9 Commits

Author SHA1 Message Date
Nikita Popov
fa8448c1b1 [NewGVN] Convert some tests to opaque pointers (NFC) 2023-01-04 16:44:50 +01:00
Bjorn Pettersson
4f73528403 [test][NewGVN] Use -passes=newgvn instead of -newgvn
Use the new PM syntax when specifying the pipeline in regression
tests previously running
  "opt -newgvn ..."

Instead we now do
  "opt -passes=newgvn ..."

Notice that this also changes the aa-pipeline to become the default
aa-pipeline instead of just basic-aa. Since these tests haven't been
explicitly requesting basic-aa in the past (compared to the test cases
updated in a separate patch involving "-basic-aa -newgvn") it is
assumed that the exact aa-pipeline isn't important for the validity
of the test cases. An alternative could have been to add
-aa-pipeline=basic-aa as well to the run lines, but that might just
add clutter in case the test cases do not care about the aa-pipeline.

This is another step to move away from the legacy PM syntax when
specifying passes in opt.

Differential Revision: https://reviews.llvm.org/D118341
2022-01-28 13:58:22 +01:00
Nuno Lopes
680d409561 [NewGVN] Use poison instead of undef to represent unreachable values
This enables more simplifications and gets us closer to removing undef.
ping @alinas
2021-12-29 15:51:29 +00:00
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
Daniel Berlin
c1305af09b NewGVN: Evaluate phi of ops expressions before creating phi node
llvm-svn: 314611
2017-09-30 23:51:54 +00:00
Daniel Berlin
94090dd13b Fix PR/33305. caused by trying to simplify expressions in phi of ops that should have no leaders.
Summary:
After a discussion with Rekka, i believe this (or a small variant)
should fix the remaining phi-of-ops problems.

Rekka's algorithm for completeness relies on looking up expressions
that should have no leader, and expecting it to fail (IE looking up
expressions that can't exist in a predecessor, and expecting it to
find nothing).

Unfortunately, sometimes these expressions can be simplified to
constants, but we need the lookup to fail anyway.  Additionally, our
simplifier outsmarts this by taking these "not quite right"
expressions, and simplifying them into other expressions or walking
through phis, etc.  In the past, we've sometimes been able to find
leaders for these expressions, incorrectly.

This change causes us to not to try to phi of ops such expressions.
We determine safety by seeing if they depend on a phi node in our
block.

This is not perfect, we can do a bit better, but this should be a
"correctness start" that we can then improve.  It also requires a
bunch of caching that i'll eventually like to eliminate.

The right solution, longer term, to the simplifier issues, is to make
the query interface for the instruction simplifier/constant folder
have the flags we need, so that we can keep most things going, but
turn off the possibly-invalid parts (threading through phis, etc).
This is an issue in another wrong code bug as well.

Reviewers: davide, mcrosier

Subscribers: sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D37175

llvm-svn: 312401
2017-09-02 02:18:44 +00:00
Chad Rosier
a5508e3119 [NewGVN] Add CL option to control the generation of phi-of-ops (disable by default).
Differential Revision: https://reviews.llvm.org/D36478539

llvm-svn: 310594
2017-08-10 14:12:57 +00:00
Daniel Berlin
36b08b2088 NewGVN: Fix PR 33461, caused by slightly overzealous verification.
llvm-svn: 305657
2017-06-19 00:24:00 +00:00