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Pull in r180121 from upstream llvm trunk:

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LoopVectorizer: Fix 15830. When scalarizing and unrolling stores make
  sure that the order in which the elements are scalarized is the same
  as the original order.
  This fixes a miscompilation in FreeBSD's regex library.

This should fix lib/libc/regex/regcomp.c at -O3 with clang 3.3 r178860
on CPUs with SSE.  Before this change, the vectorizer could incorrectly
rearrange the second loop in computejumps(), leading to possibly invalid
entries in the re_gets::charjump table.

The net result was that for example "sed s/@CC@/foo/" failed to work
correctly, leading to trouble with many configure scripts.
This commit is contained in:
Dimitry Andric 2013-04-23 18:58:39 +00:00
parent 22989042a9
commit 5c47cd667d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=249817
1 changed files with 4 additions and 4 deletions
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8
contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
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@ -1040,10 +1040,10 @@ void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) {
// Create a new entry in the WidenMap and initialize it to Undef or Null.
VectorParts &VecResults = WidenMap.splat(Instr, UndefVec);
// For each scalar that we create:
for (unsigned Width = 0; Width < VF; ++Width) {
// For each vector unroll 'part':
for (unsigned Part = 0; Part < UF; ++Part) {
// For each vector unroll 'part':
for (unsigned Part = 0; Part < UF; ++Part) {
// For each scalar that we create:
for (unsigned Width = 0; Width < VF; ++Width) {
Instruction *Cloned = Instr->clone();
if (!IsVoidRetTy)
Cloned->setName(Instr->getName() + ".cloned");