R600/SI: Don't crash when getting immediate operand size

llvm-svn: 230147

Author: arsenm

llvm/lib/Target/R600/SIInstrInfo.h

@@ -254,6 +254,13 @@ class SIInstrInfo : public AMDGPUInstrInfo {
   // instruction opcode.
   unsigned getOpSize(uint16_t Opcode, unsigned OpNo) const {
     const MCOperandInfo &OpInfo = get(Opcode).OpInfo[OpNo];
+
+    if (OpInfo.RegClass == -1) {
+      // If this is an immediate operand, this must be a 32-bit literal.
+      assert(OpInfo.OperandType == MCOI::OPERAND_IMMEDIATE);
+      return 4;
+    }
+
     return RI.getRegClass(OpInfo.RegClass)->getSize();
   }