1 files changed, 12 insertions, 14 deletions
diff --git a/contrib/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp b/contrib/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
index 619a0d4..d990bf3 100644
--- a/contrib/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
+++ b/contrib/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
@@ -310,11 +310,8 @@ static bool isPrefixAtLocation(struct InternalInstruction* insn,
                                uint8_t prefix,
                                uint64_t location)
 {
-  if (insn->prefixPresent[prefix] == 1 &&
-     insn->prefixLocations[prefix] == location)
-    return true;
-  else
-    return false;
+  return insn->prefixPresent[prefix] == 1 &&
+     insn->prefixLocations[prefix] == location;
 }
 
 /*
@@ -1369,16 +1366,17 @@ static int readModRM(struct InternalInstruction* insn) {
     switch (mod) {
     case 0x0:
       insn->eaDisplacement = EA_DISP_NONE; /* readSIB may override this */
-      switch (rm) {
-      case 0x14:
-      case 0x4:
-      case 0xc:   /* in case REXW.b is set */
+      // In determining whether RIP-relative mode is used (rm=5),
+      // or whether a SIB byte is present (rm=4),
+      // the extension bits (REX.b and EVEX.x) are ignored.
+      switch (rm & 7) {
+      case 0x4: // SIB byte is present
         insn->eaBase = (insn->addressSize == 4 ?
                         EA_BASE_sib : EA_BASE_sib64);
         if (readSIB(insn) || readDisplacement(insn))
           return -1;
         break;
-      case 0x5:
+      case 0x5: // RIP-relative
         insn->eaBase = EA_BASE_NONE;
         insn->eaDisplacement = EA_DISP_32;
         if (readDisplacement(insn))
@@ -1394,10 +1392,8 @@ static int readModRM(struct InternalInstruction* insn) {
       /* FALLTHROUGH */
     case 0x2:
       insn->eaDisplacement = (mod == 0x1 ? EA_DISP_8 : EA_DISP_32);
-      switch (rm) {
-      case 0x14:
-      case 0x4:
-      case 0xc:   /* in case REXW.b is set */
+      switch (rm & 7) {
+      case 0x4: // SIB byte is present
         insn->eaBase = EA_BASE_sib;
         if (readSIB(insn) || readDisplacement(insn))
           return -1;
@@ -1458,6 +1454,8 @@ static int readModRM(struct InternalInstruction* insn) {
     case TYPE_VK1:                                        \
     case TYPE_VK8:                                        \
     case TYPE_VK16:                                       \
+      if (index > 7)                                      \
+        *valid = 0;                                       \
       return prefix##_K0 + index;                         \
     case TYPE_MM64:                                       \
       return prefix##_MM0 + (index & 0x7);                \