From 8533ebad6f6e407215497ca50771f323058f5576 Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Wed, 10 Aug 2011 19:01:10 +0000
Subject: Add initial support for decoding NEON instructions in Thumb2 mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137236 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/Disassembler/ARMDisassembler.cpp | 54 ++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 2 deletions(-)

(limited to 'lib/Target/ARM/Disassembler/ARMDisassembler.cpp')

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index c9684e1..b6bfece 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -249,12 +249,32 @@ bool ARMDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   }
 
   MI.clear();
-  result = decodeNEONInstruction32(MI, insn, Address, this);
+  result = decodeNEONDataInstruction32(MI, insn, Address, this);
   if (result) {
+    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 false;
+    return true;
+  }
+
+  MI.clear();
+  result = decodeNEONLoadStoreInstruction32(MI, insn, Address, this);
+  if (result) {
     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 false;
+    return true;
+  }
+
+  MI.clear();
+  result = decodeNEONDupInstruction32(MI, insn, Address, this);
+  if (result) {
+    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 false;
     return true;
   }
 
@@ -434,6 +454,14 @@ bool ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   }
 
   MI.clear();
+  result = decodeCommonInstruction32(MI, insn32, Address, this);
+  if (result) {
+    Size = 4;
+    AddThumbPredicate(MI);
+    return true;
+  }
+
+  MI.clear();
   result = decodeVFPInstruction32(MI, insn32, Address, this);
   if (result) {
     Size = 4;
@@ -442,7 +470,29 @@ bool ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   }
 
   MI.clear();
-  result = decodeCommonInstruction32(MI, insn32, Address, this);
+  if (fieldFromInstruction32(insn32, 24, 4) == 0xF) {
+    uint32_t NEONDataInsn = insn32;
+    NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
+    NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
+    NEONDataInsn |= 0x12000000; // Set bits 28 and 25
+    result = decodeNEONDataInstruction32(MI, NEONDataInsn, Address, this);
+    if (result) {
+      Size = 4;
+      AddThumbPredicate(MI);
+      return true;
+    }
+  }
+
+  MI.clear();
+  result = decodeNEONLoadStoreInstruction32(MI, insn32, Address, this);
+  if (result) {
+    Size = 4;
+    AddThumbPredicate(MI);
+    return true;
+  }
+
+  MI.clear();
+  result = decodeNEONDupInstruction32(MI, insn32, Address, this);
   if (result) {
     Size = 4;
     AddThumbPredicate(MI);
-- 
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