Immediately after it is created we check if its equal to another EVT. Then we inconsistently use one or the other variables in the code below.
Instead do the equality check directly on the getValueType result and remove the variable. Use the origina VT variable throughout the remaining code.
llvm-svn: 321406
getOperand returns an SDValue that contains the node and the result number. There is no guarantee that the result number if 0. By using the -> operator we are calling SDNode::getValueType rather than SDValue::getValueType. This requires supplying a result number and we shouldn't assume it was 0.
I don't have a test case. Just noticed while cleaning up some other code and saw that it occurred in other places.
llvm-svn: 321397
Despite what the comment said there isn't better codegen for 512-bit vectors. The 128/256/512 bit implementation jus stores to memory and loads an element. There's no advantage to doing that with a larger size. In fact in many cases it causes a stack realignment and generates worse code.
llvm-svn: 321369
Previously prefetch was only considered legal if sse was enabled, but it should be supported with 3dnow as well.
The prfchw flag now imply at least some form of prefetch without the write hint is available, either the sse or 3dnow version. This is true even if 3dnow and sse are explicitly disabled.
Similarly prefetchwt1 feature implies availability of prefetchw and the the prefetcht0/1/2/nta instructions. This way we can support _MM_HINT_ET0 using prefetchw and _MM_HINT_ET1 with prefetchwt1. And its assumed that if we have levels for the write hint we would have levels for the non-write hint, thus why we enable the sse prefetch instructions.
I believe this behavior is consistent with gcc. I've updated the prefetch.ll to test all of these combinations.
llvm-svn: 321335
This should only affect what we do for v8i16. Previously we went to v8i64, but if we have VLX we only need v8i32. This prevents an unnecessary zmm usage.
llvm-svn: 321303
We should have equally good shuffle options for v8i32 with VLX. This was spotted during my attempts to remove 512-bit vectors from SKX.
We still use 512-bits for v16i1, v32i1, and v64i1. I'm less sure we can handle those well with narrower vectors. i32 and i64 element sizes get the best shuffle support.
llvm-svn: 321291
Gather/scatter can implicitly sign extend from i32->i64 on indices. So if we know the sign bit of the input to a zext is 0 we can use the implicit extension.
llvm-svn: 321209
This patch turns shuffles of fadd/fsub with fmul into fmsubadd.
Patch by Dmitry Venikov
Differential Revision: https://reviews.llvm.org/D40335
llvm-svn: 321200
The gather instruction will implicitly sign extend to the pointer width, we don't need to further extend it. This can prevent unnecessary splitting in some cases.
There's still an issue that lowering on non-VLX can introduce another sign extend that doesn't get combined with shifts from a lowered sign_extend_inreg.
llvm-svn: 321152
Not sure how to test this cause I think the worst that happens is that we don't revisit the node a second time to look for additional combines. We used UpdateNodeOperands so the updating the DAG work was already done.
llvm-svn: 321148
We try to prevent shuffle combining to value types that would stop the folding of masked operations, but by just returning early, we were failing to try different shuffle types.
The TODOs are all still relevant here to improve codegen but we're lacking test examples.
llvm-svn: 321085
As mentioned in D38318 and D40865, modern Intel processors prefer to combine multiple shuffles to a variable shuffle mask (PSHUFB/VPERMPS etc.) instead of having multiple stage 'fixed' shuffles which put more pressure on Port 5 (at the expense of extra shuffle mask loads).
This patch provides a FeatureFastVariableShuffle target flag for Haswell+ CPUs that prefers combining 2 or more fixed shuffles to a single variable shuffle (default is 3 shuffles).
The long term aim is to drive more of this from schedule data (probably via the MC) but we're not close to being ready for that yet.
Differential Revision: https://reviews.llvm.org/D41323
llvm-svn: 321074
Extension to D39729 which performed this for vXi16, with the same bit flipping to handle SMAX/SMIN/UMAX cases, vXi8 UMIN horizontal reductions can be performed.
This makes use of the fact that by performing a pair-wise i8 SHUFFLE/UMIN before PHMINPOSUW, we both get the UMIN of each pair but also zero-extend the upper bits ready for v8i16.
Differential Revision: https://reviews.llvm.org/D41294
llvm-svn: 321070
BWI supports shifting by word amounts. Even if VLX isn't support we can still widen to v32i16 and extract the lower half. For SKX its preferrable to not use 512-bit vector if we can.
llvm-svn: 321059
Previously, we were checking for MVTs with sizes betwen 8 and 64 which only includes i8, i16, i32, and i64 today. But I don't think we should assume that and should list the types that are legal for x86. I also don't think we need i64 since type legalization is guaranteed to split those up.
llvm-svn: 321058
My reading of the SDM says that all bits of the shift amount are used. If the value of the element is larger than the number of bits the result the shift result is zero. So I think we need to zero_extend here to avoid garbage in the upper bits.
In reality we lower any_extend as zero_extend so in most cases it would be hard to hit this.
llvm-svn: 321055
Note:
- X86ISelLowering: setLibcallName(SINCOS) was superfluous as
InitLibcalls() already does it.
- ARMISelLowering: Setting libcallnames for sincos/sincosf seemed
superfluous as in the darwin case it wouldn't be used while for all
other cases InitLibcalls already does it.
llvm-svn: 321036
The block I moved things that need BWI and 512-bit or VLX is incorrectly qualified with just hasBWI || hasVLX. Here I've qualified it with hasBWI && (hasAVX512 || hasVLX) where the hasAVX512 will be replaced with allowing 512-bit vectors in an upcoming patch.
llvm-svn: 320957
Summary:
We had no tests for this and we couldn't do the optimization because of a bad use count check. We need to know how many non-undef pieces of the build vector were filled in and ensure our use count is equal to that. But on the shuffle combine version we need the use count to be 2.
The missing coverage was noticed during the review of D40335.
Reviewers: RKSimon, zvi, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41133
llvm-svn: 320950
Assuming we can safely adjust the broadcast index for the new type to keep it suitably aligned, then peek through BITCASTs when looking for the broadcast source.
Fixes PR32007
llvm-svn: 320933
In those cases, the pass thru operand of the methods isn't used. The calls to the scalar version were passing a MVT::i1 zero, which is an illegal type at the stage this code runs.
llvm-svn: 320928
Previously we promoted to v8i64, but we don't need to go all the way to 512-bits. If we have VLX we can use the 256-bit instruction. And even if we don't have VLX we can widen v8i32 to v16i32 and drop the upper half.
llvm-svn: 320926
The target independent nodes will get legalized to the target specific nodes by their own legalization process. Someday I'd like to stop using a target specific for zero extends and truncates of legal types so the less places we reference the target specific opcode the better.
llvm-svn: 320863
When I wrote it I thought we were missing a potential optimization for KNL. But investigating further shows that for KNL we still do the optimal thing by widening to v4f32 and then using special isel patterns to widen again to zmm a register.
llvm-svn: 320862
Summary:
Currently we don't handle v32i1/v64i1 insert_vector_elt correctly as we fail to look at the number of elements closely and assume it can only be v16i1 or v8i1.
We also can't type legalize v64i1 insert_vector_elt correctly on KNL due to the type not being byte addressable as required by the legalizing through memory accesses path requires.
