775 Commits

Author SHA1 Message Date
Alina Sbirlea
09de66f657 [LoopStrengthReduce] Teach LoopStrengthReduce to preserve MemorySSA is available. 2020-01-24 10:13:52 -08:00
Alina Sbirlea
c4e8c14e79 [LoopStrengthReduce] Reuse utility method to clean dead instructions. [NFCI]
Create a utility wrapper for the RecursivelyDeleteTriviallyDeadInstructions utility
method, which sets to nullptr the instructions that are not trivially
dead. Use the new method in LoopStrengthReduce.
Alternative: add a bool to the same method; this option adds a marginal
amount of overhead to the other callers, and the method needs to be
updated to return a bool status when it removes/doesn't remove
instructions.
2020-01-23 16:27:32 -08:00
Florian Hahn
c2f9eea17d Revert "[SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC)."
This reverts commit 51ef53f3bd23559203fe9af82ff2facbfedc1db3, as it
breaks some bots.
2020-01-04 18:44:38 +00:00
Florian Hahn
088559d18d [SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC).
SCEVExpander modifies the underlying function so it is more suitable in
Transforms/Utils, rather than Analysis. This allows using other
transform utils in SCEVExpander.

Reviewers: sanjoy.google, efriedma, reames

Reviewed By: sanjoy.google

Differential Revision: https://reviews.llvm.org/D71537
2020-01-04 18:29:35 +00:00
Reid Kleckner
68092989f3 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Zi Xuan Wu
5d5b98eb29 recommit: [LoopVectorize][PowerPC] Estimate int and float register pressure separately in loop-vectorize
In loop-vectorize, interleave count and vector factor depend on target register number. Currently, it does not
estimate different register pressure for different register class separately(especially for scalar type,
float type should not be on the same position with int type), so it's not accurate. Specifically,
it causes too many times interleaving/unrolling, result in too many register spills in loop body and hurting performance.

So we need classify the register classes in IR level, and importantly these are abstract register classes,
and are not the target register class of backend provided in td file. It's used to establish the mapping between
the types of IR values and the number of simultaneous live ranges to which we'd like to limit for some set of those types.

For example, POWER target, register num is special when VSX is enabled. When VSX is enabled, the number of int scalar register is 32(GPR),
float is 64(VSR), but for int and float vector register both are 64(VSR). So there should be 2 kinds of register class when vsx is enabled,
and 3 kinds of register class when VSX is NOT enabled.

It runs on POWER target, it makes big(+~30%) performance improvement in one specific bmk(503.bwaves_r) of spec2017 and no other obvious degressions.

Differential revision: https://reviews.llvm.org/D67148

llvm-svn: 374634
2019-10-12 02:53:04 +00:00
Jinsong Ji
6616c06663 Revert "[LoopVectorize][PowerPC] Estimate int and float register pressure separately in loop-vectorize"
Also Revert "[LoopVectorize] Fix non-debug builds after rL374017"

This reverts commit 9f41deccc0e648a006c9f38e11919f181b6c7e0a.
This reverts commit 18b6fe07bcf44294f200bd2b526cb737ed275c04.

The patch is breaking PowerPC internal build, checked with author, reverting
on behalf of him for now due to timezone.

llvm-svn: 374091
2019-10-08 17:32:56 +00:00
Zi Xuan Wu
d4140de63c [LoopVectorize][PowerPC] Estimate int and float register pressure separately in loop-vectorize
In loop-vectorize, interleave count and vector factor depend on target register number. Currently, it does not
estimate different register pressure for different register class separately(especially for scalar type,
float type should not be on the same position with int type), so it's not accurate. Specifically,
it causes too many times interleaving/unrolling, result in too many register spills in loop body and hurting performance.

So we need classify the register classes in IR level, and importantly these are abstract register classes,
and are not the target register class of backend provided in td file. It's used to establish the mapping between
the types of IR values and the number of simultaneous live ranges to which we'd like to limit for some set of those types.

For example, POWER target, register num is special when VSX is enabled. When VSX is enabled, the number of int scalar register is 32(GPR),
float is 64(VSR), but for int and float vector register both are 64(VSR). So there should be 2 kinds of register class when vsx is enabled,
and 3 kinds of register class when VSX is NOT enabled.

It runs on POWER target, it makes big(+~30%) performance improvement in one specific bmk(503.bwaves_r) of spec2017 and no other obvious degressions.

Differential revision: https://reviews.llvm.org/D67148

llvm-svn: 374017
2019-10-08 03:28:33 +00:00
Simon Pilgrim
6fd9cdde6b [LSR] Silence static analyzer null dereference warnings with assertions. NFCI.
Add assertions to make it clear that GenerateIVChain / NarrowSearchSpaceByPickingWinnerRegs should succeed in finding non-null values

llvm-svn: 372518
2019-09-22 17:59:24 +00:00
Teresa Johnson
0062c013da Change TargetLibraryInfo analysis passes to always require Function
Summary:
This is the first change to enable the TLI to be built per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.

