Commit Graph

26388 Commits

Author SHA1 Message Date
Puyan Lotfi 3ea6b24f41 [MIR-Canon] Don't do vreg skip for independent instructions if there are none.
We don't want to create vregs if there is nothing to use them for. That causes
verifier errors.

Differential Revision: https://reviews.llvm.org/D62740

llvm-svn: 362247
2019-05-31 17:34:25 +00:00
Kevin P. Neal ac79007205 Revert revert of r362112 with minor SystemZ test file corrections.
[FPEnv] Added a special UnrollVectorOp method to deal with the chain on StrictFP opcodes

This change creates UnrollVectorOp_StrictFP. The purpose of this is to address a failure that consistently occurs when calling StrictFP functions on vectors whose number of elements is 3 + 2n on most platforms, such as PowerPC or SystemZ. The old UnrollVectorOp method does not expect that the vector that it will unroll will have a chain, so it has an assert that prevents it from running if this is the case. This new StrictFP version of the method deals with the chain while unrolling the vector. With this new function in place during vector widending, llc can run vector-constrained-fp-intrinsics.ll for SystemZ successfully.

Submitted by:	Drew Wock <drew.wock@sas.com>
Reviewed by:	Cameron McInally, Kevin P. Neal
Approved by:	Cameron McInally
Differential Revision:	https://reviews.llvm.org/D62546

llvm-svn: 362241
2019-05-31 16:32:12 +00:00
Jinsong Ji 18e7bf5c4d [MachinePipeliner][NFC] Add some debug log and statistics
This is to add some log and statistics for debugging

Differential Revision: https://reviews.llvm.org/D62165

llvm-svn: 362233
2019-05-31 15:35:19 +00:00
Puyan Lotfi 0d63cef180 [MIR-Canon] Skip the first N vreg names lazily.
This consolidates the vreg skip code into one function (SkipVRegs()).
SkipVRegs() now knows if it should skip as if it is the first initialization or
subsequent skips.

The first skip is also done the first time createVirtualRegister is called by
the cursor instead of by the cursor's constructor. This prevents verifier
errors on machine functions that have no vregs (where the verifier will
complain that there are vregs when the function uses none).

Differential Revision: https://reviews.llvm.org/D62717

llvm-svn: 362195
2019-05-31 06:02:38 +00:00
Puyan Lotfi 2a901401fe [MIR-Canon] Hardening propagateLocalCopies.
This is am almost NFC, it does the following:
- If there is no register class for a COPY's src or dst, bail.
- Fixes uses iterator invalidation bug.

Differential Revision: https://reviews.llvm.org/D62713

llvm-svn: 362191
2019-05-31 04:49:58 +00:00
Matt Arsenault 18659f84b2 MISched: Fix -misched-regpressure=0 if subreg liveness enabled
Test is waiting on fixing several more crashes in the AMDGPU scheduler
implementation with this.

llvm-svn: 362174
2019-05-30 23:31:36 +00:00
Francis Visoiu Mistrih 6ada11f134 [Remarks][NFC] Move the serialization to lib/Remarks
Separate the remark serialization to YAML from the LLVM Diagnostics.

This adds a new serialization abstraction: remarks::Serializer. It's
completely independent from lib/IR and it provides an easy way to
replace YAML by providing a new remarks::Serializer.

Differential Revision: https://reviews.llvm.org/D62632

llvm-svn: 362160
2019-05-30 21:45:59 +00:00
Puyan Lotfi daaecf98c9 [MIR-Canon] Fixing case where MachineFunction is empty.
In cases where the machine function is empty: bail on the RPO traversal.

Differential Revision: https://reviews.llvm.org/D62617

llvm-svn: 362158
2019-05-30 21:37:25 +00:00
Roman Lebedev 46511d75b5 [DAGCombine] Limit 'hoist add/sub binop w/ constant op' to non-opaque consts
I don't have a test case for these, but there is a test case for D62266
where, even after all the constant-folding patches, we still end up
with endless combine loop. Which makes sense, since we don't constant
fold for opaque constants.

llvm-svn: 362156
2019-05-30 21:10:37 +00:00
Roman Lebedev a4e3b50e26 [DAGCombiner][X86][AArch64] (x - C) + y -> (x + y) - C fold. Try 2
Summary:
Only vector tests are being affected here,
since subtraction by scalar constant is rewritten
as addition by negated constant.

