Import llvm r187614 (git 44c8e34), for lldb's use:

  Author: Daniel Malea <daniel.malea@intel.com>
  Date:   Thu Aug 1 21:18:16 2013 +0000

    Fixed the Intel-syntax X86 disassembler to respect the (existing)
    option for hexadecimal immediates, to match AT&T syntax. This also
    brings a new option for C-vs-MASM-style hex.

    Patch by Richard Mitton
    Reviewed: http://llvm-reviews.chandlerc.com/D1243

1 files changed, 49 insertions, 6 deletions

diff --git a/contrib/llvm/lib/MC/MCInstPrinter.cpp b/contrib/llvm/lib/MC/MCInstPrinter.cpp
index 73f30ff..c729d49 100644
--- a/contrib/llvm/lib/MC/MCInstPrinter.cpp
+++ b/contrib/llvm/lib/MC/MCInstPrinter.cpp
@@ -52,10 +52,53 @@ StringRef MCInstPrinter::markup(StringRef a, StringRef b) const {
     return b;
 }
 
-/// Utility function to print immediates in decimal or hex.
-format_object1<int64_t> MCInstPrinter::formatImm(const int64_t Value) const {
-  if (getPrintImmHex())
-    return format("0x%" PRIx64, Value);
-  else
-    return format("%" PRId64, Value);
+// For asm-style hex (e.g. 0ffh) the first digit always has to be a number.
+static bool needsLeadingZero(uint64_t Value)
+{
+  while(Value)
+  {
+    uint64_t digit = (Value >> 60) & 0xf;
+    if (digit != 0)
+      return (digit >= 0xa);
+    Value <<= 4;
+  }
+  return false;
+}
+
+format_object1<int64_t> MCInstPrinter::formatDec(const int64_t Value) const {
+  return format("%" PRId64, Value);
+}
+
+format_object1<int64_t> MCInstPrinter::formatHex(const int64_t Value) const {
+  switch(PrintHexStyle) {
+  case HexStyle::C:
+    if (Value < 0)
+      return format("-0x%" PRIx64, -Value);
+    else
+      return format("0x%" PRIx64, Value);
+  case HexStyle::Asm:
+    if (Value < 0) {
+      if (needsLeadingZero((uint64_t)(-Value)))
+        return format("-0%" PRIx64 "h", -Value);
+      else
+        return format("-%" PRIx64 "h", -Value);
+    } else {
+      if (needsLeadingZero((uint64_t)(Value)))
+        return format("0%" PRIx64 "h", Value);
+      else
+        return format("%" PRIx64 "h", Value);
+    }
+  }
+}
+
+format_object1<uint64_t> MCInstPrinter::formatHex(const uint64_t Value) const {
+  switch(PrintHexStyle) {
+  case HexStyle::C:
+     return format("0x%" PRIx64, Value);
+  case HexStyle::Asm:
+    if (needsLeadingZero(Value))
+      return format("0%" PRIx64 "h", Value);
+    else
+      return format("%" PRIx64 "h", Value);
+  }
 }