This patch adds support for AArch64 to cfi-verify.
This required three changes to cfi-verify. First, it generalizes checking if an instruction is a trap by adding a new isTrap flag to TableGen (and defining it for x86 and AArch64). Second, the code that ensures that the operand register is not clobbered between the CFI check and the indirect call needs to allow a single dereference (in x86 this happens as part of the jump instruction). Third, we needed to ensure that return instructions are not counted as indirect branches. Technically, returns are indirect branches and can be covered by CFI, but LLVM's forward-edge CFI does not protect them, and x86 does not consider them, so we keep that behavior.
In addition, we had to improve AArch64's code to evaluate the branch target of a MCInst to handle calls where the destination is not the first operand (which it often is not).
Differential Revision: https://reviews.llvm.org/D48836
llvm-svn: 337007
Spectre variant #1 for x86.
There is a lengthy, detailed RFC thread on llvm-dev which discusses the
high level issues. High level discussion is probably best there.
I've split the design document out of this patch and will land it
separately once I update it to reflect the latest edits and updates to
the Google doc used in the RFC thread.
This patch is really just an initial step. It isn't quite ready for
prime time and is only exposed via debugging flags. It has two major
limitations currently:
1) It only supports x86-64, and only certain ABIs. Many assumptions are
currently hard-coded and need to be factored out of the code here.
2) It doesn't include any options for more fine-grained control, either
of which control flow edges are significant or which loads are
important to be hardened.
3) The code is still quite rough and the testing lighter than I'd like.
However, this is enough for people to begin using. I have had numerous
requests from people to be able to experiment with this patch to
understand the trade-offs it presents and how to use it. We would also
like to encourage work to similar effect in other toolchains.
The ARM folks are actively developing a system based on this for
AArch64. We hope to merge this with their efforts when both are far
enough along. But we also don't want to block making this available on
that effort.
Many thanks to the *numerous* people who helped along the way here. For
this patch in particular, both Eric and Craig did a ton of review to
even have confidence in it as an early, rough cut at this functionality.
Differential Revision: https://reviews.llvm.org/D44824
llvm-svn: 336990
flow patterns including forks, merges, and even cyles.
This tries to cover a reasonably comprehensive set of patterns that
still don't require PHIs or PHI placement. The coverage was inspired by
the amazing variety of patterns produced when copy EFLAGS and restoring
it to implement Speculative Load Hardening. Without this patch, we
simply cannot make such complex and invasive changes to x86 instruction
sequences due to EFLAGS.
I've added "just" one test, but this test covers many different
complexities and corner cases of this approach. It is actually more
comprehensive, as far as I can tell, than anything that I have
encountered in the wild on SLH.
Because the test is so complex, I've tried to give somewhat thorough
comments and an ASCII-art diagram of the control flows to make it a bit
easier to read and maintain long-term.
Differential Revision: https://reviews.llvm.org/D49220
llvm-svn: 336985
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
We were accidentally connecting it to result 0 instead of result 1. This was caught by the machine verifier that noticed the flags were dead, but we were using them somehow. I'm still not clear what actually happened downstream.
llvm-svn: 336925
canWidenShuffleElements can do a better job if given a mask with ZeroableElements info. Apparently, ZeroableElements was being only used to identify AllZero candidates, but possibly we could plug it into more shuffle matchers.
Original Patch by Zvi Rackover @zvi
Differential Revision: https://reviews.llvm.org/D42044
llvm-svn: 336903
Noticed while updating D42044, lowerV2X128VectorShuffle can improve the shuffle mask with the zeroable data to create a target shuffle mask to recognise more 'zero upper 128' patterns.
NOTE: lowerV4X128VectorShuffle could benefit as well but the code needs refactoring first to discriminate between SM_SentinelUndef and SM_SentinelZero for negative shuffle indices.
Differential Revision: https://reviews.llvm.org/D49092
llvm-svn: 336900
We now use llvm.fma.f32/f64 or llvm.x86.fmadd.f32/f64 intrinsics that use scalar types rather than vector types. So we don't these special ISD nodes that operate on the lowest element of a vector.
llvm-svn: 336883
there for a long time.
The boolean tracking whether we saw a kill of the flags was supposed to
be per-block we are scanning and instead was outside that loop and never
cleared. It requires a quite contrived test case to hit this as you have
to have multiple levels of successors and interleave them with kills.
I've included such a test case here.
This is another bug found testing SLH and extracted to its own focused
patch.
llvm-svn: 336876
multiple successors where some of the uses end up killing the EFLAGS
register.
There was a bug where rather than skipping to the next basic block
queued up with uses once we saw a kill, we stopped processing the blocks
entirely. =/
Test case produces completely nonsensical code w/o this tiny fix.
This was found testing Speculative Load Hardening and split out of that
work.
Differential Revision: https://reviews.llvm.org/D49211
llvm-svn: 336874
This converts them to what clang is now using for codegen. Unfortunately, there seem to be a few kinks to work out still. I'll try to address with follow up patches.
llvm-svn: 336871
We can instead block the load folding isProfitableToFold. Then isel will emit a register->register move for the zeroing part and a separate load. The PostProcessISelDAG should be able to remove the register->register move.