No surprising test changes.

https://rise4fun.com/Alive/pbT

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs.

Reviewers: RKSimon, craig.topper, spatel

Reviewed By: RKSimon

Subscribers: javed.absar, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62257

llvm-svn: 362146
2019-05-30 20:37:49 +00:00
Roman Lebedev 57aa36ff91 [DAGCombine] (x - C) - y -> (x - y) - C fold. Try 3
Summary:
Again only vectors affected. Frustrating. Let me take a look into that..

https://rise4fun.com/Alive/AAq

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.

Reviewers: RKSimon, craig.topper, spatel

Reviewed By: RKSimon

Subscribers: javed.absar, JDevlieghere, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62294

llvm-svn: 362145
2019-05-30 20:37:39 +00:00
Roman Lebedev 63b4741534 [DAGCombine][X86][AArch64][AMDGPU] (x - y) + -1 -> add (xor y, -1), x fold. Try 3
Summary:
This prevents regressions in next patch,
and somewhat recovers from the regression to AMDGPU test in D62223.

It is indeed not great that we leave vector decrement,
don't transform it into vector add all-ones..

https://rise4fun.com/Alive/ZRl

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.

Reviewers: RKSimon, craig.topper, spatel, arsenm

Reviewed By: RKSimon, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62263

llvm-svn: 362144
2019-05-30 20:37:29 +00:00
Roman Lebedev 05ad5fd213 [DAGCombiner][X86][AArch64][SPARC][SystemZ] y - (x + C) -> (y - x) - C fold. Try 3
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?

The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`

https://rise4fun.com/Alive/ffh

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.

Reviewers: RKSimon, craig.topper, spatel, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62252

llvm-svn: 362143
2019-05-30 20:37:18 +00:00
Roman Lebedev 1d9ec7a81b [DAGCombiner][X86][AArch64][AMDGPU] (x + C) - y -> (x - y) + C fold. Try 3
Summary:
The main motivation is shown by all these `neg` instructions that are now created.
In particular, the `@reg32_lshr_by_negated_unfolded_sub_b` test.

AArch64 test changes all look good (`neg` created), or neutral.

X86 changes look neutral (vectors), or good (`neg` / `xor eax, eax` created).

I'm not sure about `X86/ragreedy-hoist-spill.ll`, it looks like the spill
is now hoisted into preheader (which should still be good?),
2 4-byte reloads become 1 8-byte reload, and are elsewhere,
but i'm not sure how that affects that loop.

I'm unable to interpret AMDGPU change, looks neutral-ish?

This is hopefully a step towards solving [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/pkdq (we are missing more patterns, i'll submit them later)

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs, and then reverted in
rL362109 to fix missing constant folds that were causing
endless combine loops.

Reviewers: craig.topper, RKSimon, spatel, arsenm

Reviewed By: RKSimon

Subscribers: bjope, qcolombet, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62223

llvm-svn: 362142
2019-05-30 20:36:54 +00:00
Roman Lebedev 7eb8b5b5dd [DAGCombine] ((c1-A)-c2) -> ((c1-c2)-A) constant-fold
Summary: https://rise4fun.com/Alive/B0A

Reviewers: t.p.northover, RKSimon, spatel, craig.topper

Reviewed By: RKSimon

Subscribers: javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62691

llvm-svn: 362135
2019-05-30 19:27:51 +00:00
Roman Lebedev 691b5e2ecc [DAGCombine] (A-C1)-C2 -> A-(C1+C2) constant-fold
Summary: https://rise4fun.com/Alive/Mb1M

Reviewers: RKSimon, craig.topper, spatel, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62689

llvm-svn: 362134
2019-05-30 19:27:42 +00:00
Roman Lebedev 0a3dbbcdfb [DAGCombine] (A+C1)-C2 -> A+(C1-C2) constant-fold
Summary:
Direct sibling of D62662, the root cause of the endless combine loop in D62257

https://rise4fun.com/Alive/d3W

Reviewers: RKSimon, craig.topper, spatel, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62664

llvm-svn: 362133
2019-05-30 19:27:32 +00:00
Roman Lebedev 9ff3159b4a [DAGCombine] Use FoldConstantArithmetic() to perform C2-(A+C1) -> (C2-C1)-A fold
Summary:
No tests change, and i'm not sure how to test this, but it's better safe than sorry.

