[PATCH] D118089: [AMDGPU] Validate dst and src2 non-overlapping restriction in asm

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:3643
+
+  if (RUCount <= 8) // 4 VGPRs or less
+    return true;
----------------
Can't you get the width directly from the operand register class without making an assumption about the number of register units?


================
Comment at: llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:3646-3653
+  for (MCRegister SubReg : TRI->subregs(Src2Reg)) {
+    if (TRI->isSubRegister(DstReg, SubReg)) {
+      Error(getRegLoc(mc2PseudoReg(Src2Reg), Operands),
+            "source 2 operand must not partially overlap with dst");
+      return false;
+    }
+  }
----------------
This is a weird overlap check. Can't you just check if you encounter the register in MCRegAliasIterator


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  https://reviews.llvm.org/D118089/new/

https://reviews.llvm.org/D118089