Commit Graph

7 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
Sanjay Patel 577c705752 [InstCombine] try to fold 'add+sub' to 'not+add'
These are reassociated versions of the same pattern and
similar transforms as in rL338200 and rL338118.

The motivation is identical to those commits:
Patterns with add/sub combos can be improved using
'not' ops. This is better for analysis and may lead
to follow-on transforms because 'xor' and 'add' are
commutative/associative. It can also help codegen.

llvm-svn: 338221
2018-07-29 18:13:16 +00:00
Sanjay Patel 2daf28f9ce [InstCombine] add tests for another sub-not variant; NFC
llvm-svn: 338220
2018-07-29 18:07:28 +00:00
Sanjay Patel 818b253d3a [InstCombine] try to fold 'sub' to 'not'
https://rise4fun.com/Alive/jDd

Patterns with add/sub combos can be improved using
'not' ops. This is better for analysis and may lead
to follow-on transforms because 'xor' and 'add' are 
commutative/associative. It can also help codegen.  

llvm-svn: 338200
2018-07-28 16:48:44 +00:00
Sanjay Patel 78e4b4d3c4 [InstCombine] not(sub X, Y) --> add (not X), Y
The tests with constants show a missing optimization.
Analysis for adds is better than subs, so this can also
help with other transforms. And codegen is better with 
adds for targets like x86 (destructive ops, no sub-from).

https://rise4fun.com/Alive/llK

llvm-svn: 338118
2018-07-27 10:54:48 +00:00
Sanjay Patel eee52b5090 [InstCombine] add tests for not+sub; NFC
llvm-svn: 338117
2018-07-27 10:45:04 +00:00