[llvm] [RISCV] Try to disassemble 48-bit and larger instructions as 32-bit instructions first. (PR #175122)

[Craig Topper via llvm-commits]

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@@ -831,15 +831,18 @@ DecodeStatus RISCVDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   if ((Bytes[0] & 0b11) != 0b11)
     return getInstruction16(MI, Size, Bytes, Address, CS);
 
-  // It's a 32 bit instruction if bit 1:0 are 0b11(checked above) and bits 4:2
-  // are not 0b111.
+  // Try to decode as a 32-bit instruction first.
+  DecodeStatus Result = getInstruction32(MI, Size, Bytes, Address, CS);
+  if (Result != MCDisassembler::Fail)
+    return Result;
+
+  // If bits [4:2] are 0b111 this might be a 48-bit or larger instruction.
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topperc wrote:

I've expanded the comment.

https://github.com/llvm/llvm-project/pull/175122