[x86] promote all multiply i8 by constant to i32

We have these 2 "isDesirable" promotion hooks (I'm not sure why we need both of them, but that's 
independent of this patch), and we can adjust them to promote "mul i8 X, C" to i32. Then, all of 
our existing LEA and other multiply expansion magic happens as it would for i32 ops.

Some of the test diffs show that we could end up with an actual 32-bit mul instruction here 
because we choose not to expand to simpler ops. That instruction could be slower depending on the 
subtarget. On the plus side, this means we don't need a separate instruction to load the constant 
operand and possibly an extra instruction to move the result. If we need to tune mul i32 further, 
we could add a later transform that tries to shrink it back to i8 based on subtarget timing.

I did not bother to duplicate all of the 32-bit test file RUNs and target settings that exist to 
test whether LEA expansion is cheap or not. The diffs here assume a default target, so that means 
LEA is generally cheap.

Differential Revision: https://reviews.llvm.org/D54803

llvm-svn: 347557

4 files changed, 128 insertions, 129 deletions

diff --git a/llvm/test/CodeGen/X86/ipra-reg-alias.ll b/llvm/test/CodeGen/X86/ipra-reg-alias.ll
index 76e604c9f62..29b2111bf34 100644
--- a/llvm/test/CodeGen/X86/ipra-reg-alias.ll
+++ b/llvm/test/CodeGen/X86/ipra-reg-alias.ll
@@ -1,19 +1,13 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc -mtriple=x86_64-- -enable-ipra -print-regusage -o - 2>&1 < %s | FileCheck %s --check-prefix=DEBUG
 ; RUN: llc -mtriple=x86_64-- -enable-ipra -o - < %s | FileCheck %s
 
