[PATCH] D77082: [AMDGPU] Handle SMRD signed offset immediate

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp:1798
 
-  if (Gen == AMDGPUSubtarget::SEA_ISLANDS) {
-    EncodedOffset =
-        AMDGPU::getSMRDEncodedLiteralOffset32(*Subtarget, ByteOffset);
-    if (EncodedOffset) {
-      Offset = CurDAG->getTargetConstant(*EncodedOffset, SL, MVT::i32);
-      return true;
-    }
+  if (!CurDAG->SignBitIsZero(ByteOffsetNode))
+    return false;
----------------
kerbowa wrote:
> arsenm wrote:
> > The GlobalISel patch seems to be missing this part?
> I think it's handled here?
> 
> AMDGPUInstructionSelector.cpp:2876
> if (!GEPInfo.Imm || **GEPInfo.Imm < 0** || !isUInt<32>(GEPInfo.Imm))
OK, the use of SignBitIsZero is confusing when it's a known constant. This should also directly check the immediate value


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77082/new/

https://reviews.llvm.org/D77082