[X86] Fix chains update when lowering BUILD_VECTOR to a vector load

The code which lowers BUILD_VECTOR of consecutive loads into a single vector
load doesn't update chains properly. As a result the vector load can be
reordered with the store to the same location.

The current code in EltsFromConsecutiveLoads only updates the chain following
the first load. The fix is to update the chains following all the loads
comprising the vector.

This is a fix for PR10114.

Reviewed By: niravd

Differential Revision: https://reviews.llvm.org/D38547

llvm-svn: 314988

2 files changed, 256 insertions, 19 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 9aae58b5555..b0e0b439257 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -6540,14 +6540,20 @@ static SDValue EltsFromConsecutiveLoads(EVT VT, ArrayRef<SDValue> Elts,
     }
   }
 
-  auto CreateLoad = [&DAG, &DL](EVT VT, LoadSDNode *LDBase) {
+  SmallVector<LoadSDNode *, 8> Loads;
+  for (int i = FirstLoadedElt; i <= LastLoadedElt; ++i)
+    if (LoadMask[i])
+      Loads.push_back(cast<LoadSDNode>(peekThroughBitcasts(Elts[i])));
+
+  auto CreateLoad = [&DAG, &DL, &Loads](EVT VT, LoadSDNode *LDBase) {
     auto MMOFlags = LDBase->getMemOperand()->getFlags();
     assert(!(MMOFlags & MachineMemOperand::MOVolatile) &&
            "Cannot merge volatile loads.");
     SDValue NewLd =
         DAG.getLoad(VT, DL, LDBase->getChain(), LDBase->getBasePtr(),
                     LDBase->getPointerInfo(), LDBase->getAlignment(), MMOFlags);
-    DAG.makeEquivalentMemoryOrdering(LDBase, NewLd);
+    for (auto *LD : Loads)
+      DAG.makeEquivalentMemoryOrdering(LD, NewLd);
     return NewLd;
   };
 
@@ -6612,7 +6618,8 @@ static SDValue EltsFromConsecutiveLoads(EVT VT, ArrayRef<SDValue> Elts,
                                   LDBase->getAlignment(),
                                   false/*isVolatile*/, true/*ReadMem*/,
                                   false/*WriteMem*/);
-      DAG.makeEquivalentMemoryOrdering(LDBase, ResNode);
+      for (auto *LD : Loads)
+        DAG.makeEquivalentMemoryOrdering(LD, ResNode);
       return DAG.getBitcast(VT, ResNode);
     }
   }
diff --git a/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll b/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
index 75587b240b8..516a4800c2a 100644
--- a/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
+++ b/llvm/test/CodeGen/X86/merge-consecutive-loads-128.ll
@@ -409,6 +409,124 @@ define <4 x i32> @merge_4i32_i32_23u5(i32* %ptr) nounwind uwtable noinline ssp {
   ret <4 x i32> %res3
 }
 
