Commit Graph

25 Commits

Author SHA1 Message Date
Craig Topper
f4c0ab8f37 [AVX512] Don't use 32-bit elements version of AND/OR/XOR/ANDN during isel unless we're matching a masked op or broadcast
Selecting 32-bit element logical ops without a select or broadcast requires matching a bitconvert on the inputs to the and. But that's a weird thing to rely on. It's entirely possible that one of the inputs doesn't have a bitcast and one does.

Since there's no functional difference, just remove the extra patterns and save some isel table size.

Differential Revision: https://reviews.llvm.org/D36854

llvm-svn: 312138
2017-08-30 16:38:33 +00:00
Craig Topper
9ecce29130 [AVX-512] Remove patterns that select vmovdqu8/16 for unmasked loads. Prefer vmovdqa64/vmovdqu64 instead.
These were taking priority over the aligned load instructions since there is no vmovda8/16. I don't think there is really a difference between aligned and unaligned on newer cpus so I don't think it matters which instructions we use.

But with this change we reduce the size of the isel table a little and we allow the aligned information to pass through to the evex->vec pass and produce the same output has avx/avx2 in some cases.

I also generally dislike patterns rooted in a bitcast which these were.

Differential Revision: https://reviews.llvm.org/D35977

llvm-svn: 309589
2017-07-31 17:35:44 +00:00
Dehao Chen
a12a4b963e Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 304371
2017-05-31 23:25:25 +00:00
Hans Wennborg
bcfc1f4e44 Revert r302938 "Add LiveRangeShrink pass to shrink live range within BB."
This also reverts follow-ups r303292 and r303298.

It broke some Chromium tests under MSan, and apparently also internal
tests at Google.

llvm-svn: 303369
2017-05-18 18:50:05 +00:00
Dehao Chen
d7d29ebf8d Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 302938
2017-05-12 19:29:27 +00:00
Craig Topper
1c93099805 [X86] Don't base domain decisions on VEXTRACTF128/VINSERTF128 if only AVX1 is available.
Seems the execution dependency pass likes to use FP instructions when most of the consuming code is integer if a vextractf128 instruction produced the register. Without AVX2 we don't have the corresponding integer instruction available.

This patch suppresses the domain on these instructions to GenericDomain if AVX2 is not supported so that they are ignored by domain fixing. If AVX2 is supported we'll report the correct domain and allow them to switch between integer and fp.

Overall I think this produces better results in the modified test cases.

llvm-svn: 294824
2017-02-11 05:32:57 +00:00
Simon Pilgrim
a8edcf036b [SelectionDAG] Add support for BITREVERSE constant folding
We were relying on constant folding of the legalized instructions to do what constant folding we had previously

llvm-svn: 292114
2017-01-16 13:39:00 +00:00
Simon Pilgrim
bcca9b527d [X86][SSE] Tests showing missing BITREVERSE constant folding
llvm-svn: 292111
2017-01-16 13:18:07 +00:00
Craig Topper
0f68f0b2ab [AVX-512] Promote AND/OR/XOR to v2i64/v4i64/v8i64 even when we have AVX512F/AVX512VL.
Previously we weren't creating masked logical operations if bitcasts appeared between the logic operation and the select. The IR optimizers can move bitcasts across logic operations and create these cases. To minimize the number of cases we need to handle, this change promotes all logic ops to an i64 vector type just like when only SSE or AVX is available.

Unfortunately, this also has the consequence of making it difficult to select unmasked VPANDD/VPORD/VPXORD in all the cases it was previously used. This is the cause of most of the test change. This shouldn't result in any functional change though.

llvm-svn: 279929
2016-08-28 06:06:28 +00:00
Simon Pilgrim
75121ab2d6 [SelectionDAG] Optimization of BITREVERSE legalization for power-of-2 integer scalar/vector types
An extension of D19978, this patch replaces the default BITREVERSE evaluation of individual bit masks+shifts with block mask+shifts when we have integer elements of power-of-2 bits in size.

After calling BSWAP to reverse the order of the constituent bytes (which typically follows a similar approach), every neighbouring 4-bits, 2-bits and finally 1-bit pairs are masked off and swapped over with shifts.

In doing so we can significantly reduce the number of operations required.

Differential Revision: https://reviews.llvm.org/D21578

llvm-svn: 276432
2016-07-22 16:46:25 +00:00
Craig Topper
324b6001c8 [X86] Add AVX512 instructions to X86InstrInfo::isAssociativeAndCommutative.
llvm-svn: 275767
2016-07-18 06:14:47 +00:00
Matthias Braun
08762f9f1e VirtRegMap: Replace some identity copies with KILL instructions.
An identity COPY like this:
   %AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.

Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).

llvm-svn: 274952
2016-07-09 00:19:07 +00:00
Simon Pilgrim
936b52c77b [X86][AVX512] Add support for 512-bit PSHUFB lowering
llvm-svn: 274444
2016-07-02 18:14:31 +00:00
Simon Pilgrim
a95787d855 [X86][AVX512] Added 512-bit BITREVERSE tests and enabled AVX512BW lowering support
llvm-svn: 273125
2016-06-19 20:59:19 +00:00
Simon Pilgrim
b7726309b9 [X86][SSSE3] Added PSHUFB LUT implementation of BITREVERSE
PSHUFB can speed up BITREVERSE of byte vectors by performing LUT on the low/high nibbles separately and ORing the results. Wider integer vector types are already BSWAP'd beforehand so also make use of this approach.

llvm-svn: 272477
2016-06-11 15:44:13 +00:00
Sanjay Patel
fc1048d379 [x86] avoid printing unnecessary sign bits of hex immediates in asm comments (PR20347)
It would be better to check the valid/expected size of the immediate operand, but this is
generally better than what we print right now.

Differential Revision: http://reviews.llvm.org/D20385

llvm-svn: 271114
2016-05-28 14:58:37 +00:00
Simon Pilgrim
463c677c49 [SelectionDAG] Attempt to split BITREVERSE vector legalization into BSWAP and BITREVERSE stages
For BITREVERSE, bit shifting/masking every bit in a vector element is a very lengthy procedure.

If the input vector type is a whole multiple of bytes wide then we can split this into a BSWAP shuffle stage (to reverse at the byte level) and then a BITREVERSE stage applied to each byte. Most vector capable targets can efficiently BSWAP using shuffles resulting in a considerable reduction in instructions.

With this patch targets would only need to implement a target specific vXi8 BITREVERSE implementation to efficiently reverse most legal vector types.

Differential Revision: http://reviews.llvm.org/D19978

llvm-svn: 269290
2016-05-12 13:09:49 +00:00
Ahmed Bougacha
0eb872067d [X86] Teach X86FixupBWInsts to promote MOV8rr/MOV16rr to MOV32rr.
This re-applies r268760, reverted in r268794.
Fixes http://llvm.org/PR27670

The original imp-defs assertion was way overzealous: forward all
implicit operands, except imp-defs of the new super-reg def (r268787
for GR64, but also possible for GR16->GR32), or imp-uses of the new
super-reg use.
While there, mark the source use as Undef, and add an imp-use of the
old source reg: that should cover any case of dead super-regs.

At the stage the pass runs, flags are unlikely to matter anyway;
still, let's be as correct as possible.

Also add MIR tests for the various interesting cases.

Original commit message:
Codesize is less (16) or equal (8), and we avoid partial
dependencies.

Differential Revision: http://reviews.llvm.org/D19999

llvm-svn: 268831
2016-05-07 01:11:17 +00:00
Nico Weber
76b0c74859 Revert r268760, it caused PR27670.
llvm-svn: 268794
2016-05-06 21:07:02 +00:00
Ahmed Bougacha
ad072149c6 [X86] Teach X86FixupBWInsts to promote MOV8rr/MOV16rr to MOV32rr.
Codesize is less (16) or equal (8), and we avoid partial dependencies.

Differential Revision: http://reviews.llvm.org/D19999

llvm-svn: 268760
2016-05-06 17:42:57 +00:00
Simon Pilgrim
8673620867 [SelectionDAG] BITREVERSE vector legalization of bit operations (REAPPLIED)
Some vector bit operations are promoted instead of having custom lowering. This patch changes the isOperationLegalOrCustom tests for vector AND/OR operations to use a new TLI helper isOperationLegalOrCustomOrPromote instead, allowing the SSE implementations to stay on the simd unit.

Differential Revision: http://reviews.llvm.org/D19805

llvm-svn: 268561
2016-05-04 22:08:51 +00:00
Simon Pilgrim
93256d06c8 Revert r268504
llvm-svn: 268526
2016-05-04 17:49:14 +00:00
Simon Pilgrim
ecd973d988 [SelectionDAG] BITREVERSE vector legalization of bit operations
Vector bit operations are typically promoted instead of having custom lowering. This patch changes the isOperationLegalOrCustom tests for vector AND/OR operations to use isOperationLegalOrPromote instead, allowing the SSE implementations to stay on the simd unit.

Differential Revision: http://reviews.llvm.org/D19805

llvm-svn: 268504
2016-05-04 15:01:13 +00:00
Simon Pilgrim
30bc5e06bf [X86][SSE] Added SSSE3/AVX/AVX2 BITREVERSE tests
Codegen is pretty bad at the moment but could use PSHUFB quite efficiently 

llvm-svn: 267347
2016-04-24 15:45:06 +00:00
Simon Pilgrim
2a917c41e4 [X86][XOP] BITREVERSE lowering using VPPERM
XOP's VPPERM has some great 'permute operations' that it can do as well as part of shuffling the bytes of a 128-bit vector - in this case we use it to perform BITREVERSE in a single instruction.

llvm-svn: 264870
2016-03-30 14:14:00 +00:00