1 to i8*), i8* bitcast ([4 x i32]* @zeroEqualityTest03.buffer2 to i8*), i64 16)
+  %call.lobit = lshr i32 %call, 31
+  %call.lobit.not = xor i32 %call.lobit, 1
+  ret i32 %call.lobit.not
+}
+
+; Validate with memcmp()?:
+define signext i32 @equalityFoldTwoConstants() {
+; CHECK-LABEL: equalityFoldTwoConstants:
+; CHECK:       # %bb.0: # %loadbb
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* bitcast ([15 x i32]* @zeroEqualityTest04.buffer1 to i8*), i8* bitcast ([15 x i32]* @zeroEqualityTest04.buffer2 to i8*), i64 16)
+  %not.tobool = icmp eq i32 %call, 0
+  %cond = zext i1 %not.tobool to i32
+  ret i32 %cond
+}
+
+define signext i32 @equalityFoldOneConstant(i8* %X) {
+; CHECK-LABEL: equalityFoldOneConstant:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    ld 4, 0(3)
+; CHECK-NEXT:    li 5, 1
+; CHECK-NEXT:    sldi 5, 5, 32
+; CHECK-NEXT:    cmpld 4, 5
+; CHECK-NEXT:    bne 0, .LBB6_2
+; CHECK-NEXT:  # %bb.1: # %loadbb1
+; CHECK-NEXT:    li 4, 3
+; CHECK-NEXT:    ld 3, 8(3)
+; CHECK-NEXT:    sldi 4, 4, 32
+; CHECK-NEXT:    ori 4, 4, 2
+; CHECK-NEXT:    cmpld 3, 4
+; CHECK-NEXT:    li 3, 0
+; CHECK-NEXT:    beq 0, .LBB6_3
+; CHECK-NEXT:  .LBB6_2: # %res_block
+; CHECK-NEXT:    li 3, 1
+; CHECK-NEXT:  .LBB6_3: # %endblock
+; CHECK-NEXT:    cntlzw 3, 3
+; CHECK-NEXT:    srwi 3, 3, 5
+; CHECK-NEXT:    blr
+  %call = tail call signext i32 @memcmp(i8* bitcast ([15 x i32]* @zeroEqualityTest04.buffer1 to i8*), i8* %X, i64 16)
+  %not.tobool = icmp eq i32 %call, 0
+  %cond = zext i1 %not.tobool to i32
+  ret i32 %cond
+}
+
+define i1 @length2_eq_nobuiltin_attr(i8* %X, i8* %Y) {
+; CHECK-LABEL: length2_eq_nobuiltin_attr:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    mflr 0
+; CHECK-NEXT:    std 0, 16(1)
+; CHECK-NEXT:    stdu 1, -32(1)
+; CHECK-NEXT:    .cfi_def_cfa_offset 32
+; CHECK-NEXT:    .cfi_offset lr, 16
+; CHECK-NEXT:    li 5, 2
+; CHECK-NEXT:    bl memcmp
+; CHECK-NEXT:    nop
+; CHECK-NEXT:    cntlzw 3, 3
+; CHECK-NEXT:    rlwinm 3, 3, 27, 31, 31
+; CHECK-NEXT:    addi 1, 1, 32
+; CHECK-NEXT:    ld 0, 16(1)
+; CHECK-NEXT:    mtlr 0
+; CHECK-NEXT:    blr
+  %m = tail call signext i32 @memcmp(i8* %X, i8* %Y, i64 2) nobuiltin
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
diff --git a/llvm/test/CodeGen/PowerPC/memcmp-mergeexpand.ll b/llvm/test/CodeGen/PowerPC/memcmp-mergeexpand.ll
new file mode 100644
index 00000000000..298ce90b74e
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/memcmp-mergeexpand.ll
@@ -0,0 +1,40 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mcpu=pwr8 -mtriple=powerpc64le-unknown-gnu-linux  < %s | FileCheck %s -check-prefix=PPC64LE
+
+; This tests interaction between MergeICmp and ExpandMemCmp.
+
+%"struct.std::pair" = type { i32, i32 }
+
+define zeroext i1 @opeq1(
+; PPC64LE-LABEL: opeq1:
+; PPC64LE:       # %bb.0: # %"entry+land.rhs.i"
+; PPC64LE-NEXT:    ld 3, 0(3)
+; PPC64LE-NEXT:    ld 4, 0(4)
+; PPC64LE-NEXT:    xor 3, 3, 4
+; PPC64LE-NEXT:    cntlzd 3, 3
+; PPC64LE-NEXT:    rldicl 3, 3, 58, 63
+; PPC64LE-NEXT:    blr
+  %"struct.std::pair"* nocapture readonly dereferenceable(8) %a,
+  %"struct.std::pair"* nocapture readonly dereferenceable(8) %b) local_unnamed_addr #0 {
+entry:
+  %first.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 0
+  %0 = load i32, i32* %first.i, align 4
+  %first1.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 0
+  %1 = load i32, i32* %first1.i, align 4
+  %cmp.i = icmp eq i32 %0, %1
+  br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit
+
+land.rhs.i:
+  %second.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 1
+  %2 = load i32, i32* %second.i, align 4
+  %second2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 1
+  %3 = load i32, i32* %second2.i, align 4
+  %cmp3.i = icmp eq i32 %2, %3
+  br label %opeq1.exit
+
+opeq1.exit:
+  %4 = phi i1 [ false, %entry ], [ %cmp3.i, %land.rhs.i ]
+  ret i1 %4
+}
+
+
diff --git a/llvm/test/CodeGen/PowerPC/memcmp.ll b/llvm/test/CodeGen/PowerPC/memcmp.ll
new file mode 100644
index 00000000000..4aa5b400dd7
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/memcmp.ll
@@ -0,0 +1,70 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -verify-machineinstrs -mcpu=pwr8 -mtriple=powerpc64le-unknown-gnu-linux  < %s | FileCheck %s -check-prefix=CHECK
+
+define signext i32 @memcmp8(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2) {
+; CHECK-LABEL: memcmp8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    ldbrx 3, 0, 3
+; CHECK-NEXT:    ldbrx 4, 0, 4
+; CHECK-NEXT:    subfc 5, 3, 4
+; CHECK-NEXT:    subfe 5, 4, 4
+; CHECK-NEXT:    subfc 4, 4, 3
+; CHECK-NEXT:    subfe 3, 3, 3
+; CHECK-NEXT:    neg 4, 5
+; CHECK-NEXT:    neg 3, 3
+; CHECK-NEXT:    subf 3, 3, 4
+; CHECK-NEXT:    extsw 3, 3
+; CHECK-NEXT:    blr
+  %t0 = bitcast i32* %buffer1 to i8*
+  %t1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %t0, i8* %t1, i64 8)
+  ret i32 %call
+}
+
+define signext i32 @memcmp4(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2) {
+; CHECK-LABEL: memcmp4:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lwbrx 3, 0, 3
+; CHECK-NEXT:    lwbrx 4, 0, 4
+; CHECK-NEXT:    sub 5, 4, 3
+; CHECK-NEXT:    sub 3, 3, 4
+; CHECK-NEXT:    rldicl 4, 5, 1, 63
+; CHECK-NEXT:    rldicl 3, 3, 1, 63
+; CHECK-NEXT:    subf 3, 3, 4
+; CHECK-NEXT:    extsw 3, 3
+; CHECK-NEXT:    blr
+  %t0 = bitcast i32* %buffer1 to i8*
+  %t1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %t0, i8* %t1, i64 4)
+  ret i32 %call
+}
+
+define signext i32 @memcmp2(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2) {
+; CHECK-LABEL: memcmp2:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lhbrx 3, 0, 3
+; CHECK-NEXT:    lhbrx 4, 0, 4
+; CHECK-NEXT:    subf 3, 4, 3
+; CHECK-NEXT:    extsw 3, 3
+; CHECK-NEXT:    blr
+  %t0 = bitcast i32* %buffer1 to i8*
+  %t1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %t0, i8* %t1, i64 2)
+  ret i32 %call
+}
+
+define signext i32 @memcmp1(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2) {
+; CHECK-LABEL: memcmp1:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    lbz 3, 0(3)
+; CHECK-NEXT:    lbz 4, 0(4)
+; CHECK-NEXT:    subf 3, 4, 3
+; CHECK-NEXT:    extsw 3, 3
+; CHECK-NEXT:    blr
+  %t0 = bitcast i32* %buffer1 to i8*
+  %t1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %t0, i8* %t1, i64 1) #2
+  ret i32 %call
+}
+
+declare signext i32 @memcmp(i8*, i8*, i64)
diff --git a/llvm/test/CodeGen/PowerPC/memcmpIR.ll b/llvm/test/CodeGen/PowerPC/memcmpIR.ll
new file mode 100644
index 00000000000..4c0de720fc6
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/memcmpIR.ll
@@ -0,0 +1,192 @@
+; RUN: llc -o - -mtriple=powerpc64le-unknown-gnu-linux -stop-after codegenprepare %s | FileCheck %s
+; RUN: llc -o - -mtriple=powerpc64-unknown-gnu-linux -stop-after codegenprepare %s | FileCheck %s --check-prefix=CHECK-BE
+
+define signext i32 @test1(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2)  {
+entry:
+  ; CHECK-LABEL: @test1(
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i64, i64*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64*
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD2]])
+  ; CHECK-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[BSWAP1]], [[BSWAP2]]
+  ; CHECK-NEXT:  br i1 [[ICMP]], label %loadbb1, label %res_block
+
+  ; CHECK-LABEL: res_block:{{.*}}
+  ; CHECK: [[ICMP2:%[0-9]+]] = icmp ult i64
+  ; CHECK-NEXT: [[SELECT:%[0-9]+]] = select i1 [[ICMP2]], i32 -1, i32 1
+  ; CHECK-NEXT: br label %endblock
+
+  ; CHECK-LABEL: loadbb1:{{.*}}
+  ; CHECK: [[BCC1:%[0-9]+]] = bitcast i32* {{.*}} to i8*
+  ; CHECK-NEXT: [[BCC2:%[0-9]+]] = bitcast i32* {{.*}} to i8*
+  ; CHECK-NEXT: [[GEP1:%[0-9]+]] = getelementptr i8, i8* [[BCC2]], i8 8
+  ; CHECK-NEXT: [[BCL1:%[0-9]+]] = bitcast i8* [[GEP1]] to i64*
+  ; CHECK-NEXT: [[GEP2:%[0-9]+]] = getelementptr i8, i8* [[BCC1]], i8 8
+  ; CHECK-NEXT: [[BCL2:%[0-9]+]] = bitcast i8* [[GEP2]] to i64*
+  ; CHECK-NEXT: [[LOAD1:%[0-9]+]] = load i64, i64* [[BCL1]]
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64* [[BCL2]]
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD2]])
+  ; CHECK-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[BSWAP1]], [[BSWAP2]]
+  ; CHECK-NEXT:  br i1 [[ICMP]], label %endblock, label %res_block
+
+  ; CHECK-BE-LABEL: @test1(
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i64, i64*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64*
+  ; CHECK-BE-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[LOAD1]], [[LOAD2]]
+  ; CHECK-BE-NEXT:  br i1 [[ICMP]], label %loadbb1, label %res_block
+
+  ; CHECK-BE-LABEL: res_block:{{.*}}
+  ; CHECK-BE: [[ICMP2:%[0-9]+]] = icmp ult i64
+  ; CHECK-BE-NEXT: [[SELECT:%[0-9]+]] = select i1 [[ICMP2]], i32 -1, i32 1
+  ; CHECK-BE-NEXT: br label %endblock
+
+  ; CHECK-BE-LABEL: loadbb1:{{.*}}
+  ; CHECK-BE: [[BCC1:%[0-9]+]] = bitcast i32* {{.*}} to i8*
+  ; CHECK-BE-NEXT: [[BCC2:%[0-9]+]] = bitcast i32* {{.*}} to i8*
+  ; CHECK-BE-NEXT: [[GEP1:%[0-9]+]] = getelementptr i8, i8* [[BCC2]], i8 8
+  ; CHECK-BE-NEXT: [[BCL1:%[0-9]+]] = bitcast i8* [[GEP1]] to i64*
+  ; CHECK-BE-NEXT: [[GEP2:%[0-9]+]] = getelementptr i8, i8* [[BCC1]], i8 8
+  ; CHECK-BE-NEXT: [[BCL2:%[0-9]+]] = bitcast i8* [[GEP2]] to i64*
+  ; CHECK-BE-NEXT: [[LOAD1:%[0-9]+]] = load i64, i64* [[BCL1]]
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64* [[BCL2]]
+  ; CHECK-BE-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[LOAD1]], [[LOAD2]]