Reviewers: spatel, RKSimon, craig.topper, t.p.northover

Reviewed By: craig.topper

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62663

llvm-svn: 362132
2019-05-30 19:27:26 +00:00
Roman Lebedev cc9a9cf237 [DAGCombine] ((A-c1)+c2) -> (A+(c2-c1)) constant-fold
Summary:
This was the root cause of the endless combine loop in D62257

https://rise4fun.com/Alive/d3W

Reviewers: RKSimon, spatel, craig.topper, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62662

llvm-svn: 362131
2019-05-30 19:27:19 +00:00
Roman Lebedev ef95679741 [DAGCombine] Use FoldConstantArithmetic() to perform ((c1-A)+c2) -> (c1+c2)-A fold
Summary: No tests change, and i'm not sure how to test this, but it's better safe than sorry.

Reviewers: spatel, RKSimon, craig.topper, t.p.northover

Reviewed By: craig.topper

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62661

llvm-svn: 362130
2019-05-30 19:27:10 +00:00
Tim Northover b7141207a4 Reapply: IR: add optional type to 'byval' function parameters
When we switch to opaque pointer types we will need some way to describe
how many bytes a 'byval' parameter should occupy on the stack. This adds
a (for now) optional extra type parameter.

If present, the type must match the pointee type of the argument.

The original commit did not remap byval types when linking modules, which broke
LTO. This version fixes that.

Note to front-end maintainers: if this causes test failures, it's probably
because the "byval" attribute is printed after attributes without any parameter
after this change.

llvm-svn: 362128
2019-05-30 18:48:23 +00:00
Puyan Lotfi 0f4446b270 [MIR-Canon] Add support for rewriting VRegs that are typed but don't have an RC.
There were crashes (addrspace-memoperands.mir was only one of them) in MIR that
had operands that came from before register classes were set. With these
operands, creating a replacement vreg (for MIR-Canon's renaming) needs to use
the vreg type rather than the RegisterClass which is not present.

Differential Revision: https://reviews.llvm.org/D62543

llvm-svn: 362122
2019-05-30 18:06:28 +00:00
Kevin P. Neal 51ce0b196a Correct error in revert of r362112.
Differential Revision:	http://reviews.llvm.org/D62546

llvm-svn: 362118
2019-05-30 17:21:45 +00:00
Kevin P. Neal d3db7b40b0 Revert r362112, it broke the bots with the message "Unsupported vector argument or return type"
Differential Revision:	http://reviews.llvm.org/D62546

llvm-svn: 362117
2019-05-30 17:10:21 +00:00
Kevin P. Neal 2e1807678d [FPEnv] Added a special UnrollVectorOp method to deal with the chain on StrictFP opcodes
This change creates UnrollVectorOp_StrictFP. The purpose of this is to address a failure that consistently occurs when calling StrictFP functions on vectors whose number of elements is 3 + 2n on most platforms, such as PowerPC or SystemZ. The old UnrollVectorOp method does not expect that the vector that it will unroll will have a chain, so it has an assert that prevents it from running if this is the case. This new StrictFP version of the method deals with the chain while unrolling the vector. With this new function in place during vector widending, llc can run vector-constrained-fp-intrinsics.ll for SystemZ successfully.

Submitted by:	Drew Wock <drew.wock@sas.com>
Reviewed by:	Cameron McInally, Kevin P. Neal
Approved by:	Cameron McInally
Differential Revision:	http://reviews.llvm.org/D62546

llvm-svn: 362112
2019-05-30 16:44:47 +00:00
Roman Lebedev 019d270e43 [DAGCombine] Revert of recommit of "binop-with-const hoisting" patches
I was looking into an endless combine loop the uncommitted follow-up patch
was causing, and it appears even these patches can exibit such an
endless loop. The root cause is that we try to hoist one binop (add/sub) with
constant operand, and if we get two such binops both of which are
eligible for this hoisting, we get stuck.

Some cases may highlight missing constant-folds.

Reverts r361871,r361872,r361873,r361874.

llvm-svn: 362109
2019-05-30 16:07:11 +00:00
Amy Huang 325003be02 CodeView - add static data members to global variable debug info.
Summary:
Add static data members to IR debug info's list of global variables
so that they are emitted as S_CONSTANT records.

