[AVR] Fix a lowering bug in AVRISelLowering.cpp

The parseFunctionArgs() method was directly reading the
arguments from a Function object, but is should have used the
arguments supplied by the SelectionDAGBuilder.

This was causing
the lowering code to only lower one argument, not two in some cases.

Thanks to @brainlag on GitHub for coming up with the working fix!

Patch-by: @brainlag on GitHub
llvm-svn: 325474

1 files changed, 6 insertions, 4 deletions

diff --git a/llvm/lib/Target/AVR/AVRISelLowering.cpp b/llvm/lib/Target/AVR/AVRISelLowering.cpp
index d9e27e91405..7ac8a136e6b 100644
--- a/llvm/lib/Target/AVR/AVRISelLowering.cpp
+++ b/llvm/lib/Target/AVR/AVRISelLowering.cpp
@@ -867,10 +867,12 @@ bool AVRTargetLowering::isOffsetFoldingLegal(
 
 /// For each argument in a function store the number of pieces it is composed
 /// of.
-static void parseFunctionArgs(const Function *F, const DataLayout *TD,
+static void parseFunctionArgs(const SmallVectorImpl<ISD::InputArg> &Ins,
                               SmallVectorImpl<unsigned> &Out) {
-  for (Argument const &Arg : F->args()) {
-    unsigned Bytes = (TD->getTypeSizeInBits(Arg.getType()) + 7) / 8;
+  for (const ISD::InputArg &Arg : Ins) {
+    if(Arg.PartOffset > 0) continue;
+    unsigned Bytes = ((Arg.ArgVT.getSizeInBits()) + 7) / 8;
+
     Out.push_back((Bytes + 1) / 2);
   }
 }
@@ -938,7 +940,7 @@ static void analyzeStandardArguments(TargetLowering::CallLoweringInfo *CLI,
     parseExternFuncCallArgs(*Outs, Args);
   } else {
     assert(F != nullptr && "function should not be null");
-    parseFunctionArgs(F, TD, Args);
+    parseFunctionArgs(*Ins, Args);
   }
 
   unsigned RegsLeft = array_lengthof(RegList8), ValNo = 0;