+  ; CHECK-BE-NEXT:  br i1 [[ICMP]], label %endblock, label %res_block
+
+  %0 = bitcast i32* %buffer1 to i8*
+  %1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %0, i8* %1, i64 16)
+  ret i32 %call
+}
+
+declare signext i32 @memcmp(i8* nocapture, i8* nocapture, i64) local_unnamed_addr #1
+
+define signext i32 @test2(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2)  {
+  ; CHECK-LABEL: @test2(
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i32, i32*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i32, i32*
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i32 @llvm.bswap.i32(i32 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i32 @llvm.bswap.i32(i32 [[LOAD2]])
+  ; CHECK-NEXT: [[CMP1:%[0-9]+]] = icmp ugt i32 [[BSWAP1]], [[BSWAP2]]
+  ; CHECK-NEXT: [[CMP2:%[0-9]+]] = icmp ult i32 [[BSWAP1]], [[BSWAP2]]
+  ; CHECK-NEXT: [[Z1:%[0-9]+]] = zext i1 [[CMP1]] to i32
+  ; CHECK-NEXT: [[Z2:%[0-9]+]] = zext i1 [[CMP2]] to i32
+  ; CHECK-NEXT: [[SUB:%[0-9]+]] = sub i32 [[Z1]], [[Z2]]
+  ; CHECK-NEXT: ret i32 [[SUB]]
+
+  ; CHECK-BE-LABEL: @test2(
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i32, i32*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i32, i32*
+  ; CHECK-BE-NEXT: [[CMP1:%[0-9]+]] = icmp ugt i32 [[LOAD1]], [[LOAD2]]
+  ; CHECK-BE-NEXT: [[CMP2:%[0-9]+]] = icmp ult i32 [[LOAD1]], [[LOAD2]]
+  ; CHECK-BE-NEXT: [[Z1:%[0-9]+]] = zext i1 [[CMP1]] to i32
+  ; CHECK-BE-NEXT: [[Z2:%[0-9]+]] = zext i1 [[CMP2]] to i32
+  ; CHECK-BE-NEXT: [[SUB:%[0-9]+]] = sub i32 [[Z1]], [[Z2]]
+  ; CHECK-BE-NEXT: ret i32 [[SUB]]
+
+entry:
+  %0 = bitcast i32* %buffer1 to i8*
+  %1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %0, i8* %1, i64 4)
+  ret i32 %call
+}
+
+define signext i32 @test3(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2)  {
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i64, i64*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64*
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i64 @llvm.bswap.i64(i64 [[LOAD2]])
+  ; CHECK-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[BSWAP1]], [[BSWAP2]]
+  ; CHECK-NEXT:  br i1 [[ICMP]], label %loadbb1, label %res_block
+
+  ; CHECK-LABEL: res_block:{{.*}}
+  ; CHECK: [[ICMP2:%[0-9]+]] = icmp ult i64
+  ; CHECK-NEXT: [[SELECT:%[0-9]+]] = select i1 [[ICMP2]], i32 -1, i32 1
+  ; CHECK-NEXT: br label %endblock
+
+  ; CHECK-LABEL: loadbb1:{{.*}}
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i32, i32*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i32, i32*
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i32 @llvm.bswap.i32(i32 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i32 @llvm.bswap.i32(i32 [[LOAD2]])
+  ; CHECK-NEXT: [[ZEXT1:%[0-9]+]] = zext i32 [[BSWAP1]] to i64
+  ; CHECK-NEXT: [[ZEXT2:%[0-9]+]] = zext i32 [[BSWAP2]] to i64
+  ; CHECK-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-NEXT:  br i1 [[ICMP]], label %loadbb2, label %res_block
+
+  ; CHECK-LABEL: loadbb2:{{.*}}
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i16, i16*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i16, i16*
+  ; CHECK-NEXT: [[BSWAP1:%[0-9]+]] = call i16 @llvm.bswap.i16(i16 [[LOAD1]])
+  ; CHECK-NEXT: [[BSWAP2:%[0-9]+]] = call i16 @llvm.bswap.i16(i16 [[LOAD2]])
+  ; CHECK-NEXT: [[ZEXT1:%[0-9]+]] = zext i16 [[BSWAP1]] to i64
+  ; CHECK-NEXT: [[ZEXT2:%[0-9]+]] = zext i16 [[BSWAP2]] to i64
+  ; CHECK-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-NEXT:  br i1 [[ICMP]], label %loadbb3, label %res_block
+
+  ; CHECK-LABEL: loadbb3:{{.*}}
+  ; CHECK: [[LOAD1:%[0-9]+]] = load i8, i8*
+  ; CHECK-NEXT: [[LOAD2:%[0-9]+]] = load i8, i8*
+  ; CHECK-NEXT: [[ZEXT1:%[0-9]+]] = zext i8 [[LOAD1]] to i32
+  ; CHECK-NEXT: [[ZEXT2:%[0-9]+]] = zext i8 [[LOAD2]] to i32
+  ; CHECK-NEXT: [[SUB:%[0-9]+]] = sub i32 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-NEXT:  br label %endblock
+
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i64, i64*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i64, i64*
+  ; CHECK-BE-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[LOAD1]], [[LOAD2]]
+  ; CHECK-BE-NEXT:  br i1 [[ICMP]], label %loadbb1, label %res_block
+
+  ; CHECK-BE-LABEL: res_block:{{.*}}
+  ; CHECK-BE: [[ICMP2:%[0-9]+]] = icmp ult i64
+  ; CHECK-BE-NEXT: [[SELECT:%[0-9]+]] = select i1 [[ICMP2]], i32 -1, i32 1
+  ; CHECK-BE-NEXT: br label %endblock
+
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i32, i32*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i32, i32*
+  ; CHECK-BE-NEXT: [[ZEXT1:%[0-9]+]] = zext i32 [[LOAD1]] to i64
+  ; CHECK-BE-NEXT: [[ZEXT2:%[0-9]+]] = zext i32 [[LOAD2]] to i64
+  ; CHECK-BE-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-BE-NEXT:  br i1 [[ICMP]], label %loadbb2, label %res_block
+
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i16, i16*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i16, i16*
+  ; CHECK-BE-NEXT: [[ZEXT1:%[0-9]+]] = zext i16 [[LOAD1]] to i64
+  ; CHECK-BE-NEXT: [[ZEXT2:%[0-9]+]] = zext i16 [[LOAD2]] to i64
+  ; CHECK-BE-NEXT: [[ICMP:%[0-9]+]] = icmp eq i64 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-BE-NEXT:  br i1 [[ICMP]], label %loadbb3, label %res_block
+
+  ; CHECK-BE: [[LOAD1:%[0-9]+]] = load i8, i8*
+  ; CHECK-BE-NEXT: [[LOAD2:%[0-9]+]] = load i8, i8*
+  ; CHECK-BE-NEXT: [[ZEXT1:%[0-9]+]] = zext i8 [[LOAD1]] to i32
+  ; CHECK-BE-NEXT: [[ZEXT2:%[0-9]+]] = zext i8 [[LOAD2]] to i32
+  ; CHECK-BE-NEXT: [[SUB:%[0-9]+]] = sub i32 [[ZEXT1]], [[ZEXT2]]
+  ; CHECK-BE-NEXT:  br label %endblock
+
+entry:
+  %0 = bitcast i32* %buffer1 to i8*
+  %1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %0, i8* %1, i64 15)
+  ret i32 %call
+}
+  ; CHECK: call = tail call signext i32 @memcmp
+  ; CHECK-BE: call = tail call signext i32 @memcmp
+define signext i32 @test4(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2)  {
+
+entry:
+  %0 = bitcast i32* %buffer1 to i8*
+  %1 = bitcast i32* %buffer2 to i8*
+  %call = tail call signext i32 @memcmp(i8* %0, i8* %1, i64 65)
+  ret i32 %call
+}
+
+define signext i32 @test5(i32* nocapture readonly %buffer1, i32* nocapture readonly %buffer2, i32 signext %SIZE)  {
+  ; CHECK: call = tail call signext i32 @memcmp
+  ; CHECK-BE: call = tail call signext i32 @memcmp
+entry:
+  %0 = bitcast i32* %buffer1 to i8*
+  %1 = bitcast i32* %buffer2 to i8*
+  %conv = sext i32 %SIZE to i64
+  %call = tail call signext i32 @memcmp(i8* %0, i8* %1, i64 %conv)
+  ret i32 %call
+}
diff --git a/llvm/test/CodeGen/X86/O3-pipeline.ll b/llvm/test/CodeGen/X86/O3-pipeline.ll
index 0026fe89936..7364d950f45 100644
--- a/llvm/test/CodeGen/X86/O3-pipeline.ll
+++ b/llvm/test/CodeGen/X86/O3-pipeline.ll
@@ -29,6 +29,10 @@
 ; CHECK-NEXT:       Loop Pass Manager
 ; CHECK-NEXT:         Induction Variable Users
 ; CHECK-NEXT:         Loop Strength Reduction
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:         Function Alias Analysis Results
+; CHECK-NEXT:       Merge contiguous icmps into a memcmp
+; CHECK-NEXT:       Expand memcmp() to load/stores
 ; CHECK-NEXT:       Lower Garbage Collection Instructions
 ; CHECK-NEXT:       Shadow Stack GC Lowering
 ; CHECK-NEXT:       Remove unreachable blocks from the CFG
diff --git a/llvm/test/CodeGen/X86/memcmp-mergeexpand.ll b/llvm/test/CodeGen/X86/memcmp-mergeexpand.ll
new file mode 100644
index 00000000000..0be463daaeb
--- /dev/null
+++ b/llvm/test/CodeGen/X86/memcmp-mergeexpand.ll
@@ -0,0 +1,51 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i686-unknown-unknown               | FileCheck %s --check-prefix=X86
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown             | FileCheck %s --check-prefix=X64
+
+; This tests interaction between MergeICmp and ExpandMemCmp.
+
+%"struct.std::pair" = type { i32, i32 }
+
+define zeroext i1 @opeq1(
+; X86-LABEL: opeq1:
+; X86:       # %bb.0: # %"entry+land.rhs.i"
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    movl 4(%ecx), %ecx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    xorl 4(%eax), %ecx
+; X86-NEXT:    orl %edx, %ecx
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: opeq1:
+; X64:       # %bb.0: # %"entry+land.rhs.i"
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    cmpq (%rsi), %rax
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %"struct.std::pair"* nocapture readonly dereferenceable(8) %a,
+  %"struct.std::pair"* nocapture readonly dereferenceable(8) %b) local_unnamed_addr #0 {
+entry:
+  %first.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 0
+  %0 = load i32, i32* %first.i, align 4
+  %first1.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 0
+  %1 = load i32, i32* %first1.i, align 4
+  %cmp.i = icmp eq i32 %0, %1
+  br i1 %cmp.i, label %land.rhs.i, label %opeq1.exit
+
+land.rhs.i:
+  %second.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %a, i64 0, i32 1
+  %2 = load i32, i32* %second.i, align 4
+  %second2.i = getelementptr inbounds %"struct.std::pair", %"struct.std::pair"* %b, i64 0, i32 1
+  %3 = load i32, i32* %second2.i, align 4
+  %cmp3.i = icmp eq i32 %2, %3
+  br label %opeq1.exit
+
+opeq1.exit:
+  %4 = phi i1 [ false, %entry ], [ %cmp3.i, %land.rhs.i ]
+  ret i1 %4
+}
+
+
diff --git a/llvm/test/CodeGen/X86/memcmp-optsize.ll b/llvm/test/CodeGen/X86/memcmp-optsize.ll
new file mode 100644
index 00000000000..b3bb3ab506f
--- /dev/null
+++ b/llvm/test/CodeGen/X86/memcmp-optsize.ll
@@ -0,0 +1,1013 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=cmov | FileCheck %s --check-prefix=X86 --check-prefix=X86-NOSSE
+; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+sse2 | FileCheck %s --check-prefix=X86 --check-prefix=X86-SSE2
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=X64 --check-prefix=X64-SSE2
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx2 | FileCheck %s --check-prefix=X64 --check-prefix=X64-AVX2
+
+; This tests codegen time inlining/optimization of memcmp
+; rdar://6480398
+
+@.str = private constant [65 x i8] c"0123456789012345678901234567890123456789012345678901234567890123\00", align 1
+
+declare i32 @memcmp(i8*, i8*, i64)
+declare i32 @bcmp(i8*, i8*, i64)
+
+define i32 @length2(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length2:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    movzwl %cx, %eax
+; X86-NEXT:    movzwl %dx, %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  ret i32 %m
+}
+
+define i1 @length2_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length2_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    cmpw (%eax), %cx
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    cmpw (%rsi), %ax
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_eq_const(i8* %X) nounwind optsize {
+; X86-LABEL: length2_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movzwl (%eax), %eax
+; X86-NEXT:    cmpl $12849, %eax # imm = 0x3231
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    cmpl $12849, %eax # imm = 0x3231
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 1), i64 2) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_eq_nobuiltin_attr(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length2_eq_nobuiltin_attr:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $2
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq_nobuiltin_attr:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    movl $2, %edx
+; X64-NEXT:    callq memcmp
+; X64-NEXT:    testl %eax, %eax
+; X64-NEXT:    sete %al
+; X64-NEXT:    popq %rcx
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind nobuiltin
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length3(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length3:
+; X86:       # %bb.0: # %loadbb
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    movzwl (%ecx), %esi
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    rolw $8, %si
+; X86-NEXT:    cmpw %si, %dx
+; X86-NEXT:    jne .LBB4_1
+; X86-NEXT:  # %bb.2: # %loadbb1
+; X86-NEXT:    movzbl 2(%eax), %eax
+; X86-NEXT:    movzbl 2(%ecx), %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    jmp .LBB4_3
+; X86-NEXT:  .LBB4_1: # %res_block
+; X86-NEXT:    setae %al
+; X86-NEXT:    movzbl %al, %eax
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:  .LBB4_3: # %endblock
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length3:
+; X64:       # %bb.0: # %loadbb
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    cmpw %cx, %ax
+; X64-NEXT:    jne .LBB4_1
+; X64-NEXT:  # %bb.2: # %loadbb1
+; X64-NEXT:    movzbl 2(%rdi), %eax
+; X64-NEXT:    movzbl 2(%rsi), %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+; X64-NEXT:  .LBB4_1: # %res_block
+; X64-NEXT:    setae %al
+; X64-NEXT:    movzbl %al, %eax
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 3) nounwind
+  ret i32 %m
+}
+
+define i1 @length3_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length3_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %edx
+; X86-NEXT:    xorw (%eax), %dx
+; X86-NEXT:    movb 2(%ecx), %cl
+; X86-NEXT:    xorb 2(%eax), %cl
+; X86-NEXT:    movzbl %cl, %eax
+; X86-NEXT:    orw %dx, %ax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length3_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    xorw (%rsi), %ax
+; X64-NEXT:    movb 2(%rdi), %cl
+; X64-NEXT:    xorb 2(%rsi), %cl
+; X64-NEXT:    movzbl %cl, %ecx
+; X64-NEXT:    orw %ax, %cx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 3) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length4(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length4:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    seta %al
+; X86-NEXT:    sbbl $0, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %ecx
+; X64-NEXT:    movl (%rsi), %edx
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    bswapl %edx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpl %edx, %ecx
+; X64-NEXT:    seta %al
+; X64-NEXT:    sbbl $0, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  ret i32 %m
+}
+
+define i1 @length4_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length4_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    cmpl (%eax), %ecx
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    cmpl (%rsi), %eax
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length4_eq_const(i8* %X) nounwind optsize {
+; X86-LABEL: length4_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    cmpl $875770417, (%eax) # imm = 0x34333231
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    cmpl $875770417, (%rdi) # imm = 0x34333231
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 1), i64 4) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length5(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length5:
+; X86:       # %bb.0: # %loadbb
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    movl (%ecx), %esi
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    bswapl %esi
+; X86-NEXT:    cmpl %esi, %edx
+; X86-NEXT:    jne .LBB9_1
+; X86-NEXT:  # %bb.2: # %loadbb1
+; X86-NEXT:    movzbl 4(%eax), %eax
+; X86-NEXT:    movzbl 4(%ecx), %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    jmp .LBB9_3
+; X86-NEXT:  .LBB9_1: # %res_block
+; X86-NEXT:    setae %al
+; X86-NEXT:    movzbl %al, %eax
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:  .LBB9_3: # %endblock
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length5:
+; X64:       # %bb.0: # %loadbb
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    movl (%rsi), %ecx
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    cmpl %ecx, %eax
+; X64-NEXT:    jne .LBB9_1
+; X64-NEXT:  # %bb.2: # %loadbb1
+; X64-NEXT:    movzbl 4(%rdi), %eax
+; X64-NEXT:    movzbl 4(%rsi), %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+; X64-NEXT:  .LBB9_1: # %res_block
+; X64-NEXT:    setae %al
+; X64-NEXT:    movzbl %al, %eax
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 5) nounwind
+  ret i32 %m
+}
+
+define i1 @length5_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length5_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    movb 4(%ecx), %cl
+; X86-NEXT:    xorb 4(%eax), %cl
+; X86-NEXT:    movzbl %cl, %eax
+; X86-NEXT:    orl %edx, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length5_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    xorl (%rsi), %eax
+; X64-NEXT:    movb 4(%rdi), %cl
+; X64-NEXT:    xorb 4(%rsi), %cl
+; X64-NEXT:    movzbl %cl, %ecx
+; X64-NEXT:    orl %eax, %ecx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 5) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length8(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length8:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
+; X86-NEXT:    movl (%esi), %ecx
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    jne .LBB11_2
+; X86-NEXT:  # %bb.1: # %loadbb1
+; X86-NEXT:    movl 4(%esi), %ecx
+; X86-NEXT:    movl 4(%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    je .LBB11_3
+; X86-NEXT:  .LBB11_2: # %res_block
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    setae %al
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:  .LBB11_3: # %endblock
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    seta %al
+; X64-NEXT:    sbbl $0, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 8) nounwind
+  ret i32 %m
+}
+
+define i1 @length8_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length8_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    movl 4(%ecx), %ecx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    xorl 4(%eax), %ecx
+; X86-NEXT:    orl %edx, %ecx
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    cmpq (%rsi), %rax
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 8) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length8_eq_const(i8* %X) nounwind optsize {
+; X86-LABEL: length8_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl $858927408, %ecx # imm = 0x33323130
+; X86-NEXT:    xorl (%eax), %ecx
+; X86-NEXT:    movl $926299444, %edx # imm = 0x37363534
+; X86-NEXT:    xorl 4(%eax), %edx
+; X86-NEXT:    orl %ecx, %edx
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    movabsq $3978425819141910832, %rax # imm = 0x3736353433323130
+; X64-NEXT:    cmpq %rax, (%rdi)
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 8) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length12_eq(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length12_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $12
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length12_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    movl 8(%rdi), %ecx
+; X64-NEXT:    xorl 8(%rsi), %ecx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 12) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length12(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length12:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $12
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length12:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    jne .LBB15_2
+; X64-NEXT:  # %bb.1: # %loadbb1
