When inlining through an 'nounwind' call, mark inlined

calls 'nounwind'.  It is important for correct C++
exception handling that nounwind markings do not get
lost, so this transformation is actually needed for
correctness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45218 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 9 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 166b484440..d7c492383f 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -8026,16 +8026,9 @@ Instruction *InstCombiner::visitCallSite(CallSite CS) {
       }
   }
 
-  if (isa<InlineAsm>(Callee) && !CS.paramHasAttr(0, ParamAttr::NoUnwind)) {
+  if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
     // Inline asm calls cannot throw - mark them 'nounwind'.
-    const ParamAttrsList *PAL = CS.getParamAttrs();
-    uint16_t RAttributes = PAL ? PAL->getParamAttrs(0) : 0;
-    RAttributes |= ParamAttr::NoUnwind;
-
-    ParamAttrsVector modVec;
-    modVec.push_back(ParamAttrsWithIndex::get(0, RAttributes));
-    PAL = ParamAttrsList::getModified(PAL, modVec);
-    CS.setParamAttrs(PAL);
+    CS.setDoesNotThrow();
     Changed = true;
   }