[RISCV] Create disjoint or in RISCVGatherScatterLowering

[el-ev]

We can create disjoint or in IRBuilder since #146350.

[llvmbot]

@llvm/pr-subscribers-backend-risc-v

Author: Iris Shi (el-ev)

Changes

We can creating disjoint or in IRBuilder since #146350.

---

Full diff: https://github.com/llvm/llvm-project/pull/151981.diff

1 Files Affected:

• (modified) llvm/lib/Target/RISCV/RISCVGatherScatterLowering.cpp (+2-3)

diff --git a/llvm/lib/Target/RISCV/RISCVGatherScatterLowering.cpp b/llvm/lib/Target/RISCV/RISCVGatherScatterLowering.cpp
index 82c0d8d4738a4..28567ada6c004 100644
--- a/llvm/lib/Target/RISCV/RISCVGatherScatterLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVGatherScatterLowering.cpp
@@ -167,9 +167,8 @@ static std::pair<Value *, Value *> matchStridedStart(Value *Start,
   default:
     llvm_unreachable("Unexpected opcode");
   case Instruction::Or:
-    // TODO: We'd be better off creating disjoint or here, but we don't yet
-    // have an IRBuilder API for that.
-    [[fallthrough]];
+    Start = Builder.CreateOr(Start, Splat, "", /* IsDisjoint = */ true);
+    break;
   case Instruction::Add:
     Start = Builder.CreateAdd(Start, Splat);
     break;

[topperc]

Don't we have IR tests for this pass that shouldn't be affected by this change?

[mshockwave]

Don't we have IR tests for this pass that shouldn't be affected by this change?

(I guess you meant "that should be affected by this change")
There is a test in test/CodeGen/RISCV/rvv/strided-load-store.ll for pattern matching disjoint OR, but not sure whether if we even have one to check whether we generate a disjoint OR. @el-ev could you add a test if there isn't one?

[topperc]

Don't we have IR tests for this pass that shouldn't be affected by this change?

(I guess you meant "that should be affected by this change") There is a test in test/CodeGen/RISCV/rvv/strided-load-store.ll for pattern matching disjoint OR, but not sure whether if we even have one to check whether we generate a disjoint OR. @el-ev could you add a test if there isn't one?

Yes that is what I meant.

[lukel97]

LGTM