[TableGen] More named sub-operands work.

Commit a538d1f13a13 first added support for named sub-operands in
CodeEmitterGen. We now add a few more features to that, enabling
further target cleanups.

1. Adds support for handling an EncoderMethod in a sub-operand in
CodeEmitterGen. Previously, the specified encoder of a sub-operand was
ignored, and only the default used.

2. Adds support for sub-operands in DecoderEmitter, along with support
for tied sub-operands.

The changes to the decoder required a few minor tweaks to a few
targets, where existing brokeness was exposed. In order to keep this
patch small, I left FIXMEs which will be addressed in upcoming
patches. (Except MIPS16, since its object file emission/decoding is
totally broken).

Differential Revision: https://reviews.llvm.org/D137653

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp b/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
index ef1f623..6a132ed 100644
--- a/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
+++ b/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
@@ -306,6 +306,9 @@ static DecodeStatus DecodeSWAP(MCInst &Inst, unsigned insn, uint64_t Address,
                                const MCDisassembler *Decoder);
 static DecodeStatus DecodeTRAP(MCInst &Inst, unsigned insn, uint64_t Address,
                                const MCDisassembler *Decoder);
+static DecodeStatus DecodeFIXMEInstruction(MCInst &MI, unsigned insn,
+                                           uint64_t Address,
+                                           const MCDisassembler *Decoder);
 
 #include "SparcGenDisassemblerTables.inc"
 
@@ -591,6 +594,15 @@ static DecodeStatus DecodeReturn(MCInst &MI, unsigned insn, uint64_t Address,
   return MCDisassembler::Success;
 }
 
+// This instruction does not have a working decoder, and needs to be
+// fixed. This "fixme" function was introduced to keep the backend compiling,
+// while making changes to tablegen code.
+static DecodeStatus DecodeFIXMEInstruction(MCInst &Inst, unsigned Insn,
+                                           uint64_t Address,
+                                           const MCDisassembler *Decoder) {
+  return MCDisassembler::Fail;
+}
+
 static DecodeStatus DecodeSWAP(MCInst &MI, unsigned insn, uint64_t Address,
                                const MCDisassembler *Decoder) {