[llvm] r220607 - [NVPTX] aligned byte-buffers for vector return types

[Jingyue Wu]

Author: jingyue
Date: Fri Oct 24 22:46:16 2014
New Revision: 220607

URL: http://llvm.org/viewvc/llvm-project?rev=220607&view=rev
Log:
[NVPTX] aligned byte-buffers for vector return types

Summary:
Fixes PR21100 which is caused by inconsistency between the declared return type
and the expected return type at the call site. The new behavior is consistent
with nvcc and the NVPTXTargetLowering::getPrototype function.

Test Plan: test/Codegen/NVPTX/vector-return.ll

Reviewers: jholewinski

Reviewed By: jholewinski

Subscribers: llvm-commits, meheff, eliben, jholewinski

Differential Revision: http://reviews.llvm.org/D5612

Added:
    llvm/trunk/test/CodeGen/NVPTX/vector-return.ll
Modified:
    llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp

Modified: llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp?rev=220607&r1=220606&r2=220607&view=diff
==============================================================================
--- llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/NVPTX/NVPTXISelLowering.cpp Fri Oct 24 22:46:16 2014
@@ -1355,7 +1355,12 @@ SDValue NVPTXTargetLowering::LowerCall(T
     //  .param .align 16 .b8 retval0[<size-in-bytes>], or
     //  .param .b<size-in-bits> retval0
     unsigned resultsz = TD->getTypeAllocSizeInBits(retTy);
-    if (retTy->isSingleValueType()) {
+    // Emit ".param .b<size-in-bits> retval0" instead of byte arrays only for
+    // these three types to match the logic in
+    // NVPTXAsmPrinter::printReturnValStr and NVPTXTargetLowering::getPrototype.
+    // Plus, this behavior is consistent with nvcc's.
+    if (retTy->isFloatingPointTy() || retTy->isIntegerTy() ||
+        retTy->isPointerTy()) {
       // Scalar needs to be at least 32bit wide
       if (resultsz < 32)
         resultsz = 32;

Added: llvm/trunk/test/CodeGen/NVPTX/vector-return.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/NVPTX/vector-return.ll?rev=220607&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/NVPTX/vector-return.ll (added)
+++ llvm/trunk/test/CodeGen/NVPTX/vector-return.ll Fri Oct 24 22:46:16 2014
@@ -0,0 +1,14 @@
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_35 | FileCheck %s
+
+declare <2 x float> @bar(<2 x float> %input)
+
+define void @foo(<2 x float> %input, <2 x float>* %output) {
+; CHECK-LABEL: @foo
+entry:
+  %call = tail call <2 x float> @bar(<2 x float> %input)
+; CHECK: .param .align 8 .b8 retval0[8];
+; CHECK: ld.param.v2.f32 {[[ELEM1:%f[0-9]+]], [[ELEM2:%f[0-9]+]]}, [retval0+0];
+  store <2 x float> %call, <2 x float>* %output, align 8
+; CHECK: st.v2.f32 [{{%rd[0-9]+}}], {[[ELEM1]], [[ELEM2]]}
+  ret void
+}