commit 971c85ebb4416b5bf8c5c878ff49fc773f04c664
author Matt Arsenault <Matthew.Arsenault@amd.com> Mon Mar 13 19:47:31 2017 +0000
committer Matt Arsenault <Matthew.Arsenault@amd.com> Mon Mar 13 19:47:31 2017 +0000
tree 404acbd2e72408b7bf3223da971875c8ae50a6c1
parent 3978b877d7773c77577353239158941e208bbfea

AMDGPU: Treat 0 as private null pointer in addrspacecast lowering

llvm-svn: 297658

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
index f6a4dc5..8a62195 100644
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -2374,21 +2374,25 @@
                          MachineMemOperand::MOInvariant);
 }
 
+// FIXME: Really support non-0 null pointers.
+static int getSegmentNullPtrValue(unsigned AS) {
+  return AS == AMDGPUAS::LOCAL_ADDRESS ? -1 : 0;
+}
+
 SDValue SITargetLowering::lowerADDRSPACECAST(SDValue Op,
                                              SelectionDAG &DAG) const {
   SDLoc SL(Op);
   const AddrSpaceCastSDNode *ASC = cast<AddrSpaceCastSDNode>(Op);
 
   SDValue Src = ASC->getOperand(0);
-
-  // FIXME: Really support non-0 null pointers.
-  SDValue SegmentNullPtr = DAG.getConstant(-1, SL, MVT::i32);
   SDValue FlatNullPtr = DAG.getConstant(0, SL, MVT::i64);
 
   // flat -> local/private
   if (ASC->getSrcAddressSpace() == AMDGPUAS::FLAT_ADDRESS) {
-    if (ASC->getDestAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
-        ASC->getDestAddressSpace() == AMDGPUAS::PRIVATE_ADDRESS) {
+    unsigned DestAS = ASC->getDestAddressSpace();
+    if (DestAS == AMDGPUAS::LOCAL_ADDRESS || DestAS == AMDGPUAS::PRIVATE_ADDRESS) {
+      SDValue SegmentNullPtr
+        = DAG.getConstant(getSegmentNullPtrValue(DestAS), SL, MVT::i32);
       SDValue NonNull = DAG.getSetCC(SL, MVT::i1, Src, FlatNullPtr, ISD::SETNE);
       SDValue Ptr = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, Src);
 
@@ -2399,8 +2403,11 @@
 
   // local/private -> flat
   if (ASC->getDestAddressSpace() == AMDGPUAS::FLAT_ADDRESS) {
-    if (ASC->getSrcAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
-        ASC->getSrcAddressSpace() == AMDGPUAS::PRIVATE_ADDRESS) {
+    unsigned SrcAS = ASC->getSrcAddressSpace();
+    if (SrcAS == AMDGPUAS::LOCAL_ADDRESS || SrcAS == AMDGPUAS::PRIVATE_ADDRESS) {
+      SDValue SegmentNullPtr
+        = DAG.getConstant(getSegmentNullPtrValue(SrcAS), SL, MVT::i32);
+
       SDValue NonNull
         = DAG.getSetCC(SL, MVT::i1, Src, SegmentNullPtr, ISD::SETNE);