From f106d176a53220f88b682583cde610c52fc8987f Mon Sep 17 00:00:00 2001
From: Sjoerd Meijer <sjoerd.meijer@arm.com>
Date: Mon, 13 Mar 2017 09:41:10 +0000
Subject: [PATCH] ARMDisassembler: loop over ARM decode tables

Loop over the ARM decode tables; this is a clean-up to reduce some code
duplication.

Differential Revision: https://reviews.llvm.org/D30814


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297608 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../ARM/Disassembler/ARMDisassembler.cpp      | 77 +++++--------------
 1 file changed, 20 insertions(+), 57 deletions(-)

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 6b4b6171e43..e812d32cc76 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -462,65 +462,28 @@ DecodeStatus ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
     return checkDecodedInstruction(MI, Size, Address, OS, CS, Insn, Result);
   }
 
-  // VFP and NEON instructions, similarly, are shared between ARM
-  // and Thumb modes.
-  Result = decodeInstruction(DecoderTableVFP32, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    return Result;
-  }
-
-  Result = decodeInstruction(DecoderTableVFPV832, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    return Result;
-  }
-
-  Result =
-      decodeInstruction(DecoderTableNEONData32, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    // Add a fake predicate operand, because we share these instruction
-    // definitions with Thumb2 where these instructions are predicable.
-    if (!DecodePredicateOperand(MI, 0xE, Address, this))
-      return MCDisassembler::Fail;
-    return Result;
-  }
-
-  Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, Insn, Address,
-                             this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    // Add a fake predicate operand, because we share these instruction
-    // definitions with Thumb2 where these instructions are predicable.
-    if (!DecodePredicateOperand(MI, 0xE, Address, this))
-      return MCDisassembler::Fail;
-    return Result;
-  }
-
-  Result =
-      decodeInstruction(DecoderTableNEONDup32, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    // Add a fake predicate operand, because we share these instruction
-    // definitions with Thumb2 where these instructions are predicable.
-    if (!DecodePredicateOperand(MI, 0xE, Address, this))
-      return MCDisassembler::Fail;
-    return Result;
-  }
+  struct DecodeTable {
+    const uint8_t *P;
+    bool DecodePred;
+  };
 
-  Result =
-      decodeInstruction(DecoderTablev8NEON32, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    return Result;
-  }
+  const DecodeTable Tables[] = {
+      {DecoderTableVFP32, false},      {DecoderTableVFPV832, false},
+      {DecoderTableNEONData32, true},  {DecoderTableNEONLoadStore32, true},
+      {DecoderTableNEONDup32, true},   {DecoderTablev8NEON32, false},
+      {DecoderTablev8Crypto32, false},
+  };
 
-  Result =
-      decodeInstruction(DecoderTablev8Crypto32, MI, Insn, Address, this, STI);
-  if (Result != MCDisassembler::Fail) {
-    Size = 4;
-    return Result;
+  for (auto Table : Tables) {
+    Result = decodeInstruction(Table.P, MI, Insn, Address, this, STI);
+    if (Result != MCDisassembler::Fail) {
+      Size = 4;
+      // Add a fake predicate operand, because we share these instruction
+      // definitions with Thumb2 where these instructions are predicable.
+      if (Table.DecodePred && !DecodePredicateOperand(MI, 0xE, Address, this))
+        return MCDisassembler::Fail;
+      return Result;
+    }
   }
 
   Size = 0;
-- 
2.50.1