+; X64-NEXT:    movl 8(%rdi), %ecx
+; X64-NEXT:    movl 8(%rsi), %edx
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    bswapl %edx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    je .LBB15_3
+; X64-NEXT:  .LBB15_2: # %res_block
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    setae %al
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:  .LBB15_3: # %endblock
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 12) nounwind
+  ret i32 %m
+}
+
+; PR33329 - https://bugs.llvm.org/show_bug.cgi?id=33329
+
+define i32 @length16(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length16:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $16
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length16:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    jne .LBB16_2
+; X64-NEXT:  # %bb.1: # %loadbb1
+; X64-NEXT:    movq 8(%rdi), %rcx
+; X64-NEXT:    movq 8(%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    je .LBB16_3
+; X64-NEXT:  .LBB16_2: # %res_block
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    setae %al
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:  .LBB16_3: # %endblock
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 16) nounwind
+  ret i32 %m
+}
+
+define i1 @length16_eq(i8* %x, i8* %y) nounwind optsize {
+; X86-NOSSE-LABEL: length16_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $16
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length16_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X86-SSE2-NEXT:    pmovmskb %xmm1, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length16_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X64-SSE2-NEXT:    pmovmskb %xmm1, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length16_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 16) nounwind
+  %cmp = icmp ne i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length16_eq_const(i8* %X) nounwind optsize {
+; X86-NOSSE-LABEL: length16_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $16
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length16_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length16_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length16_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 16) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+; PR33914 - https://bugs.llvm.org/show_bug.cgi?id=33914
+
+define i32 @length24(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length24:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $24
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length24:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $24, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 24) nounwind
+  ret i32 %m
+}
+
+define i1 @length24_eq(i8* %x, i8* %y) nounwind optsize {
+; X86-NOSSE-LABEL: length24_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $24
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length24_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu 8(%ecx), %xmm1
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm2
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X86-SSE2-NEXT:    movdqu 8(%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X86-SSE2-NEXT:    pand %xmm2, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length24_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm0 = mem[0],zero
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm2 = mem[0],zero
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X64-SSE2-NEXT:    pand %xmm1, %xmm2
+; X64-SSE2-NEXT:    pmovmskb %xmm2, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length24_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX2-NEXT:    vmovq {{.*#+}} xmm1 = mem[0],zero
+; X64-AVX2-NEXT:    vmovq {{.*#+}} xmm2 = mem[0],zero
+; X64-AVX2-NEXT:    vpcmpeqb %xmm2, %xmm1, %xmm1
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 24) nounwind
+  %cmp = icmp eq i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length24_eq_const(i8* %X) nounwind optsize {
+; X86-NOSSE-LABEL: length24_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $24
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length24_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    movdqu 8(%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pand %xmm1, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length24_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm1 = mem[0],zero
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pand %xmm1, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length24_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX2-NEXT:    vmovq {{.*#+}} xmm1 = mem[0],zero
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm1, %xmm1
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX2-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 24) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length32(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length32:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $32
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length32:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $32, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 32) nounwind
+  ret i32 %m
+}
+
+; PR33325 - https://bugs.llvm.org/show_bug.cgi?id=33325
+
+define i1 @length32_eq(i8* %x, i8* %y) nounwind optsize {
+; X86-NOSSE-LABEL: length32_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $32
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length32_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu 16(%ecx), %xmm1
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm2
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X86-SSE2-NEXT:    movdqu 16(%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X86-SSE2-NEXT:    pand %xmm2, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length32_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu 16(%rdi), %xmm1
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm2
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X64-SSE2-NEXT:    movdqu 16(%rsi), %xmm0
+; X64-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X64-SSE2-NEXT:    pand %xmm2, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length32_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 32) nounwind
+  %cmp = icmp eq i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length32_eq_const(i8* %X) nounwind optsize {
+; X86-NOSSE-LABEL: length32_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $32
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE2-LABEL: length32_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    movdqu 16(%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pand %xmm1, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length32_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu 16(%rdi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pand %xmm1, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length32_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 32) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length64(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: length64:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length64:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $64, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 64) nounwind
+  ret i32 %m
+}
+
+define i1 @length64_eq(i8* %x, i8* %y) nounwind optsize {
+; X86-LABEL: length64_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-SSE2-LABEL: length64_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    pushq %rax
+; X64-SSE2-NEXT:    movl $64, %edx
+; X64-SSE2-NEXT:    callq memcmp
+; X64-SSE2-NEXT:    testl %eax, %eax
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    popq %rcx
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length64_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vmovdqu 32(%rdi), %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb 32(%rsi), %ymm1, %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpand %ymm1, %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 64) nounwind
+  %cmp = icmp ne i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length64_eq_const(i8* %X) nounwind optsize {
+; X86-LABEL: length64_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl $.L.str
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-SSE2-LABEL: length64_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    pushq %rax
+; X64-SSE2-NEXT:    movl $.L.str, %esi
+; X64-SSE2-NEXT:    movl $64, %edx
+; X64-SSE2-NEXT:    callq memcmp
+; X64-SSE2-NEXT:    testl %eax, %eax
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    popq %rcx
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX2-LABEL: length64_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vmovdqu 32(%rdi), %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm1, %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpand %ymm1, %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 64) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @bcmp_length2(i8* %X, i8* %Y) nounwind optsize {
+; X86-LABEL: bcmp_length2:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    movzwl %cx, %eax
+; X86-NEXT:    movzwl %dx, %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: bcmp_length2:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @bcmp(i8* %X, i8* %Y, i64 2) nounwind
+  ret i32 %m
+}
+
diff --git a/llvm/test/CodeGen/X86/memcmp.ll b/llvm/test/CodeGen/X86/memcmp.ll
new file mode 100644
index 00000000000..8a7c7847fe0