-; Here only CL is clobbered so CH should not be clobbred, but CX, ECX and RCX
-; should be clobbered.
-; DEBUG: main Clobbered Registers: $ah $al $ax $cl $cx $eax $ecx $eflags $hax $rax $rcx
-
 define i8 @main(i8 %X) {
 ; CHECK-LABEL: main:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    movb $5, %cl
-; CHECK-NEXT:    # kill: def $al killed $al killed $eax
-; CHECK-NEXT:    mulb %cl
+; CHECK-NEXT:    # kill: def $edi killed $edi def $rdi
+; CHECK-NEXT:    leal (%rdi,%rdi,4), %eax
 ; CHECK-NEXT:    addb $5, %al
+; CHECK-NEXT:    # kill: def $al killed $al killed $eax
 ; CHECK-NEXT:    retq
   %inc = add i8 %X, 1
   %inc2 = mul i8 %inc, 5
diff --git a/llvm/test/CodeGen/X86/load-scalar-as-vector.ll b/llvm/test/CodeGen/X86/load-scalar-as-vector.ll
index 6a7bcf658e4..7bc9ee0fd6b 100644
--- a/llvm/test/CodeGen/X86/load-scalar-as-vector.ll
+++ b/llvm/test/CodeGen/X86/load-scalar-as-vector.ll
@@ -518,33 +518,29 @@ define <2 x i64> @urem_op0_constant(i64* %p) nounwind {
 define <16 x i8> @urem_op1_constant(i8* %p) nounwind {
 ; SSE-LABEL: urem_op1_constant:
 ; SSE:       # %bb.0:
-; SSE-NEXT:    movb (%rdi), %cl
-; SSE-NEXT:    movl %ecx, %eax
-; SSE-NEXT:    shrb %al
+; SSE-NEXT:    movb (%rdi), %al
+; SSE-NEXT:    movl %eax, %ecx
+; SSE-NEXT:    shrb %cl
+; SSE-NEXT:    movzbl %cl, %ecx
+; SSE-NEXT:    imull $49, %ecx, %ecx
+; SSE-NEXT:    shrl $10, %ecx
+; SSE-NEXT:    imull $42, %ecx, %ecx
+; SSE-NEXT:    subb %cl, %al
 ; SSE-NEXT:    movzbl %al, %eax
-; SSE-NEXT:    imull $49, %eax, %eax
-; SSE-NEXT:    shrl $10, %eax
-; SSE-NEXT:    movb $42, %dl
-; SSE-NEXT:    # kill: def $al killed $al killed $eax
-; SSE-NEXT:    mulb %dl
-; SSE-NEXT:    subb %al, %cl
-; SSE-NEXT:    movzbl %cl, %eax
 ; SSE-NEXT:    movd %eax, %xmm0
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: urem_op1_constant:
 ; AVX:       # %bb.0:
-; AVX-NEXT:    movb (%rdi), %cl
-; AVX-NEXT:    movl %ecx, %eax
-; AVX-NEXT:    shrb %al
+; AVX-NEXT:    movb (%rdi), %al
+; AVX-NEXT:    movl %eax, %ecx
+; AVX-NEXT:    shrb %cl
+; AVX-NEXT:    movzbl %cl, %ecx
+; AVX-NEXT:    imull $49, %ecx, %ecx
+; AVX-NEXT:    shrl $10, %ecx
+; AVX-NEXT:    imull $42, %ecx, %ecx
+; AVX-NEXT:    subb %cl, %al
 ; AVX-NEXT:    movzbl %al, %eax
-; AVX-NEXT:    imull $49, %eax, %eax
-; AVX-NEXT:    shrl $10, %eax
-; AVX-NEXT:    movb $42, %dl
-; AVX-NEXT:    # kill: def $al killed $al killed $eax
-; AVX-NEXT:    mulb %dl
-; AVX-NEXT:    subb %al, %cl
-; AVX-NEXT:    movzbl %cl, %eax
 ; AVX-NEXT:    vmovd %eax, %xmm0
 ; AVX-NEXT:    retq
   %x = load i8, i8* %p
diff --git a/llvm/test/CodeGen/X86/mul-constant-i8.ll b/llvm/test/CodeGen/X86/mul-constant-i8.ll
index 3c636b114f8..c3dcc12f5e9 100644
--- a/llvm/test/CodeGen/X86/mul-constant-i8.ll
+++ b/llvm/test/CodeGen/X86/mul-constant-i8.ll
@@ -25,10 +25,9 @@ define i8 @test_mul_by_2(i8 %x) {
 define i8 @test_mul_by_3(i8 %x) {
 ; X64-LABEL: test_mul_by_3:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $3, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 3
   ret i8 %m
@@ -48,10 +47,9 @@ define i8 @test_mul_by_4(i8 %x) {
 define i8 @test_mul_by_5(i8 %x) {
 ; X64-LABEL: test_mul_by_5:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $5, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 5
   ret i8 %m
@@ -60,10 +58,10 @@ define i8 @test_mul_by_5(i8 %x) {
 define i8 @test_mul_by_6(i8 %x) {
 ; X64-LABEL: test_mul_by_6:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $6, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    addl %edi, %edi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 6
   ret i8 %m
@@ -72,10 +70,10 @@ define i8 @test_mul_by_6(i8 %x) {
 define i8 @test_mul_by_7(i8 %x) {
 ; X64-LABEL: test_mul_by_7:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $7, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (,%rdi,8), %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 7
   ret i8 %m
@@ -95,10 +93,9 @@ define i8 @test_mul_by_8(i8 %x) {
 define i8 @test_mul_by_9(i8 %x) {
 ; X64-LABEL: test_mul_by_9:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $9, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 9
   ret i8 %m
@@ -107,10 +104,10 @@ define i8 @test_mul_by_9(i8 %x) {
 define i8 @test_mul_by_10(i8 %x) {
 ; X64-LABEL: test_mul_by_10:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $10, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    addl %edi, %edi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 10
   ret i8 %m
@@ -119,10 +116,10 @@ define i8 @test_mul_by_10(i8 %x) {
 define i8 @test_mul_by_11(i8 %x) {
 ; X64-LABEL: test_mul_by_11:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $11, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rdi,%rax,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 11
   ret i8 %m
@@ -131,10 +128,10 @@ define i8 @test_mul_by_11(i8 %x) {
