https://github.com/llvmbot created
https://github.com/llvm/llvm-project/pull/153958
Backport 3a4a60deffdf5bbe622326b2813583acc37cccce
Requested by: @lukel97
>From 533337d530923a680214e58b2ef955c623c6c97c Mon Sep 17 00:00:00 2001
From: XChy <xxs_...@outlook.com>
Date: Sat, 16 Aug 2025 02:38:04 +0800
Subject: [PATCH] [VectorCombine] Apply InstSimplify in scalarizeOpOrCmp to
avoid infinite loop (#153069)
Fixes #153012
As we tolerate unfoldable constant expressions in `scalarizeOpOrCmp`, we
may fold
```llvm
define void @bug(ptr %ptr1, ptr %ptr2, i64 %idx) #0 {
entry:
%158 = insertelement <2 x i64> <i64 5, i64 ptrtoint (ptr @val to i64)>, i64
%idx, i32 0
%159 = or disjoint <2 x i64> splat (i64 2), %158
store <2 x i64> %159, ptr %ptr2
ret void
}
```
to
```llvm
define void @bug(ptr %ptr1, ptr %ptr2, i64 %idx) {
entry:
%.scalar = or disjoint i64 2, %idx
%0 = or <2 x i64> splat (i64 2), <i64 5, i64 ptrtoint (ptr @val to i64)>
%1 = insertelement <2 x i64> %0, i64 %.scalar, i64 0
store <2 x i64> %1, ptr %ptr2, align 16
ret void
}
```
And it would be folded back in `foldInsExtBinop`, resulting in an
infinite loop.
This patch forces scalarization iff InstSimplify can fold the constant
expression.
(cherry picked from commit 3a4a60deffdf5bbe622326b2813583acc37cccce)
---
.../Transforms/Vectorize/VectorCombine.cpp | 28 +++++++---------
.../VectorCombine/X86/intrinsic-scalarize.ll | 3 +-
.../VectorCombine/binop-scalarize.ll | 19 +++++++++++
.../VectorCombine/intrinsic-scalarize.ll | 33 +++++++------------
4 files changed, 42 insertions(+), 41 deletions(-)
diff --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index fe8d74c43dfdc..639f8686a271e 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -74,7 +74,7 @@ class VectorCombine {
const DataLayout *DL, TTI::TargetCostKind CostKind,
bool TryEarlyFoldsOnly)
: F(F), Builder(F.getContext(), InstSimplifyFolder(*DL)), TTI(TTI),
- DT(DT), AA(AA), AC(AC), DL(DL), CostKind(CostKind),
+ DT(DT), AA(AA), AC(AC), DL(DL), CostKind(CostKind), SQ(*DL),
TryEarlyFoldsOnly(TryEarlyFoldsOnly) {}
bool run();
@@ -88,6 +88,7 @@ class VectorCombine {
AssumptionCache &AC;
const DataLayout *DL;
TTI::TargetCostKind CostKind;
+ const SimplifyQuery SQ;
/// If true, only perform beneficial early IR transforms. Do not introduce
new
/// vector operations.
@@ -1185,17 +1186,18 @@ bool VectorCombine::scalarizeOpOrCmp(Instruction &I) {
// Fold the vector constants in the original vectors into a new base vector
to
// get more accurate cost modelling.
Value *NewVecC = nullptr;
- TargetFolder Folder(*DL);
if (CI)
- NewVecC = Folder.FoldCmp(CI->getPredicate(), VecCs[0], VecCs[1]);
+ NewVecC = simplifyCmpInst(CI->getPredicate(), VecCs[0], VecCs[1], SQ);
else if (UO)
NewVecC =
- Folder.FoldUnOpFMF(UO->getOpcode(), VecCs[0], UO->getFastMathFlags());
+ simplifyUnOp(UO->getOpcode(), VecCs[0], UO->getFastMathFlags(), SQ);
else if (BO)
- NewVecC = Folder.FoldBinOp(BO->getOpcode(), VecCs[0], VecCs[1]);
- else if (II->arg_size() == 2)
- NewVecC = Folder.FoldBinaryIntrinsic(II->getIntrinsicID(), VecCs[0],
- VecCs[1], II->getType(), &I);
+ NewVecC = simplifyBinOp(BO->getOpcode(), VecCs[0], VecCs[1], SQ);
+ else if (II)
+ NewVecC = simplifyCall(II, II->getCalledOperand(), VecCs, SQ);
+
+ if (!NewVecC)
+ return false;
// Get cost estimate for the insert element. This cost will factor into
// both sequences.
