Only emit extension for zeroext/signext arguments if type is < 32 bits

[jlebar]

The testcase seems to cover the first if statement but not the second one -- is that right? If so, is it possible to write a test for the second one, too?

[jholewinski]

Add test for signext case

lib/Target/NVPTX/NVPTXISelLowering.cpp

if (!Outs[OIdx].Flags.isByVal()) {
       }
       SDVTList CopyParamVTs = DAG.getVTList(MVT::Other, MVT::Glue);
       SDValue CopyParamOps[] = { Chain,
                                  DAG.getConstant(paramCount, dl, MVT::i32),
                                  DAG.getConstant(0, dl, MVT::i32), OutV,
                                  InFlag };
 
       unsigned opcode = NVPTXISD::StoreParam;
-      if (Outs[OIdx].Flags.isZExt())
+      if (Outs[OIdx].Flags.isZExt() && VT.getSizeInBits() < 32)
         opcode = NVPTXISD::StoreParamU32;
-      else if (Outs[OIdx].Flags.isSExt())
+      else if (Outs[OIdx].Flags.isSExt() && VT.getSizeInBits() < 32)
         opcode = NVPTXISD::StoreParamS32;
       Chain = DAG.getMemIntrinsicNode(opcode, dl, CopyParamVTs, CopyParamOps,
                                       VT, MachinePointerInfo());
 
       InFlag = Chain.getValue(1);
       ++paramCount;
       continue;
     }

test/CodeGen/NVPTX/zeroext-32bit.ll

+; RUN: llc < %s -march=nvptx64 -mcpu=sm_30 | FileCheck %s
+
+; The zeroext attribute below should be silently ignored because
+; we can pass a 32-bit integer across a function call without
+; needing to extend it.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
+target triple = "nvptx64-unknown-cuda"
+
+; CHECK-LABEL: .visible .func _Z3barv
+; CHECK-NOT: cvt.u32.u16
+define void @_Z3barv()  {
+  tail call void @_Z3fooDi(i32 zeroext 0)
+  ret void
+}
+
+declare void @_Z3fooDi(i32 zeroext)