Commit Graph

6 Commits

Author SHA1 Message Date
Roman Lebedev 6a1617d67c
[SimplifyCFG] Teach SimplifyCondBranchToTwoReturns() to preserve DomTree, part 2
... for the custom case returning void.
2020-12-20 00:18:36 +03:00
Roman Lebedev b43b77ff9b
[NFCI][SimlifyCFG] simplifyOnce(): also perform DomTree validation
And that exposes that a number of tests don't *actually* manage to
maintain DomTree validity, which is inline with my observations.

Once again, SimlifyCFG pass currently does not require/preserve DomTree
by default, so this is effectively NFC.
2020-12-20 00:18:32 +03:00
Roman Lebedev 2ee724863e
[SimplifyCFG] ConstantFoldTerminator() already knows how to preserve DomTree
... so just ensure that we pass DomTreeUpdater it into it.

Fixes DomTree preservation for a number of tests,
all of which are marked as such so that they do not regress.
2020-12-18 00:37:22 +03:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Davide Italiano 48283ba3a1 [SimplifyCFG] Fix a crash when folding PHIs.
We enter MergeBlockIntoPredecessor with a block looking like this:

for.inc.us-lcssa:                                 ; preds = %cond.end
  %k.1.lcssa.ph = phi i32 [ %conv15, %cond.end ]
  %t.3.lcssa.ph = phi i32 [ %k.1.lcssa.ph, %cond.end ]
  br label %for.inc, !dbg !66

[note the first arg of the PHI being a PHI].
FoldSingleEntryPHINodes gets rid of both PHIs (calling, eraseFromParent).
But right before we call the function, we push into IncomingValues the
only argument of the PHIs, and shortly after we try to iterate over
something which has been invalidated before :(

The fix its not trying to remove PHIs which have an incoming value
coming from the same BB we're looking at.

Fixes PR37300 and rdar://problem/39910460

Differential Revision:  https://reviews.llvm.org/D46568

llvm-svn: 331824
2018-05-08 23:28:15 +00:00