62 Commits

Author SHA1 Message Date
Nikita Popov
eecb99c5f6 [Tests] Add disjoint flag to some tests (NFC)
These tests rely on SCEV looking recognizing an "or" with no common
bits as an "add". Add the disjoint flag to relevant or instructions
in preparation for switching SCEV to use the flag instead of the
ValueTracking query. The IR with disjoint flag matches what
InstCombine would produce.
2023-12-05 14:09:36 +01:00
Joshua Cao
6ed152aff4 [SCEV] Compute AddRec range computations using different type BECount
Before this patch, we can only use the MaxBECount for an AddRec's range
computation if the MaxBECount has <= bit width of the AddRec. This patch
reasons that if a MaxBECount has > bit width, and is <= the max value of
AddRec's bit width, we can still use the MaxBECount.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D151698
2023-05-31 21:05:17 -07:00
Nikita Popov
2564096655 [DependenceAnalysis] Convert tests to opaque pointers (NFC) 2022-12-16 12:06:53 +01:00
Congzhe Cao
76be554931 [DependenceAnalysis][PR56275] Normalize negative dependence analysis results
This patch is the first of the two-patch series (D130188, D130179) that
resolve PR56275 (https://github.com/llvm/llvm-project/issues/56275)
which is a missed opportunity, where a perfrectly valid case for loop
interchange failed interchange legality.

If the distance/direction vector produced by dependence analysis (DA) is
negative, it needs to be normalized (reversed). This patch provides helper
functions `isDirectionNegative()` and `normalize()` in DA that does the
normalization, and clients can query DA to do normalization if needed.

A pass option `<normalized-results>` is added to DependenceAnalysisPrinterPass,
and we leverage it to update DA test cases to make sure of test coverage. The
test cases added in `Banerjee.ll` shows that negative vectors are normalized
with `print<da><normalized-results>`.

Reviewed By: bmahjour, Meinersbur, #loopoptwg

Differential Revision: https://reviews.llvm.org/D130188
2022-08-03 19:59:00 -04:00
Florian Hahn
20d798bd47
Recommit "[SCEV] Look through single value PHIs." (take 3)
This reverts commit 1fbdbb559569641f6d509b569966901c8fb02b63.

All known issues surfaced by this patch should have been fixed now.

The fixes included fixing issues with SCEV expansion in LV and DA's
reliance on LCSSA phis.
2022-06-09 15:20:10 +01:00
Bardia Mahjour
c9677f6db4 [DA] Handle mismatching loop levels by considering them non-linear
To represent various loop levels within a nest, DA implements a special
numbering scheme (see comment atop establishNestingLevels). The goal of
this numbering scheme appears to be representing each unique loop
distinctively by using as little memory as possible. This numbering
scheme is simple when the source and destination of the dependence are
in the same loop. In such cases the level is simply the depth of the
loop in which src and dst reside. When the src and dst are not in the
same loop, we could run into the following situation exposed by
https://reviews.llvm.org/D71539. This patch fixes this by detecting
such cases in checkSubscripts and treating them as non-linear/non-affine.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D110973
2022-06-08 11:15:37 -04:00
Congzhe Cao
557b131c88 [DA] Refactor with a better API
Refactor from iteratively using BitCastInst::getOperand()
to using stripPointerCasts() instead. This is an improvement
since now we are able to analyze more cases, please refer
to test cases added in this patch.

Reviewed By: Meinersbur, #loopoptwg

Differential Revision: https://reviews.llvm.org/D123559
2022-04-13 14:51:48 -04:00
Philip Reames
0658bab870 [SCEV] Infer flags from add/gep in any block
This patch removes a compile time restriction from isSCEVExprNeverPoison. We've strengthened our ability to reason about flags on scopes other than addrecs, and this bailout prevents us from using it. The comment is also suspect as well in that we're in the middle of constructing a SCEV for I. As such, we're going to visit all operands *anyways*.

Differential Revision: https://reviews.llvm.org/D111186
2021-10-06 11:11:54 -07:00
Florian Hahn
1fbdbb5595
Revert "Recommit "[SCEV] Look through single value PHIs." (take 2)"
This reverts commit 764d9aa97905f202385b4f25f8d234630b4feef3.

This patch exposed a few additional cases where SCEV expressions are not
properly invalidated.

