For slow-hop targets, see if any single-op hops are duplicating work already done on another (dual-op) hop, which can sometimes occur as isHorizontalBinOp tries to find potential duplicates (but can't merge them itself). If so, reuse the other hop and shuffle the result.
That review is extracted from D69372.
It fixes https://bugs.llvm.org/show_bug.cgi?id=42219 bug.
For the noimplicitfloat mode, the compiler mustn't generate
floating-point code if it was not asked directly to do so.
This rule does not work with variable function arguments currently.
Though compiler correctly guards block of code, which copies xmm vararg
parameters with a check for %al, it does not protect spills for xmm registers.
Thus, such spills are generated in non-protected areas and could break code,
which does not expect floating-point data. The problem happens in -O0
optimization mode. With this optimization level there is used
FastRegisterAllocator, which spills virtual registers at basic block boundaries.
Register Allocator does not protect spills with additional control-flow modifications.
Thus to resolve that problem, it is suggested to not copy incoming physical
registers into virtual registers. Instead, store incoming physical xmm registers
into the memory from scratch.
Differential Revision: https://reviews.llvm.org/D80163
Generalize the shuffle(not(x)) -> not(shuffle(x)) fold to handle any binop with 0/-1.
Hopefully we can further generalize to help push target unary/binary shuffles through binops similar to what we do in DAGCombiner::visitVECTOR_SHUFFLE
As discussed on D97478. The removal of the custom tag causes some changes in the add/sub-overflow expansion as it no longer expands to sat-arith codegen.
We should be able to extend this "canonicalizeShuffleWithBinOps" to handle more generic binop cases where either/both operands can be cheaply shuffled.
In conjunction with the 'vperm2x128(bitcast(x),bitcast(y),c) -> bitcast(vperm2x128(x,y,c))' fold in combineTargetShuffle, this should remove any unnecessary bitcasts around vperm2x128 lane shuffles.
Extend the existing combine that handles bitcasting for fp-logic ops to also help remove logic ops across bitcasts to/from the same integer types.
This helps improve AVX512 predicate handling for D/Q logic ops and also allows DAGCombine's scalarizeExtractedBinop to remove some annoying gpr->simd->gpr transfers.
The concat_vectors regression in pr40891.ll will be addressed in a followup commit on this patch.
Differential Revision: https://reviews.llvm.org/D96206
This patch fixes some crashes coming from
X86ISelLowering::getSetCCResultType, which would occasionally return
an EVT constructed from an invalid MVT, which has a null Type pointer.
This patch refers to D95434.
Differential Revision: https://reviews.llvm.org/D97036
Fold shuffle(bop(shuffle(x,y),shuffle(z,w)),bop(shuffle(a,b),shuffle(c,d))) -> bop(shuffle(x,y),shuffle(z,w)),bop(shuffle(a,b),shuffle(c,d))
Attempt to fold from a shuffle of a pair of binops to a binop of shuffles, as long as one/both of the binop sources are also shuffles that can be merged with the outer shuffle. This should guarantee that we remove one binop without introducing any additional shuffles.
Technically there's potential for a merged shuffle's lowering to be poorer than the original shuffle, but it could also be better, and I'm not seeing any regressions as long as we keep the 'don't merge splats' rule already present in MergeInnerShuffle.
This expands and generalizes an existing X86 combine and attempts to merge either of each binop's sources (with an on-the-fly commutation of the shuffle mask) - we couldn't do that in the x86 version as it had to stay in a form that DAGCombine's MergeInnerShuffle would still recognise.
Fixes issue raised by @saugustine in rG5aa8f4c0843a where we were failing to replace null shuffle operands from MergeInnerShuffle to UNDEFs.
Differential Revision: https://reviews.llvm.org/D96345
This reverts commit 5dfba562dd.