This saves us patterns and fixes the fact that we only had unaligned load patterns. The test changes show places where we should have been using an aligned load.
llvm-svn: 336828
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
Summary:
These changes cover the PR#31399.
Now the ffs(x) function is lowered to (x != 0) ? llvm.cttz(x) + 1 : 0
and it corresponds to the following llvm code:
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 %v, 0
%.op = add nuw nsw i32 %cnt, 1
%add = select i1 %tobool, i32 0, i32 %.op
and x86 asm code:
bsfl %edi, %ecx
addl $1, %ecx
testl %edi, %edi
movl $0, %eax
cmovnel %ecx, %eax
In this case the 'test' instruction can't be eliminated because
the 'add' instruction modifies the EFLAGS, namely, ZF flag
that is set by the 'bsf' instruction when 'x' is zero.
We now produce the following code:
bsfl %edi, %ecx
movl $-1, %eax
cmovnel %ecx, %eax
addl $1, %eax
Patch by Ivan Kulagin
Reviewers: davide, craig.topper, spatel, RKSimon
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48765
llvm-svn: 336768
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
Isel currently emits movss/movsd a lot of the time and an accidental double commute turns it into a blend.
Ideally we'd select blend directly in isel under optspeed and not rely on the double commute to create blend.
llvm-svn: 336731
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
I believe isProfitableToFold will stop the load folding that this was intended to overcome.
Given an (xor load, -1), isProfitableToFold will see that the immediate can be folded with the xor using a one byte immediate since it can be sign extended. It doesn't know about NOT, but the one byte immediate check is enough to stop the fold.
llvm-svn: 336712
Now that rL336250 has landed, we should prefer 2 immediate shifts + a shuffle blend over performing a multiply. Despite the increase in instructions, this is quicker (especially for slow v4i32 multiplies), avoid loads and constant pool usage. It does mean however that we increase register pressure. The code size will go up a little but by less than what we save on the constant pool data.
This patch also adds support for v16i16 to the BLEND(SHIFT(v,c1),SHIFT(v,c2)) combine, and also prevents blending on pre-SSE41 shifts if it would introduce extra blend masks/constant pool usage.
Differential Revision: https://reviews.llvm.org/D48936
llvm-svn: 336642
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
Summary:
This adds a reverse transform for the instcombine canonicalizations
that were added in D47980, D47981.
As discussed later, that was worse at least for the code size,
and potentially for the performance, too.
https://rise4fun.com/Alive/Zmpl
Reviewers: craig.topper, RKSimon, spatel
Reviewed By: spatel
Subscribers: reames, llvm-commits
Differential Revision: https://reviews.llvm.org/D48768
llvm-svn: 336585
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
This replaces some asserts in lowerV2F64VectorShuffle with the similar asserts from lowerVIF64VectorShuffle which are more readable. The original asserts mentioned a blend, but there's no guarantee that it is a blend.
Also remove an if that the asserts prove is always true. Mask[0] is always less than 2 and Mask[1] is always at least 2. Therefore (Mask[0] >= 2) + (Mask[1] >= 2) == 1 must wlays be true.
llvm-svn: 336517
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
Summary:
{F6603964}
While there is still some discrepancies within that new group,
it is clearly separate from the other shifts.
And Agner's tables agree, these double shifts are clearly
different from the normal shifts/rotates.
I'm guessing `FeatureSlowSHLD` is related.
Indeed, a basic sched pair is *not* the /best/ match.
But keeping it in the WriteShift is /clearly/ not ideal either.
This can and likely will be fine-tuned later.
This is purely mechanical change, it does not change any numbers,
as the [lack of the change of] mca tests show.
Reviewers: craig.topper, RKSimon, andreadb
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49015
llvm-svn: 336515
Pre-AVX512 (which can perform a quick extend/shift/truncate), extending to 2 v8i16 for the PMULLW and then truncating is more performant than relying on the generic PBLENDVB vXi8 shift path and uses a similar amount of mask constant pool data.
Differential Revision: https://reviews.llvm.org/D48963
llvm-svn: 336513
Summary:
Motivation: {F6597954}
This only does the mechanical splitting, does not actually change
any numbers, as the tests added in previous revision show.
Reviewers: craig.topper, RKSimon, courbet
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48998
llvm-svn: 336511
This allows us to handle masking in a very similar way to the default rounding version that uses llvm.fma.
I had to add new rounding mode CodeGenOnly instructions to support isel when we can't find a movss to grab the upper bits from to use the b_Int instruction.
Fast-isel tests have been updated to match new clang codegen.
We are currently having trouble folding fneg into the new intrinsic. I'm going to correct that in a follow up patch to keep the size of this one down.
A future patch will also remove the old intrinsics.
llvm-svn: 336506
Splits off isKnownNeverZeroFloat to handle +/- 0 float cases.
This will make it easier to be more aggressive with the integer isKnownNeverZero tests (similar to ValueTracking), use computeKnownBits etc.
Differential Revision: https://reviews.llvm.org/D48969
llvm-svn: 336492
We penalize general SDIV/UDIV costs but don't do the same for SREM/UREM.