@@ -1203,6 +1205,7 @@ bool VectorCombine::scalarizeOpOrCmp(Instruction &I) {
InstructionCost NewCost =
ScalarOpCost + TTI.getVectorInstrCost(Instruction::InsertElement, VecTy,
CostKind, *Index, NewVecC);
+
for (auto [Idx, Op, VecC, Scalar] : enumerate(Ops, VecCs, ScalarOps)) {
if (!Scalar || (II && isVectorIntrinsicWithScalarOpAtArg(
II->getIntrinsicID(), Idx, &TTI)))
@@ -1247,15 +1250,6 @@ bool VectorCombine::scalarizeOpOrCmp(Instruction &I) {
if (auto *ScalarInst = dyn_cast<Instruction>(Scalar))
ScalarInst->copyIRFlags(&I);
- // Create a new base vector if the constant folding failed.
- if (!NewVecC) {
- if (CI)
- NewVecC = Builder.CreateCmp(CI->getPredicate(), VecCs[0], VecCs[1]);
- else if (UO || BO)
- NewVecC = Builder.CreateNAryOp(Opcode, VecCs);
- else
- NewVecC = Builder.CreateIntrinsic(VecTy, II->getIntrinsicID(), VecCs);
- }
Value *Insert = Builder.CreateInsertElement(NewVecC, Scalar, *Index);
replaceValue(I, *Insert);
return true;
diff --git a/llvm/test/Transforms/VectorCombine/X86/intrinsic-scalarize.ll
b/llvm/test/Transforms/VectorCombine/X86/intrinsic-scalarize.ll
index 5f3229398792a..ad5f5a7107c2b 100644
--- a/llvm/test/Transforms/VectorCombine/X86/intrinsic-scalarize.ll
+++ b/llvm/test/Transforms/VectorCombine/X86/intrinsic-scalarize.ll
@@ -13,8 +13,7 @@ define <2 x float> @maxnum(float %x, float %y) {
; AVX2-LABEL: define <2 x float> @maxnum(
; AVX2-SAME: float [[X:%.*]], float [[Y:%.*]]) #[[ATTR0:[0-9]+]] {
; AVX2-NEXT: [[V_SCALAR:%.*]] = call float @llvm.maxnum.f32(float [[X]],
float [[Y]])
-; AVX2-NEXT: [[TMP1:%.*]] = call <2 x float> @llvm.maxnum.v2f32(<2 x float>
poison, <2 x float> poison)
-; AVX2-NEXT: [[V:%.*]] = insertelement <2 x float> [[TMP1]], float
[[V_SCALAR]], i64 0
+; AVX2-NEXT: [[V:%.*]] = insertelement <2 x float> poison, float
[[V_SCALAR]], i64 0
; AVX2-NEXT: ret <2 x float> [[V]]
;
%x.insert = insertelement <2 x float> poison, float %x, i32 0
diff --git a/llvm/test/Transforms/VectorCombine/binop-scalarize.ll
b/llvm/test/Transforms/VectorCombine/binop-scalarize.ll
index 52a706a0b59a7..bc07f8b086496 100644
--- a/llvm/test/Transforms/VectorCombine/binop-scalarize.ll
+++ b/llvm/test/Transforms/VectorCombine/binop-scalarize.ll
@@ -20,3 +20,22 @@ define <4 x i8> @udiv_ub(i8 %x, i8 %y) {
%v = udiv <4 x i8> %x.insert, %y.insert
ret <4 x i8> %v
}
+
+
+; Unfoldable constant expression may cause infinite loop between
+; scalarizing insertelement and folding binop(insert(x,a,idx),insert(y,b,idx))
+@val = external hidden global ptr, align 8
+
+define <2 x i64> @pr153012(i64 %idx) #0 {
+; CHECK-LABEL: define <2 x i64> @pr153012(
+; CHECK-SAME: i64 [[IDX:%.*]]) {
+; CHECK-NEXT: [[ENTRY:.*:]]
+; CHECK-NEXT: [[A:%.*]] = insertelement <2 x i64> <i64 5, i64 ptrtoint (ptr
@val to i64)>, i64 [[IDX]], i32 0
+; CHECK-NEXT: [[B:%.*]] = or disjoint <2 x i64> splat (i64 2), [[A]]
+; CHECK-NEXT: ret <2 x i64> [[B]]
+;
+entry:
+ %a = insertelement <2 x i64> <i64 5, i64 ptrtoint (ptr @val to i64)>, i64
%idx, i32 0
+ %b = or disjoint <2 x i64> splat (i64 2), %a
+ ret <2 x i64> %b
+}
diff --git a/llvm/test/Transforms/VectorCombine/intrinsic-scalarize.ll
b/llvm/test/Transforms/VectorCombine/intrinsic-scalarize.ll
index 9e43a28bf1e59..abd98a4dc64b8 100644
--- a/llvm/test/Transforms/VectorCombine/intrinsic-scalarize.ll
+++ b/llvm/test/Transforms/VectorCombine/intrinsic-scalarize.ll
