From 36184ed4cd8dc0dc302b8f51f169c334b7460168 Mon Sep 17 00:00:00 2001 From: Reid Spencer Date: Fri, 2 Mar 2007 01:19:42 +0000 Subject: [PATCH] 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". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34825 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/APInt.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp index 9b000da0ee3..36f88a24798 100644 --- a/lib/Support/APInt.cpp +++ b/lib/Support/APInt.cpp @@ -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 -- 2.34.1