This patch makes general vector SREM/UREM x20 as costly as scalar, the same approach as we do for SDIV/UDIV. The patch also extends the existing SDIV/UDIV constant costs for SREM/UREM - at the moment this means the additional cost of a MUL+SUB (see D48975).
Differential Revision: https://reviews.llvm.org/D48980
llvm-svn: 336486
It's a bit neater to write T.isIntOrPtrTy() over `T.isIntegerTy() ||
T.isPointerTy()`.
I used Python's re.sub with this regex to update users:
r'([\w.\->()]+)isIntegerTy\(\)\s*\|\|\s*\1isPointerTy\(\)'
llvm-svn: 336462
We've removed the legacy FMA3 intrinsics and are now using llvm.fma and extractelement/insertelement. So we don't need patterns for the nodes that could only be created by the old intrinscis. Those ISD opcodes still exist because we haven't dropped the AVX512 intrinsics yet, but those should go to EVEX instructions.
llvm-svn: 336457
The intrinsics can be implemented with a f32/f64 llvm.fma intrinsic and an insert into a zero vector.
There are a couple regressions here due to SelectionDAG not being able to pull an fneg through an extract_vector_elt. I'm not super worried about this though as InstCombine should be able to do it before we get to SelectionDAG.
llvm-svn: 336416
This upgrades all of the intrinsics to use fneg instructions to convert fma into fmsub/fnmsub/fnmadd/fmsubadd. And uses a select instruction for masking.
This matches how clang uses the intrinsics these days.
llvm-svn: 336409
Summary:
If LOCK prefix is not the first prefix in an instruction, LLVM
disassembler silently drops the prefix.
The fix is to select a proper instruction with a builtin LOCK prefix if
one exists.
Reviewers: craig.topper
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49001
llvm-svn: 336400
We have patterns for SELECTS that top at v1i1 and we have a pattern for (v1i1 (scalar_to_vector GR8)). The patterns being removed here do the same thing as the two other patterns combined so there is no need for them.
llvm-svn: 336305
Previously we could only negate the FMADD opcodes. This used to be mostly ok when we lowered FMA intrinsics during lowering. But with the move to llvm.fma from target specific intrinsics, we can combine (fneg (fma)) to (fmsub) earlier. So if we start with (fneg (fma (fneg))) we would get stuck at (fmsub (fneg)).
This patch fixes that so we can also combine things like (fmsub (fneg)).
llvm-svn: 336304
There's a regression in here due to inability to combine fneg inputs of X86ISD::FMSUB/FNMSUB/FNMADD nodes.
More removals to come, but I wanted to stop and fix the regression that showed up in this first.
llvm-svn: 336303
We were only doing this for basic blends, despite shuffle lowering now being good enough to handle more complex blends. This means that the two v8i16 splat shifts are performed in parallel instead of serially as the general shift case.
Reapplied with a fixed (extra null tests) version of rL336113 after reversion in rL336189 - extra test case added at rL336247.
llvm-svn: 336250
This patch adds a new token type specifically for (%dx). We will now always create this token when we parse (%dx). After all operands have been parsed, if the mnemonic is in/out we'll morph this token to a regular register token. Otherwise we keep it as the special DX token which won't match any instructions.
This removes the need for passing Mnemonic through the parsing functions. It also seems closer to gas where when its used on the wrong instruction it just gets diagnosed as an invalid operand rather than a bad memory address.
llvm-svn: 336218
This might make the error message added in r335668 unneeded, but I'm not sure yet.
The check for RIP is technically unnecessary since RIP is in GR64, but that fact is kind of surprising so be explicit.
llvm-svn: 336217
Add registers still missing after r328016 (D43353):
- for bits 15-8 of SI, DI, BP, SP (*H), and R8-R15 (*BH),
- for bits 31-16 of R8-R15 (*WH).
Thanks to Craig Topper for pointing it out.
llvm-svn: 336134
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
We were only doing this for basic blends, despite shuffle lowering now being good enough to handle more complex blends. This means that the two v8i16 splat shifts are performed in parallel instead of serially as the general shift case.
llvm-svn: 336113
The X86 asm parser currently has custom parsing logic for .word. Rather than
use this custom logic, we can just use addAliasForDirective to enable the
reuse of AsmParser::parseDirectiveValue.
See also similar changes to Sparc (rL333078), AArch64 (rL333077), and Hexagon
(rL332607) backends.
Differential Revision: https://reviews.llvm.org/D47004
This is a fixed reland of rL336100. This should have been caught in
pre-commit testing so apologies for the noise.
llvm-svn: 336104
The X86 asm parser currently has custom parsing logic for .word. Rather than
use this custom logic, we can just use addAliasForDirective to enable the
reuse of AsmParser::parseDirectiveValue.
See also similar changes to Sparc (rL333078), AArch64 (rL333077), and Hexagon
(rL332607) backends.
Differential Revision: https://reviews.llvm.org/D47004
llvm-svn: 336100
We don't have PMCs to cover many of the Jaguar resources but we can at least monitor the FPU issue pipes which give an indication of the fpu uop count, just not the execution resources.
llvm-svn: 336089
It looks like someone ran clang-format over this entire file which reformatted these switches into a multiline form. But I think the single line form is more useful here.
llvm-svn: 336077
I separated out the rounding and broadcast groups into their own tables because it made the ordering in the main table easier.