+define <4 x i32> @merge_4i32_i32_23u5_inc2(i32* %ptr) nounwind uwtable noinline ssp {
+; SSE-LABEL: merge_4i32_i32_23u5_inc2:
+; SSE:       # BB#0:
+; SSE-NEXT:    movups 8(%rdi), %xmm0
+; SSE-NEXT:    incl 8(%rdi)
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: merge_4i32_i32_23u5_inc2:
+; AVX:       # BB#0:
+; AVX-NEXT:    vmovups 8(%rdi), %xmm0
+; AVX-NEXT:    incl 8(%rdi)
+; AVX-NEXT:    retq
+;
+; X32-SSE1-LABEL: merge_4i32_i32_23u5_inc2:
+; X32-SSE1:       # BB#0:
+; X32-SSE1-NEXT:    pushl %edi
+; X32-SSE1-NEXT:  .Lcfi6:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
+; X32-SSE1-NEXT:    pushl %esi
+; X32-SSE1-NEXT:  .Lcfi7:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
+; X32-SSE1-NEXT:  .Lcfi8:
+; X32-SSE1-NEXT:    .cfi_offset %esi, -12
+; X32-SSE1-NEXT:  .Lcfi9:
+; X32-SSE1-NEXT:    .cfi_offset %edi, -8
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-SSE1-NEXT:    movl 8(%ecx), %edx
+; X32-SSE1-NEXT:    movl 12(%ecx), %esi
+; X32-SSE1-NEXT:    leal 1(%edx), %edi
+; X32-SSE1-NEXT:    movl %edi, 8(%ecx)
+; X32-SSE1-NEXT:    movl 20(%ecx), %ecx
+; X32-SSE1-NEXT:    movl %esi, 4(%eax)
+; X32-SSE1-NEXT:    movl %edx, (%eax)
+; X32-SSE1-NEXT:    movl %ecx, 12(%eax)
+; X32-SSE1-NEXT:    popl %esi
+; X32-SSE1-NEXT:    popl %edi
+; X32-SSE1-NEXT:    retl $4
+;
+; X32-SSE41-LABEL: merge_4i32_i32_23u5_inc2:
+; X32-SSE41:       # BB#0:
+; X32-SSE41-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE41-NEXT:    movups 8(%eax), %xmm0
+; X32-SSE41-NEXT:    incl 8(%eax)
+; X32-SSE41-NEXT:    retl
+  %ptr0 = getelementptr inbounds i32, i32* %ptr, i64 2
+  %ptr1 = getelementptr inbounds i32, i32* %ptr, i64 3
+  %ptr3 = getelementptr inbounds i32, i32* %ptr, i64 5
+  %val0 = load i32, i32* %ptr0
+  %inc = add i32 %val0, 1
+  store i32 %inc, i32* %ptr0
+  %val1 = load i32, i32* %ptr1
+  %val3 = load i32, i32* %ptr3
+  %res0 = insertelement <4 x i32> undef, i32 %val0, i32 0
+  %res1 = insertelement <4 x i32> %res0, i32 %val1, i32 1
+  %res3 = insertelement <4 x i32> %res1, i32 %val3, i32 3
+  ret <4 x i32> %res3
+}
+
+define <4 x i32> @merge_4i32_i32_23u5_inc3(i32* %ptr) nounwind uwtable noinline ssp {
+; SSE-LABEL: merge_4i32_i32_23u5_inc3:
+; SSE:       # BB#0:
