[llvm] 6e23353 - [DAGCombiner] Fix crash caused by illegal InterVT in ForwardStoreValueToDirectLoad (#181175)

via llvm-commits llvm-commits at lists.llvm.org
Sat Feb 14 05:05:35 PST 2026


Author: 陈子昂
Date: 2026-02-14T21:05:31+08:00
New Revision: 6e23353c396098bf5cedf26091179f9d8dacb2e9

URL: https://github.com/llvm/llvm-project/commit/6e23353c396098bf5cedf26091179f9d8dacb2e9
DIFF: https://github.com/llvm/llvm-project/commit/6e23353c396098bf5cedf26091179f9d8dacb2e9.diff

LOG: [DAGCombiner] Fix crash caused by illegal InterVT in ForwardStoreValueToDirectLoad (#181175)

This patch fixes an assertion failure in ForwardStoreValueToDirectLoad
during DAGCombine.

The crash occurs when `STLF (Store-to-Load Forwarding)` creates an
illegal intermediate bitcast type (e.g., `v128i1` when bridging a
128-bit store to a `<32 x i1>` load on X86). Since `v128i1` is not a
legal mask type for the backend, it violates the expectations of the
LegalizeDAG pass.

The fix adds a `TLI.isTypeLegal(InterVT)` check to ensure that the
intermediate type used for the transformation is supported by the
target.

Fixes #181130

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/test/CodeGen/X86/dag-stlf-mismatch.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 19bcdeeefb143..e513a16ee0e27 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -20831,7 +20831,8 @@ SDValue DAGCombiner::ForwardStoreValueToDirectLoad(LoadSDNode *LD) {
 
         EVT InterVT = EVT::getVectorVT(*DAG.getContext(), EltVT,
                                        StMemSize.divideCoefficientBy(EltSize));
-        if (!TLI.isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, LDMemType))
+        if (!TLI.isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, LDMemType) ||
+            !TLI.isTypeLegal(InterVT))
           break;
 
         // In case of big-endian the offset is normalized to zero, denoting

diff  --git a/llvm/test/CodeGen/X86/dag-stlf-mismatch.ll b/llvm/test/CodeGen/X86/dag-stlf-mismatch.ll
index a1ee713b32032..309df51e303d8 100644
--- a/llvm/test/CodeGen/X86/dag-stlf-mismatch.ll
+++ b/llvm/test/CodeGen/X86/dag-stlf-mismatch.ll
@@ -1,15 +1,23 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
-; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s --check-prefix=X64
+; RUN: llc < %s -mtriple=x86_64-pc-windows-gnu -mcpu=x86-64-v4 | FileCheck %s --check-prefix=AVX512
 
 %struct.Data = type { float }
 
 define float @test_stlf_integer(ptr %p, float %v) {
-; CHECK-LABEL: test_stlf_integer:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    movl $0, (%rdi)
-; CHECK-NEXT:    xorps %xmm1, %xmm1
-; CHECK-NEXT:    mulss %xmm1, %xmm0
-; CHECK-NEXT:    retq
+; X64-LABEL: test_stlf_integer:
+; X64:       # %bb.0:
+; X64-NEXT:    movl $0, (%rdi)
+; X64-NEXT:    xorps %xmm1, %xmm1
+; X64-NEXT:    mulss %xmm1, %xmm0
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: test_stlf_integer:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    movl $0, (%rcx)
+; AVX512-NEXT:    vxorps %xmm0, %xmm0, %xmm0
+; AVX512-NEXT:    vmulss %xmm0, %xmm1, %xmm0
+; AVX512-NEXT:    retq
   store i32 0, ptr %p, align 4
   %f = load float, ptr %p, align 4
   %r = fmul float %f, %v
@@ -17,12 +25,19 @@ define float @test_stlf_integer(ptr %p, float %v) {
 }
 
 define float @test_stlf_vector(ptr %p, float %v) {
-; CHECK-LABEL: test_stlf_vector:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    xorps %xmm1, %xmm1
-; CHECK-NEXT:    movups %xmm1, (%rdi)
-; CHECK-NEXT:    mulss (%rdi), %xmm0
-; CHECK-NEXT:    retq
+; X64-LABEL: test_stlf_vector:
+; X64:       # %bb.0:
+; X64-NEXT:    xorps %xmm1, %xmm1
+; X64-NEXT:    movups %xmm1, (%rdi)
+; X64-NEXT:    mulss (%rdi), %xmm0
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: test_stlf_vector:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    vxorps %xmm0, %xmm0, %xmm0
+; AVX512-NEXT:    vmovups %xmm0, (%rcx)
+; AVX512-NEXT:    vmulss (%rcx), %xmm1, %xmm0
+; AVX512-NEXT:    retq
   store <4 x float> zeroinitializer, ptr %p, align 4
   %f = load float, ptr %p, align 4
   %r = fmul float %f, %v
@@ -30,12 +45,19 @@ define float @test_stlf_vector(ptr %p, float %v) {
 }
 
