[AMDGPU][MC] Corrected handling of tied src for atomic return MUBUF opcodes

See bug 40917: https://bugs.llvm.org/show_bug.cgi?id=40917

Reviewers: artem.tamazov, arsenm

Differential Revision: https://reviews.llvm.org/D59305

llvm-svn: 357063

1 files changed, 7 insertions, 7 deletions

diff --git a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
index 086a7d79fe1..5bf597a0cbb 100644
--- a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
+++ b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
@@ -4911,13 +4911,19 @@ void AMDGPUAsmParser::cvtMubufImpl(MCInst &Inst,
   bool HasLdsModifier = false;
   OptionalImmIndexMap OptionalIdx;
   assert(IsAtomicReturn ? IsAtomic : true);
+  unsigned FirstOperandIdx = 1;
 
-  for (unsigned i = 1, e = Operands.size(); i != e; ++i) {
+  for (unsigned i = FirstOperandIdx, e = Operands.size(); i != e; ++i) {
     AMDGPUOperand &Op = ((AMDGPUOperand &)*Operands[i]);
 
     // Add the register arguments
     if (Op.isReg()) {
       Op.addRegOperands(Inst, 1);
+      // Insert a tied src for atomic return dst.
+      // This cannot be postponed as subsequent calls to
+      // addImmOperands rely on correct number of MC operands.
+      if (IsAtomicReturn && i == FirstOperandIdx)
+        Op.addRegOperands(Inst, 1);
       continue;
     }
 
@@ -4955,12 +4961,6 @@ void AMDGPUAsmParser::cvtMubufImpl(MCInst &Inst,
     }
   }
 
-  // Copy $vdata_in operand and insert as $vdata for MUBUF_Atomic RTN insns.
-  if (IsAtomicReturn) {
-    MCInst::iterator I = Inst.begin(); // $vdata_in is always at the beginning.
-    Inst.insert(I, *I);
-  }
-
   addOptionalImmOperand(Inst, Operands, OptionalIdx, AMDGPUOperand::ImmTyOffset);
   if (!IsAtomic) { // glc is hard-coded.
     addOptionalImmOperand(Inst, Operands, OptionalIdx, AMDGPUOperand::ImmTyGLC);