Merge pull request JuliaLang#23611 from JuliaLang/tb/nvptx_as

Patch the NVPTX back-end to ignore nonrelevant address spaces.

deps/llvm.mk

@@ -440,6 +440,7 @@ $(eval $(call LLVM_PATCH,llvm-3.9.0_D27296-libssp))
 $(eval $(call LLVM_PATCH,llvm-D27609-AArch64-UABS_G3)) # Remove for 4.0
 $(eval $(call LLVM_PATCH,llvm-D27629-AArch64-large_model))
 # patches for NVPTX
+$(eval $(call LLVM_PATCH,llvm-NVPTX-addrspaces))
 $(eval $(call LLVM_PATCH,llvm-D9168_argument_alignment)) # Remove for 4.0
 $(eval $(call LLVM_PATCH,llvm-D23597_sdag_names)) # Dep for D24300, remove for 4.0
 $(eval $(call LLVM_PATCH,llvm-D24300_ptx_intrinsics)) # Remove for 4.0

deps/patches/llvm-NVPTX-addrspaces.patch

@@ -0,0 +1,30 @@
+diff -u llvm-3.9.1.orig/lib/Target/NVPTX/NVPTXISelLowering.cpp llvm-3.9.1/lib/Target/NVPTX/NVPTXISelLowering.cpp
+--- llvm-3.9.1.orig/lib/Target/NVPTX/NVPTXISelLowering.cpp 2016-07-15 20:27:10.000000000 +0200
++++ llvm-3.9.1/lib/Target/NVPTX/NVPTXISelLowering.cpp 2017-09-07 04:04:25.540721694 +0200
+@@ -888,6 +910,14 @@
+ return TargetLoweringBase::getPreferredVectorAction(VT);
+ }
+
++bool NVPTXTargetLowering::isNoopAddrSpaceCast(unsigned SrcAS,
++ unsigned DestAS) const {
++ assert(SrcAS != DestAS && "Expected different address spaces!");
++
++ return (SrcAS == ADDRESS_SPACE_GENERIC || SrcAS > ADDRESS_SPACE_LOCAL) &&
++ (DestAS == ADDRESS_SPACE_GENERIC || DestAS > ADDRESS_SPACE_LOCAL);
++}
++
+ SDValue
+ NVPTXTargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
+ SDLoc dl(Op);
+diff -u llvm-3.9.1.orig/lib/Target/NVPTX/NVPTXISelLowering.h llvm-3.9.1/lib/Target/NVPTX/NVPTXISelLowering.h
+--- llvm-3.9.1.orig/lib/Target/NVPTX/NVPTXISelLowering.h 2016-06-12 17:39:02.000000000 +0200
++++ llvm-3.9.1/lib/Target/NVPTX/NVPTXISelLowering.h 2017-09-07 04:03:39.591373952 +0200
+@@ -442,6 +442,8 @@
+ const NVPTXSubtarget &STI);
+ SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
+
++ bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override;
++
+ SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
+
+ const char *getTargetNodeName(unsigned Opcode) const override;