This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.

Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.

There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.

Reviewers: chandlerc, hfinkel

Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66428

llvm-svn: 371284
2019-09-07 03:09:36 +00:00
Chen Zheng
6fb3c7639a [PowerPC] exclude more icmps in LSR which is converted in later hardware loop pass
Differential Revision: https://reviews.llvm.org/D64795

llvm-svn: 366976
2019-07-25 01:22:08 +00:00
Rui Ueyama
1179e18f0c Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Chen Zheng
ce95cee8fb [PowerPC] Hardware Loop branch instruction's condition may not be icmp.
This fixes pr42492.
Differential Revision: https://reviews.llvm.org/D64124

llvm-svn: 365104
2019-07-04 01:51:47 +00:00
Chen Zheng
b1580fbd5c [PowerPC] exclude ICmpZero in LSR if icmp can be replaced in later hardware loop.
Differential Revision: https://reviews.llvm.org/D63477

llvm-svn: 364993
2019-07-03 01:49:03 +00:00
Amara Emerson
cbaf8a6621 Revert "[LSR] Tweak setup cost depth threshold to 10."
Changing the threshold might not be the best long term approach. Revert for now.

llvm-svn: 360589
2019-05-13 15:37:18 +00:00
Amara Emerson
88de73c897 [LSR] Tweak setup cost depth threshold to 10.
The original change introduced a depth limit of 7 which caused a 22% regression
in the Swift MapReduceLazyCollection & Ackermann benchmarks. This new threshold
still ensures that the original test case doesn't hang.

rdar://50359639

llvm-svn: 360444
2019-05-10 17:29:35 +00:00
David Green
fe632bfdc8 [LSR] Limit the recursion for setup cost
In some circumstances we can end up with setup costs that are very complex to
compute, even though the scevs are not very complex to create. This can also
lead to setupcosts that are calculated to be exactly -1, which LSR treats as an
invalid cost. This patch puts a limit on the recursion depth for setup cost to
prevent them taking too long.

Thanks to @reames for the report and test case.

Differential Revision: https://reviews.llvm.org/D60944

llvm-svn: 358958
2019-04-23 08:52:21 +00:00
Denis Bakhvalov
5e8e66a2e4 Test commit by Denis Bakhvalov
Change-Id: I4d85123a157d957434902fb14ba50926b2d56212
llvm-svn: 358619
2019-04-17 22:27:30 +00:00
Quentin Colombet
9629208747 [LSR] Rewrite misses some fixup locations if it splits critical edge
If LSR split critical edge during rewriting phi operands and
phi node has other pending fixup operands, we need to
update those pending fixups. Otherwise formulae will not be
implemented completely and some instructions will not be eliminated.

llvm.org/PR41445

Differential Revision: https://reviews.llvm.org/D60645

Patch by: Denis Bakhvalov <denis.bakhvalov@intel.com>

llvm-svn: 358457
2019-04-15 22:23:46 +00:00
Florian Hahn
cbedd648ce [LSR] Fix signed overflow in GenerateCrossUseConstantOffsets.
For the attached test case, unchecked addition of immediate starts and
ends overflows, as they can be arbitrary i64 constants.

Proof: https://rise4fun.com/Alive/Plqc

Reviewers: qcolombet, gilr, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D59218

llvm-svn: 357217
2019-03-28 22:17:29 +00:00
Florian Hahn
e9781212b4 [LSR] Check for signed overflow in NarrowSearchSpaceByDetectingSupersets.
We are adding a sign extended IR value to an int64_t, which can cause
signed overflows, as in the attached test case, where we have a formula
with BaseOffset = -1 and a constant with numeric_limits<int64_t>::min().

If the addition would overflow, skip the simplification for this
formula. Note that the target triple is required to trigger the failure.

Reviewers: qcolombet, gilr, kparzysz, efriedma

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D59211

llvm-svn: 356256
2019-03-15 12:17:36 +00:00
Sam Parker
4a0b23b067 Fix for buildbots
Remove unused private field.

llvm-svn: 356135
2019-03-14 11:38:55 +00:00
Sam Parker
432549184c [NFC][LSR] Cleanup Cost API
Create members for Loop, ScalarEvolution, DominatorTree,
TargetTransformInfo and Formula.

Differential Revision: https://reviews.llvm.org/D58389

llvm-svn: 356131
2019-03-14 11:05:07 +00:00
David Green
ca0144cb3d [LSR] Attempt to increase the accuracy of LSR's setup cost
In some loops, we end up generating loop induction variables that look like:
  {(-1 * (zext i16 (%i0 * %i1) to i32))<nsw>,+,1}
As opposed to the simpler:
  {(zext i16 (%i0 * %i1) to i32),+,-1}
i.e we count up from -limit to 0, not the simpler counting down from limit to
0. This is because the scores, as LSR calculates them, are the same and the
second is filtered in place of the first. We end up with a redundant SUB from 0
in the code.

