Fix PR212 - Bytecode reader misreads 'long -9223372036854775808'!
Fix testcase test/Regression/Assembler/2004-01-20-MaxLongLong.llx
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10928 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Reader/ReaderPrimitives.h b/lib/Bytecode/Reader/ReaderPrimitives.h
index 0366ee3..496ab2a 100644
--- a/lib/Bytecode/Reader/ReaderPrimitives.h
+++ b/lib/Bytecode/Reader/ReaderPrimitives.h
@@ -59,9 +59,13 @@
static inline int64_t read_vbr_int64(const unsigned char *&Buf,
const unsigned char *EndBuf) {
uint64_t R = read_vbr_uint64(Buf, EndBuf);
- if (R & 1)
- return -(int64_t)(R >> 1);
- else
+ if (R & 1) {
+ if (R != 1)
+ return -(int64_t)(R >> 1);
+ else // There is no such thing as -0 with integers. "-0" really means
+ // 0x8000000000000000.
+ return 1LL << 63;
+ } else
return (int64_t)(R >> 1);
}