For the first issue, the patch now tries to pick a 512-bit register with the correct number of elements and promotes to that.
For the second issue, we now extend the vector to a byte addressable type, do the stores to memory, load the two halves, and then truncate the halves back to the original type. Technically since we changed the type, we may not need two loads, but actually checking that is more work and for the v64i1 case we do need them.
Reviewers: RKSimon, delena, spatel, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40942
llvm-svn: 320849
A couple places didn't use the same SDValue variables to connect everything all the way through.
I don't have a test case for a bug in insert into the lower bits of a non-zero, non-undef vector. Not sure the best way to create that. We don't create the case when lowering concat_vectors which is the main way to get insert_subvectors.
llvm-svn: 320790
We have several instructions that were introduced in AVX512F that are only available in 512-bit form on KNL. We still make use of them for 128/256 by artificially widening and extracting during isel.
This commit separates these operations from the true 512-bit operations. This way we can qualify the normal 512-bit operations with needing 512-bit register support. And these special operations will get qualified with needing 512-bit registers OR VLX.
The 512-bit register qualification will be introduced in a future patch this just gets everything grouped to minimize deltas on that patch.
llvm-svn: 320782
Previously they were sort of interleaved in with XMM/YMM/ZMM action related code.
Trying to separate things so its easier to split 512-bit vectors later.
llvm-svn: 320781
Move it into the separate hasVLX block later in the constructor.
I'm trying to separate 128/256 and 512-bit related code so we can eventually qualify the hasAVX512 block with support for 512-bit vectors required by the prefer-vector-width feature support being talked about in D41096.
llvm-svn: 320779
Most of the -Wsign-compare warnings are due to the fact that
enums are signed by default in the MS ABI, while the
tautological comparison warnings trigger on x86 builds where
sizeof(size_t) is 4 bytes, so N > numeric_limits<unsigned>::max()
is always false.
Differential Revision: https://reviews.llvm.org/D41256
llvm-svn: 320750
Rather than adding more bits to express every
MMO flag you could want, just directly use the
MMO flags. Also fixes using a bunch of bool arguments to
getMemIntrinsicNode.
On AMDGPU, buffer and image intrinsics should always
have MODereferencable set, but currently there is no
way to do that directly during the initial intrinsic
lowering.
llvm-svn: 320746
This doesn't match the semantics of the extract_vector_elt operation. Nothing downstream knows the bits were zeroed so they still get masked or sign extended after the extrat anyway.
llvm-svn: 320723
store operation on a truncated memory (load) of vXi1 is poorly supported by LLVM and most of the time end with an assertion.
This patch fixes this issue.
Differential Revision: https://reviews.llvm.org/D39547
Change-Id: Ida5523dd09c1ad384acc0a27e9e59273d28cbdc9
llvm-svn: 320691
Pass the input vector through SimplifyDemandedBits as we only need the sign bit from each vector element of MOVMSK
We'd probably get more hits if SimplifyDemandedBits was better at handling vectors...
Differential Revision: https://reviews.llvm.org/D41119
llvm-svn: 320570
D40335 was wanting to add FMSUBADD support, but it discovered that there are two pieces of code to make FMADDSUB and only one of those is tested. So I've asked that review to implement the one path until we get tests that test the existing code.
llvm-svn: 320507
Summary:
Simplify and generalize chain handling and search for 64-bit load-store pairs.
Nontemporal test now converts 64-bit integer load-store into f64 which it realizes directly instead of splitting into two i32 pairs.
Reviewers: craig.topper, spatel
Reviewed By: craig.topper
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D40918
llvm-svn: 320505
Recognize constant arrays with the following values:
0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, .... , 2^(size - 1) -1
where //size// is the size of the array.
the result of a load with index //idx// from this array is equivalent to the result of the following:
(0xFFFFFFFF >> (sub 32, idx)) (assuming the array of type 32-bit integer).
And the result of an 'AND' operation on the returned value of such a load and another input, is exactly equivalent to the X86 BZHI instruction behavior.
See test cases in the LIT test for better understanding.
Differential Revision: https://reviews.llvm.org/D34141
llvm-svn: 320481
We may need to widen the vector to make the shifts legal, but if we do that we need to make sure we shift left/right after accounting for the new size. If not we can't guarantee we are shifting in zeros.
The test cases affected actually show cases where we should move the shifts all together, but that's another problem.
llvm-svn: 320248
We were previously using kunpck with zero inputs unnecessarily. And we had cases where we would insert into a zero vector and then insert into larger zero vector incurring two sets of shifts.
llvm-svn: 320244
For narrow sizes we'll widen the zero vector and widen the insert. Then do an extract_subvector to get back down to correct size.
This allows us to remove some patterns from the isel table that had to COPY_TO_REGCLASS to an oversized register, do the shift and then COPY_TO_REGCLASS back to the narrow register. Now this is represented explicitly in the DAG.
This seems to have perturbed the register allocation in one of the tests, but the number of instructions didn't change.
llvm-svn: 320190
These are aliases, but the thing we're checking here is that the target has
vpsllv*, not that the data type is 256-bit. Those instructions exist for
128-bit vectors too...but sadly, not for all element sizes.
llvm-svn: 320170
Previously we only allowed these through if the subvector came from a compare or test instruction which we would again check for during isel.
With this change we only check for the compare and test instructions during isel and have fallback patterns that emit the shifts if needed.
I noticed that in a lot of cases we don't actually see the compare during lowering and rely on an odd legalization of concat_vectors with a zero vector as the second argument. This keeps the concat_vectors around long enough for a later dag combine to expose the compare then we re-legalize the concat_vectors and catch the compare.
llvm-svn: 320134
We previously only supported inserting to the LSB or MSB where it was easy to zero to perform an OR to insert.
This change effectively extracts the old value and the new value, xors them together and then xors that single bit with the correct location in the original vector. This will cancel out the old value in the first xor leaving the new value in the position.
The way I've implemented this uses 3 shifts and two xors and uses an additional register. We can avoid the additional register at the cost of another shift.
llvm-svn: 320120
There's no v2i1 or v4i1 kshift, and v8i1 is only supported with AVXDQ. Isel has fake patterns to extend these types to native shifts, but makes no guarantees about the value of any bits shifted in when shifting right.
This patch promotes the vector to a type that supports a native shift first and only allows inserting into the msb of a native sized shift.
I've constructed this in a way that doesn't do the promotion if we're going to fallback to using a xmm/ymm/zmm shuffle. I think I have a plan to remove the shuffle fall back entirely. In which case we this can be simplified, but I wanted to fix the correctness issue first.
llvm-svn: 320081
Most of the code in these routines is for handling extends from vXi1 types. The 512-bit handling for other extends is very much like the AVX2 code. So make the special routines just do vXi1 types and move the other 512-bit handling to the place that handles AVX2.
llvm-svn: 319878
The patch originally broke Chromium (crbug.com/791714) due to its failing to
specify that the new pseudo instructions clobber EFLAGS. This commit fixes
that.
> Summary: This strengthens the guard and matches MSVC.
>
> Reviewers: hans, etienneb
>
> Subscribers: hiraditya, JDevlieghere, vlad.tsyrklevich, llvm-commits
>
> Differential Revision: https://reviews.llvm.org/D40622
llvm-svn: 319824
This patch, together with a matching clang patch (https://reviews.llvm.org/D39719), implements the lowering of X86 kunpack intrinsics to IR.
