https://github.com/llvmbot updated https://github.com/llvm/llvm-project/pull/139356
>From 2cacf46f35c8fa174a30a4b628a4b19e391a4798 Mon Sep 17 00:00:00 2001 From: Yingwei Zheng <dtcxzyw2...@gmail.com> Date: Sat, 10 May 2025 13:14:01 +0800 Subject: [PATCH] [X86][TargetLowering] Avoid deleting temporary nodes in `getNegatedExpression` (#139029) In the original case, the third call to `getCheaperNegatedExpression` deletes the SDNode returned by the first call. Similar to 74e6030bcbcc8e628f9a99a424342a0c656456f9, this patch uses `HandleSDNodes` to prevent nodes from being deleted by subsequent calls. Closes https://github.com/llvm/llvm-project/issues/138944. (cherry picked from commit 143cce72b1f50bc37363315793b80ae92d2b0ae3) --- llvm/lib/Target/X86/X86ISelLowering.cpp | 9 ++++++++- llvm/test/CodeGen/X86/pr138982.ll | 23 +++++++++++++++++++++++ 2 files changed, 31 insertions(+), 1 deletion(-) create mode 100644 llvm/test/CodeGen/X86/pr138982.ll diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 627cef9ead7ff..4413fbb77f415 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -54147,12 +54147,19 @@ SDValue X86TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG, if (!Flags.hasNoSignedZeros()) break; + // Because getCheaperNegatedExpression can delete nodes we need a handle to + // keep temporary nodes alive. + std::list<HandleSDNode> Handles; + // This is always negatible for free but we might be able to remove some // extra operand negations as well. SmallVector<SDValue, 4> NewOps(Op.getNumOperands(), SDValue()); - for (int i = 0; i != 3; ++i) + for (int i = 0; i != 3; ++i) { NewOps[i] = getCheaperNegatedExpression( Op.getOperand(i), DAG, LegalOperations, ForCodeSize, Depth + 1); + if (!!NewOps[i]) + Handles.emplace_back(NewOps[i]); + } bool NegA = !!NewOps[0]; bool NegB = !!NewOps[1]; diff --git a/llvm/test/CodeGen/X86/pr138982.ll b/llvm/test/CodeGen/X86/pr138982.ll new file mode 100644 index 0000000000000..32346d823a9fe --- /dev/null +++ b/llvm/test/CodeGen/X86/pr138982.ll @@ -0,0 +1,23 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5 +; RUN: llc < %s -mtriple=x86_64 -mattr=+fma | FileCheck %s + +define <4 x float> @pr138982(<4 x float> %in_vec) { +; CHECK-LABEL: pr138982: +; CHECK: # %bb.0: # %entry +; CHECK-NEXT: vxorps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0, %xmm1 +; CHECK-NEXT: vrcpps %xmm0, %xmm2 +; CHECK-NEXT: vrcpps %xmm1, %xmm1 +; CHECK-NEXT: vxorps %xmm3, %xmm3, %xmm3 +; CHECK-NEXT: vcmpneqps %xmm0, %xmm3, %xmm0 +; CHECK-NEXT: vbroadcastss {{.*#+}} xmm4 = [1.0E+0,1.0E+0,1.0E+0,1.0E+0] +; CHECK-NEXT: vblendvps %xmm0, %xmm1, %xmm4, %xmm0 +; CHECK-NEXT: vfnmadd231ps {{.*#+}} xmm0 = -(xmm3 * xmm2) + xmm0 +; CHECK-NEXT: retq +entry: + %fneg = fneg <4 x float> %in_vec + %rcp = tail call <4 x float> @llvm.x86.sse.rcp.ps(<4 x float> %fneg) + %cmp = fcmp une <4 x float> zeroinitializer, %in_vec + %sel = select <4 x i1> %cmp, <4 x float> %rcp, <4 x float> splat (float 1.000000e+00) + %fma = call nsz <4 x float> @llvm.fma.v4f32(<4 x float> %rcp, <4 x float> zeroinitializer, <4 x float> %sel) + ret <4 x float> %fma +} _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
