Summary:
Theoretically this was done to simplify the amount of isel patterns that were needed. But it also meant a substantial number of our isel patterns have to match an explicit bitcast. By making the vXi32/vXi16/vXi8 types legal for loads, DAG combiner should be able to change the load type to remove the bitcast.
I had to add some additional plain load instruction patterns and a few other special cases, but overall the isel table has reduced in size by ~12000 bytes. So it looks like this promotion was hurting us more than helping.
I still have one crash in vector-trunc.ll that I'm hoping @RKSimon can help with. It seems to relate to using getTargetConstantFromNode on a load that was shrunk due to an extract_subvector combine after the constant pool entry was created. So we end up decoding more mask elements than the load size.
I'm hoping this patch will simplify the number of patterns needed to remove the and/or/xor promotion.
Reviewers: RKSimon, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits, RKSimon
Differential Revision: https://reviews.llvm.org/D53306
llvm-svn: 344877
These included a bitcast of a load from v4f32 to v2f64, but DAG combine should have already changed the type of the load to remove the cast.
llvm-svn: 344573
Currently we hardcode instructions with ReadAfterLd if the register operands don't need to be available until the folded load has completed. This doesn't take into account the different load latencies of different memory operands (PR36957).
This patch adds a ReadAfterFold def into X86FoldableSchedWrite to replace ReadAfterLd, allowing us to specify the load latency at a scheduler class level.
I've added ReadAfterVec*Ld classes that match the XMM/Scl, XMM and YMM/ZMM WriteVecLoad classes that we currently use, we can tweak these values in future patches once this infrastructure is in place.
Differential Revision: https://reviews.llvm.org/D52886
llvm-svn: 343868
This removes an int->fp bitcast between the surrounding code and the movmsk. I had already added a hack to combineMOVMSK to try to look through this bitcast to improve the SimplifyDemandedBits there.
But I found an additional issue where the bitcast was preventing combineMOVMSK from being called again after earlier nodes in the DAG are optimized. The bitcast gets revisted, but not the user of the bitcast. By using integer types throughout, the bitcast doesn't get in the way.
llvm-svn: 343046
In r337348, I changed lowering to prefer X86ISD::UNPCKL/UNPCKH opcodes over MOVLHPS/MOVHLPS for v2f64 {0,0} and {1,1} shuffles when we have SSE2. This enabled the removal of a bunch of weirdly bitcasted isel patterns in r337349. To avoid changing the tests I placed a gross hack in isel to still emit movhlps instructions for fake unary unpckh nodes. A similar hack was not needed for unpckl and movlhps because we do execution domain switching for those. But unpckh and movhlps have swapped operand order.
This patch removes the hack.
This is a code size increase since unpckhpd requires a 0x66 prefix and movhlps does not. But if that's a big concern we should be using movhlps for all unpckhpd opcodes and let commuteInstruction turnit into unpckhpd when its an advantage.
Differential Revision: https://reviews.llvm.org/D49499
llvm-svn: 341973
A ReadAdvance was incorrectly added to the SchedReadWrite list associated with
the following SSE instructions:
sqrtss
sqrtsd
rsqrtss
rcpss
As a consequence, a wrong operand latency was computed for the register operand
used as the base address of the folded load operand.
This patch removes the wrong ReadAdvance, and updates the llvm-mca test cases.
There is still a problem with correctly modeling partial register writes on XMM
registers This other problem is currently tracked here:
https://bugs.llvm.org/show_bug.cgi?id=38813
Differential Revision: https://reviews.llvm.org/D51542
llvm-svn: 341326
Summary:
Previously the value being stored is the last operand in SDNode. This causes the type legalizer to visit the mask operand before the value operand. The type legalizer was more complicated because of this since we want the type of the value to drive the decisions.
This patch moves the value to be the first operand so we visit it first during type legalization. It also simplifies the type legalization code accordingly.
X86 is currently the only in tree target that uses this SDNode. Not sure if there are any users out of tree.
Reviewers: RKSimon, delena, hfinkel, eli.friedman
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50402
llvm-svn: 340689
AVX512 added new versions of these intrinsics that take a rounding mode. If the rounding mode is 4 the new intrinsics are equivalent to the old intrinsics.