--- /dev/null
+++ b/llvm/test/CodeGen/X86/memcmp.ll
@@ -0,0 +1,1685 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=cmov   | FileCheck %s --check-prefix=X86 --check-prefix=X86-NOSSE
+; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+sse   | FileCheck %s --check-prefix=X86 --check-prefix=SSE --check-prefix=X86-SSE1
+; RUN: llc < %s -mtriple=i686-unknown-unknown -mattr=+sse2  | FileCheck %s --check-prefix=X86 --check-prefix=SSE --check-prefix=X86-SSE2
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown             | FileCheck %s --check-prefix=X64 --check-prefix=X64-SSE2
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx  | FileCheck %s --check-prefix=X64 --check-prefix=X64-AVX --check-prefix=X64-AVX1
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx2 | FileCheck %s --check-prefix=X64 --check-prefix=X64-AVX --check-prefix=X64-AVX2
+
+; This tests codegen time inlining/optimization of memcmp
+; rdar://6480398
+
+@.str = private constant [65 x i8] c"0123456789012345678901234567890123456789012345678901234567890123\00", align 1
+
+declare i32 @memcmp(i8*, i8*, i64)
+
+define i32 @length0(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length0:
+; X86:       # %bb.0:
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length0:
+; X64:       # %bb.0:
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    retq
+   %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 0) nounwind
+   ret i32 %m
+ }
+
+define i1 @length0_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length0_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movb $1, %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length0_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movb $1, %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 0) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length0_lt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length0_lt:
+; X86:       # %bb.0:
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length0_lt:
+; X64:       # %bb.0:
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 0) nounwind
+  %c = icmp slt i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length2(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length2:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    movzwl %cx, %eax
+; X86-NEXT:    movzwl %dx, %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  ret i32 %m
+}
+
+define i1 @length2_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length2_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    cmpw (%eax), %cx
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    cmpw (%rsi), %ax
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_lt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length2_lt:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    movzwl %cx, %eax
+; X86-NEXT:    movzwl %dx, %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    shrl $31, %eax
+; X86-NEXT:    # kill: def $al killed $al killed $eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_lt:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    shrl $31, %eax
+; X64-NEXT:    # kill: def $al killed $al killed $eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  %c = icmp slt i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_gt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length2_gt:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %ecx
+; X86-NEXT:    movzwl (%eax), %eax
+; X86-NEXT:    rolw $8, %cx
+; X86-NEXT:    rolw $8, %ax
+; X86-NEXT:    movzwl %cx, %ecx
+; X86-NEXT:    movzwl %ax, %eax
+; X86-NEXT:    subl %eax, %ecx
+; X86-NEXT:    testl %ecx, %ecx
+; X86-NEXT:    setg %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_gt:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    movzwl %ax, %eax
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    testl %eax, %eax
+; X64-NEXT:    setg %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind
+  %c = icmp sgt i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_eq_const(i8* %X) nounwind {
+; X86-LABEL: length2_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movzwl (%eax), %eax
+; X86-NEXT:    cmpl $12849, %eax # imm = 0x3231
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    cmpl $12849, %eax # imm = 0x3231
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 1), i64 2) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length2_eq_nobuiltin_attr(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length2_eq_nobuiltin_attr:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $2
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length2_eq_nobuiltin_attr:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    movl $2, %edx
+; X64-NEXT:    callq memcmp
+; X64-NEXT:    testl %eax, %eax
+; X64-NEXT:    sete %al
+; X64-NEXT:    popq %rcx
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 2) nounwind nobuiltin
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length3(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length3:
+; X86:       # %bb.0: # %loadbb
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movzwl (%eax), %edx
+; X86-NEXT:    movzwl (%ecx), %esi
+; X86-NEXT:    rolw $8, %dx
+; X86-NEXT:    rolw $8, %si
+; X86-NEXT:    cmpw %si, %dx
+; X86-NEXT:    jne .LBB9_1
+; X86-NEXT:  # %bb.2: # %loadbb1
+; X86-NEXT:    movzbl 2(%eax), %eax
+; X86-NEXT:    movzbl 2(%ecx), %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+; X86-NEXT:  .LBB9_1: # %res_block
+; X86-NEXT:    setae %al
+; X86-NEXT:    movzbl %al, %eax
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length3:
+; X64:       # %bb.0: # %loadbb
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    movzwl (%rsi), %ecx
+; X64-NEXT:    rolw $8, %ax
+; X64-NEXT:    rolw $8, %cx
+; X64-NEXT:    cmpw %cx, %ax
+; X64-NEXT:    jne .LBB9_1
+; X64-NEXT:  # %bb.2: # %loadbb1
+; X64-NEXT:    movzbl 2(%rdi), %eax
+; X64-NEXT:    movzbl 2(%rsi), %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+; X64-NEXT:  .LBB9_1: # %res_block
+; X64-NEXT:    setae %al
+; X64-NEXT:    movzbl %al, %eax
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 3) nounwind
+  ret i32 %m
+}
+
+define i1 @length3_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length3_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movzwl (%ecx), %edx
+; X86-NEXT:    xorw (%eax), %dx
+; X86-NEXT:    movb 2(%ecx), %cl
+; X86-NEXT:    xorb 2(%eax), %cl
+; X86-NEXT:    movzbl %cl, %eax
+; X86-NEXT:    orw %dx, %ax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length3_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movzwl (%rdi), %eax
+; X64-NEXT:    xorw (%rsi), %ax
+; X64-NEXT:    movb 2(%rdi), %cl
+; X64-NEXT:    xorb 2(%rsi), %cl
+; X64-NEXT:    movzbl %cl, %ecx
+; X64-NEXT:    orw %ax, %cx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 3) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length4(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length4:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    seta %al
+; X86-NEXT:    sbbl $0, %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %ecx
+; X64-NEXT:    movl (%rsi), %edx
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    bswapl %edx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpl %edx, %ecx
+; X64-NEXT:    seta %al
+; X64-NEXT:    sbbl $0, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  ret i32 %m
+}
+
+define i1 @length4_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length4_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    cmpl (%eax), %ecx
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    cmpl (%rsi), %eax
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length4_lt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length4_lt:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    seta %al
+; X86-NEXT:    sbbl $0, %eax
+; X86-NEXT:    shrl $31, %eax
+; X86-NEXT:    # kill: def $al killed $al killed $eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_lt:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %ecx
+; X64-NEXT:    movl (%rsi), %edx
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    bswapl %edx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpl %edx, %ecx
+; X64-NEXT:    seta %al
+; X64-NEXT:    sbbl $0, %eax
+; X64-NEXT:    shrl $31, %eax
+; X64-NEXT:    # kill: def $al killed $al killed $eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  %c = icmp slt i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length4_gt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length4_gt:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %ecx
+; X86-NEXT:    movl (%eax), %eax
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %eax
+; X86-NEXT:    xorl %edx, %edx
+; X86-NEXT:    cmpl %eax, %ecx
+; X86-NEXT:    seta %dl
+; X86-NEXT:    sbbl $0, %edx
+; X86-NEXT:    testl %edx, %edx
+; X86-NEXT:    setg %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_gt:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    movl (%rsi), %ecx
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    xorl %edx, %edx
+; X64-NEXT:    cmpl %ecx, %eax
+; X64-NEXT:    seta %dl
+; X64-NEXT:    sbbl $0, %edx
+; X64-NEXT:    testl %edx, %edx
+; X64-NEXT:    setg %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 4) nounwind
+  %c = icmp sgt i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length4_eq_const(i8* %X) nounwind {
+; X86-LABEL: length4_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    cmpl $875770417, (%eax) # imm = 0x34333231