See PR52024, PR52023.
2021-09-30 20:53:51 +01:00
Florian Hahn
764d9aa979
Recommit "[SCEV] Look through single value PHIs." (take 2)
This reverts commit 8fdac7cb7abbeeaed016ef9eb7a087458e41e33f.

The issue causing the revert has been fixed a while ago in 60b852092c98.

Original message:

    Now that SCEVExpander can preserve LCSSA form,
    we do not have to worry about LCSSA form when
    trying to look through PHIs. SCEVExpander will take
    care of inserting LCSSA PHI nodes as required.

    This increases precision of the analysis in some cases.

    Reviewed By: mkazantsev, bmahjour

    Differential Revision: https://reviews.llvm.org/D71539
2021-09-28 10:32:17 +01:00
Arthur Eubanks
50153213c8 [test][NewPM] Remove RUN lines using -analyze
Only tests in llvm/test/Analysis.

-analyze is legacy PM-specific.

This only touches files with `-passes`.

I looked through everything and made sure that everything had a new PM equivalent.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D109040
2021-09-02 11:38:14 -07:00
Bardia Mahjour
0e08891ec1 [DA] control compile-time spent by MIV tests
Function exploreDirections() in DependenceAnalysis implements a recursive
algorithm for refining direction vectors. This algorithm has worst-case
complexity of O(3^(n+1)) where n is the number of common loop levels.
In this patch I'm adding a threshold to control the amount of time we
spend in doing MIV tests (which most of the time end up resulting in over
pessimistic direction vectors anyway).

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D107159
2021-08-05 09:50:11 -04:00
Eli Friedman
5d5b08761f [DependenceAnalysis] Guard analysis using getPointerBase().
D104806 broke some uses of getMinusSCEV() in DependenceAnalysis:
subtraction with different pointer bases returns a SCEVCouldNotCompute.
Make sure we avoid cases involving such subtractions.

Differential Revision: https://reviews.llvm.org/D106099
2021-07-15 14:57:32 -07:00
serge-sans-paille
4ab3041acb Revert "[NFC] remove explicit default value for strboolattr attribute in tests"
This reverts commit bda6e5bee04c75b1f1332b4fd1ac4e8ef6c3c247.

See https://lab.llvm.org/buildbot/#/builders/109/builds/15424 for instance
2021-05-24 19:43:40 +02:00
serge-sans-paille
bda6e5bee0 [NFC] remove explicit default value for strboolattr attribute in tests
Since d6de1e1a71406c75a4ea4d5a2fe84289f07ea3a1, no attributes is quivalent to
setting attribute to false.

This is a preliminary commit for https://reviews.llvm.org/D99080
2021-05-24 19:31:04 +02:00
Andy Kaylor
7086025d65 [Dependence Analysis] Enable delinearization of fixed sized arrays
Patch by Artem Radzikhovskyy!

Allow delinearization of fixed sized arrays if we can prove that the GEP indices do not overflow the array dimensions. The checks applied are similar to the ones that are used for delinearization of parametric size arrays. Make sure that the GEP indices are non-negative and that they are smaller than the range of that dimension.

Changes Summary:

- Updated the LIT tests with more exact values, as we are able to delinearize and apply more exact tests
- profitability.ll - now able to delinearize in all cases, no need to use -da-disable-delinearization-checks flag and run the test twice
- loop-interchange-optimization-remarks.ll - in one of the cases we are able to delinearize without using -da-disable-delinearization-checks
- SimpleSIVNoValidityCheckFixedSize.ll - removed unnecessary "-da-disable-delinearization-checks" flag. Now can get the exact answer without it.
- SimpleSIVNoValidityCheckFixedSize.ll and PreliminaryNoValidityCheckFixedSize.ll - made negative tests more explicit, in order to demonstrate the need for "-da-disable-delinearization-checks" flag

Differential Revision: https://reviews.llvm.org/D101486
2021-05-10 10:30:15 -07:00
Andy Kaylor
0a82d885a4 [Dependence Analysis] Fix ExactSIV producing wrong analysis
Patch by Artem Radzikhovskyy!

Symptom: ExactSIV test produced incorrect analysis of dependencies see LIT tests
Bug: At the end of the algorithm when determining dependence direction original author forgot to divide intermediate results by gcd and round result toward zero

Although this bug can be fixed with significantly fewer changes I opted to write the code in such a way that reflects the original algorithm that Banerjee proposed, for easier reference in the future. This surprisingly results in shorter code, and fewer quotient and max/min calculations.