Further splitting of the tables might make it possible to directly index using bits from the TSFlags, but its probably not worth it right now.
llvm-svn: 336075
findCommutedOpIndices does the pre-checking for whether commuting is possible. There should be no reason left to fail in commuteInstructionImpl. There was a missing pre-check that I've added there and changed the check to an assert in commuteInstructionImpl.
llvm-svn: 336070
I've check the disassembler tables and this shouldn't be reachable. Which is good since if it was reachable there should have been a 'return' after the addOperand line.
llvm-svn: 336066
Also move the static folding tables, their search functions and the new class into new cpp/h files.
The unfolding table is effectively static data. It's just a different ordering and a subset of the static folding tables.
By putting it in a separate ManagedStatic we ensure we only have one copy instead of one per X86InstrInfo object. This way also makes it only get initialized when really needed.
llvm-svn: 336056
The class only exists to hold a DenseMap and is only created as a ManagedStatic. It used to expose a single static method that outside code was expected to use.
This patch moves that static function out of the class and moves it implementation into the cpp file. It can now access the ManagedStatic directly by name without the need for the other static method that accessed the ManagedStatic.
llvm-svn: 336055
There are no instructions that use them so they weren't causing any bad matches. But they weren't being diagnosed as "invalid register name" if they were used and would instead trigger some form of invalid operand.
llvm-svn: 336054
I believe all of these are constants so legalizing them should be pretty trivial, but this saves a step.
In one case it looks like we may have been creating a shift amount larger than the shift input itself.
llvm-svn: 336052
This combine runs pretty late and causes us to introduce a shift after the op legalization phase has run. We need to be sure we create the shift with the proper type for the shift amount. If we don't do this, we will still re-legalize the operation properly, but we won't get a chance to fully optimize the truncate that gets inserted.
So this patch adds the necessary truncate when the shift is created. I've also narrowed the subtract that gets created to always be an i32 type. The truncate would have trigered SimplifyDemandedBits to optimize it anyway. But using a more appropriate VT here is free and saves an optimization step.
llvm-svn: 336051
The important part is the creation of the SHLD/SHRD nodes. The compare and the conditional move can use target independent nodes that can be legalized on their own. This gives some opportunities to trigger the optimizations present in the lowering for those things. And its just better to limit the number of places we emit target specific nodes.
The changed test cases still aren't optimal.
Differential Revision: https://reviews.llvm.org/D48619
llvm-svn: 335998
Previously we used a DenseMap which is costly to set up due to multiple full table rehashes as the size increases and causes the table to be reallocated.
This patch changes the table to a vector of structs. We now walk the reg->mem tables and push new entries in the mem->reg table for each row not marked TB_NO_REVERSE. Once all the table entries have been created, we sort the vector. Then we can use a binary search for lookups.
Differential Revision: https://reviews.llvm.org/D48585
llvm-svn: 335994
This uses the same technique as for shifts - split the rotation into 4/2/1-bit partial rotations and select those partials based on the amount bit, making use of PBLENDVB if available. This halves the use of PBLENDVB compared to expanding to shifts, which can be a slow op.
Unfortunately I haven't found a decent way to share much of this code with the shift equivalent.
Differential Revision: https://reviews.llvm.org/D48655
llvm-svn: 335957
This is a follow up to r335753. At the time I forgot about isProfitableToFold which makes this pretty easy.
Differential Revision: https://reviews.llvm.org/D48706
llvm-svn: 335895
Reverting because this is causing failures in the LLDB test suite on
GreenDragon.
LLVM ERROR: unsupported relocation with subtraction expression, symbol
'__GLOBAL_OFFSET_TABLE_' can not be undefined in a subtraction
expression
llvm-svn: 335894
Targets should be able to define whether or not they support the outliner
without the outliner being added to the pass pipeline. Before this, the
outliner pass would be added, and ask the target whether or not it supports the
outliner.
After this, it's possible to query the target in TargetPassConfig, before the
outliner pass is created. This ensures that passing -enable-machine-outliner
will not modify the pass pipeline of any target that does not support it.
https://reviews.llvm.org/D48683
llvm-svn: 335887
Add NoTrapAfterNoreturn target option which skips emission of traps
behind noreturn calls even if TrapUnreachable is enabled.
Enable the feature on Mach-O to save code size; Comments suggest it is
not possible to enable it for the other users of TrapUnreachable.
rdar://41530228
DifferentialRevision: https://reviews.llvm.org/D48674
llvm-svn: 335877
These are all benign races and only visible in !NDEBUG. tsan complains
about it, but a simple atomic bool is sufficient to make it happy.
llvm-svn: 335823
This more efficient for the isel table generator since we can use CheckChildInteger instead of MoveChild, CheckPredicate, MoveParent. This reduced the table size by 1-2K.
