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| author | Chris Lattner <sabre@nondot.org> | 2007-12-29 00:59:12 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2007-12-29 00:59:12 +0000 |
| commit | 4184789740e3002e707462ad719f92b6dafececd (patch) | |
| tree | 3a4b2801eec43c18234716a5e3f1572e4c5f83bb /lib/Transforms/Utils/Local.cpp | |
| parent | dfe7b0a4ec643bbd915eb7d4bc08db270725ff1e (diff) | |
| download | external_llvm-4184789740e3002e707462ad719f92b6dafececd.zip external_llvm-4184789740e3002e707462ad719f92b6dafececd.tar.gz external_llvm-4184789740e3002e707462ad719f92b6dafececd.tar.bz2 | |
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
Diffstat (limited to 'lib/Transforms/Utils/Local.cpp')
| -rw-r--r-- | lib/Transforms/Utils/Local.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 187ebdc..4b648b3 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<TerminatorInst>(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<IntrinsicInst>(I)) + // Safe to delete llvm.stacksave if dead. + if (II->getIntrinsicID() == Intrinsic::stacksave) + return true; + return false; } |