[llvm] r327877 - [PowerPC] Make AddrSpaceCast noop

[Nemanja Ivanovic via llvm-commits]

Author: nemanjai
Date: Mon Mar 19 11:50:02 2018
New Revision: 327877

URL: http://llvm.org/viewvc/llvm-project?rev=327877&view=rev
Log:
[PowerPC] Make AddrSpaceCast noop

PowerPC targets do not use address spaces. As a result, we can get selection
failures with address space casts. This patch makes those casts noops.

Patch by Valentin Churavy.

Differential revision: https://reviews.llvm.org/D43781

Added:
    llvm/trunk/test/CodeGen/PowerPC/addrspacecast.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h

Modified: llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h?rev=327877&r1=327876&r2=327877&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h Mon Mar 19 11:50:02 2018
@@ -884,6 +884,11 @@ namespace llvm {
       }
     };
 
+    bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
+      // Addrspacecasts are always noops.
+      return true;
+    }
+
     bool canReuseLoadAddress(SDValue Op, EVT MemVT, ReuseLoadInfo &RLI,
                              SelectionDAG &DAG,
                              ISD::LoadExtType ET = ISD::NON_EXTLOAD) const;

Added: llvm/trunk/test/CodeGen/PowerPC/addrspacecast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/addrspacecast.ll?rev=327877&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/addrspacecast.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/addrspacecast.ll Mon Mar 19 11:50:02 2018
@@ -0,0 +1,22 @@
+; RUN: llc -mtriple=powerpc64le-unknown-linux-gnu %s -o - | FileCheck %s
+
+; Check that codegen for an addrspace cast succeeds without error.
+define <4 x i32 addrspace(1)*> @f (<4 x i32*> %x) {
+  %1 = addrspacecast <4 x i32*> %x to <4 x i32 addrspace(1)*>
+  ret <4 x i32 addrspace(1)*> %1
+  ; CHECK-LABEL: @f
+}
+
+; Check that fairly complicated addrspace cast and operations succeed without error.
+%struct = type opaque
+define void @g (%struct addrspace(10)** %x) {
+  %1 = load %struct addrspace(10)*, %struct addrspace(10)** %x
+  %2 = addrspacecast %struct addrspace(10)* %1 to %struct addrspace(11)*
+  %3 = bitcast %struct addrspace(11)* %2 to i8 addrspace(11)*
+  %4 = getelementptr i8, i8 addrspace(11)* %3, i64 16
+  %5 = bitcast i8 addrspace(11)* %4 to %struct addrspace(10)* addrspace(11)*
+  %6 = load %struct addrspace(10)*, %struct addrspace(10)* addrspace(11)* %5
+  store %struct addrspace(10)* %6, %struct addrspace(10)** undef
+  ret void
+  ; CHECK-LABEL: @g
+}