The AVX512 intrinsics were being lowered to ISD opcodes, but the legacy SSE intrinsics were left as intrinsics. This resulted in the AVX512 instructions needing separate patterns for the ISD opcodes and the legacy SSE intrinsics.
Now we convert SSE intrinsics and AVX512 intrinsics with rounding mode 4 to the same ISD opcode so we can share the isel patterns.
llvm-svn: 339749
Move all the patterns to X86InstrVecCompiler.td so we can keep SSE/AVX/AVX512 all in one place.
To save some patterns we'll use an existing DAG combine to convert f128 fand/for/fxor to integer when sse2 is enabled. This allows use to reuse all the existing patterns for v2i64.
I believe this now makes SHA instructions the only case where VEX/EVEX and legacy encoded instructions could be generated simultaneously.
llvm-svn: 338821
Ideally our ISD node types going into the isel table would have types consistent with their instruction domain. This prevents us having to duplicate patterns with different types for the same instruction.
Unfortunately, it seems our shuffle combining is currently relying on this a little remove some bitcasts. This seems to enable some switching between shufps and shufd. Hopefully there's some way we can address this in the combining.
Differential Revision: https://reviews.llvm.org/D49280
llvm-svn: 337590
The X86ISD::MOVLHPS/MOVHLPS should now only be emitted in SSE1 only. This means that the v2i64/v2f64 types would be illegal thus we don't need these patterns.
llvm-svn: 337349
I'm trying to restrict the MOVLHPS/MOVHLPS ISD nodes to SSE1 only. With SSE2 we can use unpcks. I believe this will allow some patterns to be cleaned up to require fewer bitcasts.
I've put in an odd isel hack to still select MOVHLPS instruction from the unpckh node to avoid changing tests and because movhlps is a shorter encoding. Ideally we'd do execution domain switching on this, but the operands are in the wrong order and are tied. We might be able to try a commute in the domain switching using custom code.
We already support domain switching for UNPCKLPD and MOVLHPS.
llvm-svn: 337348
Previously we passed 'null_frag' into the instruction definition. The multiclass is shared with MOVHPD which doesn't use null_frag. It turns out by passing X86Movsd it produces patterns equivalent to some standalone patterns.
llvm-svn: 337299
This unfortunately requires a bunch of bitcasts to be added added to SUBREG_TO_REG, COPY_TO_REGCLASS, and instructions in output patterns. Otherwise tablegen seems to default to picking f128 and then we fail when something tries to get the register class for f128 which isn't always valid.
The test changes are because we were previously mixing fr128 and vr128 due to contrainRegClass finding FR128 first and passes like live range shrinking weren't handling that well.
llvm-svn: 337147
128-bit ops implicitly zero the upper bits. This should address the comment about domain crossing for the integer version without AVX2 since we can use a 128-bit VBLENDW without AVX2.
The only bad thing I see here is that we failed to reuse an vxorps in some of the tests, but I think that's already known issue.
llvm-svn: 337134
AVX512 doesn't have an immediate controlled blend instruction. But blend throughput is still better than movss/sd on SKX.
This commit changes AVX512 to use the AVX blend instructions instead of MOVSS/MOVSD. This constrains the register allocation since it won't be able to use XMM16-31, but hopefully the increased throughput and reduced port 5 pressure makes up for that.
llvm-svn: 337083
These were supposed to be integer types since we are selecting integer instructions.
Found while preparing to remove these patterns for another patch.
llvm-svn: 337057
Previously we iseled to blend, commuted to another blend, and then commuted back to movss/movsd or blend depending on optsize. Now we do it directly.
llvm-svn: 336976
This is not an optimization we should be doing in isel. This is more suitable for a DAG combine.
My main concern is a future time when we support more FPENV. Changing a packed op to a scalar op could cause us to miss some exceptions that should have occured if we had done a packed op. A DAG combine would be better able to manage this.
llvm-svn: 336971
Before revision 336728, the "mayLoad" flag for instruction (V)MOVLPSrm was
inferred directly from the "default" pattern associated with the instruction
definition.
r336728 removed special node X86Movlps, and all the patterns associated to it.
