When DAE drops the varargs part of a function, ensure any

attributes on the vararg call arguments are also dropped.

llvm-svn: 45892

2 files changed, 19 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 3550d713525..b8770121eb0 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -175,16 +175,29 @@ bool DAE::DeleteDeadVarargs(Function &Fn) {
     // Pass all the same arguments.
     Args.assign(CS.arg_begin(), CS.arg_begin()+NumArgs);
 
+    // Drop any attributes that were on the vararg arguments.
+    const ParamAttrsList *PAL = CS.getParamAttrs();
+    if (PAL && PAL->getParamIndex(PAL->size() - 1) > NumArgs) {
+      ParamAttrsVector ParamAttrsVec;
+      for (unsigned i = 0; PAL->getParamIndex(i) <= NumArgs; ++i) {
+        ParamAttrsWithIndex PAWI;
+        PAWI = ParamAttrsWithIndex::get(PAL->getParamIndex(i),
+                                        PAL->getParamAttrsAtIndex(i));
+        ParamAttrsVec.push_back(PAWI);
+      }
+      PAL = ParamAttrsList::get(ParamAttrsVec);
+    }
+
     Instruction *New;
     if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
       New = new InvokeInst(NF, II->getNormalDest(), II->getUnwindDest(),
                            Args.begin(), Args.end(), "", Call);
       cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<InvokeInst>(New)->setParamAttrs(CS.getParamAttrs());
+      cast<InvokeInst>(New)->setParamAttrs(PAL);
     } else {
       New = new CallInst(NF, Args.begin(), Args.end(), "", Call);
       cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<CallInst>(New)->setParamAttrs(CS.getParamAttrs());
+      cast<CallInst>(New)->setParamAttrs(PAL);
       if (cast<CallInst>(Call)->isTailCall())
         cast<CallInst>(New)->setTailCall();
     }
diff --git a/llvm/test/Transforms/DeadArgElim/2007-12-20-ParamAttrs.ll b/llvm/test/Transforms/DeadArgElim/2007-12-20-ParamAttrs.ll
index 94181f3dbff..bd30942633d 100644
--- a/llvm/test/Transforms/DeadArgElim/2007-12-20-ParamAttrs.ll
+++ b/llvm/test/Transforms/DeadArgElim/2007-12-20-ParamAttrs.ll
@@ -2,6 +2,9 @@
 ; RUN: llvm-as < %s | opt -deadargelim | llvm-dis | grep signext | count 2
 ; RUN: llvm-as < %s | opt -deadargelim | llvm-dis | not grep inreg
 ; RUN: llvm-as < %s | opt -deadargelim | llvm-dis | not grep zeroext
+; RUN: llvm-as < %s | opt -deadargelim | llvm-dis | not grep byval
+
+	%struct = type { }
 
 @g = global i8 0
 
@@ -11,6 +14,6 @@ define internal i8 @foo(i8* inreg %p, i8 signext %y, ... ) zeroext nounwind {
 }
 
 define i32 @bar() {
-	%A = call i8(i8*, i8, ...)* @foo(i8* inreg null, i8 signext 1, i8 2) zeroext nounwind
+	%A = call i8(i8*, i8, ...)* @foo(i8* inreg null, i8 signext 1, %struct* byval null ) zeroext nounwind
 	ret i32 0
 }