[llvm-commits] [llvm] r94937 - in /llvm/trunk: lib/Transforms/Scalar/TailRecursionElimination.cpp test/Transforms/TailCallElim/no-return-calls.ll

[Evan Cheng]

Author: evancheng
Date: Sat Jan 30 18:59:31 2010
New Revision: 94937

URL: http://llvm.org/viewvc/llvm-project?rev=94937&view=rev
Log:
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.

Added:
    llvm/trunk/test/Transforms/TailCallElim/no-return-calls.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp?rev=94937&r1=94936&r2=94937&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/TailRecursionElimination.cpp Sat Jan 30 18:59:31 2010
@@ -184,10 +184,11 @@
   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;
 }

Added: llvm/trunk/test/Transforms/TailCallElim/no-return-calls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/TailCallElim/no-return-calls.ll?rev=94937&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/TailCallElim/no-return-calls.ll (added)
+++ llvm/trunk/test/Transforms/TailCallElim/no-return-calls.ll Sat Jan 30 18:59:31 2010
@@ -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()