Changes Summary:

- fixed findGCD to return valid x and y so that they match the function description where: ax - by = gcd(a,b)
- Fixed ExactSIV test, to produce proper results
- Documented the extension of Banerjee's algorithm that the original code author introduced. Banerjee's original algorithm only tested whether Dst depends on Src, the extension also allows us to test whether Src depends on Dst, in one pass.
- ExactRDIV test worked fine. Since it uses findGCD(), it needed to be updated.Since ExactRDIV test has very few changes from the core algorithm of ExactSIV I modified the test to have consistent format as ExactSIV.
- Updated the LIT tests to be testing for correct values.

Differential Revision: https://reviews.llvm.org/D100331
2021-04-27 12:24:00 -07:00
Arthur Eubanks
6f66ad13c5 [DependenceAnalysis][NewPM] Fix tests to work under NPM
All tests had corresponding NPM lines, simply pin non-NPM lines to legacy PM.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D87665
2020-09-15 11:11:23 -07:00
Arthur Eubanks
47acbcf09a [tbaa] Rename type-based-aa -> tbaa
For consistency with legacy pass name.
Helps with 37 instances of "unknown pass name 'tbaa'" in check-llvm under NPM.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D84967
2020-07-30 19:51:35 -07:00
Fangrui Song
f31811f2dc [BasicAA] Rename deprecated -basicaa to -basic-aa
Follow-up to D82607
Revert an accidental change (empty.ll) of D82683
2020-06-26 20:41:37 -07:00
Eli Friedman
9b9454af8a Require "target datalayout" to be at the beginning of an IR file.
This will allow us to use the datalayout to disambiguate other
constructs in IR, like load alignment. Split off from D78403.

Differential Revision: https://reviews.llvm.org/D78413
2020-04-20 11:55:49 -07:00
Bardia Mahjour
1b811ff8a9 [DA] Delinearization of fixed-size multi-dimensional arrays
Summary:
Currently the dependence analysis in LLVM is unable to compute accurate
dependence vectors for multi-dimensional fixed size arrays.
This is mainly because the delinearization algorithm in scalar evolution
relies on parametric terms to be present in the access functions. In the
case of fixed size arrays such parametric terms are not present, but we
can use the indexes from GEP instructions to recover the subscripts for
each dimension of the arrays. This patch adds this ability under the
existing option `-da-disable-delinearization-checks`.

Authored By: bmahjour

Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu

Reviewed By: Meinersbur

Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72178
2020-02-27 10:29:01 -05:00
Fangrui Song
502a77f125 Migrate function attribute "no-frame-pointer-elim" to "frame-pointer"="all" as cleanups after D56351 2019-12-24 15:57:33 -08:00
Bardia Mahjour
916d37a2bc [DA] Improve dump to show source and sink of the dependence
Summary:
The current da printer shows the dependence without indicating
which instructions are being considered as the src vs dst. It
also silently ignores call instructions, despite the fact that
they create confused dependence edges to other memory
instructions. This patch addresses these two issues plus a
couple of minor non-functional improvements.

Authored By: bmahjour

Reviewer: dmgreen, fhahn, philip.pfaffe, chandlerc

Reviewed By: dmgreen, fhahn

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71088
2019-12-11 11:48:16 -05:00
Bardia Mahjour
474c713fc7 [NFC] Test commit access
llvm-svn: 372033
2019-09-16 20:44:15 +00:00
Whitney Tsang
05bf5f9328 [DA] Add an option to control delinearization validity checks
Summary: Dependence Analysis performs static checks to confirm validity
of delinearization. These checks often fail for 64-bit targets due to
type conversions and integer wrapping that prevent simplification of the
SCEV expressions. These checks would also fail at compile-time if the
lower bound of the loops are compile-time unknown.
Author: bmahjour
Reviewer: Meinersbur, jdoerfert, kbarton, dmgreen, fhahn
Reviewed By: Meinersbur, jdoerfert, dmgreen
Subscribers: fhahn, hiraditya, javed.absar, llvm-commits, Whitney,
etiotto
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D62610

llvm-svn: 362952
2019-06-10 15:29:07 +00:00
Philip Pfaffe
9438585fe4 [DA][NewPM] Handle transitive dependencies in the new-pm version of DA
Summary:
The analysis result of DA caches pointers to AA, SCEV, and LI, but it
never checks for their invalidation. Fix that.

