Author: Gabriel Baraldi Date: 2026-01-26T09:40:50Z New Revision: b30dd8f1ad837af62991f00ca270b76538cf90c4
URL: https://github.com/llvm/llvm-project/commit/b30dd8f1ad837af62991f00ca270b76538cf90c4 DIFF: https://github.com/llvm/llvm-project/commit/b30dd8f1ad837af62991f00ca270b76538cf90c4.diff LOG: [SLPVectorizer] Check std::optional coming out of getPointersDiff (#175784) Fixes https://github.com/llvm/llvm-project/issues/175768 There are other unchecked uses std::optional in this pass but I couldn't figure out a test that triggers them (cherry picked from commit 72a20b8e29876106aa918d03ef95f27a6bf0fa0d) Added: llvm/test/Transforms/SLPVectorizer/X86/crash_getpointersdiff-nullopt.ll Modified: llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp Removed: ################################################################################ diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp index 7808e922dd90a..a717043508132 100644 --- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -7082,12 +7082,17 @@ bool BoUpSLP::analyzeConstantStrideCandidate( Value *Ptr0, Value *PtrN, StridedPtrInfo &SPtrInfo) const { const size_t Sz = PointerOps.size(); SmallVector<int64_t> SortedOffsetsFromBase(Sz); - // Go through `PointerOps` in sorted order and record offsets from `Ptr0`. + // Go through `PointerOps` in sorted order and record offsets from + // PointerOps[0]. We use PointerOps[0] rather than Ptr0 because + // sortPtrAccesses only validates getPointersDiff for pairs relative to + // PointerOps[0]. This is safe since only offset diff erences are used below. for (unsigned I : seq<unsigned>(Sz)) { Value *Ptr = SortedIndices.empty() ? PointerOps[I] : PointerOps[SortedIndices[I]]; - SortedOffsetsFromBase[I] = - *getPointersDiff(ScalarTy, Ptr0, ScalarTy, Ptr, *DL, *SE); + std::optional<int64_t> Offset = + getPointersDiff(ScalarTy, PointerOps[0], ScalarTy, Ptr, *DL, *SE); + assert(Offset && "sortPtrAccesses should have validated this pointer"); + SortedOffsetsFromBase[I] = *Offset; } // The code below checks that `SortedOffsetsFromBase` looks as follows: @@ -7436,10 +7441,18 @@ BoUpSLP::LoadsState BoUpSLP::canVectorizeLoads( Ptr0 = PointerOps[Order.front()]; PtrN = PointerOps[Order.back()]; } - std::optional<int64_t> Diff = - getPointersDiff(ScalarTy, Ptr0, ScalarTy, PtrN, *DL, *SE); + // sortPtrAccesses validates getPointersDiff for all pointers relative to + // PointerOps[0], so compute the span using PointerOps[0] as intermediate: + // Diff = offset(PtrN) - offset(Ptr0) relative to PointerOps[0] + std::optional<int64_t> Diff0 = + getPointersDiff(ScalarTy, PointerOps[0], ScalarTy, Ptr0, *DL, *SE); + std::optional<int64_t> DiffN = + getPointersDiff(ScalarTy, PointerOps[0], ScalarTy, PtrN, *DL, *SE); + assert(Diff0 && DiffN && + "sortPtrAccesses should have validated these pointers"); + int64_t Diff = *DiffN - *Diff0; // Check that the sorted loads are consecutive. - if (static_cast<uint64_t>(*Diff) == Sz - 1) + if (static_cast<uint64_t>(Diff) == Sz - 1) return LoadsState::Vectorize; if (isMaskedLoadCompress(VL, PointerOps, Order, *TTI, *DL, *SE, *AC, *DT, *TLI, [&](Value *V) { @@ -7451,7 +7464,7 @@ BoUpSLP::LoadsState BoUpSLP::canVectorizeLoads( cast<LoadInst>(Order.empty() ? VL.front() : VL[Order.front()]) ->getAlign(); if (analyzeConstantStrideCandidate(PointerOps, ScalarTy, Alignment, Order, - *Diff, Ptr0, PtrN, SPtrInfo)) + Diff, Ptr0, PtrN, SPtrInfo)) return LoadsState::StridedVectorize; } if (!TTI->isLegalMaskedGather(VecTy, CommonAlignment) || diff --git a/llvm/test/Transforms/SLPVectorizer/X86/crash_getpointers diff -nullopt.ll b/llvm/test/Transforms/SLPVectorizer/X86/crash_getpointers diff -nullopt.ll new file mode 100644 index 0000000000000..cbbac32febdb3 --- /dev/null +++ b/llvm/test/Transforms/SLPVectorizer/X86/crash_getpointers diff -nullopt.ll @@ -0,0 +1,109 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -passes=slp-vectorizer -S -mtriple=x86_64-unknown-linux-gnu | FileCheck %s + +; Test that SLP vectorizer doesn't crash when getPointersDiff returns +; std::nullopt for pointers that can't be compared. + +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define void @test(i64 %arg0, i64 %arg1) { +; CHECK-LABEL: @test( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[INIT:%.*]] = add i64 [[ARG0:%.*]], 1 +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: loop: +; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[INIT]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[REDUCE:%.*]] ] +; CHECK-NEXT: [[COUNTER:%.*]] = phi i64 [ 1, [[ENTRY]] ], [ [[COUNTER_NEXT:%.*]], [[REDUCE]] ] +; CHECK-NEXT: [[OFF0:%.*]] = add i64 [[IV]], -4 +; CHECK-NEXT: [[PTR:%.*]] = call ptr null(ptr null, ptr null) +; CHECK-NEXT: [[IDX0:%.*]] = add i64 [[ARG1:%.*]], [[OFF0]] +; CHECK-NEXT: [[IDX0_SCALED:%.*]] = shl i64 [[IDX0]], 3 +; CHECK-NEXT: [[GEP0:%.*]] = getelementptr i8, ptr [[PTR]], i64 [[IDX0_SCALED]] +; CHECK-NEXT: [[GEP0_OFF:%.*]] = getelementptr i8, ptr [[GEP0]], i64 -8 +; CHECK-NEXT: [[TMP0:%.*]] = load <4 x double>, ptr [[GEP0_OFF]], align 8 +; CHECK-NEXT: [[IDX4:%.*]] = add i64 [[ARG1]], [[IV]] +; CHECK-NEXT: [[IDX4_SCALED:%.*]] = shl i64 [[IDX4]], 3 +; CHECK-NEXT: [[GEP4:%.*]] = getelementptr i8, ptr [[PTR]], i64 [[IDX4_SCALED]] +; CHECK-NEXT: [[GEP4_OFF:%.*]] = getelementptr i8, ptr [[GEP4]], i64 -8 +; CHECK-NEXT: [[LOAD4:%.*]] = load double, ptr [[GEP4_OFF]], align 8 +; CHECK-NEXT: [[LOAD5:%.*]] = load double, ptr [[GEP4]], align 8 +; CHECK-NEXT: br label [[REDUCE]] +; CHECK: dead: +; CHECK-NEXT: br label [[REDUCE]] +; CHECK: reduce: +; CHECK-NEXT: [[PHI4:%.*]] = phi double [ [[LOAD4]], [[LOOP]] ], [ 0.000000e+00, [[DEAD:%.*]] ] +; CHECK-NEXT: [[PHI5:%.*]] = phi double [ [[LOAD5]], [[LOOP]] ], [ 0.000000e+00, [[DEAD]] ] +; CHECK-NEXT: [[TMP1:%.*]] = phi <4 x double> [ [[TMP0]], [[LOOP]] ], [ poison, [[DEAD]] ] +; CHECK-NEXT: [[TMP2:%.*]] = call double @llvm.vector.reduce.fminimum.v4f64(<4 x double> [[TMP1]]) +; CHECK-NEXT: [[TMP3:%.*]] = call double @llvm.minimum.f64(double [[TMP2]], double [[PHI4]]) +; CHECK-NEXT: [[TMP4:%.