Now instruction (V)MOVLPSrm doesn't have a pattern associated to it, and the
'mayLoad/hasSideEffects' flags are left unset.
When the instruction info is emitted by tablegen, method
CodeGenDAGPatterns::InferInstructionFlags() sees that (V)MOVLPSrm doesn't have a
pattern, and flags are undefined. So, it conservatively sets the
"hasSideEffects" flag for it.
As a consequence, we were losing the 'mayLoad' flag, and we were gaining a
'hasSideEffect' flag in its place.
This patch fixes the issue (originally reported by Michael Holmen).
The mca tests show the differences in the instruction info flags. Instructions
that were affected by this problem were: MOVLPSrm/VMOVLPSrm/VMOVLPSZ128rm.
Differential Revision: https://reviews.llvm.org/D49182
llvm-svn: 336818
These patterns looked for a MOVSS/SD followed by a scalar_to_vector. Or a scalar_to_vector followed by a load.
In both cases we emitted a MOVSS/SD for the MOVSS/SD part, a REG_CLASS for the scalar_to_vector, and a MOVSS/SD for the load.
But we have patterns that do each of those 3 things individually so there's no reason to build large patterns.
Most of the test changes are just reorderings. The one test that had a meaningful change is pr30430.ll and it appears to be a regression. But its doing -O0 so I think it missed a lot of opportunities and was just getting lucky before.
llvm-svn: 336762
Some added 20 and some added 15. Its unclear when to use which value and whether they are required at all.
This patch removes them all. If we start finding real world issues we may need to add them back with proper tests.
llvm-svn: 336735
These ISD nodes try to select the MOVLPS and MOVLPD instructions which are special load only instructions. They load data and merge it into the lower 64-bits of an XMM register. They are logically equivalent to our MOVSD node plus a load.
There was only one place in X86ISelLowering that used MOVLPD and no places that selected MOVLPS. The one place that selected MOVLPD had to choose between it and MOVSD based on whether there was a load. But lowering is too early to tell if the load can really be folded. So in isel we have patterns that use MOVSD for MOVLPD if we can't find a load.
We also had patterns that select the MOVLPD instruction for a MOVSD if we can find a load, but didn't choose the MOVLPD ISD opcode for some reason.
So it seems better to just standardize on MOVSD ISD opcode and manage MOVSD vs MOVLPD instruction with isel patterns.
llvm-svn: 336728
We're missing the EVEX equivalents of these patterns and seem to get along fine.
I think we end up with X86vzload for the obvious IR cases that would produce this DAG.
llvm-svn: 336638
These patterns mapped (v2f64 (X86vzmovl (v2f64 (scalar_to_vector FR64:$src)))) to a MOVSD and an zeroing XOR. But the complexity of a pattern for (v2f64 (X86vzmovl (v2f64))) that selects MOVQ is artificially and hides this MOVSD pattern.
Weirder still, the SSE version of the pattern was explicitly blocked on SSE41, but yet we had copied it to AVX and AVX512.
llvm-svn: 336556
It only existed on SSE and AVX version. AVX512 version didn't have it.
I checked the generated table and this didn't seem necessary to creat a match preference.
llvm-svn: 336516
Similarily, don't fold fp128 loads into SSE instructions if the load isn't aligned. Unless we're targeting an AMD CPU that doesn't check alignment on arithmetic instructions.
Should fix PR38001
llvm-svn: 336121
This patch handles back-end folding of generic patterns created by lowering the
X86 rounding intrinsics to native IR in cases where the instruction isn't a
straightforward packed values rounding operation, but a masked operation or a
scalar operation.
Differential Revision: https://reviews.llvm.org/D45203
llvm-svn: 335037
We already have these aliases for EVEX enocded instructions, but not for the GPR, MMX, SSE, and VEX versions.
Also remove the vpextrw.s EVEX alias. That's not something gas implements.
llvm-svn: 334922
Summary:
The tests in:
https://bugs.llvm.org/show_bug.cgi?id=37751
...show miscompiles because we wrongly mapped and folded x86-specific intrinsics into generic DAG nodes.