Reviewers: chandlerc, dmgreen, bogner

Reviewed By: dmgreen

Subscribers: hiraditya, bollu, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D56381

llvm-svn: 352986
2019-02-03 12:25:41 +00:00
James Y Knight
693d39dd12 Remove irrelevant references to legacy git repositories from
compiler identification lines in test-cases.

(Doing so only because it's then easier to search for references which
are actually important and need fixing.)

llvm-svn: 351200
2019-01-15 16:18:52 +00:00
Philip Pfaffe
efb5ad1c58 [DA][NewPM] Add a printerpass and port the testsuite
The new-pm version of DA is untested. Testing requires a printer, so
add that and use it in the existing DA tests.

Differential Revision: https://reviews.llvm.org/D56386

llvm-svn: 350624
2019-01-08 14:06:58 +00:00
David Green
8699492304 [DA] Delinearise AddRecs if we can prove they don't wrap
We can prove that some delinearized subscripts do not wrap around to become
negative by the fact that they are from inbound geps of load/store locations.
This helps improve the delinearisation in cases where we can't prove that they
are non-negative from SCEV alone.

Differential Revision: https://reviews.llvm.org/D48481

llvm-svn: 335481
2018-06-25 15:13:26 +00:00
David Green
d143c65de3 [DA] Enable -da-delinearize by default
This enables da-delinearize in Dependence Analysis for delinearizing array
accesses into multiple dimensions. This can help to increase the power of
Dependence analysis on multi-dimensional arrays and prevent having to fall
back to the slower and less accurate MIV tests. It adds static checks on the
bounds of the arrays to ensure that one dimension doesn't overflow into
another, and brings our code in line with our tests.

Differential Revision: https://reviews.llvm.org/D45872

llvm-svn: 335217
2018-06-21 11:53:16 +00:00
David Green
2911b3a07a [DA] Fix direction vectors for weakZeroSrcSIV
Both weakZeroSrcSIV and weakZeroDstSIV are currently giving the same
direction vectors. Fix weakZeroSrcSIVtest by flipping the directions
it gives.

Differential Revision: https://reviews.llvm.org/D46678

llvm-svn: 333658
2018-05-31 14:55:29 +00:00
David Green
5ef933b02c [DA] Improve alias checking in dependence analysis
Improve the alias analysis to account for cases where we
know that src/dst pairs cannot alias due to things like
TBAA. As we know they are noalias, we know no dependency
can occur. Also fixes issues around the size parameter
to AA being incorrect.

Differential Revision: https://reviews.llvm.org/D42381

llvm-svn: 329692
2018-04-10 11:37:21 +00:00
Sebastian Pop
bf6e1c26cf DA: remove uses of GEP, only ask SCEV
It's been quite some time the Dependence Analysis (DA) is broken,
as it uses the GEP representation to "identify" multi-dimensional arrays.
It even wrongly detects multi-dimensional arrays in single nested loops:

from test/Analysis/DependenceAnalysis/Coupled.ll, example @couple6
;; for (long int i = 0; i < 50; i++) {
;; A[i][3*i - 6] = i;
;; *B++ = A[i][i];

DA used to detect two subscripts, which makes no sense in the LLVM IR
or in C/C++ semantics, as there are no guarantees as in Fortran of
subscripts not overlapping into a next array dimension:

maximum nesting levels = 1
SrcPtrSCEV = %A
DstPtrSCEV = %A
using GEPs
subscript 0
    src = {0,+,1}<nuw><nsw><%for.body>
    dst = {0,+,1}<nuw><nsw><%for.body>
    class = 1
    loops = {1}
subscript 1
    src = {-6,+,3}<nsw><%for.body>
    dst = {0,+,1}<nuw><nsw><%for.body>
    class = 1
    loops = {1}
Separable = {}
Coupled = {1}

With the current patch, DA will correctly work on only one dimension:

maximum nesting levels = 1
SrcSCEV = {(-2424 + %A)<nsw>,+,1212}<%for.body>
DstSCEV = {%A,+,404}<%for.body>
subscript 0
    src = {(-2424 + %A)<nsw>,+,1212}<%for.body>
    dst = {%A,+,404}<%for.body>
    class = 1
    loops = {1}
Separable = {0}
Coupled = {}

This change removes all uses of GEP from DA, and we now only rely
on the SCEV representation.

The patch does not turn on -da-delinearize by default, and so the DA analysis
will be more conservative in the case of multi-dimensional memory accesses in
nested loops.

