Commit Graph

15 Commits

Author SHA1 Message Date
Nikita Popov 2b494f85f1 [CVP] Remove -cvp-dont-add-nowrap-flags option
This option was originally added to work around a bug in LFTR.
The bug has long since been fixed.
2021-03-07 18:19:31 +01:00
Luqman Aden 2993661cc0 [CorrelatedValuePropagation] Mark subs that we know not to wrap with nuw/nsw.
Summary:
Teach CorrelatedValuePropagation to also handle sub instructions in addition to add. Relatively simple since makeGuaranteedNoWrapRegion already understood sub instructions. Only subtle change is which range is passed as "Other" to that function, since sub isn't commutative.

Note that CorrelatedValuePropagation::processAddSub is still hidden behind a default-off flag as IndVarSimplify hasn't yet been fixed to strip the added nsw/nuw flags and causes a miscompile. (PR31181)

Reviewers: sanjoy, apilipenko, nikic

Reviewed By: nikic

Subscribers: hiraditya, jfb, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60036

llvm-svn: 358816
2019-04-20 13:14:18 +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
Anna Thomas 61aec18d46 [CVP] Process binary operations even when def is local
Summary:
This patch adds processing of binary operations when the def of operands are in
the same block (i.e. local processing).

Earlier we bailed out in such cases (the bail out was introduced in rL252032)
because LVI at that time was more precise about context at the end of basic
blocks, which implied local def and use analysis didn't benefit CVP.

Since then we've added support for LVI in presence of assumes and guards. The
test cases added show how local def processing in CVP helps adding more
information to the ashr, sdiv, srem and add operators.

Note: processCmp which suffers from the same problem will
be handled in a later patch.

Reviewers: philip, apilipenko, SjoerdMeijer, hfinkel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38766

llvm-svn: 315634
2017-10-12 22:39:52 +00:00
Craig Topper b60f866a8b [LVI] Teach LVI to reason about ORs of icmps similar to how it reasons about ANDs of icmps
Summary: LVI can reason about an AND of icmps on the true dest of a branch. I believe we can do similar for the false dest of ORs. This allows us to get the same answer for the demorganed versions of some of the AND test cases as you can see.

Reviewers: anna, reames

Reviewed By: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34431

llvm-svn: 306076
2017-06-23 01:08:16 +00:00
Hans Wennborg 5cd9a9bf8c Revert r282872 "CVP. Turn marking adds as no wrap on by default"
While not CVP's fault, this caused miscompiles (PR31181). Reverting
until those are resolved.

(This also reverts the follow-ups r288154 and r288161 which removed the
flag.)

llvm-svn: 296030
2017-02-23 22:29:00 +00:00
Artur Pilipenko 5365746723 [CVP] Remove use of removed flag (-cvp-dont-process-adds) from the test
The flag was removed by 288154

llvm-svn: 288161
2016-11-29 16:43:30 +00:00
Artur Pilipenko 615b820af6 CVP. Turn marking adds as no wrap (introduced by r278107) off by default
It causes a regression on our internal benchmark. Introduce cvp-dont-process flag and set it off by default while investigating the regression.

llvm-svn: 279082
2016-08-18 16:08:35 +00:00
Artur Pilipenko 6669f253d5 [LVI] Take range metadata into account while calculating icmp condition constraints
Take range metadata into account for conditions like this:

%length = load i32, i32* %length_ptr, !range !{i32 0, i32 2147483647}
%cmp = icmp ult i32 %a, %length

This is a common pattern for range checks where the length of the array is dynamically loaded.

Reviewed By: sanjoy

Differential Revision: https://reviews.llvm.org/D23267

llvm-svn: 278496
2016-08-12 10:14:11 +00:00
Artur Pilipenko fd223d5d25 [LVI] Handle conditions in the form of (cond1 && cond2)
Teach LVI how to gather information from conditions in the form of (cond1 && cond2). Our out-of-tree front-end emits range checks in this form.

Reviewed By: sanjoy

Differential Revision: http://reviews.llvm.org/D23200

llvm-svn: 278231
2016-08-10 15:13:15 +00:00
Artur Pilipenko e896325ca3 Add a test case for r278217 "[LVI] Relax the assertion about LVILatticeVal type in getConstantRange"
llvm-svn: 278226
2016-08-10 13:51:01 +00:00
Artur Pilipenko e171ea8a33 Teach CorrelatedValuePropagation to mark adds as no wrap
This is a resubmission of previously reverted r277592. It was hitting overly strong assertion in getConstantRange which was relaxed in r278217.

Use LVI to prove that adds do not wrap. The change is motivated by https://llvm.org/bugs/show_bug.cgi?id=28620 bug and it's the first step to fix that problem.

Reviewed By: sanjoy

Differential Revision: http://reviews.llvm.org/D23059

llvm-svn: 278220
2016-08-10 13:08:34 +00:00
Renato Golin f583097434 Revert "Teach CorrelatedValuePropagation to mark adds as no wrap"
This reverts commit r277592, trying to fix the AArch64 42VMA buildbot.

llvm-svn: 277607
2016-08-03 16:20:48 +00:00
Artur Pilipenko 68cb947cc9 Teach CorrelatedValuePropagation to mark adds as no wrap
Use LVI to prove that adds do not wrap. The change is motivated by https://llvm.org/bugs/show_bug.cgi?id=28620 bug and it's the first step to fix that problem.

Reviewed By: sanjoy

Differential Revision: http://reviews.llvm.org/D23059

llvm-svn: 277592
2016-08-03 13:11:39 +00:00