Differential Revision: https://reviews.llvm.org/D39720
Change-Id: I4088d9428478f9457f6afddc90bd3d66b3daf0a1
llvm-svn: 319778
Previously we used a wider element type and truncated. But its more efficient to keep the element type and drop unused elements.
If BWI isn't supported and we have a i16 or i8 type, we'll extend it to be i32 and still use a truncate.
llvm-svn: 319740
Previously we used a wider element type and truncated. But its more efficient to keep the element type and drop unused elements.
If BWI isn't supported and we have a i16 or i8 type, we'll extend it to be i32 and still use a truncate.
llvm-svn: 319728
The getConstant function can take care of creating the APInt internally.
getZeroVector will take care of using the correct type for the build vector to avoid re-lowering.
The test change here is because execution domain constraints apparently pass through undef inputs of a zeroing xor. So the different ordering of register allocation here caused the dependency to change.
llvm-svn: 319725
Move the AVX512 code out of LowerAVXExtend. LowerAVXExtend has two callers but one of them pre-checks for AVX-512 so the code is only live from the other caller. So move the AVX-512 checks up to that caller for symmetry.
Move all of the i1 input type code in Lower_AVX512ZeroExend together.
llvm-svn: 319724
These instructions can be used by widening to 512-bits and extracting back to 128/256. We do similar to several other instructions already.
llvm-svn: 319641
We already do this as a DAG combine. The version during lowering can only trigger if known bits changes something that improves known bits analysis. But this means we should be improving known bits analysis to work on the unlowered form instead.
llvm-svn: 319640
The default legalization for v2i32 is promotion to v2i64. This results in a gather that reads 64-bit elements rather than 32. If one of the elements is near a page boundary this can cause an illegal access that can fault.
We also miscalculate the scale for the gather which is an even worse problem, but we probably could have found a separate way to fix that.
llvm-svn: 319521
As part of the unification of the debug format and the MIR format, avoid
printing "vreg" for virtual registers (which is one of the current MIR
possibilities).
Basically:
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/%vreg([0-9]+)/%\1/g"
* grep -nr '%vreg' . and fix if needed
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/ vreg([0-9]+)/ %\1/g"
* grep -nr 'vreg[0-9]\+' . and fix if needed
Differential Revision: https://reviews.llvm.org/D40420
llvm-svn: 319427
Normal type legalization will widen everything. This requires forcing 0s into the mask register. We can instead choose the form that only reads 2 elements without zeroing the mask.
llvm-svn: 319406
Previously we had an isel pattern to add the truncate. Instead use Promote to add the truncate to the DAG before isel.
The Promote legalization code had to be updated to prevent an infinite loop if promotion took multiple steps because it wasn't remembering the previously tried value.
llvm-svn: 319259
These lines all exist identically either under SSE2, AVX2 or AVX512. Given that VLX implies all of those, these aren't providing anything new.
llvm-svn: 319124
Which VTs are considered simple is determined by the superset of the legal types of all targets in LLVM. If we're looking at VTs that are going to be split down to 512-bits we should allow any VT not just simple ones since the simple list changes over time as new targets are added.
llvm-svn: 319110
We don't do this for narrow vectors under AVX or SSE features. We also don't set them to Expand like we do for many vectors op. Nor does TargetLoweringBase.cpp. This leads me to believe these default to Legal.
llvm-svn: 319103
I don't have a good test case for this at the moment. I was playing around with a change in legalizing and triggered this code to produce a PSHUFD with sse1 only.
llvm-svn: 319066
Similar for vXi16/vXi8 with BWI.
Any vector larger than 512 bits will be split to 512 bits during legalization. But without this we will fold sexts with them before that making it difficult to recover leading to scalarization.
llvm-svn: 319059
Summary:
These instructions zero the non-scalar part of the lower 128-bits which makes them different than the FMA3 instructions which pass through the non-scalar part of the lower 128-bits.
I've only added fmadd because we should be able to derive all other variants using operand negation in the intrinsic header like we do for AVX512.
I think there are still some missed negate folding opportunities with the FMA4 instructions in light of this behavior difference that I hadn't noticed before.
I've split the tests so that we can use different intrinsics for scalar testing between the two. I just copied the tests split the RUN lines and changed out the scalar intrinsics.
fma4-fneg-combine.ll is a new test to make sure we negate the fma4 intrinsics correctly though there are a couple TODOs in it.
Reviewers: RKSimon, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39851
llvm-svn: 318984
v4i32 isn't a legal type with sse1 only and would end up getting scalarized otherwise.
This isn't completely ideal as it doesn't handle cases like v8i32 that would get split to v4i32. But it at least helps with code written using the clang intrinsic header.
llvm-svn: 318967
This optimization can occur after type legalization and emit a vselect with v4i32 type. But that type is not legal with sse1. This ultimately gets scalarized by the second type legalization that runs after vector op legalization, but that's really intended to handle the scalar types that might be introduced by legalizing vector ops.
For now just stop this from happening by disabling the optimization with sse1.
llvm-svn: 318965
(V)PHMINPOSUW determines the UMIN element in an v8i16 input, with suitable bit flipping it can also be used for SMAX/SMIN/UMAX cases as well.
This patch matches vXi16 SMAX/SMIN/UMAX/UMIN horizontal reductions and reduces the input down to a v8i16 vector before calling (V)PHMINPOSUW.
A later patch will use this for v16i8 reductions as well (PR32841).
Differential Revision: https://reviews.llvm.org/D39729
llvm-svn: 318917
This makes the fact that X86 needs an explicit mask output not part of the type constraint for the ISD::MSCATTER.
This also gives the X86ISD::MGATHER/MSCATTER nodes a common base class simplifying the address selection code in X86ISelDAGToDAG.cpp
llvm-svn: 318823
Now we consistently represent the mask result without relying on isel ignoring it.
We now have a more general SDNode and type constraints to represent these nodes in isel patterns. This allows us to present both both vXi1 and XMM/YMM mask types with a single set of constraints.
llvm-svn: 318821
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).
llvm-svn: 318490
Only do this pre-legalize in case we're using the sign extend to legalize for KNL.
This recovers all of the tests that changed when I stopped SelectionDAGBuilder from deleting sign extends.
There's more work that could be done here particularly to fix the i8->i64 test case that experienced split.
llvm-svn: 318468
The wider element type will normally cause legalize to try to split and scalarize the gather/scatter, but we can't handle that. Instead, truncate the index early so the gather/scatter node is insulated from the legalization.
This really shouldn't happen in practice since InstCombine will normalize index types to the same size as pointers.
llvm-svn: 318452
This allows us to remove extra extend creation during lowering and more accurately reflects the semantics of the instruction.
While there add an extra output VT to X86 masked gather node to better match the isel pattern predicate. Currently we're exploiting the fact that the isel table doesn't count how many output results a node actually has if the result type of any can be inferred from the first result and the type constraints defined in tablegen. I think we might ultimately want to lower all MGATHER/MSCATTER to an X86ISD node with the extra mask result and stop relying on this hole in the isel checking.
llvm-svn: 318278
The VRNDSCALE instructions implement a superset of the (V)ROUND instructions. They are equivalent if the upper 4-bits of the immediate are 0.