+; SSE-NEXT:    movups 8(%rdi), %xmm0
+; SSE-NEXT:    incl 12(%rdi)
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: merge_4i32_i32_23u5_inc3:
+; AVX:       # BB#0:
+; AVX-NEXT:    vmovups 8(%rdi), %xmm0
+; AVX-NEXT:    incl 12(%rdi)
+; AVX-NEXT:    retq
+;
+; X32-SSE1-LABEL: merge_4i32_i32_23u5_inc3:
+; X32-SSE1:       # BB#0:
+; X32-SSE1-NEXT:    pushl %edi
+; X32-SSE1-NEXT:  .Lcfi10:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
+; X32-SSE1-NEXT:    pushl %esi
+; X32-SSE1-NEXT:  .Lcfi11:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
+; X32-SSE1-NEXT:  .Lcfi12:
+; X32-SSE1-NEXT:    .cfi_offset %esi, -12
+; X32-SSE1-NEXT:  .Lcfi13:
+; X32-SSE1-NEXT:    .cfi_offset %edi, -8
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-SSE1-NEXT:    movl 8(%ecx), %edx
+; X32-SSE1-NEXT:    movl 12(%ecx), %esi
+; X32-SSE1-NEXT:    leal 1(%esi), %edi
+; X32-SSE1-NEXT:    movl %edi, 12(%ecx)
+; X32-SSE1-NEXT:    movl 20(%ecx), %ecx
+; X32-SSE1-NEXT:    movl %esi, 4(%eax)
+; X32-SSE1-NEXT:    movl %edx, (%eax)
+; X32-SSE1-NEXT:    movl %ecx, 12(%eax)
+; X32-SSE1-NEXT:    popl %esi
+; X32-SSE1-NEXT:    popl %edi
+; X32-SSE1-NEXT:    retl $4
+;
+; X32-SSE41-LABEL: merge_4i32_i32_23u5_inc3:
+; X32-SSE41:       # BB#0:
+; X32-SSE41-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE41-NEXT:    movups 8(%eax), %xmm0
+; X32-SSE41-NEXT:    incl 12(%eax)
+; X32-SSE41-NEXT:    retl
+  %ptr0 = getelementptr inbounds i32, i32* %ptr, i64 2
+  %ptr1 = getelementptr inbounds i32, i32* %ptr, i64 3
+  %ptr3 = getelementptr inbounds i32, i32* %ptr, i64 5
+  %val0 = load i32, i32* %ptr0
+  %val1 = load i32, i32* %ptr1
+  %inc = add i32 %val1, 1
+  store i32 %inc, i32* %ptr1
+  %val3 = load i32, i32* %ptr3
+  %res0 = insertelement <4 x i32> undef, i32 %val0, i32 0
+  %res1 = insertelement <4 x i32> %res0, i32 %val1, i32 1
+  %res3 = insertelement <4 x i32> %res1, i32 %val3, i32 3
+  ret <4 x i32> %res3
+}
+
 define <4 x i32> @merge_4i32_i32_3zuu(i32* %ptr) nounwind uwtable noinline ssp {
 ; SSE-LABEL: merge_4i32_i32_3zuu:
 ; SSE:       # BB#0:
@@ -513,6 +631,118 @@ define <4 x i32> @merge_4i32_i32_45zz(i32* %ptr) nounwind uwtable noinline ssp {
   ret <4 x i32> %res1
 }
 
