https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/140703
Backport c9d6249 Requested by: @MacDue >From 7d2c28923c503b3e6301ccc038529162f4f33913 Mon Sep 17 00:00:00 2001 From: Benjamin Maxwell <benjamin.maxw...@arm.com> Date: Tue, 20 May 2025 10:43:50 +0100 Subject: [PATCH] [SDAG] Ensure load is included in output chain of sincos expansion (#140525) The load not being included in the chain meant that it could materialize after a `@llvm.lifetime.end` annotation on the pointer. This could result in miscompiles if the stack slot is reused for another value. Fixes https://github.com/llvm/llvm-project/issues/140491 (cherry picked from commit c9d62491981fe720c1b3255fa2f9ddf744590c65) --- .../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 9 ++- .../CodeGen/X86/pr140491-sincos-lifetimes.ll | 70 +++++++++++++++++++ 2 files changed, 76 insertions(+), 3 deletions(-) create mode 100644 llvm/test/CodeGen/X86/pr140491-sincos-lifetimes.ll diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index b416c0efbbc4f..eecfb41c2d319 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -2660,16 +2660,19 @@ bool SelectionDAG::expandMultipleResultFPLibCall( continue; } MachinePointerInfo PtrInfo; + SDValue LoadResult = + getLoad(Node->getValueType(ResNo), DL, CallChain, ResultPtr, PtrInfo); + SDValue OutChain = LoadResult.getValue(1); + if (StoreSDNode *ST = ResultStores[ResNo]) { // Replace store with the library call. - ReplaceAllUsesOfValueWith(SDValue(ST, 0), CallChain); + ReplaceAllUsesOfValueWith(SDValue(ST, 0), OutChain); PtrInfo = ST->getPointerInfo(); } else { PtrInfo = MachinePointerInfo::getFixedStack( getMachineFunction(), cast<FrameIndexSDNode>(ResultPtr)->getIndex()); } - SDValue LoadResult = - getLoad(Node->getValueType(ResNo), DL, CallChain, ResultPtr, PtrInfo); + Results.push_back(LoadResult); } diff --git a/llvm/test/CodeGen/X86/pr140491-sincos-lifetimes.ll b/llvm/test/CodeGen/X86/pr140491-sincos-lifetimes.ll new file mode 100644 index 0000000000000..2ca99bdc4b316 --- /dev/null +++ b/llvm/test/CodeGen/X86/pr140491-sincos-lifetimes.ll @@ -0,0 +1,70 @@ +; RUN: llc < %s | FileCheck %s + +; This test is reduced from https://github.com/llvm/llvm-project/issues/140491. +; It checks that when `@llvm.sincos.f32` is expanded to a call to +; `sincosf(float, float* out_sin, float* out_cos)` and the store of `%cos` to +; `%computed` is folded into the `sincosf` call. The use of `%cos`in the later +; `fneg %cos` -- which expands to a load of `%computed`, will perform the load +; before the `@llvm.lifetime.end.p0(%computed)` to ensure the correct value is +; taken for `%cos`. + +target triple = "x86_64-sie-ps5" + +declare void @use_ptr(ptr readonly) + +define i32 @sincos_stack_slot_with_lifetime(float %in) { +; CHECK-LABEL: sincos_stack_slot_with_lifetime: +; CHECK: # %bb.0: # %entry +; CHECK-NEXT: pushq %rbx +; CHECK-NEXT: .cfi_def_cfa_offset 16 +; CHECK-NEXT: subq $32, %rsp +; CHECK-NEXT: .cfi_def_cfa_offset 48 +; CHECK-NEXT: .cfi_offset %rbx, -16 +; CHECK-NEXT: leaq 12(%rsp), %rdi +; CHECK-NEXT: leaq 8(%rsp), %rbx +; CHECK-NEXT: movq %rbx, %rsi +; CHECK-NEXT: callq sincosf@PLT +; CHECK-NEXT: movss 8(%rsp), %xmm0 # xmm0 = mem[0],zero,zero,zero +; CHECK-NEXT: movaps %xmm0, 16(%rsp) # 16-byte Spill +; CHECK-NEXT: movq %rbx, %rdi +; CHECK-NEXT: callq use_ptr +; CHECK-NEXT: movss 12(%rsp), %xmm0 # xmm0 = mem[0],zero,zero,zero +; CHECK-NEXT: xorps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0 +; CHECK-NEXT: movss %xmm0, 8(%rsp) +; CHECK-NEXT: leaq 8(%rsp), %rdi +; CHECK-NEXT: callq use_ptr +; CHECK-NEXT: movaps 16(%rsp), %xmm0 # 16-byte Reload +; CHECK-NEXT: xorps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0 +; CHECK-NEXT: movss %xmm0, 8(%rsp) +; CHECK-NEXT: leaq 8(%rsp), %rdi +; CHECK-NEXT: callq use_ptr +; CHECK-NEXT: xorl %eax, %eax +; CHECK-NEXT: addq $32, %rsp +; CHECK-NEXT: .cfi_def_cfa_offset 16 +; CHECK-NEXT: popq %rbx +; CHECK-NEXT: .cfi_def_cfa_offset 8 +; CHECK-NEXT: retq +entry: + %computed = alloca float, align 4 + %computed1 = alloca float, align 4 + %computed3 = alloca float, align 4 + %sincos = tail call { float, float } @llvm.sincos.f32(float %in) + %sin = extractvalue { float, float } %sincos, 0 + %cos = extractvalue { float, float } %sincos, 1 + call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %computed) + store float %cos, ptr %computed, align 4 + call void @use_ptr(ptr nonnull %computed) + call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %computed) + call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %computed1) + %fneg_sin = fneg float %sin + store float %fneg_sin, ptr %computed1, align 4 + call void @use_ptr(ptr nonnull %computed1) + call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %computed1) + call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %computed3) + %fneg_cos = fneg float %cos + store float %fneg_cos, ptr %computed3, align 4 + call void @use_ptr(ptr nonnull %computed3) + call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %computed3) + ret i32 0 +} + _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