Related to https://bugs.llvm.org/show_bug.cgi?id=41615.

Reviewers: rnk

Subscribers: aprantl, cfe-commits, llvm-commits, thakis

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D62167

llvm-svn: 362038
2019-05-29 21:45:34 +00:00
Tim Northover 71ee3d0237 Revert "IR: add optional type to 'byval' function parameters"
The IRLinker doesn't delve into the new byval attribute when mapping types, and
this breaks LTO.

llvm-svn: 362029
2019-05-29 20:46:38 +00:00
Benjamin Kramer 107f8d9873 [DAGCombiner] Replace gathers with a zero mask with the passthru value
These can be created by the legalizer when splitting a larger gather.

See https://llvm.org/PR42055 for a motivating example.

Differential Revision: https://reviews.llvm.org/D62613

llvm-svn: 362015
2019-05-29 19:24:19 +00:00
Tim Northover 6e07f16fae IR: add optional type to 'byval' function parameters
When we switch to opaque pointer types we will need some way to describe
how many bytes a 'byval' parameter should occupy on the stack. This adds
a (for now) optional extra type parameter.

If present, the type must match the pointee type of the argument.

Note to front-end maintainers: if this causes test failures, it's probably
because the "byval" attribute is printed after attributes without any parameter
after this change.

llvm-svn: 362012
2019-05-29 19:12:48 +00:00
Sam McCall 4f09d9fcfa Qualify use of llvm::empty that's ambiguous with std::empty
llvm-svn: 361968
2019-05-29 15:02:16 +00:00
Richard Trieu c77aff7e17 Inline a variable into debug section to fix unused variable warning.
llvm-svn: 361927
2019-05-29 04:09:32 +00:00
Richard Trieu e8698ead9d Inline value into debug statement to avoid unused variable warning.
llvm-svn: 361924
2019-05-29 03:43:01 +00:00
Peter Collingbourne 31fda09b2d Add IR support, ELF section and user documentation for partitioning feature.
The partitioning feature was proposed here:
http://lists.llvm.org/pipermail/llvm-dev/2019-February/130583.html

This is mostly just documentation. The feature itself will be contributed
in subsequent patches.

Differential Revision: https://reviews.llvm.org/D60242

llvm-svn: 361923
2019-05-29 03:29:01 +00:00
Jinsong Ji f6cb3bcb4c Support resource tracking with InstrSchedModel
The current design use DFA to do resource tracking in SMS,
and DFA only support InstrItins, and also has scaling limitation.

This patch extend SMS to allow Subtarget to use ProcResource in
InstrSchedModel instead.

Differential Revision: https://reviews.llvm.org/D62163

llvm-svn: 361919
2019-05-29 03:02:59 +00:00
Pengfei Wang 72e3f9662b Revert "[X86] Use 'llvm_unreachable' instead of nullptr in unreachable code to"
This reverts commit c1b3716614bc0a107e6f41a7d3d503baefad8a5b.

llvm-svn: 361918
2019-05-29 02:49:59 +00:00
Pengfei Wang 818c652643 [X86] Use 'llvm_unreachable' instead of nullptr in unreachable code to
avoid static check fail

RegClassOrBank is an object of RegClassOrRegBank, which is defined as
using llvm::RegClassOrRegBank = typedef PointerUnion<const
TargetRegisterClass *, const RegisterBank *>
so control flow can not get here. Use ""llvm_unreachable" here to avoid
"null pointer" confusion.

Patch by Shengchen Kan (skan)

Differential Revision: https://reviews.llvm.org/D62006

Signed-off-by: pengfei <pengfei.wang@intel.com>
llvm-svn: 361912
2019-05-29 02:20:37 +00:00
Quentin Colombet a6f57ad2c9 [RegUsageInfoCollector] Don't mark as saved registers that don't have subregister lanes
To determine the list of clobbered registers, the RegUsageInfoCollector pass
uses the list of callee saved registers provided by the target and then augments
it with the list of registers which have all their subregisters saved. It then
basically does the difference between all the registers and the saved registers
to come up with what is clobbered (plus it checks that the register is defined
within that functions).

The patch fixes a bug where when register does not have any subregister lane,
hence when checking if any of its subregister are not saved, we would find none
and think the register is saved as well.

