Commit Graph

3 Commits

Author SHA1 Message Date
Roman Lebedev d536de1e7b [NFC][InstCombine] A few more tests for masked merge add/xor -> or with constant mask
llvm-svn: 330325
2018-04-19 13:02:17 +00:00
Roman Lebedev f84bfb2147 [InstCombine] Simplify 'xor' to 'or' if no common bits are set.
Summary:
In order to get the whole fold as specified in [[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]],
let's first handle the simple straight-forward things.
Let's start with the `and` -> `or` simplification.

The one obvious thing missing here: the constant mask is not handled.
I have an idea how to handle it, but it will require some thinking,
and is not strictly required here, so i've left that for later.

https://rise4fun.com/Alive/Pkmg

Reviewers: spatel, craig.topper, eli.friedman, jingyue

Reviewed By: spatel

Subscribers: llvm-commits

Was reviewed as part of https://reviews.llvm.org/D45631

llvm-svn: 330103
2018-04-15 18:59:44 +00:00
Roman Lebedev 8db3e115e7 [InstCombine][NFC] masked-merge: add 'and' tests, too.
(and plain 'or', for completeness sake.)

After submitting D45631, i have realized that it will *already*
affect 'and' pattern, and it was obvious that there were no
good test patterns to show that.

Since the masked-merge.ll is getting kinda big,
unify naming schemes a bit, and split into 'xor'/'and'/'or'
testfiles, with the only difference being the last operation.

llvm-svn: 330072
2018-04-13 21:57:01 +00:00