[llvm] r224861 - [X86] Don't fail disassembly if REX.R/REX.B is used on an MMX register. Similar fix to not fail to disassembler CR9-CR15 references.

[Craig Topper]

Author: ctopper
Date: Fri Dec 26 12:19:44 2014
New Revision: 224861

URL: http://llvm.org/viewvc/llvm-project?rev=224861&view=rev
Log:
[X86] Don't fail disassembly if REX.R/REX.B is used on an MMX register. Similar fix to not fail to disassembler CR9-CR15 references.

Modified:
    llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
    llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
    llvm/trunk/test/MC/Disassembler/X86/prefixes.txt

Modified: llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp?rev=224861&r1=224860&r2=224861&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp (original)
+++ llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp Fri Dec 26 12:19:44 2014
@@ -1447,9 +1447,7 @@ static int readModRM(struct InternalInst
     case TYPE_MM64:                                       \
     case TYPE_MM32:                                       \
     case TYPE_MM:                                         \
-      if (index > 7)                                      \
-        *valid = 0;                                       \
-      return prefix##_MM0 + index;                        \
+      return prefix##_MM0 + (index & 0x7);                \
     case TYPE_SEGMENTREG:                                 \
       if (index > 5)                                      \
         *valid = 0;                                       \
@@ -1459,8 +1457,6 @@ static int readModRM(struct InternalInst
         *valid = 0;                                       \
       return prefix##_DR0 + index;                        \
     case TYPE_CONTROLREG:                                 \
-      if (index > 8)                                      \
-        *valid = 0;                                       \
       return prefix##_CR0 + index;                        \
     }                                                     \
   }

Modified: llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h?rev=224861&r1=224860&r2=224861&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h (original)
+++ llvm/trunk/lib/Target/X86/Disassembler/X86DisassemblerDecoder.h Fri Dec 26 12:19:44 2014
@@ -352,7 +352,14 @@ namespace X86Disassembler {
   ENTRY(CR5)          \
   ENTRY(CR6)          \
   ENTRY(CR7)          \
-  ENTRY(CR8)
+  ENTRY(CR8)          \
+  ENTRY(CR9)          \
+  ENTRY(CR10)         \
+  ENTRY(CR11)         \
+  ENTRY(CR12)         \
+  ENTRY(CR13)         \
+  ENTRY(CR14)         \
+  ENTRY(CR15)
 
 #define ALL_EA_BASES  \
   EA_BASES_16BIT      \

Modified: llvm/trunk/test/MC/Disassembler/X86/prefixes.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/Disassembler/X86/prefixes.txt?rev=224861&r1=224860&r2=224861&view=diff
==============================================================================
--- llvm/trunk/test/MC/Disassembler/X86/prefixes.txt (original)
+++ llvm/trunk/test/MC/Disassembler/X86/prefixes.txt Fri Dec 26 12:19:44 2014
@@ -54,6 +54,15 @@
 # CHECK-NEXT: stosq
 0xf3 0xf3 0x48 0xab
 
+
+# Test that we can disassembler control registers above CR8
+# CHECK: movq %cr15, %rax
+0x44 0x0f 0x20 0xf8
+
+# Test that MMX ignore REX.R and REX.B.
+# CHECK: movq %mm0, %mm1
+0x46 0x0f 0x7f 0xc1
+
 # Test that a prefix on it's own works. It's debatable as to if this is 
 # something that is considered valid, but however as LLVM's own disassembler
 # has decided to disassemble prefixes as being separate opcodes, it therefore