I disabled some interchange tests, as the DA is not able to disambiguate
the dependence anymore. To make DA stronger, we may need to
compute a bound on the number of iterations based on the access functions
and array dimensions.

The patch cleans up all the CHECKs in test/Transforms/LoopInterchange/*.ll to
avoid checking for snippets of LLVM IR: this form of checking is very hard to
maintain. Instead, we now check for output of the pass that are more meaningful
than dozens of lines of LLVM IR. Some tests now require -debug messages and thus
only enabled with asserts.

Patch written by Sebastian Pop and Aditya Kumar.

Differential Revision: https://reviews.llvm.org/D35430

llvm-svn: 326837
2018-03-06 21:55:59 +00:00
Daniel Neilson
1e68724d24 Remove alignment argument from memcpy/memmove/memset in favour of alignment attributes (Step 1)
Summary:
 This is a resurrection of work first proposed and discussed in Aug 2015:
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
and initially landed (but then backed out) in Nov 2015:
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

 The @llvm.memcpy/memmove/memset intrinsics currently have an explicit argument
which is required to be a constant integer. It represents the alignment of the
dest (and source), and so must be the minimum of the actual alignment of the
two.

 This change is the first in a series that allows source and dest to each
have their own alignments by using the alignment attribute on their arguments.

 In this change we:
1) Remove the alignment argument.
2) Add alignment attributes to the source & dest arguments. We, temporarily,
   require that the alignments for source & dest be equal.

 For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 100, i32 4, i1 false)
will now read
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dest, i8* align 4 %src, i32 100, i1 false)

 Downstream users may have to update their lit tests that check for
@llvm.memcpy/memmove/memset call/declaration patterns. The following extended sed script
may help with updating the majority of your tests, but it does not catch all possible
patterns so some manual checking and updating will be required.

s~declare void @llvm\.mem(set|cpy|move)\.p([^(]*)\((.*), i32, i1\)~declare void @llvm.mem\1.p\2(\3, i1)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* \3, i8 \4, i8 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* \3, i8 \4, i16 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* \3, i8 \4, i32 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* \3, i8 \4, i64 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* \3, i8 \4, i128 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* align \6 \3, i8 \4, i8 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* align \6 \3, i8 \4, i16 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* align \6 \3, i8 \4, i32 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* align \6 \3, i8 \4, i64 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* align \6 \3, i8 \4, i128 \5, i1 \7)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* \4, i8\5* \6, i8 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* \4, i8\5* \6, i16 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* \4, i8\5* \6, i32 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* \4, i8\5* \6, i64 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* \4, i8\5* \6, i128 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* align \8 \4, i8\5* align \8 \6, i8 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* align \8 \4, i8\5* align \8 \6, i16 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* align \8 \4, i8\5* align \8 \6, i32 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* align \8 \4, i8\5* align \8 \6, i64 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* align \8 \4, i8\5* align \8 \6, i128 \7, i1 \9)~g

 The remaining changes in the series will:
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
   source and dest alignments.
Step 3) Update Clang to use the new IRBuilder API.
Step 4) Update Polly to use the new IRBuilder API.
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
        and those that use use MemIntrinsicInst::[get|set]Alignment() to use
        getDestAlignment() and getSourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
        MemIntrinsicInst::[get|set]Alignment() methods.

Reviewers: pete, hfinkel, lhames, reames, bollu

Reviewed By: reames

Subscribers: niosHD, reames, jholewinski, qcolombet, jfb, sanjoy, arsenm, dschuff, dylanmckay, mehdi_amini, sdardis, nemanjai, david2050, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, llvm-commits

Differential Revision: https://reviews.llvm.org/D41675

llvm-svn: 322965
2018-01-19 17:13:12 +00:00
Brendon Cahoon
cb8c7b912d [DependenceAnalysis] Make sure base objects are the same when comparing GEPs
The dependence analysis was returning incorrect information when using the GEPs
to compute dependences. The analysis uses the GEP indices under certain
conditions, but was doing it incorrectly when the base objects of the GEP are
aliases, but pointing to different locations in the same array.

This patch adds another check for the base objects. If the base pointer SCEVs
are not equal, then the dependence analysis should fall back on the path
that uses the whole SCEV for the dependence check. This fixes PR33567.