+define <4 x i32> @merge_4i32_i32_45zz_inc4(i32* %ptr) nounwind uwtable noinline ssp {
+; SSE-LABEL: merge_4i32_i32_45zz_inc4:
+; SSE:       # BB#0:
+; SSE-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero
+; SSE-NEXT:    incl 16(%rdi)
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: merge_4i32_i32_45zz_inc4:
+; AVX:       # BB#0:
+; AVX-NEXT:    vmovsd {{.*#+}} xmm0 = mem[0],zero
+; AVX-NEXT:    incl 16(%rdi)
+; AVX-NEXT:    retq
+;
+; X32-SSE1-LABEL: merge_4i32_i32_45zz_inc4:
+; X32-SSE1:       # BB#0:
+; X32-SSE1-NEXT:    pushl %edi
+; X32-SSE1-NEXT:  .Lcfi14:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
+; X32-SSE1-NEXT:    pushl %esi
+; X32-SSE1-NEXT:  .Lcfi15:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
+; X32-SSE1-NEXT:  .Lcfi16:
+; X32-SSE1-NEXT:    .cfi_offset %esi, -12
+; X32-SSE1-NEXT:  .Lcfi17:
+; X32-SSE1-NEXT:    .cfi_offset %edi, -8
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-SSE1-NEXT:    movl 16(%ecx), %edx
+; X32-SSE1-NEXT:    movl 20(%ecx), %esi
+; X32-SSE1-NEXT:    leal 1(%edx), %edi
+; X32-SSE1-NEXT:    movl %edi, 16(%ecx)
+; X32-SSE1-NEXT:    movl %esi, 4(%eax)
+; X32-SSE1-NEXT:    movl %edx, (%eax)
+; X32-SSE1-NEXT:    movl $0, 12(%eax)
+; X32-SSE1-NEXT:    movl $0, 8(%eax)
+; X32-SSE1-NEXT:    popl %esi
+; X32-SSE1-NEXT:    popl %edi
+; X32-SSE1-NEXT:    retl $4
+;
+; X32-SSE41-LABEL: merge_4i32_i32_45zz_inc4:
+; X32-SSE41:       # BB#0:
+; X32-SSE41-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE41-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero
+; X32-SSE41-NEXT:    incl 16(%eax)
+; X32-SSE41-NEXT:    retl
+  %ptr0 = getelementptr inbounds i32, i32* %ptr, i64 4
+  %ptr1 = getelementptr inbounds i32, i32* %ptr, i64 5
+  %val0 = load i32, i32* %ptr0
+  %inc = add i32 %val0, 1
+  store i32 %inc, i32* %ptr0
+  %val1 = load i32, i32* %ptr1
+  %res0 = insertelement <4 x i32> zeroinitializer, i32 %val0, i32 0
+  %res1 = insertelement <4 x i32> %res0, i32 %val1, i32 1
+  ret <4 x i32> %res1
+}
+
+define <4 x i32> @merge_4i32_i32_45zz_inc5(i32* %ptr) nounwind uwtable noinline ssp {
+; SSE-LABEL: merge_4i32_i32_45zz_inc5:
+; SSE:       # BB#0:
+; SSE-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero
+; SSE-NEXT:    incl 20(%rdi)
+; SSE-NEXT:    retq
+;
+; AVX-LABEL: merge_4i32_i32_45zz_inc5:
+; AVX:       # BB#0:
+; AVX-NEXT:    vmovsd {{.*#+}} xmm0 = mem[0],zero
+; AVX-NEXT:    incl 20(%rdi)
+; AVX-NEXT:    retq
+;
+; X32-SSE1-LABEL: merge_4i32_i32_45zz_inc5:
+; X32-SSE1:       # BB#0:
+; X32-SSE1-NEXT:    pushl %edi
+; X32-SSE1-NEXT:  .Lcfi18:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
+; X32-SSE1-NEXT:    pushl %esi
+; X32-SSE1-NEXT:  .Lcfi19:
+; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
+; X32-SSE1-NEXT:  .Lcfi20:
+; X32-SSE1-NEXT:    .cfi_offset %esi, -12
+; X32-SSE1-NEXT:  .Lcfi21:
+; X32-SSE1-NEXT:    .cfi_offset %edi, -8
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; X32-SSE1-NEXT:    movl 16(%ecx), %edx
+; X32-SSE1-NEXT:    movl 20(%ecx), %esi
+; X32-SSE1-NEXT:    leal 1(%esi), %edi
+; X32-SSE1-NEXT:    movl %edi, 20(%ecx)
+; X32-SSE1-NEXT:    movl %esi, 4(%eax)
+; X32-SSE1-NEXT:    movl %edx, (%eax)
+; X32-SSE1-NEXT:    movl $0, 12(%eax)
+; X32-SSE1-NEXT:    movl $0, 8(%eax)
+; X32-SSE1-NEXT:    popl %esi
+; X32-SSE1-NEXT:    popl %edi
+; X32-SSE1-NEXT:    retl $4
+;
+; X32-SSE41-LABEL: merge_4i32_i32_45zz_inc5:
+; X32-SSE41:       # BB#0:
+; X32-SSE41-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X32-SSE41-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero
+; X32-SSE41-NEXT:    incl 20(%eax)
+; X32-SSE41-NEXT:    retl
+  %ptr0 = getelementptr inbounds i32, i32* %ptr, i64 4
+  %ptr1 = getelementptr inbounds i32, i32* %ptr, i64 5
+  %val0 = load i32, i32* %ptr0
+  %val1 = load i32, i32* %ptr1
+  %inc = add i32 %val1, 1
+  store i32 %inc, i32* %ptr1
+  %res0 = insertelement <4 x i32> zeroinitializer, i32 %val0, i32 0
+  %res1 = insertelement <4 x i32> %res0, i32 %val1, i32 1
+  ret <4 x i32> %res1
+}
+
 define <8 x i16> @merge_8i16_i16_23u567u9(i16* %ptr) nounwind uwtable noinline ssp {
 ; SSE-LABEL: merge_8i16_i16_23u567u9:
 ; SSE:       # BB#0:
@@ -527,14 +757,14 @@ define <8 x i16> @merge_8i16_i16_23u567u9(i16* %ptr) nounwind uwtable noinline s
 ; X32-SSE1-LABEL: merge_8i16_i16_23u567u9:
 ; X32-SSE1:       # BB#0:
 ; X32-SSE1-NEXT:    pushl %edi
-; X32-SSE1-NEXT:  .Lcfi6:
+; X32-SSE1-NEXT:  .Lcfi22:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
 ; X32-SSE1-NEXT:    pushl %esi
-; X32-SSE1-NEXT:  .Lcfi7:
+; X32-SSE1-NEXT:  .Lcfi23:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
-; X32-SSE1-NEXT:  .Lcfi8:
+; X32-SSE1-NEXT:  .Lcfi24:
 ; X32-SSE1-NEXT:    .cfi_offset %esi, -12
-; X32-SSE1-NEXT:  .Lcfi9:
+; X32-SSE1-NEXT:  .Lcfi25:
 ; X32-SSE1-NEXT:    .cfi_offset %edi, -8
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
@@ -667,24 +897,24 @@ define <16 x i8> @merge_16i8_i8_01u3456789ABCDuF(i8* %ptr) nounwind uwtable noin
 ; X32-SSE1-LABEL: merge_16i8_i8_01u3456789ABCDuF:
 ; X32-SSE1:       # BB#0:
 ; X32-SSE1-NEXT:    pushl %ebp
-; X32-SSE1-NEXT:  .Lcfi10:
+; X32-SSE1-NEXT:  .Lcfi26:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
 ; X32-SSE1-NEXT:    pushl %ebx
-; X32-SSE1-NEXT:  .Lcfi11:
+; X32-SSE1-NEXT:  .Lcfi27:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
 ; X32-SSE1-NEXT:    pushl %edi
-; X32-SSE1-NEXT:  .Lcfi12:
+; X32-SSE1-NEXT:  .Lcfi28:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 16
 ; X32-SSE1-NEXT:    pushl %esi
-; X32-SSE1-NEXT:  .Lcfi13:
+; X32-SSE1-NEXT:  .Lcfi29:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 20
-; X32-SSE1-NEXT:  .Lcfi14:
+; X32-SSE1-NEXT:  .Lcfi30:
 ; X32-SSE1-NEXT:    .cfi_offset %esi, -20
-; X32-SSE1-NEXT:  .Lcfi15:
+; X32-SSE1-NEXT:  .Lcfi31:
 ; X32-SSE1-NEXT:    .cfi_offset %edi, -16
-; X32-SSE1-NEXT:  .Lcfi16:
+; X32-SSE1-NEXT:  .Lcfi32:
 ; X32-SSE1-NEXT:    .cfi_offset %ebx, -12
-; X32-SSE1-NEXT:  .Lcfi17:
+; X32-SSE1-NEXT:  .Lcfi33:
 ; X32-SSE1-NEXT:    .cfi_offset %ebp, -8
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx
@@ -917,14 +1147,14 @@ define <2 x i64> @merge_2i64_i64_12_volatile(i64* %ptr) nounwind uwtable noinlin
 ; X32-SSE1-LABEL: merge_2i64_i64_12_volatile:
 ; X32-SSE1:       # BB#0:
 ; X32-SSE1-NEXT:    pushl %edi
-; X32-SSE1-NEXT:  .Lcfi18:
+; X32-SSE1-NEXT:  .Lcfi34:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 8
 ; X32-SSE1-NEXT:    pushl %esi
-; X32-SSE1-NEXT:  .Lcfi19:
+; X32-SSE1-NEXT:  .Lcfi35:
 ; X32-SSE1-NEXT:    .cfi_def_cfa_offset 12
-; X32-SSE1-NEXT:  .Lcfi20:
+; X32-SSE1-NEXT:  .Lcfi36:
 ; X32-SSE1-NEXT:    .cfi_offset %esi, -12
-; X32-SSE1-NEXT:  .Lcfi21:
+; X32-SSE1-NEXT:  .Lcfi37:
 ; X32-SSE1-NEXT:    .cfi_offset %edi, -8
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X32-SSE1-NEXT:    movl {{[0-9]+}}(%esp), %ecx