I wish there was a way to share the values with X86BaseInfo.h and still use a PatFrag like this. These numbers are fixed by the X86 intrinsic spec going back many years and we should never need to change them. So we shouldn't waste table bytes to support sharing.
llvm-svn: 335806
BMI2 added new shift by register instructions that have the ability to fold a load.
Normally without doing anything special isel would prefer folding a load over folding an immediate because the load folding pattern has higher "complexity". This would require an instruction to move the immediate into a register. We would rather fold the immediate instead and have a separate instruction for the load.
We used to enforce this priority by artificially lowering the complexity of the load pattern.
This patch changes this to instead reject the load fold in isProfitableToFoldLoad if there is an immediate. This is more consistent with other binops and feels less hacky.
llvm-svn: 335804
If we turn X86ISD::AND into ISD::AND, we delete N. But we were continuing onto the next block of code even though N no longer existed.
Just happened to notice it. I assume asan didn't notice it because we explicitly unpoison deleted nodes and give them a DELETE_NODE opcode.
llvm-svn: 335787
The %eiz/%riz are dummy registers that force the encoder to emit a SIB byte when it normally wouldn't. By emitting them in the disassembly output we ensure that assembling the disassembler output would also produce a SIB byte.
This should match the behavior of objdump from binutils.
llvm-svn: 335768
If we are just modifying a single bit at a variable bit position we can use the BT* instructions to make the change instead of shifting a 1(or rotating a -1) and doing a binop. These instruction also ignore the upper bits of their index input so we can also remove an and if one is present on the index.
Fixes PR37938.
llvm-svn: 335754
I think the intrinsics named 'avx512.mask.' should refer to the previous behavior of taking a mask argument in the intrinsic instead of using a 'select' or 'and' instruction in IR to accomplish the masking. This is more consistent with the goal that eventually we will have no intrinsics that have masking builtin. When we reach that goal, we should have no intrinsics named "avx512.mask".
llvm-svn: 335744
Nothing was using this relationship. By splitting them we no longer need to worry about register or memory entries being empty in a group.
The memory folding tables in X86InstrInfo.cpp can be used to access this relationship if needed.
llvm-svn: 335694
Right now, when we use RIP-relative instructions in 32-bit mode, we'll just
assert and crash.
This adds an error message which tells the user that they can't do that in
32-bit mode, so that we don't crash (and also can see the issue outside of
assert builds).
llvm-svn: 335658
Summary:
If a routine with no stack frame makes a sibling call, we need to
preserve the stack space check even if the local stack frame is empty,
since the call target could be a "no-split" function (in which case
the linker needs to be able to fix up the prolog sequence in order to
switch to a larger stack).
This fixes PR37807.
Reviewers: cherry, javed.absar
Subscribers: srhines, llvm-commits
Differential Revision: https://reviews.llvm.org/D48444
llvm-svn: 335604
These opcodes have a fixed type of i8 for their immediate and shouldn't have anything to do with the scalar shift amount used by target independent shift nodes.
llvm-svn: 335578
Summary:
Same idea as D48529, but restricted to X86 and done very late to avoid any surprises where subtract might be better for DAG combining.
This seems like the safest way to do this trick. And we consider doing it as a DAG combine later.
Reviewers: spatel, RKSimon
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48557
llvm-svn: 335575
This recommits r335562 and 335563 as a single commit.
The frontend will surround the intrinsic with the appropriate marshalling to/from a scalar type to match the sigature of the builtin that software expects.
By exposing the vXi1 type directly in the llvm intrinsic we make it available to optimizers much earlier. This can enable the scalar marshalling code to be optimized away.
llvm-svn: 335568
std::lower_bound doesn't require the thing to search for to be the same type as the table entries. We just need to define an appropriate comparison function that can take an table entry and an intrinsic number.
llvm-svn: 335518
The large code model allows code and data segments to exceed 2GB, which
means that some symbol references may require a displacement that cannot
be encoded as a displacement from RIP. The large PIC model even relaxes
the assumption that the GOT itself is within 2GB of all code. Therefore,
we need a special code sequence to materialize it:
.LtmpN:
leaq .LtmpN(%rip), %rbx
movabsq $_GLOBAL_OFFSET_TABLE_-.LtmpN, %rax # Scratch
addq %rax, %rbx # GOT base reg
From that, non-local references go through the GOT base register instead
of being PC-relative loads. Local references typically use GOTOFF
symbols, like this:
movq extern_gv@GOT(%rbx), %rax
movq local_gv@GOTOFF(%rbx), %rax
All calls end up being indirect:
movabsq $local_fn@GOTOFF, %rax
addq %rbx, %rax
callq *%rax
The medium code model retains the assumption that the code segment is
less than 2GB, so calls are once again direct, and the RIP-relative
loads can be used to access the GOT. Materializing the GOT is easy:
leaq _GLOBAL_OFFSET_TABLE_(%rip), %rbx # GOT base reg
DSO local data accesses will use it:
movq local_gv@GOTOFF(%rbx), %rax
Non-local data accesses will use RIP-relative addressing, which means we
may not always need to materialize the GOT base:
movq extern_gv@GOTPCREL(%rip), %rax
Direct calls are basically the same as they are in the small code model:
They use direct, PC-relative addressing, and the PLT is used for calls
to non-local functions.