This patch tries to make the calculation of the setup cost a little more
thoroughly, recursing into the scev members to better approximate the setup
required. The cost function for comparing LSR costs is:

return std::tie(C1.NumRegs, C1.AddRecCost, C1.NumIVMuls, C1.NumBaseAdds,
                C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
       std::tie(C2.NumRegs, C2.AddRecCost, C2.NumIVMuls, C2.NumBaseAdds,
                C2.ScaleCost, C2.ImmCost, C2.SetupCost);
So this will only alter results if none of the other variables turn out to be
different.

Differential Revision: https://reviews.llvm.org/D58770

llvm-svn: 355597
2019-03-07 13:44:40 +00:00
Max Kazantsev
32ede157ac [NFC] Rename DontDeleteUselessPHIs --> KeepOneInputPHIs
llvm-svn: 353801
2019-02-12 07:09:29 +00:00
Sam Parker
555093ddca [LSR] Generate cross iteration indexes
Modify GenerateConstantOffsetsImpl to create offsets that can be used
by indexed addressing modes. If formulae can be generated which
result in the constant offset being the same size as the recurrence,
we can generate a pre-indexed access. This allows the pointer to be
updated via the single pre-indexed access so that (hopefully) no
add/subs are required to update it for the next iteration. For small
cores, this can significantly improve performance DSP-like loops.

Differential Revision: https://reviews.llvm.org/D55373

llvm-svn: 353403
2019-02-07 13:32:54 +00:00
Max Kazantsev
e5dfdc9b69 [LSR] Check SCEV on isZero() after extend. PR40514
When LSR first adds SCEVs to BaseRegs, it only does it if `isZero()` has
returned false. In the end, in invocation of `InsertFormula`, it asserts that
all values there are still not zero constants. However between these two
points, it makes some transformations, in particular extends them to wider
type.

SCEV does not give us guarantee that if `S` is not a constant zero, then
`sext(S)` is also not a constant zero. It might have missed some optimizing
transforms when it was calculating `S` and then made them when it took `sext`.
For example, it may happen if previously optimizing transforms were limited
by depth or somehow else.

This patch adds a bailout when we may end up with a zero SCEV after extension.

Differential Revision: https://reviews.llvm.org/D57565
Reviewed By: samparker

llvm-svn: 353136
2019-02-05 04:30:37 +00:00
Chandler Carruth
ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Sam Parker
c0aac1b8cd [LoopStrengthReduce] ComplexityLimit as an option
Convert ComplexityLimit into a command line value.

Differential Revision: https://reviews.llvm.org/D54899

llvm-svn: 347843
2018-11-29 08:34:22 +00:00
Gil Rapaport
964f5ac5c8 [LSR] Combine unfolded offset into invariant register
LSR reassociates constants as unfolded offsets when the constants fit as
immediate add operands, which currently prevents such constants from being
combined later with loop invariant registers.
This patch modifies GenerateCombinations() to generate a second formula which
includes the unfolded offset in the combined loop-invariant register.

This commit fixes a bug in the original patch (committed at r345114, reverted
at r345123).

Differential Revision: https://reviews.llvm.org/D51861

llvm-svn: 346390
2018-11-08 09:01:19 +00:00
Gil Rapaport
375b47405c Revert r345114
Investigating fails.

llvm-svn: 345123
2018-10-24 08:41:22 +00:00
Gil Rapaport
20e5de3e82 [LSR] Combine unfolded offset into invariant register
LSR reassociates constants as unfolded offsets when the constants fit as
immediate add operands, which currently prevents such constants from being
combined later with loop invariant registers.
This patch modifies GenerateCombinations() to generate a second formula which
includes the unfolded offset in the combined loop-invariant register.

Differential Revision: https://reviews.llvm.org/D51861

llvm-svn: 345114
2018-10-24 07:08:38 +00:00
Fangrui Song
c2791239be llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)
Summary: The convenience wrapper in STLExtras is available since rL342102.

Reviewers: dblaikie, javed.absar, JDevlieghere, andreadb

Subscribers: MatzeB, sanjoy, arsenm, dschuff, mehdi_amini, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, javed.absar, gbedwell, jrtc27, mgrang, atanasyan, steven_wu, george.burgess.iv, dexonsmith, kristina, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D52573

llvm-svn: 343163
2018-09-27 02:13:45 +00:00
Tim Shen
7a93f1342e [LSR] If no Use is interesting, early return.
Summary:
By looking at the callers of getUse(), we can see that even though
IVUsers may offer uses, but they may not be interesting to
LSR. It's possible that none of them is interesting.

