/// Utility function to decode a ULEB128 value.
-inline uint64_t decodeULEB128(const uint8_t *p, unsigned *n = 0) {
+inline uint64_t decodeULEB128(const uint8_t *p, unsigned *n = nullptr) {
const uint8_t *orig_p = p;
uint64_t Value = 0;
unsigned Shift = 0;
do {
- Value += (*p & 0x7f) << Shift;
+ Value += uint64_t(*p & 0x7f) << Shift;
Shift += 7;
} while (*p++ >= 128);
if (n)
return Value;
}
-/// Utility function to get the size of the ULEB128-encoded value.
-inline unsigned getULEB128Size(uint64_t Value) {
- unsigned Size = 0;
+/// Utility function to decode a SLEB128 value.
+inline int64_t decodeSLEB128(const uint8_t *p, unsigned *n = nullptr) {
+ const uint8_t *orig_p = p;
+ int64_t Value = 0;
+ unsigned Shift = 0;
+ uint8_t Byte;
do {
- Value >>= 7;
- Size += sizeof(int8_t);
- } while (Value);
- return Size;
+ Byte = *p++;
+ Value |= ((Byte & 0x7f) << Shift);
+ Shift += 7;
+ } while (Byte >= 128);
+ // Sign extend negative numbers.
+ if (Byte & 0x40)
+ Value |= (-1ULL) << Shift;
+ if (n)
+ *n = (unsigned)(p - orig_p);
+ return Value;
}
-/// Utility function to get the size of the SLEB128-encoded value.
-inline unsigned getSLEB128Size(int64_t Value) {
- unsigned Size = 0;
- int Sign = Value >> (8 * sizeof(Value) - 1);
- bool IsMore;
- do {
- unsigned Byte = Value & 0x7f;
- Value >>= 7;
- IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
- Size += sizeof(int8_t);
- } while (IsMore);
- return Size;
-}
+/// Utility function to get the size of the ULEB128-encoded value.
+extern unsigned getULEB128Size(uint64_t Value);
+
+/// Utility function to get the size of the SLEB128-encoded value.
+extern unsigned getSLEB128Size(int64_t Value);
} // namespace llvm