8 Commits

Author SHA1 Message Date
Nikita Popov
2caaec65c0 [InstCombine] Regenerate all test checks (NFC)
Due to an improvement to name preservation, a lot of InstCombine
tests now show spurious diffs when regenerated.

Rather than regenerating individual files when they get touched,
mass-regenerate all UTC-based InstCombine tests. I have then reset
a number of files showing suspicious diffs where the UTC output
has clearly been manually adjusted. I apologize if I missed
anything in the mass of changes.
2023-04-06 18:38:11 +02:00
Nikita Popov
a266af7211 [InstCombine] Canonicalize SPF to min/max intrinsics
Now that integer min/max intrinsics have good support in both
InstCombine and other passes, start canonicalizing SPF min/max
to intrinsic min/max.

Once this sticks, we can stop matching SPF min/max in various
places, and can remove hacks we have for preventing infinite loops
and breaking of SPF canonicalization.

Differential Revision: https://reviews.llvm.org/D98152
2022-02-24 09:01:20 +01:00
Bjorn Pettersson
acdc419c89 [test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC
Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://reviews.llvm.org/D119081
2022-02-07 14:26:59 +01:00
Sanjay Patel
ee34d9b210 [InstCombine] use redirect of input file in regression tests; NFC
This is a repeat of 1880092722 from 2009. We should have less risk
of hitting bugs at this point because we auto-generate positive CHECK
lines only, but this makes things consistent.

Copying the original commit msg:
"Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename."
2020-09-29 11:06:25 -04:00
Nikita Popov
8058196677 [InstCombine] Process newly inserted instructions in the correct order
InstCombine operates on the basic premise that the operands of the
currently processed instruction have already been simplified. It
achieves this by pushing instructions to the worklist in reverse
program order, so that instructions are popped off in program order.
The worklist management in the main combining loop also makes sure
to uphold this invariant.

However, the same is not true for all the code that is performing
manual worklist management. The largest problem (addressed in this
patch) are instructions inserted by InstCombine's IRBuilder. These
will be pushed onto the worklist in order of insertion (generally
matching program order), which means that a) the users of the
original instruction will be visited first, as they are pushed later
in the main loop and b) the newly inserted instructions will be
visited in reverse program order.

This causes a number of problems: First, folds operate on instructions
that have not had their operands simplified, which may result in
optimizations being missed (ran into this in
https://reviews.llvm.org/D72048#1800424, which was the original
motivation for this patch). Additionally, this increases the amount
of folds InstCombine has to perform, both within one iteration, and
by increasing the number of total iterations.

This patch addresses the issue by adding a Worklist.AddDeferred()
method, which is used for instructions inserted by IRBuilder. These
will only be added to the real worklist after the combine finished,
and in reverse order, so they will end up processed in program order.
I should note that the same should also be done to nearly all other
uses of Worklist.Add(), but I'm starting with just this occurrence,
which has by far the largest test fallout.

Most of the test changes are due to
https://bugs.llvm.org/show_bug.cgi?id=44521 or other cases where
we don't canonicalize something. These are neutral. One regression
has been addressed in D73575 and D73647. The remaining regression
in an shl+sdiv fold can't really be fixed without dropping another
transform, but does not seem particularly problematic in the first
place.

Differential Revision: https://reviews.llvm.org/D73411
2020-01-30 09:40:10 +01:00
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
Craig Topper
8fc05ce340 [InstCombine] Fold (xor (min/max X, Y), -1) -> (max/min ~X, ~Y) when X and Y are freely invertible.
This allows the xor to be removed completely.

This might help with recomitting r341674, but seems good regardless.

Coincidentally fixes PR38915.

Differential Revision: https://reviews.llvm.org/D51964

llvm-svn: 342163
2018-09-13 18:52:58 +00:00