Commit Graph

15 Commits

Author SHA1 Message Date
Florian Hahn 242c98614b [PredicateInfo] Use SmallVector instead of SmallPtrSet.
We do not need the SmallPtrSet to avoid adding duplicates to
OpsToRename, because we already keep a ValueInfo mapping. If we see an
op for the first time, Infos will be empty and we can also add it to
OpsToRename.

We process operands by visiting BBs depth-first and then iterate over
all instructions & users, so the order should be deterministic.
Therefore we can skip one round of sorting, which we purely needed for
guaranteeing a deterministic order when iterating over the SmallPtrSet.

Reviewers: efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D64816

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367028 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-25 15:35:10 +00:00
Taewook Oh 3e20d61b66 [PredicateInfo] Do not process unreachable operands.
Summary: We should excluded unreachable operands from processing as their DFS visitation order is undefined. When `renameUses` function sorts `OpsToRename` (https://fburl.com/d2wubn60), the comparator assumes that the parent block of the operand has a corresponding dominator tree node. This is not the case for unreachable operands and crashes the compiler.

Reviewers: dberlin, mgrang, davide

Subscribers: efriedma, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61154

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360796 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-15 19:35:38 +00:00
Eric Christopher 598198edbc Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358552 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-17 04:52:47 +00:00
Eric Christopher 02cc44c1b9 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358546 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-17 02:12:23 +00:00
Florian Hahn ae8e83e5e7 [PredicateInfo] Use custom mangling to support ssa_copy with unnamed types.
This is a workaround and it would be better to fix this generally, but
doing it generally is quite tricky. See D48541 and PR38117.

Doing it in PredicateInfo directly allows us to use the type address to
differentiate different unnamed types, because neither the created
declarations nor the ssa_copy calls should be visible after
PredicateInfo got destroyed.

Reviewers: efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D49126


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337828 91177308-0d34-0410-b5e6-96231b3b80d8
2018-07-24 14:49:52 +00:00
Florian Hahn a65852c5d7 [PredicateInfo] Order instructions in different BBs by DFSNumIn.
Using OrderedInstructions::dominates as comparator for instructions in
BBs without dominance relation can cause a non-deterministic order
between such instructions. That in turn can cause us to materialize
copies in a non-deterministic order. While this does not effect
correctness, it causes some minor non-determinism in the final generated
code, because values have slightly different labels.

Without this patch, running -print-predicateinfo on a reasonably large
module produces slightly different output on each run.

This patch uses the dominator trees DFSInNum to order instruction from
different BBs, which should enforce a deterministic ordering and
guarantee that dominated instructions come after the instructions that
dominate them.

Reviewers: dberlin, efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D48230


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335150 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-20 17:42:01 +00:00
Mandeep Singh Grang 89c6743f22 [ADT] Enable reverse iteration for DenseMap
Reviewers: mehdi_amini, dexonsmith, dblaikie, davide, chandlerc, davidxl, echristo, efriedma

Reviewed By: dblaikie

Subscribers: rsmith, mgorny, emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D35043

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311730 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-24 23:02:48 +00:00
Daniel Berlin e6be55f220 PredicateInfo: Don't insert conditional info when a conditional branch jumps to the same target regardless of condition
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305416 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-14 21:19:52 +00:00
NAKAMURA Takumi 4e7fb91232 Introduce the new feature "abi-breaking-checks" to satisfy -reverse-iterate in llvm/test/Transforms/Util/PredicateInfo/
A few tests in llvm/test/Transforms/Util/PredicateInfo/ are using -reverse-iterate.
The option -reverse-iterate is enabled with +Asserts in usual cases, but it can be turned on/off regardless of LLVM_ENABLE_ASSERTIONS.

I wonder if this were incompatible to https://reviews.llvm.org/D33908 (r304757).

Differential Revision: https://reviews.llvm.org/D33854

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304851 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-07 00:22:52 +00:00
Mandeep Singh Grang 4fc1ca19cd [PredicateInfo] Enable -reverse-iterate tests only for +Asserts builds
Summary: The flag -reverse-iterate is present only on +Asserts builds.

Reviewers: dberlin, davide, RKSimon, efriedma, chapuni

Reviewed By: efriedma, chapuni

Subscribers: chapuni, llvm-commits

Differential Revision: https://reviews.llvm.org/D33795

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304498 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-01 23:52:59 +00:00
Mandeep Singh Grang 9cc122269f [PredicateInfo] Fix non-determinism in codegen uncovered by reverse iterating SmallPtrSet
Summary:
Sort OpsToRename before iterating to make iteration order deterministic.

Thanks to Daniel Berlin for the sorting logic.

Reviewers: dberlin, RKSimon, efriedma, davide

Reviewed By: dberlin, davide

Subscribers: sanjoy, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D33265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304447 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-01 18:36:24 +00:00
Daniel Berlin 4ddfe6915d PredicateInfo: Support switch statements
Summary:
Depends on D29606 and D29682

Makes us pass GVN's edge.ll (we also will pass a few other testcases
they just need cleaning up).

Thoughts on the Predicate* hiearchy of classes especially welcome :)
(it's not clear to me how best to organize it, and currently, the getBlock* seems ... uglier than maybe wasting a field somewhere or something).

Reviewers: davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29747

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295889 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-22 22:20:58 +00:00
Daniel Berlin 33e17b4040 PredicateInfo: Clean up predicate info a little, using insertion
helpers, and fixing support for the renaming the comparison.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295581 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-18 23:06:38 +00:00
Daniel Berlin 8697d189a9 PredicateInfo: Handle critical edges
Summary:
This adds support for placing predicateinfo such that it affects critical edges.

This fixes the issues mentioned by Nuno on the mailing list.

Depends on D29519

Reviewers: davide, nlopes

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29606

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294921 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-12 22:12:20 +00:00
Daniel Berlin 94f2e5a1f1 Add PredicateInfo utility and printing pass
Summary:
This patch adds a utility to build extended SSA (see "ABCD: eliminating
array bounds checks on demand"), and an intrinsic to support it. This
is then used to get functionality equivalent to propagateEquality in
GVN, in NewGVN (without having to replace instructions as we go). It
would work similarly in SCCP or other passes. This has been talked
about a few times, so i built a real implementation and tried to
productionize it.

Copies are inserted for operands used in assumes and conditional
branches that are based on comparisons (see below for more)

Every use affected by the predicate is renamed to the appropriate
intrinsic result.

E.g.
%cmp = icmp eq i32 %x, 50
br i1 %cmp, label %true, label %false
true:
ret i32 %x
false:
ret i32 1

will become

%cmp = icmp eq i32, %x, 50
br i1 %cmp, label %true, label %false
true:
; Has predicate info
; branch predicate info { TrueEdge: 1 Comparison: %cmp = icmp eq i32 %x, 50 }
%x.0 = call @llvm.ssa_copy.i32(i32 %x)
ret i32 %x.0
false:
ret i23 1

(you can use -print-predicateinfo to get an annotated-with-predicateinfo dump)

This enables us to easily determine what operations are affected by a
given predicate, and how operations affected by a chain of
predicates.

Reviewers: davide, sanjoy

Subscribers: mgorny, llvm-commits, Prazek

Differential Revision: https://reviews.llvm.org/D29519

Update for review comments

Fix a bug Nuno noticed where we are giving information about and/or on edges where the info is not useful and easy to use wrong

Update for review comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294351 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-07 21:10:46 +00:00