 define i8 @test_mul_by_12(i8 %x) {
 ; X64-LABEL: test_mul_by_12:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $12, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    shll $2, %edi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 12
   ret i8 %m
@@ -143,10 +140,10 @@ define i8 @test_mul_by_12(i8 %x) {
 define i8 @test_mul_by_13(i8 %x) {
 ; X64-LABEL: test_mul_by_13:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $13, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
+; X64-NEXT:    leal (%rdi,%rax,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 13
   ret i8 %m
@@ -156,9 +153,10 @@ define i8 @test_mul_by_14(i8 %x) {
 ; X64-LABEL: test_mul_by_14:
 ; X64:       # %bb.0:
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $14, %cl
+; X64-NEXT:    shll $4, %eax
+; X64-NEXT:    subl %edi, %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 14
   ret i8 %m
@@ -167,10 +165,10 @@ define i8 @test_mul_by_14(i8 %x) {
 define i8 @test_mul_by_15(i8 %x) {
 ; X64-LABEL: test_mul_by_15:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $15, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rax,%rax,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 15
   ret i8 %m
@@ -190,10 +188,11 @@ define i8 @test_mul_by_16(i8 %x) {
 define i8 @test_mul_by_17(i8 %x) {
 ; X64-LABEL: test_mul_by_17:
 ; X64:       # %bb.0:
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $17, %cl
+; X64-NEXT:    shll $4, %eax
+; X64-NEXT:    leal (%rax,%rdi), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 17
   ret i8 %m
@@ -202,10 +201,10 @@ define i8 @test_mul_by_17(i8 %x) {
 define i8 @test_mul_by_18(i8 %x) {
 ; X64-LABEL: test_mul_by_18:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $18, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    addl %edi, %edi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 18
   ret i8 %m
@@ -214,10 +213,10 @@ define i8 @test_mul_by_18(i8 %x) {
 define i8 @test_mul_by_19(i8 %x) {
 ; X64-LABEL: test_mul_by_19:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $19, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rdi,%rax,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 19
   ret i8 %m
@@ -226,10 +225,10 @@ define i8 @test_mul_by_19(i8 %x) {
 define i8 @test_mul_by_20(i8 %x) {
 ; X64-LABEL: test_mul_by_20:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $20, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    shll $2, %edi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 20
   ret i8 %m
@@ -238,10 +237,10 @@ define i8 @test_mul_by_20(i8 %x) {
 define i8 @test_mul_by_21(i8 %x) {
 ; X64-LABEL: test_mul_by_21:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $21, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rdi,%rax,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 21
   ret i8 %m
@@ -250,10 +249,11 @@ define i8 @test_mul_by_21(i8 %x) {
 define i8 @test_mul_by_22(i8 %x) {
 ; X64-LABEL: test_mul_by_22:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $22, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rdi,%rax,4), %eax
+; X64-NEXT:    addl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 22
   ret i8 %m
@@ -262,10 +262,11 @@ define i8 @test_mul_by_22(i8 %x) {
 define i8 @test_mul_by_23(i8 %x) {
 ; X64-LABEL: test_mul_by_23:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $23, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
+; X64-NEXT:    shll $3, %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 23
   ret i8 %m
@@ -274,10 +275,10 @@ define i8 @test_mul_by_23(i8 %x) {
 define i8 @test_mul_by_24(i8 %x) {
 ; X64-LABEL: test_mul_by_24:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $24, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    shll $3, %edi
+; X64-NEXT:    leal (%rdi,%rdi,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 24
   ret i8 %m
@@ -286,10 +287,10 @@ define i8 @test_mul_by_24(i8 %x) {
 define i8 @test_mul_by_25(i8 %x) {
 ; X64-LABEL: test_mul_by_25:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $25, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rax,%rax,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 25
   ret i8 %m
@@ -298,10 +299,11 @@ define i8 @test_mul_by_25(i8 %x) {
 define i8 @test_mul_by_26(i8 %x) {
 ; X64-LABEL: test_mul_by_26:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $26, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rax,%rax,4), %eax
+; X64-NEXT:    addl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 26
   ret i8 %m
@@ -310,10 +312,10 @@ define i8 @test_mul_by_26(i8 %x) {
 define i8 @test_mul_by_27(i8 %x) {
 ; X64-LABEL: test_mul_by_27:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $27, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rax,%rax,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 27
   ret i8 %m