This patch lowers the legacy intrinsics to the VRNDSCALE ISD node and masks the upper bits of the immediate to 0. This allows us to take advantage of the larger register encoding space.
We should maybe consider converting VRNDSCALE back to VROUND in the EVEX to VEX pass if the extended registers are not being used.
I notice some load folding opportunities being missed for the VRNDSCALESS/SD instructions that I'll try to fix in future patches.
llvm-svn: 318008
I want to reuse the VRNDSCALE node for the legacy SSE rounding intrinsics so that those intrinsics can use EVEX instructions. All of these nodes share tablegen multiclasses so I split them all so that they all remain similar in their implementations.
llvm-svn: 318007
matchBinOpReduction currently matches against a single opcode, but we already have a case where we repeat calls to try to match against AND/OR and I'll be shortly adding another case for SMAX/SMIN/UMAX/UMIN (D39729).
This NFCI patch alters matchBinOpReduction to try and pattern match against any of the provided list of candidate bin ops at once to save time.
Differential Revision: https://reviews.llvm.org/D39726
llvm-svn: 317985
r317453 added new ISD nodes without rounding modes that were added to an existing if/else chain. But all the previous nodes handled there included a rounding mode. The final code after this if/else chain expected an extra operand that isn't present for the new nodes.
llvm-svn: 317748
The EVEX to VEX pass is already assuming this is true under AVX512VL. We had special patterns to use zmm instructions if VLX and F16C weren't available.
Instead just make AVX512 imply F16C to make the EVEX to VEX behavior explicitly legal and remove the extra patterns.
All known CPUs with AVX512 have F16C so this should safe for now.
llvm-svn: 317521
We still early-out for X86ISD::PEXTRW/X86ISD::PEXTRB so no actual change in behaviour, but it'll make it easier to add support in a future patch.
llvm-svn: 317485
combineExtractWithShuffle can handle more complex shuffles/bitcasts than we can with the equivalent code in XFormVExtractWithShuffleIntoLoad.
Mainly a compile time improvement now (combineExtractWithShuffle combines will have always failed late on inside XFormVExtractWithShuffleIntoLoad), and will let us merge combineExtractVectorElt_SSE in a future commit.
llvm-svn: 317481
Added TESTM and TESTNM to the list of instructions that already zeroing unused upper bits
and does not need the redundant shift left and shift right instructions afterwards.
Added a pattern for TESTM and TESTNM in iselLowering, so now icmp(neq,and(X,Y), 0) goes folds into TESTM
and icmp(eq,and(X,Y), 0) goes folds into TESTNM
This commit is a preparation for lowering the test and testn X86 intrinsics to IR.
Differential Revision: https://reviews.llvm.org/D38732
llvm-svn: 317465
Summary:
Try to lower a BUILD_VECTOR composed of extract-extract chains that can be
reasoned to be a permutation of a vector by indices in a non-constant vector.
We saw this pattern created by ISPC, which resolts to creating it due to the
requirement that shufflevector's mask operand be a *constant* vector.
I didn't check this but we could possibly use this pattern for lowering the X86 permute
C-instrinsics instead of llvm.x86 instrinsics.
This change can be followed by more improvements:
1. Handle vectors with undef elements.
2. Utilize pshufb and zero-mask-blending to support more effiecient
construction of vectors with constant-0 elements.
3. Use smaller-element vectors of same width, and "interpolate" the indices,
when no native operation available.
Reviewers: RKSimon, craig.topper
Reviewed By: RKSimon
Subscribers: chandlerc, DavidKreitzer
Differential Revision: https://reviews.llvm.org/D39126
llvm-svn: 317463
This patch, together with a matching clang patch (https://reviews.llvm.org/D38683), implements the lowering of X86 broadcastm intrinsics to IR.
Differential Revision: https://reviews.llvm.org/D38684
Change-Id: I709ac0b34641095397e994c8ff7e15d1315b3540
llvm-svn: 317458
Next step is to use them for the legacy FMA scalar intrinsics as well. This will enable the legacy intrinsics to use EVEX encoded opcodes and the extended registers.
llvm-svn: 317453
Summary:
AVX512 added RCP14 and RSQRT instructions which improve accuracy over the legacy RCP and RSQRT instruction, but not enough accuracy to remove the need for a Newton Raphson refinement.
Currently we use these new instructions for the legacy packed SSE instrinics, but not the scalar instrinsics. And we use it for fast math optimization of division and reciprocal sqrt.
I think switching the legacy instrinsics maybe surprising to the user since it changes the answer based on which processor you're using regardless of any fastmath settings. It's also weird that we did something different between scalar and packed.
As far at the reciprocal estimation, I think it creates unnecessary deltas in our output behavior (and prevents EVEX->VEX). A little playing around with gcc and icc and godbolt suggest they don't change which instructions they use here.
This patch adds new X86ISD nodes for the RCP14/RSQRT14 and uses those for the new intrinsics. Leaving the old intrinsics to use the old instructions.
Going forward I think our focus should be on
-Supporting 512-bit vectors, which will have to use the RCP14/RSQRT14.
-Using RSQRT28/RCP28 to remove the Newton Raphson step on processors with AVX512ER
-Supporting double precision.
Reviewers: zvi, DavidKreitzer, RKSimon
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39583
llvm-svn: 317413
This allows masked operations to be used and allows the register allocator to use YMM16-31 if necessary.
As a follow up I'll look into teaching EVEX->VEX how to turn this back into PERM2X128 if any of the additional features don't work out.
llvm-svn: 317403
Similar to the existing code to lower to PACKSS, we can use PACKUS if the input vector's leading zero bits extend all the way to the packed/truncated value.
We have to account for pre-SSE41 targets not supporting PACKUSDW
llvm-svn: 317315
Similar to the existing code to lower to PACKSS, we can use PACKUS if the input vector's leading zero bits extend all the way to the packed/truncated value.
We have to account for pre-SSE41 targets not supporting PACKUSDW
llvm-svn: 317128
So far we've only been using PACKSS truncations with 'all-bits or zero-bits' patterns (vector comparison results etc.). When really we can safely use it for any case as long as the number of sign bits reach down to the last 16-bits (or 8-bits if we're truncating to bytes).
The next steps after this is add the equivalent support for PACKUS and to support packing to sub-128 bit vectors for truncating stores etc.
Differential Revision: https://reviews.llvm.org/D39476
llvm-svn: 317086
Summary:
INC/DEC don't update the carry flag so we need to make sure we don't try to use it.
This patch introduces new X86ISD opcodes for locked INC/DEC. Teaches lowerAtomicArithWithLOCK to emit these nodes if INC/DEC is not slow or the function is being optimized for size. An additional flag is added that allows the INC/DEC to be disabled if the caller determines that the carry flag is being requested.
The test_sub_1_cmp_1_setcc_ugt test is currently showing this bug. The other test case changes are recovering cases that were regressed in r316860.
This should fully fix PR35068 finishing the fix started in r316860.
Reviewers: RKSimon, zvi, spatel
Reviewed By: zvi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39411
llvm-svn: 316913
If the carry flag is being used, this transformation isn't safe.
This does prevent some test cases from using DEC now, but I'll try to look into that separately.
