Do not mark no-return calls tail calls. It'll screw up special calls like longjmp and it doesn't make much sense for performance reason. If my logic is faulty, please let me know.

llvm-svn: 94937
This commit is contained in:
Evan Cheng 2010-01-31 00:59:31 +00:00
parent 288edb5bda
commit d86d3fe0c3
2 changed files with 17 additions and 4 deletions

View File

@ -184,10 +184,11 @@ bool TailCallElim::runOnFunction(Function &F) {
if (!FunctionContainsEscapingAllocas)
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
if (CallInst *CI = dyn_cast<CallInst>(I)) {
CI->setTailCall();
MadeChange = true;
}
if (CallInst *CI = dyn_cast<CallInst>(I))
if (!CI->doesNotReturn()) {
CI->setTailCall();
MadeChange = true;
}
return MadeChange;
}

View File

@ -0,0 +1,12 @@
; RUN: opt < %s -tailcallelim -S | FileCheck %s
define void @t() nounwind ssp {
entry:
; CHECK: entry:
; CHECK: %0 = call i32 @foo()
; CHECK: ret void
%0 = call i32 @foo() nounwind noreturn
ret void
}
declare i32 @foo()