6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-14 16:33:28 +00:00
Code Issues Projects Releases Wiki Activity

require that the branch being controlled by the IV

Browse Source 
exits the loop.  With this information we can guarantee 
the iteration count of the loop is bounded by the 
compare.  I think this xforms is finally safe now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100285 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-04-03 07:21:39 +00:00
parent 96fd76638b
commit d52c072777
1 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
lib/Transforms/Scalar/IndVarSimplify.cpp
View File

@ -691,8 +691,15 @@ void IndVarSimplify::HandleFloatingPointIV(Loop *L, PHINode *PN) {
BranchInst *TheBr = cast<BranchInst>(Compare->use_back());
// FIXME: Need to verify that the branch actually controls the iteration count
// We need to verify that the branch actually controls the iteration count
// of the loop. If not, the new IV can overflow and no one will notice.
// The branch block must be in the loop and one of the successors must be out
// of the loop.
assert(TheBr->isConditional() && "Can't use fcmp if not conditional");
if (!L->contains(TheBr->getParent()) ||
(L->contains(TheBr->getSuccessor(0)) &&
L->contains(TheBr->getSuccessor(1))))
return;
// If it isn't a comparison with an integer-as-fp (the exit value), we can't