Fixes PR35068.
llvm-svn: 316860
This code attempted to say that v8i16/v16i16 VSELECT is legal if BWI and VLX are enabled, but the only way we could reach this point is if the condition was not a vXi1 type. Which means it really wasn't legal.
We don't have any tests that exercise this code. So I'm hoping it wasn't really reachable.
llvm-svn: 316851
If the extend type is 64-bits, emit a 32-bit -> 64-bit extend after the UDIVREM8_ZEXT_HREG/UDIVREM8_SEXT_HREG operation.
This gives a shorter encoding for the second extend in the sext case, and allows us to completely remove the second extend in the zext case.
This also adds known bit and num sign bits support for UDIVREM8_ZEXT_HREG/SDIVREM8_SEXT_HREG.
Differential Revision: https://reviews.llvm.org/D38275
llvm-svn: 316702
Instead of loading (a potential ton of) scalar constants, load those as a vector and then insert into it.
Differential Revision: https://reviews.llvm.org/D38756
llvm-svn: 316685
By using the widest type possible for PACKSS truncation we have a better chance of being able to peek through bitcasts and improves other combines driven by ComputeNumSignBits.
llvm-svn: 316448
Remove AssertZext and instead add PEXTRW/PEXTRB support to computeKnownBitsForTargetNode to simplify instruction selection.
Differential Revision: https://reviews.llvm.org/D39169
llvm-svn: 316336
Summary: __multi3 is not available on x86 (32-bit). Setting lib call name for MULI_128 to nullptr forces DAGTypeLegalizer::ExpandIntRes_MUL to generate instructions for 128-bit multiply instead of a call to an undefined function. This fixes PR20871 though it may be worth looking at why licm and indvars combine to generate 65-bit multiplies in that test.
Patch by Riyaz V Puthiyapurayil
Reviewers: craig.topper, schweitz
Reviewed By: craig.topper, schweitz
Subscribers: RKSimon, llvm-commits
Differential Revision: https://reviews.llvm.org/D38668
llvm-svn: 316254
x86 has its own copy of integer absolute pattern matching to combine directly to a SUB+CMOV.
This patch removes the x86 combine and adds custom lowering support for ISD::ABS instead, allowing us to use the DAGCombiner version.
Additional test cases are already covered by iabs.ll (rL315706 and rL315711).
Differential Revision: https://reviews.llvm.org/D38895
llvm-svn: 316162
Summary:
This was impeding our ability to combine the extending shuffles with other shuffles as you can see from the test changes.
There's one special case that needed to be added to use VZEXT directly for v8i8->v8i64 since the custom lowering requires v64i8.
Reviewers: RKSimon, zvi, delena
Reviewed By: delena
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38714
llvm-svn: 315860
Summary:
It's better to use our shuffle lowering code to handle these than loading an immediate into a k-register.
It really feels like this should be a DAG combine optimization rather than a lowering operation, but that's a problem for another day.
Reviewers: RKSimon, delena, zvi
Reviewed By: delena
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38932
llvm-svn: 315849
If we are applying a byte mask to a value extracted from a shuffle, see if we can combine the mask into shuffle.
Fixes the last issue with PR22415
llvm-svn: 315807
This is particularly important for AVX512VL where we are better able to recognize the VBROADCAST loads to fold with other operations.
For AVX512VL we now use X86ISD::VBROADCAST for all of the patterns and remove the 128-bit X86ISD::VMOVDDUP.
We may be able to use this for AVX1 as well which would allow us to remove more isel patterns.
I also had to add X86ISD::VBROADCAST as a node to call combineShuffle for so that we treat it similar to X86ISD::MOVDDUP.
Differential Revision: https://reviews.llvm.org/D38836
llvm-svn: 315768
Summary: We seem to inconsistently create CMOV nodes some with a Glue result and some without. But I can't find any cases that use the Glue result. So I've tried to remove all the place that did this.
Reviewers: RKSimon, spatel, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38664
llvm-svn: 315686
Legalization of fp128 assumes things that we should have asserts for,
so that's another potential improvement.
Differential Revision: https://reviews.llvm.org/D38771
llvm-svn: 315485
Summary:
On behalf of julia.koval@intel.com
The patch transforms canonical version of unsigned saturation, which is sub(max(a,b),a) or sub(a,min(a,b)) to special psubus insturuction on targets, which support it(8bit and 16bit uints).
umax(a,b) - b -> subus(a,b)
a - umin(a,b) -> subus(a,b)
There is also extra case handled, when right part of sub is 32 bit and can be truncated, using UMIN(this transformation was discussed in https://reviews.llvm.org/D25987).
The example of special case code:
```
void foo(unsigned short *p, int max, int n) {
int i;
unsigned m;
for (i = 0; i < n; i++) {
m = *--p;
*p = (unsigned short)(m >= max ? m-max : 0);
}
}
```
Max in this example is truncated to max_short value, if it is greater than m, or just truncated to 16 bit, if it is not. It is vaid transformation, because if max > max_short, result of the expression will be zero.
Here is the table of types, I try to support, special case items are bold:
| Size | 128 | 256 | 512
| ----- | ----- | ----- | -----
| i8 | v16i8 | v32i8 | v64i8
| i16 | v8i16 | v16i16 | v32i16
| i32 | | **v8i32** | **v16i32**
| i64 | | | **v8i64**
Reviewers: zvi, spatel, DavidKreitzer, RKSimon
Reviewed By: zvi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37534
llvm-svn: 315237
We believe that despite AMD's documentation, that they really do support all 32 comparision predicates under AVX.
Differential Revision: https://reviews.llvm.org/D38609
llvm-svn: 315201
Return the combined shuffle from combineX86ShufflesRecursively and perform the combineTo in the caller.
Makes it easier for future patches to use this in functions that aren't actually shuffles themselves.
llvm-svn: 315195
Summary:
We currently disable some converting of shuffles to MOVSS/MOVSD during legalization if SSE41 is enabled. But later during shuffle combining we go back to prefering MOVSS/MOVSD.
Additionally we have patterns that look for BLENDIs to detect scalar arithmetic operations. I believe due to the combining using MOVSS/MOVSD these are unnecessary.
Interestingly, we still codegen blend instructions even though lowering/isel emit movss/movsd instructions. Turns out machine CSE commutes them to blend, and then commuting those blends back into blends that are equivalent to the original movss/movsd.
This patch fixes the inconsistency in legalization to prefer MOVSS/MOVSD. The one test change was caused by this change. The problem is that we have integer types and are mostly selecting integer instructions except for the shufps. This shufps forced the execution domain, but the vpblendw couldn't have its domain changed with a naive instruction swap. We could fix this by special casing VPBLENDW based on the immediate to widen the element type.
The rest of the patch is removing all the excess scalar patterns.
Long term we should probably add isel patterns to make MOVSS/MOVSD emit blends directly instead of relying on the double commute. We may also want to consider emitting movss/movsd for optsize. I also wonder if we should still use the VEX encoded blendi instructions even with AVX512. Blends have better throughput, and that may outweigh the register constraint.
Reviewers: RKSimon, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38023
llvm-svn: 315181
Recognise cases when we can merge the shuffles with their horizontal (HADD/HSUB/PACK) instruction inputs.