Differential Revision: https://reviews.llvm.org/D34702

llvm-svn: 307203
2017-07-05 21:35:47 +00:00
Brendon Cahoon
86f783e315 [DependenceAnalysis] Check if result of getConstantPart is null
A seg-fault occurs due to a reference of a null pointer, which is
the value returned by getConstantPart. This function returns
null if the constant part is not found. The code that calls this
function needs to check for the null return value.

Differential Revision: http://reviews.llvm.org/D18718

llvm-svn: 265319
2016-04-04 18:13:18 +00:00
Pete Cooper
67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Pete Cooper
72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Matthew Simpson
ddb4d9741f [SCEV] Consistently Handle Expressions That Cannot Be Divided
This patch addresses the issue of SCEV division asserting on some
input expressions (e.g., non-affine expressions) and quietly giving
up on others.  When giving up, we set the quotient to be equal to
zero and the remainder to be equal to the numerator. With this
patch, we always quietly give up when we cannot perform the
division.

This patch also adds a test case for DependenceAnalysis that
previously caused an assertion.

Differential Revision: http://reviews.llvm.org/D11725

llvm-svn: 247314
2015-09-10 18:12:47 +00:00
Chandler Carruth
7b560d40bd [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible
with the new pass manager, and no longer relying on analysis groups.

This builds essentially a ground-up new AA infrastructure stack for
LLVM. The core ideas are the same that are used throughout the new pass
manager: type erased polymorphism and direct composition. The design is
as follows:

- FunctionAAResults is a type-erasing alias analysis results aggregation
  interface to walk a single query across a range of results from
  different alias analyses. Currently this is function-specific as we
  always assume that aliasing queries are *within* a function.

- AAResultBase is a CRTP utility providing stub implementations of
  various parts of the alias analysis result concept, notably in several
  cases in terms of other more general parts of the interface. This can
  be used to implement only a narrow part of the interface rather than
  the entire interface. This isn't really ideal, this logic should be
  hoisted into FunctionAAResults as currently it will cause
  a significant amount of redundant work, but it faithfully models the
  behavior of the prior infrastructure.

- All the alias analysis passes are ported to be wrapper passes for the
  legacy PM and new-style analysis passes for the new PM with a shared
  result object. In some cases (most notably CFL), this is an extremely
  naive approach that we should revisit when we can specialize for the
  new pass manager.

- BasicAA has been restructured to reflect that it is much more
  fundamentally a function analysis because it uses dominator trees and
  loop info that need to be constructed for each function.

All of the references to getting alias analysis results have been
updated to use the new aggregation interface. All the preservation and
other pass management code has been updated accordingly.

The way the FunctionAAResultsWrapperPass works is to detect the
available alias analyses when run, and add them to the results object.
This means that we should be able to continue to respect when various
passes are added to the pipeline, for example adding CFL or adding TBAA
passes should just cause their results to be available and to get folded
into this. The exception to this rule is BasicAA which really needs to
be a function pass due to using dominator trees and loop info. As
a consequence, the FunctionAAResultsWrapperPass directly depends on
BasicAA and always includes it in the aggregation.

This has significant implications for preserving analyses. Generally,
most passes shouldn't bother preserving FunctionAAResultsWrapperPass
because rebuilding the results just updates the set of known AA passes.
The exception to this rule are LoopPass instances which need to preserve
all the function analyses that the loop pass manager will end up
needing. This means preserving both BasicAAWrapperPass and the
aggregating FunctionAAResultsWrapperPass.

Now, when preserving an alias analysis, you do so by directly preserving
that analysis. This is only necessary for non-immutable-pass-provided
alias analyses though, and there are only three of interest: BasicAA,
GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is
preserved when needed because it (like DominatorTree and LoopInfo) is
marked as a CFG-only pass. I've expanded GlobalsAA into the preserved
set everywhere we previously were preserving all of AliasAnalysis, and
I've added SCEVAA in the intersection of that with where we preserve
SCEV itself.

One significant challenge to all of this is that the CGSCC passes were
actually using the alias analysis implementations by taking advantage of
a pretty amazing set of loop holes in the old pass manager's analysis
management code which allowed analysis groups to slide through in many
cases. Moving away from analysis groups makes this problem much more
obvious. To fix it, I've leveraged the flexibility the design of the new
PM components provides to just directly construct the relevant alias
analyses for the relevant functions in the IPO passes that need them.
This is a bit hacky, but should go away with the new pass manager, and
is already in many ways cleaner than the prior state.

