AMDGPU: Add 32-bit constant address space

Note: This is a candidate for LLVM 6.0, because it was planned to be
      in that release but was delayed due to a long review period.

Merge conflict in release_60 - resolution:
    Add "-p6:32:32" into the second (non-amdgiz) string.

Only scalar loads support 32-bit pointers. An address in a VGPR will
fail to compile. That's OK because the results of loads will only be used
in places where VGPRs are forbidden.

Updated AMDGPUAliasAnalysis and used SReg_64_XEXEC.
The tests cover all uses cases we need for Mesa.

Reviewers: arsenm, nhaehnle

Subscribers: kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D41651

llvm-svn: 324487

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
index 50311c241f2..0367ce724ce 100644
--- a/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
@@ -447,7 +447,8 @@ bool isGlobalSegment(const GlobalValue *GV) {
 }
 
 bool isReadOnlySegment(const GlobalValue *GV) {
-  return GV->getType()->getAddressSpace() == AMDGPUAS::CONSTANT_ADDRESS;
+  return GV->getType()->getAddressSpace() == AMDGPUAS::CONSTANT_ADDRESS ||
+         GV->getType()->getAddressSpace() == AMDGPUAS::CONSTANT_ADDRESS_32BIT;
 }
 
 bool shouldEmitConstantsToTextSection(const Triple &TT) {
@@ -916,6 +917,9 @@ bool isUniformMMO(const MachineMemOperand *MMO) {
       isa<Constant>(Ptr) || isa<GlobalValue>(Ptr))
     return true;
 
+  if (MMO->getAddrSpace() == AMDGPUAS::CONSTANT_ADDRESS_32BIT)
+    return true;
+
   if (const Argument *Arg = dyn_cast<Argument>(Ptr))
     return isArgPassedInSGPR(Arg);