Replaces an older implementation which performed some of this during lowering, expanding an existing target shuffle combine stage instead.
Differential Revision: https://reviews.llvm.org/D38506
llvm-svn: 315150
The SjLj intrinsics in the X86 backend are intended for use with
SjLj exception handling as well, since SVN r271244.
Differential Revision: https://reviews.llvm.org/D38532
llvm-svn: 315146
The code which lowers BUILD_VECTOR of consecutive loads into a single vector
load doesn't update chains properly. As a result the vector load can be
reordered with the store to the same location.
The current code in EltsFromConsecutiveLoads only updates the chain following
the first load. The fix is to update the chains following all the loads
comprising the vector.
This is a fix for PR10114.
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D38547
llvm-svn: 314988
Early out from vector shift by immediates that will exceed eltsize - don't bother making an unnecessary ComputeNumSignBits recursive call.
llvm-svn: 314903
The previous version didn't work if the jump table base address didn't
fit in 32 bit, since it was encoded as an immediate offset. And in case
the jump table is encoded as 32 bit label differences, we need to
load and add them to the table base first.
This solves the first half of the issues mentioned in PR34720.
Also fix some of the errors pointed out by -verify-machineinstrs, by
using GR32_NOSPRegClass.
Differential Revision: https://reviews.llvm.org/D38333
llvm-svn: 314876
If the upper bits of a truncation shuffle patterns have at least the minimum number of sign/zero bits on their inputs then we can safely use PACKSS/PACKUS as shuffles.
Partial fix for https://bugs.llvm.org/show_bug.cgi?id=34773
Differential Revision: https://reviews.llvm.org/D38472
llvm-svn: 314788
This makes sure the LSDA pointer isn't truncated to 32 bit.
Make LowerINTRINSIC_WO_CHAIN a member function instead of a static
function, so that it can use the getGlobalWrapperKind method.
This solves the second half of the issues mentioned in PR34720.
Differential Revision: https://reviews.llvm.org/D38343
llvm-svn: 314767
The refactoring in
"[X86][SSE] Add createPackShuffleMask helper function. NFCI."
resulted in warning when compiling the code (seen in build bots).
This patch restores some types from int to unsigned to avoid
those warnings.
llvm-svn: 314667
Implemented by splitting into two v32i8 mulhu/mulhs and concatenating the results.
Differential Revision: https://reviews.llvm.org/D38307
llvm-svn: 314584
If we have BWI, we can truncate in a much simpler way by using vpmovwb. This even works without VLX by using the wider zmm->ymm truncate with a subvector extract.
Differential Revision: https://reviews.llvm.org/D38375
llvm-svn: 314457
We aren't do any in register extends here so we should be able to just the target independent nodes directly and allow them to be lowered as necessary.
llvm-svn: 314447
Summary: If we have BWI instructions we can widen to v32i16 to do the multiply instead of splitting.
Reviewers: RKSimon, spatel, zvi
Reviewed By: zvi
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38305
llvm-svn: 314432
Previously we were using one of the subvector indices twice. The included test case causes an assert without this change.
Thanks to Simon Pilgrim for catching this.
llvm-svn: 314429
We already have zeroable bits in an APInt. We might as well use that instead of checking for an all zero BUILD_VECTOR.
Differential Revision: https://reviews.llvm.org/D37950
llvm-svn: 314332
In some cases the result psadbw is smaller than the type of the add that started the match. Currently in these cases we are using a smaller add and inserting the result.
If we instead combine the psadbw with zeros and use the full size add we can take advantage of implicit zeroing we get if we emit a narrower move before the add.
In a future patch, I want to make isel aware that the psadbw itself already zeroed the upper bits and remove the move entirely.
Differential Revision: https://reviews.llvm.org/D37453
llvm-svn: 314331
As commented on D37849 and rL313547, AVX1 targets were missing a chance to use vmovmskpd for v4f64/v4i64 results for bool vector bitcasts
llvm-svn: 314293
This is necessary, but not sufficient, for having working SJLJ exception
handling on x86_64.
Differential Revision: https://reviews.llvm.org/D38254
llvm-svn: 314277
The callsite value is already stored indexed from 0 in
the _Unwind_Context struct. When accessed via the functions
_Unwind_GetIP and _Unwind_SetIP, the value is indexed from 1,
but those functions handle the offseting. When reading directly
from the struct here, we shouldn't subtract 1.
This matches the code generated by the ARM target, where SJLJ
exception handling is used by default on iOS.
This makes clang-built object files for 32 bit x86 mingw work when
linked with libgcc/libstdc++.
Differential Revision: https://reviews.llvm.org/D38251
llvm-svn: 314276
The XOP rotations act as ROTL with +ve values and ROTR with -ve values, which means that we can treat them all as ROTL with unsigned modulo. We already check that we're only trying to lower as ROTL for XOP rotations.
Differential Revision: https://reviews.llvm.org/D37949
llvm-svn: 314207
This required changing the ISD opcode for these instructions to have the commutable operands first and the addend last. This way tablegen can autogenerate the additional patterns for us.
llvm-svn: 314083
This patch acts as a reverse to combineBitcastvxi1 - bitcasting a scalar integer to a boolean vector and extending it 'in place' to the requested legal type.
Currently this doesn't handle AVX512 at all - but the current mask register approach is lacking for some cases.
Differential Revision: https://reviews.llvm.org/D35320
llvm-svn: 314076
This is a follow-up from D38181 (r314023). We have to put 64-bit
constants into a register using a separate instruction, so we
should try harder to avoid that.
From what I see, we're not likely to encounter this pattern in the
DAG because the upstream setcc combines from this don't (usually?)
produce this pattern. If we fix that, then this will become more
relevant. Since the cost of handling this case is just loosening
the predicate of the existing fold, we might as well do it now.
llvm-svn: 314064
The (non-)obvious win comes from saving 3 bytes by using the 0x83 'and' opcode variant instead of 0x81.
There are also better improvements based on known-bits that allow us to eliminate the mask entirely.
As noted, this could be extended. There are potentially other wins from always shifting first, but doing
that reveals a tangle of problems in other pattern matching. We do this transform generically in
instcombine, but we often have icmp IR that doesn't match that pattern, so we must account for this
in the backend.
Differential Revision: https://reviews.llvm.org/D38181
llvm-svn: 314023
Combine CMOV[i16]<-[SIGN,ZERO,ANY]_EXTEND to [i32,i64] into CMOV[i32,i64].
One example of where it is useful is:
before (20 bytes)
<foo>:
test $0x1,%dil
mov $0x307e,%ax
mov $0xffff,%cx
cmovne %ax,%cx
movzwl %cx,%eax
retq
after (18 bytes)
<foo>:
test $0x1,%dil
mov $0x307e,%ecx
mov $0xffff,%eax
cmovne %ecx,%eax
retq
Reviewers: craig.topper, aaboud, spatel, RKSimon, zvi
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36711
llvm-svn: 313982
The shuffle combining and lowerVectorShuffleAsLanePermuteAndBlend were both still trying to use VPERM2XF128 for unary shuffles when AVX2 is enabled. VPERM2X128 takes two inputs meaning when we use it for a unary shuffle one of those inputs is left undefined creating a false dependency on whatever register gets allocated there.