This patch corrects the mappings in X86IntrinsicsInfo.h and adds isel matching corresponding to the new patterns. The complete tests for the failure cases should be in avx-cvttp2si.ll and sse-cvttp2si.ll and avx512-cvttp2i.ll
Reviewers: RKSimon, gbedwell, spatel
Reviewed By: spatel
Subscribers: mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D47993
llvm-svn: 334685
We were missing packed isel folding patterns for all of sse41, avx, and avx512.
For some reason avx512 had scalar load folding patterns under optsize(due to partial/undef reg update), but we didn't have the equivalent sse41 and avx patterns.
Sometimes we would get load folding due to peephole pass anyway, but we're also missing avx512 instructions from the load folding table. I'll try to fix that in another patch.
Some of this was spotted in the review for D47993.
This patch adds all the folds to isel, adds a few spot tests, and disables the peephole pass on a few tests to ensure we're testing some of these patterns.
llvm-svn: 334460
Summary:
The new rules are straightforward. The main rules to keep in mind
are:
1. NAME is an implicit template argument of class and multiclass,
and will be substituted by the name of the instantiating def/defm.
2. The name of a def/defm in a multiclass must contain a reference
to NAME. If such a reference is not present, it is automatically
prepended.
And for some additional subtleties, consider these:
3. defm with no name generates a unique name but has no special
behavior otherwise.
4. def with no name generates an anonymous record, whose name is
unique but undefined. In particular, the name won't contain a
reference to NAME.
Keeping rules 1&2 in mind should allow a predictable behavior of
name resolution that is simple to follow.
The old "rules" were rather surprising: sometimes (but not always),
NAME would correspond to the name of the toplevel defm. They were
also plain bonkers when you pushed them to their limits, as the old
version of the TableGen test case shows.
Having NAME correspond to the name of the toplevel defm introduces
"spooky action at a distance" and breaks composability:
refactoring the upper layers of a hierarchy of nested multiclass
instantiations can cause unexpected breakage by changing the value
of NAME at a lower level of the hierarchy. The new rules don't
suffer from this problem.
Some existing .td files have to be adjusted because they ended up
depending on the details of the old implementation.
Change-Id: I694095231565b30f563e6fd0417b41ee01a12589
Reviewers: tra, simon_tatham, craig.topper, MartinO, arsenm, javed.absar
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D47430
llvm-svn: 333900
1. Introduction of mask scalar TableGen patterns.
2. Introduction of new scalar move TableGen patterns
and refactoring of existing ones.
3. Folding of pattern created by introducing scalar
masking in Clang header files.
Patch by tkrupa
Differential Revision: https://reviews.llvm.org/D47012
llvm-svn: 333419
This property is needed in order to follow values movement between
registers. This property is used in TII to implement method that
returns true if simple copy like instruction is recognized, along
with source and destination machine operands.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D45204
llvm-svn: 333093
BtVer2 - fix NumMicroOp and account for the Lat+6cy GPR->XMM and Lat+1cy XMm->GPR delays (see rL332737)
The high number of MOVD/MOVQ equivalent instructions meant that there were a number of missed patterns in SNB/Znver1:
SNB - add missing GPR<->MMX costs (taken from Agner / Intel AOM)
Znver1 - add missing GPR<->XMM MOVQ costs (taken from Agner)
llvm-svn: 332745
Retag some instructions that were missed when we split off vector load/store/moves - MOVQ/MOVD etc.
Fixes BtVer2/SLM which have different behaviours for GPR stores.
llvm-svn: 332718
Retag some instructions that were missed when we split off vector load/store/moves - MOVSS/MOVSD/MOVHPD/MOVHPD/MOVLPD/MOVLPS etc.