@@ -5,8 +5,7 @@ define <4 x i32> @umax_fixed(i32 %x, i32 %y) {
; CHECK-LABEL: define <4 x i32> @umax_fixed(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32
[[Y]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x i32> @llvm.umax.v4i32(<4 x i32>
poison, <4 x i32> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> poison, i32 [[V_SCALAR]],
i64 0
; CHECK-NEXT: ret <4 x i32> [[V]]
;
%x.insert = insertelement <4 x i32> poison, i32 %x, i32 0
@@ -19,8 +18,7 @@ define <vscale x 4 x i32> @umax_scalable(i32 %x, i32 %y) {
; CHECK-LABEL: define <vscale x 4 x i32> @umax_scalable(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32
[[Y]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 4 x i32>
@llvm.umax.nxv4i32(<vscale x 4 x i32> poison, <vscale x 4 x i32> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> poison, i32
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <vscale x 4 x i32> [[V]]
;
%x.insert = insertelement <vscale x 4 x i32> poison, i32 %x, i32 0
@@ -33,8 +31,7 @@ define <4 x i32> @umax_fixed_lhs_const(i32 %x) {
; CHECK-LABEL: define <4 x i32> @umax_fixed_lhs_const(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 1, i32 [[X]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x i32> @llvm.umax.v4i32(<4 x i32> <i32
1, i32 2, i32 3, i32 4>, <4 x i32> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> poison, i32 [[V_SCALAR]],
i64 0
; CHECK-NEXT: ret <4 x i32> [[V]]
;
%x.insert = insertelement <4 x i32> poison, i32 %x, i32 0
@@ -46,8 +43,7 @@ define <4 x i32> @umax_fixed_rhs_const(i32 %x) {
; CHECK-LABEL: define <4 x i32> @umax_fixed_rhs_const(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32 1)
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x i32> @llvm.umax.v4i32(<4 x i32>
poison, <4 x i32> <i32 1, i32 2, i32 3, i32 4>)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x i32> poison, i32 [[V_SCALAR]],
i64 0
; CHECK-NEXT: ret <4 x i32> [[V]]
;
%x.insert = insertelement <4 x i32> poison, i32 %x, i32 0
@@ -59,8 +55,7 @@ define <vscale x 4 x i32> @umax_scalable_lhs_const(i32 %x) {
; CHECK-LABEL: define <vscale x 4 x i32> @umax_scalable_lhs_const(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 42, i32 [[X]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 4 x i32>
@llvm.umax.nxv4i32(<vscale x 4 x i32> splat (i32 42), <vscale x 4 x i32> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> poison, i32
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <vscale x 4 x i32> [[V]]
;
%x.insert = insertelement <vscale x 4 x i32> poison, i32 %x, i32 0
@@ -72,8 +67,7 @@ define <vscale x 4 x i32> @umax_scalable_rhs_const(i32 %x) {
; CHECK-LABEL: define <vscale x 4 x i32> @umax_scalable_rhs_const(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call i32 @llvm.umax.i32(i32 [[X]], i32 42)
-; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 4 x i32>
@llvm.umax.nxv4i32(<vscale x 4 x i32> poison, <vscale x 4 x i32> splat (i32 42))
-; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> [[TMP1]], i32
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x i32> poison, i32
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <vscale x 4 x i32> [[V]]
;
%x.insert = insertelement <vscale x 4 x i32> poison, i32 %x, i32 0
@@ -100,8 +94,7 @@ define <4 x float> @fabs_fixed(float %x) {