If we have VPERMQ/PD we should prefer those since they only have a single input.
Differential Revision: https://reviews.llvm.org/D37947
llvm-svn: 313542
The same code appears earlier in the function. This represents an earlier version of what became r313373 that I still had sitting in my local repo.
llvm-svn: 313465
I've moved the test cases from the InstCombine optimizations to the backend to keep the coverage we had there. It covered every possible immediate so I've preserved the resulting shuffle mask for each of those immediates.
llvm-svn: 313450
The early out for AVX2 in lowerV2X128VectorShuffle is positioned in a weird spot below some shuffle mask equivalency checks.
But I think we want to allow VPERMQ for any unary shuffle.
Differential Revision: https://reviews.llvm.org/D37893
llvm-svn: 313373
When handling a v64i1 build vector of constants on 32-bit targets we were creating an illegal i64 constant that we then bitcasted back to v64i1. We need to instead create two 32-bit constants, bitcast them to v32i1 and concat the result. We should also take care to handle the halves being all zeros/ones after the split.
This patch splits the build vector and then recursively lowers the two pieces. This allows us to handle the all ones and all zeros cases with minimal effort. Ideally we'd just do the split and concat, and let lowering get called again on the new nodes, but getNode has special handling for CONCAT_VECTORS that reassembles the pieces back into a single BUILD_VECTOR. Hopefully the two temporary BUILD_VECTORS we had to create to do this that don't get returned don't cause any issues.
Fixes PR34605.
Differential Revision: https://reviews.llvm.org/D37858
llvm-svn: 313366
Load with zero-extend and sign-extend from v2i8 to v2i32 is "Legal" since SSE4.1 and may be performed using PMOVZXBD , PMOVSXBD instructions.
llvm-svn: 313121
Fuchsia's lowest API layer has been renamed from Magenta to Zircon.
In LLVM proper, this is only mentioned in comments.
Patch by Roland McGrath
Differential Revision: https://reviews.llvm.org/D37763
llvm-svn: 313105
The masked store instruction only cares about the sign-bit of each mask element,
so the compare s<0 isn't needed.
As noted in PR11210:
https://bugs.llvm.org/show_bug.cgi?id=11210
...fixing this should allow us to eliminate x86-specific masked store intrinsics in IR.
(Although more testing will be needed to confirm that.)
I filed a bug to track improvements for AVX512:
https://bugs.llvm.org/show_bug.cgi?id=34584
Differential Revision: https://reviews.llvm.org/D37446
llvm-svn: 313089
Recognizing this pattern during DAG combine hides information about the 'and' and the shift from other combines. I think it should be recognized at isel so its as late as possible. But it can't be done with table based isel because you need to be able to look at both immediates. This patch moves it to custom isel in X86ISelDAGToDAG.cpp.
This does break a couple tests in tbm_patterns because we are now emitting an and_flag node or (cmp and, 0) that we dont' recognize yet. We already had this problem for several other TBM patterns so I think this fine and we can address of them together.
I've also fixed a bug where the combine to BEXTR was preventing us from using a trick of zero extending AH to handle extracts of bits 15:8. We might still want to use BEXTR if it enables load folding. But honestly I hope we narrowed the load instead before got to isel.
I think we should probably also support matching BEXTR from (srl/srl (and mask << C), C). But that should be a different patch.
Differential Revision: https://reviews.llvm.org/D37592
llvm-svn: 313054
Summary:
r275950 added support for turning (trunc (X >> N) to i1) into BT(X, N). But that's no longer necessary now that i1 isn't legal.
This patch removes the support for that, but preserves some of the refactorings done in that commit.
Reviewers: guyblank, RKSimon, spatel, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37673
llvm-svn: 312925
Helps improve combineLogicBlendIntoPBLENDV support by allowing us to peek into through PACKSS truncations of vector comparison results.
Differential Revision: https://reviews.llvm.org/D37680
llvm-svn: 312916
First step towards making it possible to use the shuffle combines for cases where we don't want to call DCI.CombineTo() with the result.
llvm-svn: 312884
Summary:
Just because INC/DEC is a little slow on some processors doesn't mean we shouldn't prefer it when optimizing for size.
This appears to match gcc behavior.
Reviewers: chandlerc, zvi, RKSimon, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37177
llvm-svn: 312866
Summary:
Add patterns for
fptoui <16 x float> to <16 x i8>
fptoui <16 x float> to <16 x i16>
Reviewers: igorb, delena, craig.topper
Reviewed By: craig.topper
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37505
llvm-svn: 312704
Intrinsic handling is still creating these nodes with 32-bit elements as well. But at least this gets rid of 8 and 16.
Ideally, someday we'll convert the intrinsics to generic vector shuffles and remove the intrinsics.
llvm-svn: 312702
Summary:
Most instructions in AVX work “in-lane”, that is, each source element is applied only to other
elements of the same lane, thus a cross lane permutation is costly and needs more than one instrution.
AVX2 includes instructions to perform any-to-any permutation of words over a 256-bit register
and vectorized table lookup.
This should also Fix PR34369
Differential Revision: https://reviews.llvm.org/D37388
llvm-svn: 312608
In a future patch, I plan to teach isel to use a small vector move with implicit zeroing of the upper elements when it sees the (insert_subvector zero, X, 0) pattern.
llvm-svn: 312448
This is limited to a set of patterns based on the example in PR34111:
https://bugs.llvm.org/show_bug.cgi?id=34111
...but as I was investigating this, I see that horizontal patterns can go wrong in many,
many other ways that would not be handled by this patch. Each data type may even go
different in the DAG after starting with the same basic IR pattern, so even proper IR
canonicalization won't fix it all.
Differential Revision: https://reviews.llvm.org/D37357
llvm-svn: 312379
Prior to this patch we had a DAG combine that tried to bypass an X86ISD::ADD with -1 being added to the carry flag of some previous operation. We would then pass the carry flag directly to user.
But this is only safe if the user is looking for the carry flag and not the zero flag.
So we need to only do this combine in a context where we know what flag the consumer is using.
Fixes PR34381.
Differential Revision: https://reviews.llvm.org/D37317
llvm-svn: 312285
Summary:
This patch adjusts the patterns to make the result type of the broadcast node vXf64/vXi64. Then adds a bitcast to vXi32 after that. Intrinsic lowering was also adjusted to generate this new pattern.
Fixes PR34357
We should probably just drop the intrinsic entirely and use native IR, but I'll leave that for a future patch.
Any idea what instruction we should be lowering the floating point 128-bit result version of this pattern to? There's a 128-bit v2i32 integer broadcast but not an fp one.
Reviewers: aymanmus, zvi, igorb
Reviewed By: aymanmus
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37286
llvm-svn: 312101
EXTRACT_SUBVECTOR was marked Custom solely so we could combine it with BUILD_VECTOR operations to create smaller BUILD_VECTORS during Legalization. But that sort of combining should really be done by the DAG combiner.
This patch adds the last piece of needed supported DAG combine to handle this. Once that's done we can make the EXTRACT_SUBVECTOR operations Legal.
Differential Revision: https://reviews.llvm.org/D37197
llvm-svn: 311893
We used to do a late DAG combine to move the bitcasts out of the way, but I'm starting to think that it's better to canonicalize extract_subvector's type to match the type of its input. I've seen some cases where we've formed two different extract_subvector from the same node where one had a bitcast and the other didn't.