Another significant challenge is that various facilities of the old
alias analysis infrastructure just don't fit any more. The most
significant of these is the alias analysis 'counter' pass. That pass
relied on the ability to snoop on AA queries at different points in the
analysis group chain. Instead, I'm planning to build printing
functionality directly into the aggregation layer. I've not included
that in this patch merely to keep it smaller.

Note that all of this needs a nearly complete rewrite of the AA
documentation. I'm planning to do that, but I'd like to make sure the
new design settles, and to flesh out a bit more of what it looks like in
the new pass manager first.

Differential Revision: http://reviews.llvm.org/D12080

llvm-svn: 247167
2015-09-09 17:55:00 +00:00
Hal Finkel
0ef2b10f16 Fix how DependenceAnalysis calls delinearization
Fix how DependenceAnalysis calls delinearization, mirroring what is done in
Delinearization.cpp (mostly by making sure to call getSCEVAtScope before
delinearizing, and by removing the unnecessary 'Pairs == 1' check).

Patch by Vaivaswatha Nagaraj!

llvm-svn: 245408
2015-08-19 02:56:36 +00:00
Jingyue Wu
a84feb1727 [DependenceAnalysis] Extend unifySubscriptType for handling coupled subscript groups.
Summary:
In continuation to an earlier commit to DependenceAnalysis.cpp by jingyue (r222100), the type for all subscripts in a coupled group need to be the same since constraints from one subscript may be propagated to another during testing. During testing, new SCEVs may be created and the operands for these need to be the same.
This patch extends unifySubscriptType() to work on lists of subscript pairs, ensuring a common extended type for all of them.

Test Plan:
Added a test case to NonCanonicalizedSubscript.ll which causes dependence analysis to crash without this fix.

All regression tests pass.

Reviewers: spop, sebpop, jingyue

Reviewed By: jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9698

llvm-svn: 238573
2015-05-29 16:58:08 +00:00
James Molloy
c0661aeaf8 [DependenceAnalysis] Fix for PR21585: collectUpperBound triggers asserts
collectUpperBound hits an assertion when the back edge count is wider then the desired type.

If that happens, truncate the backedge count.

Patch by Philip Pfaffe!

llvm-svn: 237439
2015-05-15 12:17:22 +00:00
David Blaikie
f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
Karthik Bhat
8d7f7eda14 Fix a memory corruption in Dependency Analysis.
This crash occurs due to memory corruption when trying to update dependency
direction based on Constraints.

This crash was observed during lnt regression of Polybench benchmark test case dynprog.

Review: http://reviews.llvm.org/D8059
llvm-svn: 231788
2015-03-10 14:32:02 +00:00
Karthik Bhat
8d0099bdab Fix a crash in Dependency Analysis.
This crash in Dependency analysis is because we assume here that in case of UsefulGEP
both source and destination have the same number of operands which may not be true.
This incorrect assumption results in crash while populating Pairs. Fix the same.

This crash was observed during lnt regression for code such as-
  struct s{
    int A[10][10];
    int C[10][10][10]; 
  } S;
  void dep_constraint_crash_test(int k,int N)  {
     for( int i=0;i<N;i++)
       for( int j=0;j<N;j++)
         S.A[0][0] = S.C[0][0][k];
  }
Review: http://reviews.llvm.org/D8162

llvm-svn: 231784
2015-03-10 13:31:03 +00:00
David Blaikie
a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie
79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Jingyue Wu
0fa125a77d [DependenceAnalysis] Allow subscripts of different types
Summary:
Several places in DependenceAnalysis assumes both SCEVs in a subscript pair
share the same integer type. For instance, isKnownPredicate calls
SE->getMinusSCEV(X, Y) which asserts X and Y share the same type. However,
DependenceAnalysis fails to ensure this assumption when producing a subscript
pair, causing tests such as NonCanonicalizedSubscript to crash. With this
patch, DependenceAnalysis runs unifySubscriptType before producing any
subscript pair, ensuring the assumption.

Test Plan:
Added NonCanonicalizedSubscript.ll on which DependenceAnalysis before the fix
crashed because subscripts have different types.

Reviewers: spop, sebpop, jingyue

Reviewed By: jingyue

Subscribers: eliben, meheff, llvm-commits

Differential Revision: http://reviews.llvm.org/D6289

llvm-svn: 222100
2014-11-16 16:52:44 +00:00