; CHECK-LABEL: define <4 x float> @fabs_fixed(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call float @llvm.fabs.f32(float [[X]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x float> @llvm.fabs.v4f32(<4 x float>
poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> [[TMP1]], float
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> poison, float
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <4 x float> [[V]]
;
%x.insert = insertelement <4 x float> poison, float %x, i32 0
@@ -113,8 +106,7 @@ define <vscale x 4 x float> @fabs_scalable(float %x) {
; CHECK-LABEL: define <vscale x 4 x float> @fabs_scalable(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call float @llvm.fabs.f32(float [[X]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 4 x float>
@llvm.fabs.nxv4f32(<vscale x 4 x float> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x float> [[TMP1]],
float [[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x float> poison, float
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <vscale x 4 x float> [[V]]
;
%x.insert = insertelement <vscale x 4 x float> poison, float %x, i32 0
@@ -126,8 +118,7 @@ define <4 x float> @fma_fixed(float %x, float %y, float %z)
{
; CHECK-LABEL: define <4 x float> @fma_fixed(
; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]], float [[Z:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call float @llvm.fma.f32(float [[X]],
float [[Y]], float [[Z]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x float> @llvm.fma.v4f32(<4 x float>
poison, <4 x float> poison, <4 x float> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> [[TMP1]], float
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> poison, float
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <4 x float> [[V]]
;
%x.insert = insertelement <4 x float> poison, float %x, i32 0
@@ -141,8 +132,7 @@ define <vscale x 4 x float> @fma_scalable(float %x, float
%y, float %z) {
; CHECK-LABEL: define <vscale x 4 x float> @fma_scalable(
; CHECK-SAME: float [[X:%.*]], float [[Y:%.*]], float [[Z:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call float @llvm.fma.f32(float [[X]],
float [[Y]], float [[Z]])
-; CHECK-NEXT: [[TMP1:%.*]] = call <vscale x 4 x float>
@llvm.fma.nxv4f32(<vscale x 4 x float> poison, <vscale x 4 x float> poison,
<vscale x 4 x float> poison)
-; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x float> [[TMP1]],
float [[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <vscale x 4 x float> poison, float
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <vscale x 4 x float> [[V]]
;
%x.insert = insertelement <vscale x 4 x float> poison, float %x, i32 0
@@ -156,8 +146,7 @@ define <4 x float> @scalar_argument(float %x) {
; CHECK-LABEL: define <4 x float> @scalar_argument(
; CHECK-SAME: float [[X:%.*]]) {
; CHECK-NEXT: [[V_SCALAR:%.*]] = call float @llvm.powi.f32.i32(float [[X]],
i32 42)
-; CHECK-NEXT: [[TMP1:%.*]] = call <4 x float> @llvm.powi.v4f32.i32(<4 x
float> poison, i32 42)
-; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> [[TMP1]], float
[[V_SCALAR]], i64 0
+; CHECK-NEXT: [[V:%.*]] = insertelement <4 x float> poison, float
[[V_SCALAR]], i64 0
; CHECK-NEXT: ret <4 x float> [[V]]
;
%x.insert = insertelement <4 x float> poison, float %x, i32 0
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