This patch adds reasonably comprehensive testing of LEA, but there are
lots of interesting folding opportunities that are unimplemented.
I restricted the MCJIT/eh-lg-pic.ll test to Linux, since the large PIC
code model is not implemented for MachO yet.
Differential Revision: https://reviews.llvm.org/D47211
llvm-svn: 335508
With the static tables sorted we can binary search them directly for reg->mem lookups. This removes 6 DenseMaps that had to be created when X86InstrInfo is constructed.
We still have one Mem->Reg DenseMap for the reverse direction. This is created just as before by walking the reg->mem arrays to populate it.
Differential Revision: https://reviews.llvm.org/D48527
llvm-svn: 335501
We should be blocking the operand while we are in the routine that tries to find commutable operand indices. Doing it later means we might have missed out on another valid set of operands we could have commuted.
The intrinsic case was the only case that could really prevent commuting in getFMA3OpcodeToCommuteOperands. All the other cases in getThreeSrcCommuteCase were not reachable conditions as they were protected by findThreeSrcCommutedOpIndices.
With that abort case pushed earlier, we can remove all the abort checks and replace with asserts.
llvm-svn: 335446
They appear to be untested other than the test case for p37879.ll and I believe we should be using SimplifyDemandedElts here to handle these cases.
llvm-svn: 335436
For some reason the 64-bit patterns were separated from their 8/16/32-bit friends, but only for add/sub/mul. For and/or/xor they were together.
llvm-svn: 335429
-Ensure EIP isn't used with an index reigster.
-Ensure EIP isn't used as index register.
-Ensure base register isn't a vector register.
-Ensure eiz/riz usage matches the size of their base register.
llvm-svn: 335412
Previously, to support (%dx) we left a wide open hole in our 16-bit memory address checking. This let this address value be used with any instruction without error in the parser. It would later fail in the encoder with an assertion failure on debug builds and who knows what on release builds.
This patch passes the mnemonic down to the memory operand parsing function so we can allow the (%dx) form only on specific instructions.
llvm-svn: 335403
This allows us to check these:
-16-bit addressing doesn't support scale so we should error if we find one there.
-Multiplying ESP/RSP by a scale even if the scale is 1 should be an error because ESP/RSP can't be an index.
llvm-svn: 335398
By default, the second register gets assigned to the index register slot. But ESP can't be an index register so we need to swap it with the other register.
There's still a slight bug that we allow [EAX+ESP*1]. The existence of the multiply even though its with 1 should force ESP to the index register and trigger an error, but it doesn't currently.
llvm-svn: 335394
The second register is the index register and should only be %si or %di if used with a base register. And in that case the base register should be %bp or %bx.
This makes us compatible with gas.
We do still need to support both orders with Intel syntax which uses [bp+si] and [si+bp]
llvm-svn: 335384
(%bp) can't be encoded without a displacement. The encoding is instead used for displacement alone. So a 1 byte displacement of 0 must be used. But if there is an index register we can encode without a displacement.
llvm-svn: 335379
Changing the logic of scalar mask folding to check for valid input types rather
than against invalid ones, making it more robust and fixing PR37879.
Differential Revision: https://reviews.llvm.org/D48366
llvm-svn: 335323
Summary:
The large code model allows code and data segments to exceed 2GB, which
means that some symbol references may require a displacement that cannot
be encoded as a displacement from RIP. The large PIC model even relaxes
the assumption that the GOT itself is within 2GB of all code. Therefore,
we need a special code sequence to materialize it:
.LtmpN:
leaq .LtmpN(%rip), %rbx
movabsq $_GLOBAL_OFFSET_TABLE_-.LtmpN, %rax # Scratch
addq %rax, %rbx # GOT base reg
From that, non-local references go through the GOT base register instead
of being PC-relative loads. Local references typically use GOTOFF
symbols, like this:
movq extern_gv@GOT(%rbx), %rax
movq local_gv@GOTOFF(%rbx), %rax
All calls end up being indirect:
movabsq $local_fn@GOTOFF, %rax
addq %rbx, %rax
callq *%rax
The medium code model retains the assumption that the code segment is
less than 2GB, so calls are once again direct, and the RIP-relative
loads can be used to access the GOT. Materializing the GOT is easy:
leaq _GLOBAL_OFFSET_TABLE_(%rip), %rbx # GOT base reg
DSO local data accesses will use it:
movq local_gv@GOTOFF(%rbx), %rax
Non-local data accesses will use RIP-relative addressing, which means we
may not always need to materialize the GOT base:
movq extern_gv@GOTPCREL(%rip), %rax
Direct calls are basically the same as they are in the small code model:
They use direct, PC-relative addressing, and the PLT is used for calls
to non-local functions.
This patch adds reasonably comprehensive testing of LEA, but there are
lots of interesting folding opportunities that are unimplemented.