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length4_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    cmpl $875770417, (%rdi) # imm = 0x34333231
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 1), i64 4) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length5(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length5:
+; X86:       # %bb.0: # %loadbb
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    movl (%ecx), %esi
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    bswapl %esi
+; X86-NEXT:    cmpl %esi, %edx
+; X86-NEXT:    jne .LBB16_1
+; X86-NEXT:  # %bb.2: # %loadbb1
+; X86-NEXT:    movzbl 4(%eax), %eax
+; X86-NEXT:    movzbl 4(%ecx), %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+; X86-NEXT:  .LBB16_1: # %res_block
+; X86-NEXT:    setae %al
+; X86-NEXT:    movzbl %al, %eax
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length5:
+; X64:       # %bb.0: # %loadbb
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    movl (%rsi), %ecx
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    cmpl %ecx, %eax
+; X64-NEXT:    jne .LBB16_1
+; X64-NEXT:  # %bb.2: # %loadbb1
+; X64-NEXT:    movzbl 4(%rdi), %eax
+; X64-NEXT:    movzbl 4(%rsi), %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    retq
+; X64-NEXT:  .LBB16_1: # %res_block
+; X64-NEXT:    setae %al
+; X64-NEXT:    movzbl %al, %eax
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 5) nounwind
+  ret i32 %m
+}
+
+define i1 @length5_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length5_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    movb 4(%ecx), %cl
+; X86-NEXT:    xorb 4(%eax), %cl
+; X86-NEXT:    movzbl %cl, %eax
+; X86-NEXT:    orl %edx, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length5_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    xorl (%rsi), %eax
+; X64-NEXT:    movb 4(%rdi), %cl
+; X64-NEXT:    xorb 4(%rsi), %cl
+; X64-NEXT:    movzbl %cl, %ecx
+; X64-NEXT:    orl %eax, %ecx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 5) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length5_lt(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length5_lt:
+; X86:       # %bb.0: # %loadbb
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    movl (%ecx), %esi
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    bswapl %esi
+; X86-NEXT:    cmpl %esi, %edx
+; X86-NEXT:    jne .LBB18_1
+; X86-NEXT:  # %bb.2: # %loadbb1
+; X86-NEXT:    movzbl 4(%eax), %eax
+; X86-NEXT:    movzbl 4(%ecx), %ecx
+; X86-NEXT:    subl %ecx, %eax
+; X86-NEXT:    jmp .LBB18_3
+; X86-NEXT:  .LBB18_1: # %res_block
+; X86-NEXT:    setae %al
+; X86-NEXT:    movzbl %al, %eax
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:  .LBB18_3: # %endblock
+; X86-NEXT:    shrl $31, %eax
+; X86-NEXT:    # kill: def $al killed $al killed $eax
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length5_lt:
+; X64:       # %bb.0: # %loadbb
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    movl (%rsi), %ecx
+; X64-NEXT:    bswapl %eax
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    cmpl %ecx, %eax
+; X64-NEXT:    jne .LBB18_1
+; X64-NEXT:  # %bb.2: # %loadbb1
+; X64-NEXT:    movzbl 4(%rdi), %eax
+; X64-NEXT:    movzbl 4(%rsi), %ecx
+; X64-NEXT:    subl %ecx, %eax
+; X64-NEXT:    shrl $31, %eax
+; X64-NEXT:    # kill: def $al killed $al killed $eax
+; X64-NEXT:    retq
+; X64-NEXT:  .LBB18_1: # %res_block
+; X64-NEXT:    setae %al
+; X64-NEXT:    movzbl %al, %eax
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:    shrl $31, %eax
+; X64-NEXT:    # kill: def $al killed $al killed $eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 5) nounwind
+  %c = icmp slt i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length7_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length7_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    movl 3(%ecx), %ecx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    xorl 3(%eax), %ecx
+; X86-NEXT:    orl %edx, %ecx
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length7_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movl (%rdi), %eax
+; X64-NEXT:    movl 3(%rdi), %ecx
+; X64-NEXT:    xorl (%rsi), %eax
+; X64-NEXT:    xorl 3(%rsi), %ecx
+; X64-NEXT:    orl %eax, %ecx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 7) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length8(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length8:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl %esi
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
+; X86-NEXT:    movl (%esi), %ecx
+; X86-NEXT:    movl (%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    jne .LBB20_2
+; X86-NEXT:  # %bb.1: # %loadbb1
+; X86-NEXT:    movl 4(%esi), %ecx
+; X86-NEXT:    movl 4(%eax), %edx
+; X86-NEXT:    bswapl %ecx
+; X86-NEXT:    bswapl %edx
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    je .LBB20_3
+; X86-NEXT:  .LBB20_2: # %res_block
+; X86-NEXT:    xorl %eax, %eax
+; X86-NEXT:    cmpl %edx, %ecx
+; X86-NEXT:    setae %al
+; X86-NEXT:    leal -1(%eax,%eax), %eax
+; X86-NEXT:  .LBB20_3: # %endblock
+; X86-NEXT:    popl %esi
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    seta %al
+; X64-NEXT:    sbbl $0, %eax
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 8) nounwind
+  ret i32 %m
+}
+
+define i1 @length8_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length8_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-NEXT:    movl (%ecx), %edx
+; X86-NEXT:    movl 4(%ecx), %ecx
+; X86-NEXT:    xorl (%eax), %edx
+; X86-NEXT:    xorl 4(%eax), %ecx
+; X86-NEXT:    orl %edx, %ecx
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    cmpq (%rsi), %rax
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 8) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length8_eq_const(i8* %X) nounwind {
+; X86-LABEL: length8_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl $858927408, %ecx # imm = 0x33323130
+; X86-NEXT:    xorl (%eax), %ecx
+; X86-NEXT:    movl $926299444, %edx # imm = 0x37363534
+; X86-NEXT:    xorl 4(%eax), %edx
+; X86-NEXT:    orl %ecx, %edx
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length8_eq_const:
+; X64:       # %bb.0:
+; X64-NEXT:    movabsq $3978425819141910832, %rax # imm = 0x3736353433323130
+; X64-NEXT:    cmpq %rax, (%rdi)
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 8) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length9_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length9_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $9
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length9_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    movb 8(%rdi), %cl
+; X64-NEXT:    xorb 8(%rsi), %cl
+; X64-NEXT:    movzbl %cl, %ecx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 9) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length10_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length10_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $10
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length10_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    movzwl 8(%rdi), %ecx
+; X64-NEXT:    xorw 8(%rsi), %cx
+; X64-NEXT:    movzwl %cx, %ecx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 10) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length11_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length11_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $11
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length11_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    movq 3(%rdi), %rcx
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    xorq 3(%rsi), %rcx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 11) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length12_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length12_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $12
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length12_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    movl 8(%rdi), %ecx
+; X64-NEXT:    xorl 8(%rsi), %ecx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    setne %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 12) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length12(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length12:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $12
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length12:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    jne .LBB27_2
+; X64-NEXT:  # %bb.1: # %loadbb1
+; X64-NEXT:    movl 8(%rdi), %ecx
+; X64-NEXT:    movl 8(%rsi), %edx
+; X64-NEXT:    bswapl %ecx
+; X64-NEXT:    bswapl %edx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    je .LBB27_3
+; X64-NEXT:  .LBB27_2: # %res_block
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    setae %al
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:  .LBB27_3: # %endblock
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 12) nounwind
+  ret i32 %m
+}
+
+define i1 @length13_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length13_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $13
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length13_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    movq 5(%rdi), %rcx
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    xorq 5(%rsi), %rcx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 13) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length14_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length14_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $14