That's obviously wrong.

The code was actually kind of checking for something like that with the
CoveredBySubRegs bit. What this bit says is that a register is completely
covered by its subregisters.
We required that this bit was set, to check that a register was saved by its
subregister lanes, since without this bit, we potentially would miss to check
some part of the register.

However, this bit is used de facto on registers that don't have any
subregisters (e.g., on ARM) and the code was not prepared for that.

This patch fixes this by checking that a register has subregisters before
declaring it saved when none of its lanes are modified.

llvm-svn: 361901
2019-05-28 23:43:12 +00:00
Adhemerval Zanella 6d7bf5e8df [CodeGen] Add lrint/llrint builtins
This patch add the ISD::LRINT and ISD::LLRINT along with new
intrinsics.  The changes are straightforward as for other
floating-point rounding functions, with just some adjustments
required to handle the return value being an interger.

The idea is to optimize lrint/llrint generation for AArch64
in a subsequent patch.  Current semantic is just route it to libm
symbol.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D62017

llvm-svn: 361875
2019-05-28 20:47:44 +00:00
Roman Lebedev dfc34f0211 [DAGCombine] (x - C) - y -> (x - y) - C fold. Try 2
Summary:
Again only vectors affected. Frustrating. Let me take a look into that..

https://rise4fun.com/Alive/AAq

This is a recommit, originally committed in rL361856, but reverted
to investigate test-suite compile-time hangs.

Reviewers: RKSimon, craig.topper, spatel

Reviewed By: RKSimon

Subscribers: javed.absar, JDevlieghere, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62294

llvm-svn: 361874
2019-05-28 20:40:10 +00:00
Roman Lebedev d485c6bc9f [DAGCombine][X86][AArch64][AMDGPU] (x - y) + -1 -> add (xor y, -1), x fold. Try 2
Summary:
This prevents regressions in next patch,
and somewhat recovers from the regression to AMDGPU test in D62223.

It is indeed not great that we leave vector decrement,
don't transform it into vector add all-ones..

https://rise4fun.com/Alive/ZRl

This is a recommit, originally committed in rL361855, but reverted
to investigate test-suite compile-time hangs.

Reviewers: RKSimon, craig.topper, spatel, arsenm

Reviewed By: RKSimon, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62263

llvm-svn: 361873
2019-05-28 20:40:03 +00:00
Roman Lebedev 96c9986199 [DAGCombiner][X86][AArch64][SPARC][SystemZ] y - (x + C) -> (y - x) - C fold. Try 2
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?

The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`

https://rise4fun.com/Alive/ffh

This is a recommit, originally committed in rL361853, but reverted
to investigate test-suite compile-time hangs.

Reviewers: RKSimon, craig.topper, spatel, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62252

llvm-svn: 361872
2019-05-28 20:39:55 +00:00
Roman Lebedev 2feb7e56e2 [DAGCombiner][X86][AArch64][AMDGPU] (x + C) - y -> (x - y) + C fold. Try 2
Summary:
The main motivation is shown by all these `neg` instructions that are now created.
In particular, the `@reg32_lshr_by_negated_unfolded_sub_b` test.

AArch64 test changes all look good (`neg` created), or neutral.

X86 changes look neutral (vectors), or good (`neg` / `xor eax, eax` created).

I'm not sure about `X86/ragreedy-hoist-spill.ll`, it looks like the spill
is now hoisted into preheader (which should still be good?),
2 4-byte reloads become 1 8-byte reload, and are elsewhere,
but i'm not sure how that affects that loop.

I'm unable to interpret AMDGPU change, looks neutral-ish?

This is hopefully a step towards solving [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/pkdq (we are missing more patterns, i'll submit them later)

This is a recommit, originally committed in rL361852, but reverted
to investigate test-suite compile-time hangs.

