[AMDGPU] Add comments on SITargetLowering::widenLoad

jayfoad · jayfoad · commit a3fc0f9d2b73 · 2024-01-17T10:40:24.000Z
diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -9884,6 +9884,8 @@ static SDValue getLoadExtOrTrunc(SelectionDAG &DAG,
   llvm_unreachable("invalid ext type");
 }
 
+// Try to turn 8 and 16-bit scalar loads into SMEM eligible 32-bit loads.
+// TODO: Skip this on GFX12 which does have scalar sub-dword loads.
 SDValue SITargetLowering::widenLoad(LoadSDNode *Ld, DAGCombinerInfo &DCI) const {
   SelectionDAG &DAG = DCI.DAG;
   if (Ld->getAlign() < Align(4) || Ld->isDivergent())

Original file line number	Diff line number	Diff line change
`@@ -9884,6 +9884,8 @@ static SDValue getLoadExtOrTrunc(SelectionDAG &DAG,`
`9884`	`9884`	`llvm_unreachable("invalid ext type");`
`9885`	`9885`	`}`
`9886`	`9886`
	`9887`	`+// Try to turn 8 and 16-bit scalar loads into SMEM eligible 32-bit loads.`
	`9888`	`+// TODO: Skip this on GFX12 which does have scalar sub-dword loads.`
`9887`	`9889`	`SDValue SITargetLowering::widenLoad(LoadSDNode *Ld, DAGCombinerInfo &DCI) const {`
`9888`	`9890`	`SelectionDAG &DAG = DCI.DAG;`
`9889`	`9891`	`if (Ld->getAlign() < Align(4) \|\| Ld->isDivergent())`