From 391016025a72612577cc7b8046fed60bed1aa858 Mon Sep 17 00:00:00 2001 From: James Molloy Date: Thu, 1 Mar 2012 14:32:18 +0000 Subject: [PATCH] Fix a codegen fault in which log2 or exp2 could be dead-code eliminated even though they could have sideeffects. Only allow log2/exp2 to be converted to an intrinsic if they are declared "readnone". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151807 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 6 ++++-- test/CodeGen/ARM/log2_not_readnone.ll | 15 +++++++++++++++ test/CodeGen/X86/log2_not_readnone.ll | 15 +++++++++++++++ 3 files changed, 34 insertions(+), 2 deletions(-) create mode 100644 test/CodeGen/ARM/log2_not_readnone.ll create mode 100644 test/CodeGen/X86/log2_not_readnone.ll diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 0038633cd6e..4a6f409a16c 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -5627,7 +5627,8 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) { (LibInfo->has(LibFunc::log2l) && Name == "log2l")) { if (I.getNumArgOperands() == 1 && // Basic sanity checks. I.getArgOperand(0)->getType()->isFloatingPointTy() && - I.getType() == I.getArgOperand(0)->getType()) { + I.getType() == I.getArgOperand(0)->getType() && + I.onlyReadsMemory()) { SDValue Tmp = getValue(I.getArgOperand(0)); setValue(&I, DAG.getNode(ISD::FLOG2, getCurDebugLoc(), Tmp.getValueType(), Tmp)); @@ -5638,7 +5639,8 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) { (LibInfo->has(LibFunc::exp2l) && Name == "exp2l")) { if (I.getNumArgOperands() == 1 && // Basic sanity checks. I.getArgOperand(0)->getType()->isFloatingPointTy() && - I.getType() == I.getArgOperand(0)->getType()) { + I.getType() == I.getArgOperand(0)->getType() && + I.onlyReadsMemory()) { SDValue Tmp = getValue(I.getArgOperand(0)); setValue(&I, DAG.getNode(ISD::FEXP2, getCurDebugLoc(), Tmp.getValueType(), Tmp)); diff --git a/test/CodeGen/ARM/log2_not_readnone.ll b/test/CodeGen/ARM/log2_not_readnone.ll new file mode 100644 index 00000000000..4d567eda65d --- /dev/null +++ b/test/CodeGen/ARM/log2_not_readnone.ll @@ -0,0 +1,15 @@ +; RUN: llc -march arm %s -o - | FileCheck %s + +; Log2 and exp2 are string-matched to intrinsics. If they are not declared +; readnone, they can't be changed to intrinsics (because they can change errno). + +declare double @log2(double) +declare double @exp2(double) + +define void @f() { + ; CHECK: bl log2 + %1 = call double @log2(double 0.000000e+00) + ; CHECK: bl exp2 + %2 = call double @exp2(double 0.000000e+00) + ret void +} diff --git a/test/CodeGen/X86/log2_not_readnone.ll b/test/CodeGen/X86/log2_not_readnone.ll new file mode 100644 index 00000000000..a971b0b442f --- /dev/null +++ b/test/CodeGen/X86/log2_not_readnone.ll @@ -0,0 +1,15 @@ +; RUN: llc -march x86 %s -o - | FileCheck %s + +; Log2 and exp2 are string-matched to intrinsics. If they are not declared +; readnone, they can't be changed to intrinsics (because they can change errno). + +declare double @log2(double) +declare double @exp2(double) + +define void @f() { + ; CHECK: calll log2 + %1 = call double @log2(double 0.000000e+00) + ; CHECK: calll exp2 + %2 = call double @exp2(double 0.000000e+00) + ret void +} -- 2.34.1