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-rw-r--r--include/llvm/Support/LEB128.h41
1 files changed, 39 insertions, 2 deletions
diff --git a/include/llvm/Support/LEB128.h b/include/llvm/Support/LEB128.h
index 00c7eeaebc..410edd4dc7 100644
--- a/include/llvm/Support/LEB128.h
+++ b/include/llvm/Support/LEB128.h
@@ -19,7 +19,7 @@
namespace llvm {
-/// Utility function to encode a SLEB128 value.
+/// Utility function to encode a SLEB128 value to an output stream.
static inline void encodeSLEB128(int64_t Value, raw_ostream &OS) {
bool More;
do {
@@ -34,7 +34,7 @@ static inline void encodeSLEB128(int64_t Value, raw_ostream &OS) {
} while (More);
}
-/// Utility function to encode a ULEB128 value.
+/// Utility function to encode a ULEB128 value to an output stream.
static inline void encodeULEB128(uint64_t Value, raw_ostream &OS,
unsigned Padding = 0) {
do {
@@ -53,6 +53,43 @@ static inline void encodeULEB128(uint64_t Value, raw_ostream &OS,
}
}
+/// Utility function to encode a ULEB128 value to a buffer. Returns
+/// the length in bytes of the encoded value.
+static inline unsigned encodeULEB128(uint64_t Value, uint8_t *p,
+ unsigned Padding = 0) {
+ uint8_t *orig_p = p;
+ do {
+ uint8_t Byte = Value & 0x7f;
+ Value >>= 7;
+ if (Value != 0 || Padding != 0)
+ Byte |= 0x80; // Mark this byte that that more bytes will follow.
+ *p++ = Byte;
+ } while (Value != 0);
+
+ // Pad with 0x80 and emit a null byte at the end.
+ if (Padding != 0) {
+ for (; Padding != 1; --Padding)
+ *p++ = '\x80';
+ *p++ = '\x00';
+ }
+ return (unsigned)(p - orig_p);
+}
+
+
+/// Utility function to decode a ULEB128 value.
+static inline uint64_t decodeULEB128(const uint8_t *p, unsigned *n = 0) {
+ const uint8_t *orig_p = p;
+ uint64_t Value = 0;
+ unsigned Shift = 0;
+ do {
+ Value += (*p & 0x7f) << Shift;
+ Shift += 7;
+ } while (*p++ >= 128);
+ if (n)
+ *n = (unsigned)(p - orig_p);
+ return Value;
+}
+
} // namespace llvm
#endif // LLVM_SYSTEM_LEB128_H