Fixes BtVer2/SLM which have different behaviours for GPR stores.
llvm-svn: 332714
The FIXME comments were about preventing load folding to avoid a partial xmm update. But these instructions use GPR as input when the load isn't folded. This won't help prevent a partial xmm update.
llvm-svn: 332573
A lot of the models still have too many InstRW overrides for these new classes - this needs cleaning up but I wanted to get the classes in first
llvm-svn: 332451
BtVer2 - Fixes schedules for (V)CVTPS2PD instructions
A lot of the Intel models still have too many InstRW overrides for these new classes - this needs cleaning up but I wanted to get the classes in first
llvm-svn: 332376
Btver2 - VCVTPH2PSYrm needs to double pump the AGU
Broadwell - missing VCVTPS2PH*mr stores extra latency
Allows us to remove the WriteCvtF2FSt conversion store class
llvm-svn: 332357
MOVNTPD/MOVNTPS should be WriteFStore
Standardized BDW/HSW/SKL/SKX WriteFStore/WriteVecStore - fixes some missed instregex patterns. (V)MASKMOVDQU was already using the default, its costs gets increased but is still nowhere near the real cost of that nasty instruction....
llvm-svn: 331864
Split to support single/double for scalar, XMM and YMM/ZMM instructions - removing InstrRW overrides for these instructions.
Fixes Atom ADDSUBPD instruction and reclassifies VFPCLASS as WriteFCmp which is closer in behaviour.
llvm-svn: 331672
These are more like cross-lane shuffles than regular shuffles - we already do this for AVX512 equivalents.
Differential Revision: https://reviews.llvm.org/D46229
llvm-svn: 331659
WriteFRcp/WriteFRsqrt are split to support scalar, XMM and YMM/ZMM instructions.
WriteFSqrt is split into single/double/long-double sizes and scalar, XMM, YMM and ZMM instructions.
This removes all InstrRW overrides for these instructions.
NOTE: There were a couple of typos in the Znver1 model - notably a 1cy throughput for SQRT that is highly unlikely and doesn't tally with Agner.
NOTE: I had to add Agner's numbers for several targets for WriteFSqrt80.
llvm-svn: 331629
Split off from SchedWriteFAdd for fp rounding/bit-manipulation instructions.
Fixes an issue on btver2 which only had the ymm version using the JSTC pipe instead of JFPA.
llvm-svn: 331515
This took a bit of extra work as on Intel targets the old (V)PSLLDrr/(V)PSLLDrm style instructions act differently - I ended up creating WriteVecShiftImm classes for XMM/YMM/ZMM vector shift by immediate and retaining WriteVecShift as the default (used only by MMX) plus WriteVecShiftX/WriteVecShiftY. X86SchedWriteWidths hides most of this thank goodness.
llvm-svn: 331472
We need to split most of the scheduler classes by vector width to remove more of the InstRW overrides, this patch should make this easier/tidier by allowing us to pass the X86SchedWriteWidths wrapper to multi-width multiclasses and then split as required.
I've included fields for Scl (scalar float/double), MMX (MMX integer), XMM, YMM and ZMM widths. These fields mostly share the same classes but it should give us the flexibility that we may need in the future.
This patch has replaced a set of example SSE/AVX512 instruction cases but isn't exhaustive as it gets very noisy before we really need the functionality.
Differential Revision: https://reviews.llvm.org/D46266
llvm-svn: 331208
Many of these aliases exist to give one syntax or the other a slightly different mnemonic and the other variant gets a duplicate of its normal mnemonic
This patch restricts a lot of these to only one variant so we don't get the duplication.
This removes a lot of duplicate entries from the matcher table. It also reduces the number of warnings printed when you enable the ambiguous match warning in tablegen.
llvm-svn: 331117
Summary:
Previously the flag intrinsics always used the index instructions even if a mask instruction also exists.
To fix fix this I've created a single ISD node type that returns index, mask, and flags. The SelectionDAG CSE process will merge all flavors of intrinsics with the same inputs to a s ingle node. Then during isel we just have to look at which results are used to know what instruction to generate. If both mask and index are used we'll need to emit two instructions. But for all other cases we can emit a single instruction.
Since I had to do manual isel anyway, I've removed the pseudo instructions and custom inserter code that was working around tablegen limitations with multiple implicit defs.
I've also renamed the recently added sse42.ll test case to sttni.ll since it focuses on that subset of the sse4.2 instructions.
Reviewers: chandlerc, RKSimon, spatel
Reviewed By: chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46202
llvm-svn: 331091
Split off pinsr/pextr and extractps instructions.
(Mostly) fixes PR36887.
Note: It might be worth adding a WriteFInsertLd class as well in the future.
Differential Revision: https://reviews.llvm.org/D45929
llvm-svn: 330714
Craig Topper