From 741c0aea08feab0ebd1932aaa8dd38836b2073ea Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 29 Dec 2007 00:59:12 +0000 Subject: dead calls to llvm.stacksave can be deleted, even though they have potential side-effects. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45392 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/Local.cpp | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'lib/Transforms/Utils/Local.cpp') diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 187ebdc797..4b648b3b8b 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -17,6 +17,7 @@ #include "llvm/DerivedTypes.h" #include "llvm/Instructions.h" #include "llvm/Intrinsics.h" +#include "llvm/IntrinsicInst.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Target/TargetData.h" #include "llvm/Support/GetElementPtrTypeIterator.h" @@ -173,8 +174,16 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) { bool llvm::isInstructionTriviallyDead(Instruction *I) { if (!I->use_empty() || isa(I)) return false; - if (!I->mayWriteToMemory()) return true; + if (!I->mayWriteToMemory()) + return true; + // Special case intrinsics that "may write to memory" but can be deleted when + // dead. + if (IntrinsicInst *II = dyn_cast(I)) + // Safe to delete llvm.stacksave if dead. + if (II->getIntrinsicID() == Intrinsic::stacksave) + return true; + return false; } -- cgit v1.2.3-18-g5258