That commit causes an assertion failure with the following repro:
typedef long b __attribute__((__vector_size__(16)));
b *d;
b e;
b __attribute__((__always_inline__)) c(b h, b i) {
return (__attribute__((__vector_size__(8 * sizeof(short)))) short)h + i;
}
j() {
b k, l, m, n, o[6], p, q;
m = d[5];
b r = m;
b s = f(r, 8);
q = s;
l = d[1];
p = l;
t(q);
n = c(m, l);
o[1] = c(s, f(p, 8));
k = __builtin_shufflevector(n, o[1], 0, 2);
e = __builtin_ia32_psrlwi128(k, j);
}
./bin/clang -cc1 -triple x86_64-grtev4-linux-gnu -emit-obj -O1 -std=c99 test.c
Fold shuffle(bop(shuffle(x,y),shuffle(z,w)),bop(shuffle(a,b),shuffle(c,d))) -> bop(shuffle(x,y),shuffle(z,w)),bop(shuffle(a,b),shuffle(c,d))
Attempt to fold from a shuffle of a pair of binops to a binop of shuffles, as long as one/both of the binop sources are also shuffles that can be merged with the outer shuffle. This should guarantee that we remove one binop without introducing any additional shuffles.
Technically there's potential for a merged shuffle's lowering to be poorer than the original shuffle, but it could also be better, and I'm not seeing any regressions as long as we keep the 'don't merge splats' rule already present in MergeInnerShuffle.
This expands and generalizes an existing X86 combine and attempts to merge either of each binop's sources (with an on-the-fly commutation of the shuffle mask) - we couldn't do that in the x86 version as it had to stay in a form that DAGCombine's MergeInnerShuffle would still recognise.
Differential Revision: https://reviews.llvm.org/D96345
Begin transitioning the X86 vector code to recognise sub(umax(a,b) ,b) or sub(a,umin(a,b)) USUBSAT patterns to make it more generic and available to all targets.
This initial patch just moves the basic umin/umax patterns to DAG, removing some vector-only checks on the way - these are some of the patterns that the legalizer will try to expand back to so we can be reasonably relaxed about matching these pre-legalization.
We can handle the trunc(sub(..))) variants as well, which helps with patterns where we were promoting to a wider type to detect overflow/saturation.
The remaining x86 code requires some cleanup first - some of it isn't actually tested etc. I also need to resurrect D25987.
Differential Revision: https://reviews.llvm.org/D96413
Fold shufps(hop(x,y),hop(z,w)) -> permute(hop(x,z)) - this is very similar to the equivalent unpack fold.
I did start trying to convert foldShuffleOfHorizOp to handle generic shuffle masks but we're relying on a lot of special cases at the moment.
I don't think we have any reason to believe the FP_ROUND here doesn't change the value.
Found while trying to see if we still need the fp128 block in CanCombineFCOPYSIGN_EXTEND_ROUND.
Removing that check caused this FP_ROUND to fire for fp128 which introduced a libcall expansion that asserted for this being a 1.
Reviewed By: RKSimon, pengfei
Differential Revision: https://reviews.llvm.org/D96098
Now that PR48908 has been dealt with, we can handle v4f64 permute cases by extracting the low/high lane VPERMILPD masks and creating a new mask based on which lanes are referenced by the VPERM2F128 mask.
Extends D95779 to permit insertion into float/doubles vectors while avoiding a lot of aliased memory traffic.
The scalar value is already on the simd unit, so we only need to transfer and splat the index value, then perform the select.
SSE4 codegen is a little bulky due to the tied register requirements of (non-VEX) BLENDPS/PD but the extra moves are cheap so shouldn't be an actual problem.
Differential Revision: https://reviews.llvm.org/D95866
With predicate masks, AVX512 can efficiently perform variable-index vector insertion with 2 broadcasts + 1 comparison, avoiding a lot of aliased memory traffic.
Differential Revision: https://reviews.llvm.org/D95779
This is directly analogous to the existing no_caller_saved_registers, but with the opposite intention. A function or call so marked shifts the responsibility of spilling the usual CSRs to it's caller.