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length14_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    movq 6(%rdi), %rcx
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    xorq 6(%rsi), %rcx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 14) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+define i1 @length15_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length15_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $15
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: length15_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rax
+; X64-NEXT:    movq 7(%rdi), %rcx
+; X64-NEXT:    xorq (%rsi), %rax
+; X64-NEXT:    xorq 7(%rsi), %rcx
+; X64-NEXT:    orq %rax, %rcx
+; X64-NEXT:    sete %al
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 15) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+; PR33329 - https://bugs.llvm.org/show_bug.cgi?id=33329
+
+define i32 @length16(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length16:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $16
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length16:
+; X64:       # %bb.0:
+; X64-NEXT:    movq (%rdi), %rcx
+; X64-NEXT:    movq (%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    jne .LBB31_2
+; X64-NEXT:  # %bb.1: # %loadbb1
+; X64-NEXT:    movq 8(%rdi), %rcx
+; X64-NEXT:    movq 8(%rsi), %rdx
+; X64-NEXT:    bswapq %rcx
+; X64-NEXT:    bswapq %rdx
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    je .LBB31_3
+; X64-NEXT:  .LBB31_2: # %res_block
+; X64-NEXT:    xorl %eax, %eax
+; X64-NEXT:    cmpq %rdx, %rcx
+; X64-NEXT:    setae %al
+; X64-NEXT:    leal -1(%rax,%rax), %eax
+; X64-NEXT:  .LBB31_3: # %endblock
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 16) nounwind
+  ret i32 %m
+}
+
+define i1 @length16_eq(i8* %x, i8* %y) nounwind {
+; X86-NOSSE-LABEL: length16_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $16
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length16_eq:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $16
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    setne %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length16_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X86-SSE2-NEXT:    pmovmskb %xmm1, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length16_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X64-SSE2-NEXT:    pmovmskb %xmm1, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX-LABEL: length16_eq:
+; X64-AVX:       # %bb.0:
+; X64-AVX-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX-NEXT:    setne %al
+; X64-AVX-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 16) nounwind
+  %cmp = icmp ne i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length16_eq_const(i8* %X) nounwind {
+; X86-NOSSE-LABEL: length16_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $16
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length16_eq_const:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $16
+; X86-SSE1-NEXT:    pushl $.L.str
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    sete %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length16_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length16_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX-LABEL: length16_eq_const:
+; X64-AVX:       # %bb.0:
+; X64-AVX-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm0, %xmm0
+; X64-AVX-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX-NEXT:    sete %al
+; X64-AVX-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 16) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+; PR33914 - https://bugs.llvm.org/show_bug.cgi?id=33914
+
+define i32 @length24(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length24:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $24
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length24:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $24, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 24) nounwind
+  ret i32 %m
+}
+
+define i1 @length24_eq(i8* %x, i8* %y) nounwind {
+; X86-NOSSE-LABEL: length24_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $24
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length24_eq:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $24
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    sete %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length24_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu 8(%ecx), %xmm1
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm2
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X86-SSE2-NEXT:    movdqu 8(%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X86-SSE2-NEXT:    pand %xmm2, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length24_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm1
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm0 = mem[0],zero
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm2 = mem[0],zero
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X64-SSE2-NEXT:    pand %xmm1, %xmm2
+; X64-SSE2-NEXT:    pmovmskb %xmm2, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX-LABEL: length24_eq:
+; X64-AVX:       # %bb.0:
+; X64-AVX-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX-NEXT:    vmovq {{.*#+}} xmm1 = mem[0],zero
+; X64-AVX-NEXT:    vmovq {{.*#+}} xmm2 = mem[0],zero
+; X64-AVX-NEXT:    vpcmpeqb %xmm2, %xmm1, %xmm1
+; X64-AVX-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX-NEXT:    sete %al
+; X64-AVX-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 24) nounwind
+  %cmp = icmp eq i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length24_eq_const(i8* %X) nounwind {
+; X86-NOSSE-LABEL: length24_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $24
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length24_eq_const:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $24
+; X86-SSE1-NEXT:    pushl $.L.str
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    setne %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length24_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    movdqu 8(%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pand %xmm1, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length24_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movq {{.*#+}} xmm1 = mem[0],zero
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pand %xmm1, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX-LABEL: length24_eq_const:
+; X64-AVX:       # %bb.0:
+; X64-AVX-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX-NEXT:    vmovq {{.*#+}} xmm1 = mem[0],zero
+; X64-AVX-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm1, %xmm1
+; X64-AVX-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm0, %xmm0
+; X64-AVX-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX-NEXT:    setne %al
+; X64-AVX-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 24) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length32(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length32:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $32
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length32:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $32, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 32) nounwind
+  ret i32 %m
+}
+
+; PR33325 - https://bugs.llvm.org/show_bug.cgi?id=33325
+
+define i1 @length32_eq(i8* %x, i8* %y) nounwind {
+; X86-NOSSE-LABEL: length32_eq:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $32
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length32_eq:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $32
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    sete %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length32_eq:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu 16(%ecx), %xmm1
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm2
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X86-SSE2-NEXT:    movdqu 16(%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X86-SSE2-NEXT:    pand %xmm2, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length32_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu 16(%rdi), %xmm1
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm2
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X64-SSE2-NEXT:    movdqu 16(%rsi), %xmm0
+; X64-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X64-SSE2-NEXT:    pand %xmm2, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX1-LABEL: length32_eq:
+; X64-AVX1:       # %bb.0:
+; X64-AVX1-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX1-NEXT:    vmovdqu 16(%rdi), %xmm1
+; X64-AVX1-NEXT:    vpcmpeqb 16(%rsi), %xmm1, %xmm1
+; X64-AVX1-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX1-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX1-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX1-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX1-NEXT:    sete %al
+; X64-AVX1-NEXT:    retq
+;
+; X64-AVX2-LABEL: length32_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 32) nounwind
+  %cmp = icmp eq i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length32_eq_prefer128(i8* %x, i8* %y) nounwind "prefer-vector-width"="128" {
+; X86-NOSSE-LABEL: length32_eq_prefer128:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $32
