From 3f04b5068619ca0411521c9871f4bfc6b04f951f Mon Sep 17 00:00:00 2001
From: Artyom Skrobov <Artyom.Skrobov@arm.com>
Date: Wed, 30 Oct 2013 18:10:09 +0000
Subject: [PATCH] [ARM] NEON instructions were erroneously decoded from certain
 invalid encodings

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193705 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../ARM/Disassembler/ARMDisassembler.cpp      | 40 +++++++++----------
 .../MC/Disassembler/ARM/thumb-neon-crypto.txt |  8 ++++
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 5be1b6957a4..cbf1429dbe6 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -829,28 +829,28 @@ DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
       Check(result, AddThumbPredicate(MI));
       return result;
     }
-  }
 
-  MI.clear();
-  uint32_t NEONCryptoInsn = insn32;
-  NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
-  NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
-  NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
-  result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
-                             Address, this, STI);
-  if (result != MCDisassembler::Fail) {
-    Size = 4;
-    return result;
-  }
+    MI.clear();
+    uint32_t NEONCryptoInsn = insn32;
+    NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
+    NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
+    NEONCryptoInsn |= 0x12000000; // Set bits 28 and 25
+    result = decodeInstruction(DecoderTablev8Crypto32, MI, NEONCryptoInsn,
+                               Address, this, STI);
+    if (result != MCDisassembler::Fail) {
+      Size = 4;
+      return result;
+    }
 
-  MI.clear();
-  uint32_t NEONv8Insn = insn32;
-  NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
-  result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
-                             this, STI);
-  if (result != MCDisassembler::Fail) {
-    Size = 4;
-    return result;
+    MI.clear();
+    uint32_t NEONv8Insn = insn32;
+    NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
+    result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
+                               this, STI);
+    if (result != MCDisassembler::Fail) {
+      Size = 4;
+      return result;
+    }
   }
 
   MI.clear();
diff --git a/test/MC/Disassembler/ARM/thumb-neon-crypto.txt b/test/MC/Disassembler/ARM/thumb-neon-crypto.txt
index 30b5fb6695a..c725c7f5dc3 100644
--- a/test/MC/Disassembler/ARM/thumb-neon-crypto.txt
+++ b/test/MC/Disassembler/ARM/thumb-neon-crypto.txt
@@ -33,3 +33,11 @@
 
 0xe0 0xef 0xa1 0x0e
 # CHECK: vmull.p64  q8, d16, d17
+
+# This used to be incorrectly decoded into an sha256h.32 [0x00,0xff,0x40,0x0c]
+# The other similar encodings are stc2 [0x00,0xfd,0x40,0x0c] and cdp2 [0x00,0xfe,0x40,0x0c]
+0x00 0xfc 0x40 0x0c
+# CHECK-NOT: sha256h.32
+# CHECK-NOT: stc2
+# CHECK-NOT: cdp2
+
-- 
2.34.1