Fix a problem where shifting by 64-bits leads to incorrect results on PPC

but not on X86 becuase shift by word size is "undefined".

llvm-svn: 34825
This commit is contained in:
Reid Spencer 2007-03-02 01:19:42 +00:00
parent 32bc81341b
commit c442c84c8f
1 changed files with 4 additions and 1 deletions

View File

@ -938,7 +938,10 @@ APInt &APInt::sext(uint32_t width) {
if (wordsBefore == wordsAfter) {
uint32_t newWordBits = width % APINT_BITS_PER_WORD;
// The extension is contained to the wordsBefore-1th word.
uint64_t mask = (~0ULL >> (APINT_BITS_PER_WORD - newWordBits)) << wordBits;
uint64_t mask = ~0ULL;
if (newWordBits)
mask >>= APINT_BITS_PER_WORD - newWordBits;
mask <<= wordBits;
if (wordsBefore == 1)
VAL |= mask;
else