Reviewers: craig.topper, RKSimon, spatel, arsenm

Reviewed By: RKSimon

Subscribers: bjope, qcolombet, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62223

llvm-svn: 361871
2019-05-28 20:39:39 +00:00
Roman Lebedev 272d70c366 Revert DAGCombine "hoist binop with const" folds
Appear to introduce test-suite compile-time hang.

http://lab.llvm.org:8011/builders/clang-cmake-x86_64-sde-avx512-linux/builds/22825

This reverts r361852,r361853,r361854,r361855,r361856

llvm-svn: 361865
2019-05-28 19:04:21 +00:00
Roman Lebedev 7669665432 [DAGCombine] (x - C) - y -> (x - y) - C fold
Summary:
Again only vectors affected. Frustrating. Let me take a look into that..

https://rise4fun.com/Alive/AAq

Reviewers: RKSimon, craig.topper, spatel

Reviewed By: RKSimon

Subscribers: javed.absar, JDevlieghere, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62294

llvm-svn: 361856
2019-05-28 17:54:21 +00:00
Roman Lebedev 8c9b3e4e4a [DAGCombine][X86][AArch64][AMDGPU] (x - y) + -1 -> add (xor y, -1), x fold
Summary:
This prevents regressions in next patch,
and somewhat recovers from the regression to AMDGPU test in D62223.

It is indeed not great that we leave vector decrement,
don't transform it into vector add all-ones..

https://rise4fun.com/Alive/ZRl

Reviewers: RKSimon, craig.topper, spatel, arsenm

Reviewed By: RKSimon, arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62263

llvm-svn: 361855
2019-05-28 17:54:13 +00:00
Roman Lebedev 6a24c9b9ab [DAGCombiner][X86][AArch64] (x - C) + y -> (x + y) - C fold
Summary:
Only vector tests are being affected here,
since subtraction by scalar constant is rewritten
as addition by negated constant.

No surprising test changes.

https://rise4fun.com/Alive/pbT

Reviewers: RKSimon, craig.topper, spatel

Reviewed By: RKSimon

Subscribers: javed.absar, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62257

llvm-svn: 361854
2019-05-28 17:54:04 +00:00
Roman Lebedev 1499f65ac1 [DAGCombiner][X86][AArch64][SPARC][SystemZ] y - (x + C) -> (y - x) - C fold
Summary:
Direct sibling of D62223 patch.
While i don't have a direct motivational pattern for this,
it would seem to make sense to handle both patterns (or none),
for symmetry?

The aarch64 changes look neutral;
sparc and systemz look like improvement (one less instruction each);
x86 changes - 32bit case improves, 64bit case shows that LEA no longer
gets constructed, which may be because that whole test is `-mattr=+slow-lea,+slow-3ops-lea`

https://rise4fun.com/Alive/ffh

Reviewers: RKSimon, craig.topper, spatel, t.p.northover

Reviewed By: t.p.northover

Subscribers: t.p.northover, jyknight, javed.absar, kristof.beyls, fedor.sergeev, jrtc27, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62252

llvm-svn: 361853
2019-05-28 17:53:54 +00:00
Roman Lebedev 19f51ec04a [DAGCombiner][X86][AArch64][AMDGPU] (x + C) - y -> (x - y) + C fold
Summary:
The main motivation is shown by all these `neg` instructions that are now created.
In particular, the `@reg32_lshr_by_negated_unfolded_sub_b` test.

AArch64 test changes all look good (`neg` created), or neutral.

X86 changes look neutral (vectors), or good (`neg` / `xor eax, eax` created).

I'm not sure about `X86/ragreedy-hoist-spill.ll`, it looks like the spill
is now hoisted into preheader (which should still be good?),
2 4-byte reloads become 1 8-byte reload, and are elsewhere,
but i'm not sure how that affects that loop.

I'm unable to interpret AMDGPU change, looks neutral-ish?

This is hopefully a step towards solving [[ https://bugs.llvm.org/show_bug.cgi?id=41952 | PR41952 ]].

https://rise4fun.com/Alive/pkdq (we are missing more patterns, i'll submit them later)

Reviewers: craig.topper, RKSimon, spatel, arsenm

Reviewed By: RKSimon

Subscribers: bjope, qcolombet, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, javed.absar, dstuttard, tpr, t-tye, kristof.beyls, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62223

llvm-svn: 361852
2019-05-28 17:53:43 +00:00
Simon Pilgrim 9cd9624fb6 [DAG] LegalizeVectorTypes - reduce scope of local variables. NFCI.
Move the element index/count variables into the block where they are actually used - appeases cppcheck and helps avoid shadow variable warnings.

llvm-svn: 361821
2019-05-28 13:46:26 +00:00