Reviewers: sanjoy

Subscribers: jlebar, hiraditya, bixia, llvm-commits

Differential Revision: https://reviews.llvm.org/D49049

llvm-svn: 337072
2018-07-13 23:40:00 +00:00
Hiroshi Inoue
51b6fc883d [NFC] fix trivial typos in comments
llvm-svn: 334687
2018-06-14 05:41:49 +00:00
Daniil Fukalov
59789f7759 reapply r334209 with fixes for harfbuzz in Chromium
r334209 description:
[LSR] Check yet more intrinsic pointer operands

the patch fixes another assertion in isLegalUse()

Differential Revision: https://reviews.llvm.org/D47794

llvm-svn: 334300
2018-06-08 16:22:52 +00:00
Reid Kleckner
6f69900d44 Revert r334209 "[LSR] Check yet more intrinsic pointer operands"
This causes cast failures when compiling harfbuzz in Chromium.
Reproducer on the way.

llvm-svn: 334254
2018-06-08 00:43:27 +00:00
Daniil Fukalov
debbd7365f [LSR] Check yet more intrinsic pointer operands
the patch fixes another assertion in isLegalUse()

Differential Revision: https://reviews.llvm.org/D47794

llvm-svn: 334209
2018-06-07 17:30:58 +00:00
David Blaikie
93054c1e87 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Evgeny Stupachenko
1fcb36773e Fix LSR compile time hang.
Summary:
Limit number of reassociations in GenerateReassociationsImpl.

Reviewers: qcolombet, mkazantsev

Differential Revision: https://reviews.llvm.org/D46039

From: Evgeny Stupachenko <evstupac@gmail.com>
                         <evgeny.v.stupachenko@intel.com>
llvm-svn: 332426
2018-05-16 02:48:50 +00:00
Nicola Zaghen
9667127c14 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Adrian Prantl
076a6683eb Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Nico Weber
fcf0230e34 IWYU for llvm-config.h in llvm, additions.
See r331124 for how I made a list of files missing the include.
I then ran this Python script:

    for f in open('filelist.txt'):
        f = f.strip()
        fl = open(f).readlines()

        found = False
        for i in xrange(len(fl)):
            p = '#include "llvm/'
            if not fl[i].startswith(p):
                continue
            if fl[i][len(p):] > 'Config':
                fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
                found = True
                break
        if not found:
            print 'not found', f
        else:
            open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184
2018-04-30 14:59:11 +00:00
Mandeep Singh Grang
4e39759fa1 [Transforms] Change std::sort to llvm::sort in response to r327219
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.

Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.

Reviewers: kcc, pcc, danielcdh, jmolloy, sanjoy, dberlin, ruiu

Reviewed By: ruiu

Subscribers: ruiu, llvm-commits

Differential Revision: https://reviews.llvm.org/D45142

llvm-svn: 330059
2018-04-13 19:47:57 +00:00
David Blaikie
2efa3f569e Transforms: Introduce Transforms/Utils.h rather than spreading the declarations amongst Scalar.h and IPO.h
Fixes layering - Transforms/Utils shouldn't depend on including a Scalar
or IPO header, because Scalar and IPO depend on Utils.

llvm-svn: 328717
2018-03-28 17:44:36 +00:00
Krzysztof Parzyszek
bd36a69b34 [LSR] Allow giving priority to post-incrementing addressing modes
Implement TTI interface for targets to indicate that the LSR should give
priority to post-incrementing addressing modes.

Combination of patches by Sebastian Pop and Brendon Cahoon.

Differential Revision: https://reviews.llvm.org/D44758

llvm-svn: 328490
2018-03-26 13:10:09 +00:00
David Blaikie
a9b82b5ec4 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Adam Nemet
daee4e2694 Revert "[LSR] Avoid UB overflow when examining reuse opportunities"
This reverts commit r324943.

Breaking bots, reverting for Gerolf.

llvm-svn: 324958
2018-02-12 22:42:13 +00:00
Gerolf Hoflehner
c74d0ab4e8 [LSR] Avoid UB overflow when examining reuse opportunities
llvm-svn: 324943
2018-02-12 21:49:32 +00:00
Sanjay Patel
a19541c05c [LoopStrengthReduce, x86] don't add cost for a cmp that will be macro-fused (PR35681)
In the motivating case from PR35681 and represented by the macro-fuse-cmp test:
https://bugs.llvm.org/show_bug.cgi?id=35681
...there's a 37 -> 31 byte size win for the loop because we eliminate the big base 
address offsets.

SPEC2017 on Ryzen shows no significant perf difference.

Differential Revision: https://reviews.llvm.org/D42607

llvm-svn: 324289
2018-02-05 23:43:05 +00:00