 define float @test_stlf_bitcast(ptr %p, float %v) {
-; CHECK-LABEL: test_stlf_bitcast:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    xorps %xmm1, %xmm1
-; CHECK-NEXT:    movups %xmm1, (%rdi)
-; CHECK-NEXT:    mulss (%rdi), %xmm0
-; CHECK-NEXT:    retq
+; X64-LABEL: test_stlf_bitcast:
+; X64:       # %bb.0:
+; X64-NEXT:    xorps %xmm1, %xmm1
+; X64-NEXT:    movups %xmm1, (%rdi)
+; X64-NEXT:    mulss (%rdi), %xmm0
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: test_stlf_bitcast:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    vxorps %xmm0, %xmm0, %xmm0
+; AVX512-NEXT:    vmovups %xmm0, (%rcx)
+; AVX512-NEXT:    vmulss (%rcx), %xmm1, %xmm0
+; AVX512-NEXT:    retq
   store <2 x i64> zeroinitializer, ptr %p, align 4
   %f = load float, ptr %p, align 4
   %r = fmul float %f, %v
@@ -44,28 +66,65 @@ define float @test_stlf_bitcast(ptr %p, float %v) {
 
 declare void @ext_func(ptr byval(%struct.Data) align 4 %p)
 define void @test_stlf_late_byval(ptr %ptr) nounwind {
-; CHECK-LABEL: test_stlf_late_byval:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    pushq %rax
-; CHECK-NEXT:    movl $0, (%rdi)
-; CHECK-NEXT:    movl $0, (%rsp)
-; CHECK-NEXT:    callq ext_func at PLT
-; CHECK-NEXT:    popq %rax
-; CHECK-NEXT:    retq
+; X64-LABEL: test_stlf_late_byval:
+; X64:       # %bb.0:
+; X64-NEXT:    pushq %rax
+; X64-NEXT:    movl $0, (%rdi)
+; X64-NEXT:    movl $0, (%rsp)
+; X64-NEXT:    callq ext_func at PLT
+; X64-NEXT:    popq %rax
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: test_stlf_late_byval:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    subq $40, %rsp
+; AVX512-NEXT:    movl $0, (%rcx)
+; AVX512-NEXT:    movl $0, {{[0-9]+}}(%rsp)
+; AVX512-NEXT:    leaq {{[0-9]+}}(%rsp), %rcx
+; AVX512-NEXT:    callq ext_func
+; AVX512-NEXT:    addq $40, %rsp
+; AVX512-NEXT:    retq
   store i32 0, ptr %ptr, align 4
   call void @ext_func(ptr byval(%struct.Data) align 4 %ptr)
   ret void
 }
 
 define float @test_stlf_variable(ptr %p, i32 %val, float %v) {
-; CHECK-LABEL: test_stlf_variable:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    movd %esi, %xmm1
-; CHECK-NEXT:    movl %esi, (%rdi)
-; CHECK-NEXT:    mulss %xmm1, %xmm0
-; CHECK-NEXT:    retq
+; X64-LABEL: test_stlf_variable:
+; X64:       # %bb.0:
+; X64-NEXT:    movd %esi, %xmm1
+; X64-NEXT:    movl %esi, (%rdi)
+; X64-NEXT:    mulss %xmm1, %xmm0
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: test_stlf_variable:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    vmovd %edx, %xmm0
+; AVX512-NEXT:    movl %edx, (%rcx)
+; AVX512-NEXT:    vmulss %xmm2, %xmm0, %xmm0
+; AVX512-NEXT:    retq
   store i32 %val, ptr %p, align 4
   %f = load float, ptr %p, align 4
   %r = fmul float %f, %v
   ret float %r
 }
+
+define <32 x i1> @v32i1_bitcast_crash(<4 x i8> %arg) nounwind {
+; X64-LABEL: v32i1_bitcast_crash:
+; X64:       # %bb.0:
+; X64-NEXT:    movq %rdi, %rax
+; X64-NEXT:    movss %xmm0, (%rdi)
+; X64-NEXT:    retq
+;
+; AVX512-LABEL: v32i1_bitcast_crash:
+; AVX512:       # %bb.0:
+; AVX512-NEXT:    subq $24, %rsp
+; AVX512-NEXT:    vmovaps (%rcx), %xmm0
+; AVX512-NEXT:    vmovaps %xmm0, (%rsp)
+; AVX512-NEXT:    kmovd (%rsp), %k0
+; AVX512-NEXT:    vpmovm2b %k0, %ymm0
+; AVX512-NEXT:    addq $24, %rsp
+; AVX512-NEXT:    retq
+  %res = bitcast <4 x i8> %arg to <32 x i1>
+  ret <32 x i1> %res
+}


        


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