Reviewers: chandlerc, echristo
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D47211
llvm-svn: 335297
This should help in lowering the following four intrinsics:
_mm256_cvtepi32_epi8
_mm256_cvtepi64_epi16
_mm256_cvtepi64_epi8
_mm512_cvtepi64_epi8
Differential Revision: https://reviews.llvm.org/D46957
llvm-svn: 335238
These were being over cautious for costs for one/two op general shuffles - VSHUFPD doesn't have to replicate the same shuffle in both lanes like VSHUFPS does.
llvm-svn: 335216
I don't believe there is any real reason to have separate X86 specific opcodes for vector compares. Setcc has the same behavior just uses a different encoding for the condition code.
I had to change the CondCodeAction for SETLT and SETLE to prevent some transforms from changing SETGT lowering.
Differential Revision: https://reviews.llvm.org/D43608
llvm-svn: 335173
This patch teaches llvm-mca how to identify register writes that implicitly zero
the upper portion of a super-register.
On X86-64, a general purpose register is implemented in hardware as a 64-bit
register. Quoting the Intel 64 Software Developer's Manual: "an update to the
lower 32 bits of a 64 bit integer register is architecturally defined to zero
extend the upper 32 bits". Also, a write to an XMM register performed by an AVX
instruction implicitly zeroes the upper 128 bits of the aliasing YMM register.
This patch adds a new method named clearsSuperRegisters to the MCInstrAnalysis
interface to help identify instructions that implicitly clear the upper portion
of a super-register. The rest of the patch teaches llvm-mca how to use that new
method to obtain the information, and update the register dependencies
accordingly.
I compared the kernels from tests clear-super-register-1.s and
clear-super-register-2.s against the output from perf on btver2. Previously
there was a large discrepancy between the estimated IPC and the measured IPC.
Now the differences are mostly in the noise.
Differential Revision: https://reviews.llvm.org/D48225
llvm-svn: 335113
Summary:
First off: i do not have any access to that processor,
so this is purely theoretical, no benchmarks.
I have been looking into b**d**ver2 scheduling profile, and while cross-referencing
the existing b**t**ver2, znver1 profiles, and the reference docs
(`Software Optimization Guide for AMD Family {15,16,17}h Processors`),
i have noticed that only b**t**ver2 scheduling profile specifies these.
Also, there is no mca test coverage.
Reviewers: RKSimon, craig.topper, courbet, GGanesh, andreadb
Reviewed By: GGanesh
Subscribers: gbedwell, vprasad, ddibyend, shivaram, Ashutosh, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D47676
llvm-svn: 335099
Summary:
I ran llvm-exegesis on SKX, SKL, BDW, HSW, SNB.
Atom is from Agner and SLM is a guess.
I've left AMD processors alone.
Reviewers: RKSimon, craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48079
llvm-svn: 335097
Summary:
After r335018, the static tables are guaranteed sorted by the EVEX opcode to convert. We can use this to do a binary search and remove the need for any secondary data structures.
Right now one table is 736 entries and the other is 482 entries. It might make sense to merge the two tables as a follow up. The effort it takes to select the table is probably similar to the extra binary search step it would require for a larger table.
I haven't done any measurements to see if this has any effect on compile time, but I don't imagine that EVEX->VEX conversion is a place we spend a lot of time.
Reviewers: RKSimon, spatel, chandlerc
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48312
llvm-svn: 335092
insertOutlinerPrologue was not used by any target, and prologue-esque code was
beginning to appear in insertOutlinerEpilogue. Refactor that into one function,
buildOutlinedFrame.
This just removes insertOutlinerPrologue and renames insertOutlinerEpilogue.
llvm-svn: 335076
FMA3Info only exists as a managed static. As far as I know the ManagedStatic construction proccess is thread safe. It doesn't look like we ever access the ManagedStatic object without immediately doing a query on it that would require the map to be populated. So I don't think we're ever deferring the calculation of the tables from the construction of the object.
So I think we should be able to just populate the FMA3Info map directly in the constructor and get rid of all of the initGroupsOnce stuff.
Differential Revision: https://reviews.llvm.org/D48194
llvm-svn: 335064
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
This adds an EVEX2VEXOverride string to the X86 instruction class in X86InstrFormats.td. If this field is set it will add manual entry in the EVEX->VEX tables that doesn't check the encoding information.
Then use this mechanism to map VMOVDU/A8/16, 128-bit VALIGN, and VPSHUFF/I instructions to VEX instructions.
Finally, remove the manual table from the emitter.
This has the bonus of fully sorting the autogenerated EVEX->VEX tables by their EVEX instruction enum value. We may be able to use this to do a binary search for the conversion and get rid of the need to create a DenseMap.
llvm-svn: 335018
EVEX makes heavy use of the VEX.W bit to indicate 64-bit element vs 32-bit elements. Many of the VEX instructions were split into 2 versions with different masking granularity.
The EVEX->VEX table generate can collapse the two versions if the VEX version uses is tagged as VEX_WIG. But if the VEX version is instead marked VEX.W==0 we can't combine them because we don't know if there is also a VEX version with VEX.W==1.
This patch adds a new VEX_W1X tag that indicates the EVEX instruction encodes with VEX.W==1, but is safe to convert to a VEX instruction with VEX.W==0.
