Commit Graph

5 Commits

Author SHA1 Message Date
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
Roman Lebedev c0ecd06428 Revert rL333106 / D46814: [InstCombine] Fold unfolded masked merge pattern with variable mask!
In post-commit review, Eric Christopher notes that many
new MSan warnings are being observed with this patch.

The probable reason is: if 'y' is undef here and we could
evaluate it twice and get different results.
We can't increase the number of uses of a value.

llvm-svn: 333631
2018-05-31 06:00:36 +00:00
Roman Lebedev 6b6c553bb8 [InstCombine] Fold unfolded masked merge pattern with variable mask!
Summary:
Finally fixes [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]].

Now that the backend is all done, we can finally fold it!

The canonical unfolded masked merge pattern is
```(x &  m) | (y & ~m)```
There is a second, equivalent variant:
```(x | ~m) & (y |  m)```
Only one of them (the or-of-and's i think) is canonical.
And if the mask is not a constant, we should fold it to:
```((x ^ y) & M) ^ y```

https://rise4fun.com/Alive/ndQw

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: nicholas, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D46814

llvm-svn: 333106
2018-05-23 17:47:52 +00:00
Roman Lebedev ffec58bce6 [InstCombine][NFC] Add tests for one more masked merge pattern.
This pattern came up in D46494.
I'm pretty sure we want to canonicalize it from
	(x | ~m) & (y &  m)
to
	(x &  m) | (y & ~m)

https://rise4fun.com/Alive/TEM

llvm-svn: 331625
2018-05-07 09:42:45 +00:00