Simplify test for sret attribute in instcombine

This change is correct because the verifier requires that at most one
argument be marked 'sret'.

NFC, removes a use of AttributeList slot APIs.

llvm-svn: 300784

1 files changed, 6 insertions, 12 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 7ed999fa70b..e7aa1a45737 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -4068,21 +4068,15 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
   }
 
   if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
-      !CallerPAL.isEmpty())
+      !CallerPAL.isEmpty()) {
     // In this case we have more arguments than the new function type, but we
     // won't be dropping them.  Check that these extra arguments have attributes
     // that are compatible with being a vararg call argument.
-    for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
-      unsigned Index = CallerPAL.getSlotIndex(i - 1);
-      if (Index <= FT->getNumParams())
-        break;
-
-      // Check if it has an attribute that's incompatible with varargs.
-      AttributeList PAttrs = CallerPAL.getSlotAttributes(i - 1);
-      if (PAttrs.hasAttribute(Index, Attribute::StructRet))
-        return false;
-    }
-
+    unsigned SRetIdx;
+    if (CallerPAL.hasAttrSomewhere(Attribute::StructRet, &SRetIdx) &&
+        SRetIdx > FT->getNumParams())
+      return false;
+  }
 
   // Okay, we decided that this is a safe thing to do: go ahead and start
   // inserting cast instructions as necessary.