This allows us to remove a bunch of manual EVEX->VEX table entries. We may want to look into splitting up the VEX_WPrefix field which would simplify the disassembler.
llvm-svn: 335017
The code was previously checking the L2 and L flag on 3 separate lines, treating the combination as an encoding. Instead its better to think of the L2 bit as being something that can't be done with VEX and early returning. Then we just need to check the L bit.
llvm-svn: 335015
The instructions that use this class don't have another source register. So I think this was just marking one of the address operands as ReadAfterLd?
llvm-svn: 334994
Rather than having an exclusion list in tablegen sources, add a flag to the X86 instruction records that can be used to suppress checking for convertibility.
llvm-svn: 334971
Previously we heap allocated the X86InstrFMA3Group objects which were created by passing them small register/memory opcode arrays that existed as individual static tables.
Rather than a bunch of small static arrays we now have one large static table of X86InstrFMA3Group objects. Rather than storing a pointer to the opcode arrays in the X86InstrFMA3Group object, we now store have a register and memory array as part of the object. If a group doesn't have memory or register opcodes, the array entries will be 0.
This greatly simplifies the destruction of the X86InstrFMA3Info object. We no longer need to delete the X86InstrFMA3Group objects as we destruct the DenseMap. And we don't need to keep track of which ones we already deleted.
This reduces the llc binary size on my local machine by ~50k. I can only assume that's really due to the fact that we had something like 512 small static arrays that we passed to the init functions either one at a time or in pairs. So there were between 256 and 512 distinct calls to the init functions in the initOnceImpl method.
llvm-svn: 334925
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
The .s assembly strings allow the reversed forms to be targeted from assembly which matches gas behavior. But when printing the instructions we should print them without the .s to match other tooling like objdump. By using InstAliases we can use the normal string in the instruction and just hide it from the assembly parser.
Ideally we'd add the .s versions to the legacy SSE and VEX versions as well for full compatibility with gas. Not sure how we got to state where only EVEX was supported.
llvm-svn: 334920
These increases the size of the static tables, but is closer to what we would get if used the autogenerated table directly. This reduces the remaining large deltas between what's in the manual table and what's in the autogenerated table.
llvm-svn: 334915
Some of the calls to hasSingleUseFromRoot were passing the load itself. If the load's chain result has a user this would count against that. By getting the true parent of the match and ensuring any intermediate between the match and the load have a single use we can avoid this case. isLegalToFold will take care of checking users of the load's data output.
This fixed at least fma-scalar-memfold.ll to succed without the peephole pass.
llvm-svn: 334908
These all have a short form encoding that the assembler already prefers. Though that preference seems to only be based on order in the .td fie. Hiding the long form saves space in the table and prevents us from breaking the implicit order based priority.
llvm-svn: 334897
VMOVPQIto64Zmr is not a 64-bit mode only instruction. But I don't know how to test this because VMOVPQIto64mr should always have priority over it in 32-bit mode since its only advantage is XMM16-XMM31 which aren't usable in 32-bit mode.
VMOVPQIto64Zrr is a 64-bit mode only instruction, but we don't need to explicitly mark it as such because it uses a GR64 register which won't parse in 32-bit mode.
llvm-svn: 334896
Not sure any of these matter today because I don't think we ever produce them with IMPLICIT_DEF as an input. But by listing them we don't be suprised in the future.
llvm-svn: 334867
An earlier commit prevented folds from the peephole pass by checking for IMPLICIT_DEF. But later in the pipeline IMPLICIT_DEF just becomes and Undef flag on the input register so we need to check for that case too.
llvm-svn: 334848
I think this covers most of the unmasked vector instructions. We're still missing a lot of the masked instructions.
There are some test changes here because of the new folding support. I don't think these particular cases should be folded because it creates an undef register dependency. I think the changes introduced in r334175 are not handling stack folding. They're only blocking the peephole pass.
llvm-svn: 334800
isVectorClearMaskLegal() is the TLI hook used by the generic
DAGCombiner::XformToShuffleWithZero().
We've grown to accomodate/expect this transform to shuffle
(disabling it more generally results in many regressions).
So I'm narrowly excluding the 256-bit types that clearly
are not worthwhile for AVX1.
I think in most cases we are able to recover by converting
the shuffle back into 'and' ops, but the cases in:
https://bugs.llvm.org/show_bug.cgi?id=37749
...show that there are cracks.
llvm-svn: 334759
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
This shortcoming was noted in D47330, and the test diffs show we already
had other examples where we failed to fold to a SHRUNKBLEND:
/// Dynamic (non-constant condition) vector blend where only the sign bits
/// of the condition elements are used. This is used to enforce that the
/// condition mask is not valid for generic VSELECT optimizations.
This patch implements an idea from D48043 and would obsolete that patch
because it catches more cases (notable the AVX1 case that was missed there).
All we're doing is allowing the existing transform to fire more often by
removing the post-legalize constraint. All of the relevant feature checks
and other predicates are left as-is.
Differential Revision: https://reviews.llvm.org/D48078
llvm-svn: 334592
Previously we were whitelisting in instructions based on their SchedRW value. With the masked store instructions explicitly removed via NotMemoryFoldable, we don't seem to need this check anymore.
llvm-svn: 334563
Craig Topper