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    sete %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length32_eq_prefer128:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $32
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    sete %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length32_eq_prefer128:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X86-SSE2-NEXT:    movdqu (%ecx), %xmm0
+; X86-SSE2-NEXT:    movdqu 16(%ecx), %xmm1
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm2
+; X86-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X86-SSE2-NEXT:    movdqu 16(%eax), %xmm0
+; X86-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X86-SSE2-NEXT:    pand %xmm2, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    sete %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length32_eq_prefer128:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu 16(%rdi), %xmm1
+; X64-SSE2-NEXT:    movdqu (%rsi), %xmm2
+; X64-SSE2-NEXT:    pcmpeqb %xmm0, %xmm2
+; X64-SSE2-NEXT:    movdqu 16(%rsi), %xmm0
+; X64-SSE2-NEXT:    pcmpeqb %xmm1, %xmm0
+; X64-SSE2-NEXT:    pand %xmm2, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX-LABEL: length32_eq_prefer128:
+; X64-AVX:       # %bb.0:
+; X64-AVX-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX-NEXT:    vmovdqu 16(%rdi), %xmm1
+; X64-AVX-NEXT:    vpcmpeqb 16(%rsi), %xmm1, %xmm1
+; X64-AVX-NEXT:    vpcmpeqb (%rsi), %xmm0, %xmm0
+; X64-AVX-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX-NEXT:    sete %al
+; X64-AVX-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 32) nounwind
+  %cmp = icmp eq i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length32_eq_const(i8* %X) nounwind {
+; X86-NOSSE-LABEL: length32_eq_const:
+; X86-NOSSE:       # %bb.0:
+; X86-NOSSE-NEXT:    pushl $0
+; X86-NOSSE-NEXT:    pushl $32
+; X86-NOSSE-NEXT:    pushl $.L.str
+; X86-NOSSE-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NOSSE-NEXT:    calll memcmp
+; X86-NOSSE-NEXT:    addl $16, %esp
+; X86-NOSSE-NEXT:    testl %eax, %eax
+; X86-NOSSE-NEXT:    setne %al
+; X86-NOSSE-NEXT:    retl
+;
+; X86-SSE1-LABEL: length32_eq_const:
+; X86-SSE1:       # %bb.0:
+; X86-SSE1-NEXT:    pushl $0
+; X86-SSE1-NEXT:    pushl $32
+; X86-SSE1-NEXT:    pushl $.L.str
+; X86-SSE1-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-SSE1-NEXT:    calll memcmp
+; X86-SSE1-NEXT:    addl $16, %esp
+; X86-SSE1-NEXT:    testl %eax, %eax
+; X86-SSE1-NEXT:    setne %al
+; X86-SSE1-NEXT:    retl
+;
+; X86-SSE2-LABEL: length32_eq_const:
+; X86-SSE2:       # %bb.0:
+; X86-SSE2-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-SSE2-NEXT:    movdqu (%eax), %xmm0
+; X86-SSE2-NEXT:    movdqu 16(%eax), %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm1
+; X86-SSE2-NEXT:    pcmpeqb {{\.LCPI.*}}, %xmm0
+; X86-SSE2-NEXT:    pand %xmm1, %xmm0
+; X86-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X86-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X86-SSE2-NEXT:    setne %al
+; X86-SSE2-NEXT:    retl
+;
+; X64-SSE2-LABEL: length32_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    movdqu (%rdi), %xmm0
+; X64-SSE2-NEXT:    movdqu 16(%rdi), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm1
+; X64-SSE2-NEXT:    pcmpeqb {{.*}}(%rip), %xmm0
+; X64-SSE2-NEXT:    pand %xmm1, %xmm0
+; X64-SSE2-NEXT:    pmovmskb %xmm0, %eax
+; X64-SSE2-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX1-LABEL: length32_eq_const:
+; X64-AVX1:       # %bb.0:
+; X64-AVX1-NEXT:    vmovdqu (%rdi), %xmm0
+; X64-AVX1-NEXT:    vmovdqu 16(%rdi), %xmm1
+; X64-AVX1-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm1, %xmm1
+; X64-AVX1-NEXT:    vpcmpeqb {{.*}}(%rip), %xmm0, %xmm0
+; X64-AVX1-NEXT:    vpand %xmm1, %xmm0, %xmm0
+; X64-AVX1-NEXT:    vpmovmskb %xmm0, %eax
+; X64-AVX1-NEXT:    cmpl $65535, %eax # imm = 0xFFFF
+; X64-AVX1-NEXT:    setne %al
+; X64-AVX1-NEXT:    retq
+;
+; X64-AVX2-LABEL: length32_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 32) nounwind
+  %c = icmp ne i32 %m, 0
+  ret i1 %c
+}
+
+define i32 @length64(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: length64:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: length64:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $64, %edx
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 64) nounwind
+  ret i32 %m
+}
+
+define i1 @length64_eq(i8* %x, i8* %y) nounwind {
+; X86-LABEL: length64_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    setne %al
+; X86-NEXT:    retl
+;
+; X64-SSE2-LABEL: length64_eq:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    pushq %rax
+; X64-SSE2-NEXT:    movl $64, %edx
+; X64-SSE2-NEXT:    callq memcmp
+; X64-SSE2-NEXT:    testl %eax, %eax
+; X64-SSE2-NEXT:    setne %al
+; X64-SSE2-NEXT:    popq %rcx
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX1-LABEL: length64_eq:
+; X64-AVX1:       # %bb.0:
+; X64-AVX1-NEXT:    pushq %rax
+; X64-AVX1-NEXT:    movl $64, %edx
+; X64-AVX1-NEXT:    callq memcmp
+; X64-AVX1-NEXT:    testl %eax, %eax
+; X64-AVX1-NEXT:    setne %al
+; X64-AVX1-NEXT:    popq %rcx
+; X64-AVX1-NEXT:    retq
+;
+; X64-AVX2-LABEL: length64_eq:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vmovdqu 32(%rdi), %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb 32(%rsi), %ymm1, %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb (%rsi), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpand %ymm1, %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    setne %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %call = tail call i32 @memcmp(i8* %x, i8* %y, i64 64) nounwind
+  %cmp = icmp ne i32 %call, 0
+  ret i1 %cmp
+}
+
+define i1 @length64_eq_const(i8* %X) nounwind {
+; X86-LABEL: length64_eq_const:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $0
+; X86-NEXT:    pushl $64
+; X86-NEXT:    pushl $.L.str
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-SSE2-LABEL: length64_eq_const:
+; X64-SSE2:       # %bb.0:
+; X64-SSE2-NEXT:    pushq %rax
+; X64-SSE2-NEXT:    movl $.L.str, %esi
+; X64-SSE2-NEXT:    movl $64, %edx
+; X64-SSE2-NEXT:    callq memcmp
+; X64-SSE2-NEXT:    testl %eax, %eax
+; X64-SSE2-NEXT:    sete %al
+; X64-SSE2-NEXT:    popq %rcx
+; X64-SSE2-NEXT:    retq
+;
+; X64-AVX1-LABEL: length64_eq_const:
+; X64-AVX1:       # %bb.0:
+; X64-AVX1-NEXT:    pushq %rax
+; X64-AVX1-NEXT:    movl $.L.str, %esi
+; X64-AVX1-NEXT:    movl $64, %edx
+; X64-AVX1-NEXT:    callq memcmp
+; X64-AVX1-NEXT:    testl %eax, %eax
+; X64-AVX1-NEXT:    sete %al
+; X64-AVX1-NEXT:    popq %rcx
+; X64-AVX1-NEXT:    retq
+;
+; X64-AVX2-LABEL: length64_eq_const:
+; X64-AVX2:       # %bb.0:
+; X64-AVX2-NEXT:    vmovdqu (%rdi), %ymm0
+; X64-AVX2-NEXT:    vmovdqu 32(%rdi), %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm1, %ymm1
+; X64-AVX2-NEXT:    vpcmpeqb {{.*}}(%rip), %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpand %ymm1, %ymm0, %ymm0
+; X64-AVX2-NEXT:    vpmovmskb %ymm0, %eax
+; X64-AVX2-NEXT:    cmpl $-1, %eax
+; X64-AVX2-NEXT:    sete %al
+; X64-AVX2-NEXT:    vzeroupper
+; X64-AVX2-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* getelementptr inbounds ([65 x i8], [65 x i8]* @.str, i32 0, i32 0), i64 64) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+; This checks that we do not do stupid things with huge sizes.
+define i32 @huge_length(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: huge_length:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $2147483647 # imm = 0x7FFFFFFF
+; X86-NEXT:    pushl $-1
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    retl
+;
+; X64-LABEL: huge_length:
+; X64:       # %bb.0:
+; X64-NEXT:    movabsq $9223372036854775807, %rdx # imm = 0x7FFFFFFFFFFFFFFF
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 9223372036854775807) nounwind
+  ret i32 %m
+}
+
+define i1 @huge_length_eq(i8* %X, i8* %Y) nounwind {
+; X86-LABEL: huge_length_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl $2147483647 # imm = 0x7FFFFFFF
+; X86-NEXT:    pushl $-1
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: huge_length_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    movabsq $9223372036854775807, %rdx # imm = 0x7FFFFFFFFFFFFFFF
+; X64-NEXT:    callq memcmp
+; X64-NEXT:    testl %eax, %eax
+; X64-NEXT:    sete %al
+; X64-NEXT:    popq %rcx
+; X64-NEXT:    retq
+
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 9223372036854775807) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}
+
+; This checks non-constant sizes.
+define i32 @nonconst_length(i8* %X, i8* %Y, i64 %size) nounwind {
+; X86-LABEL: nonconst_length:
+; X86:       # %bb.0:
+; X86-NEXT:    jmp memcmp # TAILCALL
+;
+; X64-LABEL: nonconst_length:
+; X64:       # %bb.0:
+; X64-NEXT:    jmp memcmp # TAILCALL
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 %size) nounwind
+  ret i32 %m
+}
+
+define i1 @nonconst_length_eq(i8* %X, i8* %Y, i64 %size) nounwind {
+; X86-LABEL: nonconst_length_eq:
+; X86:       # %bb.0:
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    pushl {{[0-9]+}}(%esp)
+; X86-NEXT:    calll memcmp
+; X86-NEXT:    addl $16, %esp
+; X86-NEXT:    testl %eax, %eax
+; X86-NEXT:    sete %al
+; X86-NEXT:    retl
+;
+; X64-LABEL: nonconst_length_eq:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    callq memcmp
+; X64-NEXT:    testl %eax, %eax
+; X64-NEXT:    sete %al
+; X64-NEXT:    popq %rcx
+; X64-NEXT:    retq
+  %m = tail call i32 @memcmp(i8* %X, i8* %Y, i64 %size) nounwind
+  %c = icmp eq i32 %m, 0
+  ret i1 %c
+}