Add some more test cases to ensure we've also got most of the zero masking covered too.
llvm-svn: 311837
The comment for this code indicated that it should work similar to our
handling of add lowering above: if we see uses of an instruction other
than flag usage and store usage, it tries to avoid the specialized
X86ISD::* nodes that are designed for flag+op modeling and emits an
explicit test.
Problem is, only the add case actually did this. In all the other cases,
the logic was incomplete and inverted. Any time the value was used by
a store, we bailed on the specialized X86ISD node. All of this appears
to have been historical where we had different logic here. =/
Turns out, we have quite a few patterns designed around these nodes. We
should actually form them. I fixed the code to match what we do for add,
and it has quite a positive effect just within some of our test cases.
The only thing close to a regression I see is using:
notl %r
testl %r, %r
instead of:
xorl -1, %r
But we can add a pattern or something to fold that back out. The
improvements seem more than worth this.
I've also worked with Craig to update the comments to no longer be
actively contradicted by the code. =[ Some of this still remains
a mystery to both Craig and myself, but this seems like a large step in
the direction of consistency and slightly more accurate comments.
Many thanks to Craig for help figuring out this nasty stuff.
Differential Revision: https://reviews.llvm.org/D37096
llvm-svn: 311737
This goes back to a discussion about IR canonicalization. We'd like to preserve and convert
more IR to 'select' than we currently do because that's likely the best choice in IR:
http://lists.llvm.org/pipermail/llvm-dev/2016-September/105335.html
...but that's often not true for codegen, so we need to account for this pattern coming in
to the backend and transform it to better DAG ops.
Steps in this patch:
1. Add an EVT param to the existing convertSelectOfConstantsToMath() TLI hook to more finely
enable this transform. Other targets will probably want that anyway to distinguish scalars
from vectors. We're using that here to exclude AVX512 targets, but it may not be necessary.
2. Convert a vselect to ext+add. This eliminates a constant load/materialization, and the
vector ext is often free.
Implementing a more general fold using xor+and can be a follow-up for targets that don't have
a legal vselect. It's also possible that we can remove the TLI hook for the special case fold
implemented here because we're eliminating a constant, but it needs to be tested on other
targets.
Differential Revision: https://reviews.llvm.org/D36840
llvm-svn: 311731
This patch is intended to enable the use of basic double letter constraints used in GCC extended inline asm {Yi Y2 Yz Y0 Ym Yt}.
Supersedes D35204
Clang counterpart: D36371
Differential Revision: https://reviews.llvm.org/D36369
llvm-svn: 311644
There are no 512-bit blend instructions so we shouldn't create SHRUNKBLEND for them.
On a side note, it looks like there may be a missed opportunity for constant folding TESTM when LHS and RHS are equal.
This fixes PR34139.
Differential Revision: https://reviews.llvm.org/D36992
llvm-svn: 311572
There's no reason to have a target specific node with the same semantics as a target independent opcode.
This should simplify D36335 so that it doesn't need to touch X86ISelDAGToDAG.cpp
Differential Revision: https://reviews.llvm.org/D36983
llvm-svn: 311568
This partially reverts r311429 in favor of making ISD::isConstantSplatVector do something not confusing. Turns out the only other user of it was also having to deal with the weird property of it returning a smaller size.
So rather than continue to deal with this quirk everywhere, just make the interface do something sane.
Differential Revision: https://reviews.llvm.org/D37039
llvm-svn: 311510
ISD::isConstantSplatVector can shrink to the smallest splat width. But we don't check the size of the resulting APInt at all. This can cause us to misinterpret the results.
This patch just adds a flag to prevent the APInt from changing width.
Fixes PR34271.
Differential Revision: https://reviews.llvm.org/D36996
llvm-svn: 311429
rather than doing a separate comparison.
This both saves an explicit comparision and avoids the use of `xadd`
which introduces register constraints and other challenges to the
generated code.
The motivating case is from atomic reference counts where `1` is the
sentinel rather than `0` for whatever reason. This can and should be
lowered efficiently on x86 by just using a different flag, however the
x86 code only handled the `0` case.
There remains some further opportunities here that are currently hidden
due to canonicalization. I've included test cases that show these and
FIXMEs. However, I don't at the moment have any production use cases and
they seem substantially harder to address.
Differential Revision: https://reviews.llvm.org/D36945
llvm-svn: 311317
According to the X86ISelLowering.h, UMUL results are low, high, and flags. But this place was treating result 1 or 2 as flags.
Differential Revision: https://reviews.llvm.org/D36654
llvm-svn: 310846
Summary:
The flag result is an i32 type. But its only really used for connectivity. I don't think anything even assumes a particular format. We don't ever do any real operations on it. So known bits don't help us optimize anything.
My main motivation is that the UMUL behavior is actually wrong. I was going to fix this in D36654, but then realized there was just no reason for it to be here.
Reviewers: RKSimon, zvi, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36657
llvm-svn: 310845
Previously it would not return true for extracting either of the upper quarters of a 512-bit registers.
For mask registers we support extracting anything from index 0. And otherwise we only support extracting the upper half of a register.
Differential Revision: https://reviews.llvm.org/D36638
llvm-svn: 310794
Summary:
Without the SrcVT its hard to know what is really being asked for. For example if your target has 128, 256, and 512 bit vectors. Maybe extracting 128 from 256 is cheap, but maybe extracting 128 from 512 is not.
For x86 we do support extracting a quarter of a 512-bit register. But for i1 vectors we don't have isel patterns for extracting arbitrary pieces. So we need this to have a correct implementation of isExtractSubvectorCheap for mask vectors.
Reviewers: RKSimon, zvi, efriedma
Reviewed By: RKSimon
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D36649
llvm-svn: 310793
Add an X86 combine for TESTM when one of the operands is a BUILD_VECTOR(0,0,...).
TESTM op0, BUILD_VECTOR(0,0,...) -> BUILD_VECTOR(0,0,...)
TESTM BUILD_VECTOR(0,0,...), op1 -> BUILD_VECTOR(0,0,...)
Differential Revision:
https://reviews.llvm.org/D36536
llvm-svn: 310787
Summary:
Previously we were creating the flag result with MVT::Other which is interpretted as a Chain node. If we used a memory form of the instruction we would end up with a copyToReg that consumed the chain result of the adcx instruction instead of the flag result.
Pretty sure we should be using MVT::i32 here, that's what we do other places we create these node types.
We should probably consider this for 5.0 as well.
Reviewers: RKSimon, zvi, spatel
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36645
llvm-svn: 310784
Summary:
Previously we would use these instructions if sse was disabled and fastmath was enabled.
As mentioned in D28335, this is a bad idea.
Reviewers: efriedma, scanon, DavidKreitzer
Reviewed By: DavidKreitzer
Subscribers: zvi, llvm-commits
Differential Revision: https://reviews.llvm.org/D36344
llvm-svn: 310762
Summary:
This autoupgrades most of the broadcast intrinsics. They've been unused in clang for some time.
This leaves the 32x2 intrinsics because they are still used in clang.
Reviewers: RKSimon, zvi, igorb
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36606
llvm-svn: 310725
Craig Topper