@@ -322,10 +324,11 @@ define i8 @test_mul_by_27(i8 %x) {
 define i8 @test_mul_by_28(i8 %x) {
 ; X64-LABEL: test_mul_by_28:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $28, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rax,%rax,2), %eax
+; X64-NEXT:    addl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 28
   ret i8 %m
@@ -334,10 +337,12 @@ define i8 @test_mul_by_28(i8 %x) {
 define i8 @test_mul_by_29(i8 %x) {
 ; X64-LABEL: test_mul_by_29:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $29, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rax,%rax,2), %eax
+; X64-NEXT:    addl %edi, %eax
+; X64-NEXT:    addl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 29
   ret i8 %m
@@ -347,9 +352,10 @@ define i8 @test_mul_by_30(i8 %x) {
 ; X64-LABEL: test_mul_by_30:
 ; X64:       # %bb.0:
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $30, %cl
+; X64-NEXT:    shll $5, %eax
+; X64-NEXT:    subl %edi, %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 30
   ret i8 %m
@@ -359,9 +365,9 @@ define i8 @test_mul_by_31(i8 %x) {
 ; X64-LABEL: test_mul_by_31:
 ; X64:       # %bb.0:
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $31, %cl
+; X64-NEXT:    shll $5, %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 31
   ret i8 %m
@@ -381,10 +387,10 @@ define i8 @test_mul_by_32(i8 %x) {
 define i8 @test_mul_by_37(i8 %x) {
 ; X64-LABEL: test_mul_by_37:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $37, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rdi,%rax,4), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 37
   ret i8 %m
@@ -393,10 +399,10 @@ define i8 @test_mul_by_37(i8 %x) {
 define i8 @test_mul_by_41(i8 %x) {
 ; X64-LABEL: test_mul_by_41:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $41, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    leal (%rdi,%rax,8), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 41
   ret i8 %m
@@ -406,9 +412,10 @@ define i8 @test_mul_by_62(i8 %x) {
 ; X64-LABEL: test_mul_by_62:
 ; X64:       # %bb.0:
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $62, %cl
+; X64-NEXT:    shll $6, %eax
+; X64-NEXT:    subl %edi, %eax
+; X64-NEXT:    subl %edi, %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 62
   ret i8 %m
@@ -417,10 +424,11 @@ define i8 @test_mul_by_62(i8 %x) {
 define i8 @test_mul_by_66(i8 %x) {
 ; X64-LABEL: test_mul_by_66:
 ; X64:       # %bb.0:
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
 ; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $66, %cl
+; X64-NEXT:    shll $6, %eax
+; X64-NEXT:    leal (%rax,%rdi,2), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 66
   ret i8 %m
@@ -429,10 +437,10 @@ define i8 @test_mul_by_66(i8 %x) {
 define i8 @test_mul_by_73(i8 %x) {
 ; X64-LABEL: test_mul_by_73:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $73, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    leal (%rdi,%rax,8), %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, 73
   ret i8 %m
@@ -452,10 +460,11 @@ define i8 @test_mul_by_520(i8 %x) {
 define i8 @test_mul_by_neg10(i8 %x) {
 ; X64-LABEL: test_mul_by_neg10:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $-10, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    addl %edi, %edi
+; X64-NEXT:    leal (%rdi,%rdi,4), %eax
+; X64-NEXT:    negl %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, -10
   ret i8 %m
@@ -464,10 +473,11 @@ define i8 @test_mul_by_neg10(i8 %x) {
 define i8 @test_mul_by_neg36(i8 %x) {
 ; X64-LABEL: test_mul_by_neg36:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl %edi, %eax
-; X64-NEXT:    movb $-36, %cl
+; X64-NEXT:    # kill: def $edi killed $edi def $rdi
+; X64-NEXT:    shll $2, %edi
+; X64-NEXT:    leal (%rdi,%rdi,8), %eax
+; X64-NEXT:    negl %eax
 ; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    mulb %cl
 ; X64-NEXT:    retq
   %m = mul i8 %x, -36
   ret i8 %m
diff --git a/llvm/test/CodeGen/X86/urem-i8-constant.ll b/llvm/test/CodeGen/X86/urem-i8-constant.ll
index d4fd92c0464..ae218405c0e 100644
--- a/llvm/test/CodeGen/X86/urem-i8-constant.ll
+++ b/llvm/test/CodeGen/X86/urem-i8-constant.ll
@@ -6,14 +6,13 @@
 define i8 @foo(i8 %tmp325) {
 ; CHECK-LABEL: foo:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movzbl {{[0-9]+}}(%esp), %ecx
-; CHECK-NEXT:    imull $111, %ecx, %eax
-; CHECK-NEXT:    shrl $12, %eax
-; CHECK-NEXT:    movb $37, %dl
+; CHECK-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
+; CHECK-NEXT:    imull $111, %eax, %ecx
+; CHECK-NEXT:    shrl $12, %ecx
+; CHECK-NEXT:    leal (%ecx,%ecx,8), %edx
+; CHECK-NEXT:    leal (%ecx,%edx,4), %ecx
+; CHECK-NEXT:    subb %cl, %al
 ; CHECK-NEXT:    # kill: def $al killed $al killed $eax
-; CHECK-NEXT:    mulb %dl
-; CHECK-NEXT:    subb %al, %cl
-; CHECK-NEXT:    movl %ecx, %eax
 ; CHECK-NEXT:    retl
   %t546 = urem i8 %tmp325, 37
   ret i8 %t546