[llvm-commits] [llvm] r152414 - in /llvm/trunk: lib/Target/X86/Disassembler/X86DisassemblerDecoder.c test/MC/Disassembler/X86/simple-tests.txt utils/TableGen/X86RecognizableInstr.cpp

[Kevin Enderby]

Author: enderby
Date: Fri Mar  9 11:52:49 2012
New Revision: 152414

URL: http://llvm.org/viewvc/llvm-project?rev=152414&view=rev
Log:
Fix the x86 disassembler to at least print the lock prefix if it is the first
prefix.  Added a FIXME to remind us this still does not work when it is not the
first prefix.

Modified:
    llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
    llvm/trunk/test/MC/Disassembler/X86/simple-tests.txt
    llvm/trunk/utils/TableGen/X86RecognizableInstr.cpp

Modified: llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c?rev=152414&r1=152413&r2=152414&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c (original)
+++ llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c Fri Mar  9 11:52:49 2012
@@ -312,6 +312,13 @@
     
     if (consumeByte(insn, &byte))
       return -1;
+
+    // If the the first byte is a LOCK prefix break and let it be disassembled
+    // as a lock "instruction", by creating an <MCInst #xxxx LOCK_PREFIX>.
+    // FIXME there is currently no way to get the disassembler to print the
+    // lock prefix if it is not the first byte.
+    if (insn->readerCursor - 1 == insn->startLocation && byte == 0xf0)
+      break;
     
     switch (byte) {
     case 0xf0:  /* LOCK */

Modified: llvm/trunk/test/MC/Disassembler/X86/simple-tests.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/Disassembler/X86/simple-tests.txt?rev=152414&r1=152413&r2=152414&view=diff
==============================================================================
--- llvm/trunk/test/MC/Disassembler/X86/simple-tests.txt (original)
+++ llvm/trunk/test/MC/Disassembler/X86/simple-tests.txt Fri Mar  9 11:52:49 2012
@@ -724,3 +724,8 @@
 
 # CHECK: vpermil2ps $1, 4(%rax), %xmm2, %xmm3, %xmm0
 0xc4 0xe3 0xe1 0x48 0x40 0x04 0x21
+
+# rdar://8812056 lldb doesn't print the x86 lock prefix when disassembling
+# CHECK: lock
+# CHECK: xaddq	%rcx, %rbx
+0xf0 0x48 0x0f 0xc1 0xcb

Modified: llvm/trunk/utils/TableGen/X86RecognizableInstr.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/X86RecognizableInstr.cpp?rev=152414&r1=152413&r2=152414&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/X86RecognizableInstr.cpp (original)
+++ llvm/trunk/utils/TableGen/X86RecognizableInstr.cpp Fri Mar  9 11:52:49 2012
@@ -405,13 +405,13 @@
     return FILTER_STRONG;
     
     
-  // Filter out artificial instructions
+  // Filter out artificial instructions but leave in the LOCK_PREFIX so it is
+  // printed as a separate "instruction".
     
   if (Name.find("_Int") != Name.npos       ||
       Name.find("Int_") != Name.npos       ||
       Name.find("_NOREX") != Name.npos     ||
-      Name.find("2SDL") != Name.npos       ||
-      Name == "LOCK_PREFIX")
+      Name.find("2SDL") != Name.npos)
     return FILTER_STRONG;
 
   // Filter out instructions with segment override prefixes.