*]] = call double @llvm.minimum.f64(double [[PHI5]], double 0.000000e+00) +; CHECK-NEXT: [[TMP5:%.*]] = call double @llvm.minimum.f64(double [[TMP3]], double [[TMP4]]) +; CHECK-NEXT: [[MIN6:%.*]] = call double @llvm.minimum.f64(double [[TMP5]], double 0.000000e+00) +; CHECK-NEXT: [[COUNTER_NEXT]] = add i64 [[COUNTER]], 1 +; CHECK-NEXT: [[IV_NEXT]] = add i64 [[COUNTER]], [[INIT]] +; CHECK-NEXT: br label [[LOOP]] +; +entry: + %init = add i64 %arg0, 1 + br label %loop + +loop: + %iv = phi i64 [ %init, %entry ], [ %iv.next, %reduce ] + %counter = phi i64 [ 1, %entry ], [ %counter.next, %reduce ] + %off0 = add i64 %iv, -4 + %off1 = add i64 %iv, -3 + %off2 = add i64 %iv, -2 + %off3 = add i64 %iv, -1 + %ptr = call ptr null(ptr null, ptr null) + %idx0 = add i64 %arg1, %off0 + %idx0.scaled = shl i64 %idx0, 3 + %gep0 = getelementptr i8, ptr %ptr, i64 %idx0.scaled + %gep0.off = getelementptr i8, ptr %gep0, i64 -8 + %load0 = load double, ptr %gep0.off, align 8 + %idx1 = add i64 %arg1, %off1 + %idx1.scaled = shl i64 %idx1, 3 + %gep1 = getelementptr i8, ptr %ptr, i64 %idx1.scaled + %gep1.off = getelementptr i8, ptr %gep1, i64 -8 + %load1 = load double, ptr %gep1.off, align 8 + %idx2 = add i64 %arg1, %off2 + %idx2.scaled = shl i64 %idx2, 3 + %gep2 = getelementptr i8, ptr %ptr, i64 %idx2.scaled + %gep2.off = getelementptr i8, ptr %gep2, i64 -8 + %load2 = load double, ptr %gep2.off, align 8 + %idx3 = add i64 %arg1, %off3 + %idx3.scaled = shl i64 %idx3, 3 + %gep3 = getelementptr i8, ptr %ptr, i64 %idx3.scaled + %gep3.off = getelementptr i8, ptr %gep3, i64 -8 + %load3 = load double, ptr %gep3.off, align 8 + %idx4 = add i64 %arg1, %iv + %idx4.scaled = shl i64 %idx4, 3 + %gep4 = getelementptr i8, ptr %ptr, i64 %idx4.scaled + %gep4.off = getelementptr i8, ptr %gep4, i64 -8 + %load4 = load double, ptr %gep4.off, align 8 + %load5 = load double, ptr %gep4, align 8 + br label %reduce + +dead: + br label %reduce + +reduce: + %phi0 = phi double [ %load0, %loop ], [ 0.000000e+00, %dead ] + %phi1 = phi double [ %load1, %loop ], [ 0.000000e+00, %dead ] + %phi2 = phi double [ %load2, %loop ], [ 0.000000e+00, %dead ] + %phi3 = phi double [ %load3, %loop ], [ 0.000000e+00, %dead ] + %phi4 = phi double [ %load4, %loop ], [ 0.000000e+00, %dead ] + %phi5 = phi double [ %load5, %loop ], [ 0.000000e+00, %dead ] + %min0 = call double @llvm.minimum.f64(double 0.000000e+00, double %phi0) + %min1 = call double @llvm.minimum.f64(double %min0, double %phi1) + %min2 = call double @llvm.minimum.f64(double %min1, double %phi2) + %min3 = call double @llvm.minimum.f64(double %min2, double %phi3) + %min4 = call double @llvm.minimum.f64(double %min3, double %phi4) + %min5 = call double @llvm.minimum.f64(double %min4, double %phi5) + %min6 = call double @llvm.minimum.f64(double %min5, double 0.000000e+00) + %counter.next = add i64 %counter, 1 + %iv.next = add i64 %counter, %init + br label %loop +} + +declare double @llvm.minimum.f64(double, double) _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
