[AMDGPU][MC] Disabled use of 2 different literals with SOP2/SOPC instructions

See bug 39319: https://bugs.llvm.org/show_bug.cgi?id=39319

Reviewers: artem.tamazov, arsenm, rampitec

Differential Revision: https://reviews.llvm.org/D56847

llvm-svn: 351549

2 files changed, 41 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
index 3f9af27a2e5..4a3f4d6e915 100644
--- a/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
+++ b/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
@@ -1084,6 +1084,7 @@ private:
   OperandMatchResultTy parseExpTgtImpl(StringRef Str, uint8_t &Val);
 
   bool validateInstruction(const MCInst &Inst, const SMLoc &IDLoc);
+  bool validateSOPLiteral(const MCInst &Inst) const;
   bool validateConstantBusLimitations(const MCInst &Inst);
   bool validateEarlyClobberLimitations(const MCInst &Inst);
   bool validateIntClampSupported(const MCInst &Inst);
@@ -2461,8 +2462,46 @@ bool AMDGPUAsmParser::validateMIMGD16(const MCInst &Inst) {
   return true;
 }
 
+bool AMDGPUAsmParser::validateSOPLiteral(const MCInst &Inst) const {
+  unsigned Opcode = Inst.getOpcode();
+  const MCInstrDesc &Desc = MII.get(Opcode);
+  if (!(Desc.TSFlags & (SIInstrFlags::SOP2 | SIInstrFlags::SOPC)))
+    return true;
+
+  const int Src0Idx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::src0);
+  const int Src1Idx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::src1);
+
+  const int OpIndices[] = { Src0Idx, Src1Idx };
+
+  unsigned NumLiterals = 0;
+  uint32_t LiteralValue;
+
+  for (int OpIdx : OpIndices) {
+    if (OpIdx == -1) break;
+
+    const MCOperand &MO = Inst.getOperand(OpIdx);
+    if (MO.isImm() &&
+        // Exclude special imm operands (like that used by s_set_gpr_idx_on)
+        AMDGPU::isSISrcOperand(Desc, OpIdx) &&
+        !isInlineConstant(Inst, OpIdx)) {
+      uint32_t Value = static_cast<uint32_t>(MO.getImm());
+      if (NumLiterals == 0 || LiteralValue != Value) {
+        LiteralValue = Value;
+        ++NumLiterals;
+      }
+    }
+  }
+
+  return NumLiterals <= 1;
+}
+
 bool AMDGPUAsmParser::validateInstruction(const MCInst &Inst,
                                           const SMLoc &IDLoc) {
+  if (!validateSOPLiteral(Inst)) {
+    Error(IDLoc,
+      "only one literal operand is allowed");
+    return false;
+  }
   if (!validateConstantBusLimitations(Inst)) {
     Error(IDLoc,
       "invalid operand (violates constant bus restrictions)");
diff --git a/llvm/lib/Target/AMDGPU/SOPInstructions.td b/llvm/lib/Target/AMDGPU/SOPInstructions.td
index ca5e981ac5c..ee72d28dd6c 100644
--- a/llvm/lib/Target/AMDGPU/SOPInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SOPInstructions.td
@@ -302,6 +302,8 @@ class SOP2_Real<bits<7> op, SOP_Pseudo ps> :
   // copy relevant pseudo op flags
   let SubtargetPredicate = ps.SubtargetPredicate;
   let AsmMatchConverter  = ps.AsmMatchConverter;
+  let UseNamedOperandTable = ps.UseNamedOperandTable;
+  let TSFlags = ps.TSFlags;
 
   // encoding
   bits<7> sdst;