[APInt] Fix extractBits to correctly handle Result.isSingleWord() case.
Summary: extractBits assumes that `!this->isSingleWord() implies !Result.isSingleWord()`, which may not necessarily be true. Handle both cases.
Reviewers: RKSimon
Subscribers: sanjoy, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D43363
llvm-svn: 325311
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 1ea6319..48b9613 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -428,11 +428,12 @@
unsigned NumSrcWords = getNumWords();
unsigned NumDstWords = Result.getNumWords();
+ uint64_t *DestPtr = Result.isSingleWord() ? &Result.U.VAL : Result.U.pVal;
for (unsigned word = 0; word < NumDstWords; ++word) {
uint64_t w0 = U.pVal[loWord + word];
uint64_t w1 =
(loWord + word + 1) < NumSrcWords ? U.pVal[loWord + word + 1] : 0;
- Result.U.pVal[word] = (w0 >> loBit) | (w1 << (APINT_BITS_PER_WORD - loBit));
+ DestPtr[word] = (w0 >> loBit) | (w1 << (APINT_BITS_PER_WORD - loBit));
}
return Result.clearUnusedBits();