An indirect call site and callee which don't agree on the attribute is ill defined.
The motivation for this change is that being able to prune callee saves (without modifying other details of the calling convention) is sometimes useful when generating stubs and adapters. There's no intention to expose this as a source language feature; this is expected to be used by frontends to implement adapters where warranted.
Some specific examples of use cases:
* GC compatible compiled code wants to call an externally defined library function without needing to track pointer values through CSRs.
* debug enabled code wants to call precompiled library which doesn't provide enough information to track CSRs while preserving debug quality in caller.
* adapter stub entering hand written assembler which doesn't follow normal calling conventions.
We can only legally extract from the lowest 128-bit subvector, so extract the correct subvector to allow us to handle 256/512-bit vector element extracts.
If the shuffle mask can't be widened to match the original extracted element width, see if the upper bits are zeroable - which allows us to extract+zero-extend the smaller extraction.
Ensure we check the valuetypes of all the HOP(SHUFFLE(X,Y),SHUFFLE(X,Y)) shuffle input ops - there was a copy+paste typo (noticed by MSVC analyzer) that meant we were checking the same input from one of the shuffles twice.
I haven't been able to create a test case for this yet - I don't think its currently possible to create a target/faux binary shuffle that scales to a 2x128 shuffle mask from two different value types.
Unlike VPERMILPS, VPERMILPD can have non-repeating masks in each 128-bit subvector, we weren't accounting for this when folding vperm2f128(vpermilpd(x,c),vpermilpd(y,c)) -> vpermilpd(vperm2f128(x,y),c).
I'm intending to add support for this but wanted to get a minimal fix in first for merging into 12.xx.
Fixes PR48908
We're relying on the source inputs for shuffle combining having already been widened to the root size (otherwise the offset logic falls over) - we're going to be supporting different sized shuffle inputs soon, so we need to explicitly make the minimum widened width the original root size.
We allow insert_subvector lowering of all legal types, so don't always cast to the vXi64/vXf64 shuffle types - this is only necessary for X86ISD::SHUF128/X86ISD::VPERM2X128 patterns later.
Simplify vperm2x128(concat(X,Y),concat(Z,W)) folding.
Use collectConcatOps / ISD::INSERT_SUBVECTOR to find the source subvectors instead of hardcoded immediate matching.
combineX86ShufflesConstants/canonicalizeShuffleMaskWithHorizOp can both handle/earlyout shuffles with inputs of different widths, so delay widening as late as possible to make it easier to match constant folds etc.
The plan is to eventually move the widening inside combineX86ShuffleChain so that we don't create any new nodes unless we successfully combine the shuffles.
rGbe69e66b1cd8 added the fold, but DAGCombiner.visitVECTOR_SHUFFLE doesn't merge shuffles if the inner shuffle is a splat, so we need to bail.
The non-fast-horiz-ops paths see some minor regressions, we might be able to improve on this after lowering to target shuffles.
Fix PR48823
We already have an experimental option to tune loop alignment. Its impact
is very wide (and there is a suspicion that it's not always profitable). We want
to have something more narrow to play with. This patch adds similar option that
overrides preferred alignment for innermost loops. This is for experimental
purposes, default values do not change the existing behavior.
Differential Revision: https://reviews.llvm.org/D94895
Reviewed By: pengfei
We already handle "vperm2x128 (ins ?, X, C1), (ins ?, X, C1), 0x31" for shuffling of the upper subvectors, but we weren't dealing with the case when we were splatting the upper subvector from a single source.
As discussed on D56387, if we're shifting to extract the upper/lower half of a vXi64 vector then we're actually better off performing this at the subvector level as its very likely to fold into something.
combineConcatVectorOps can perform this in reverse if necessary.
If a srl doesn't introduce any sign bits into the truncated result, then replace with a sra to let us use a PACKSS truncation - fixes a regression noticed in D56387 on pre-SSE41 targets that don't have PACKUSDW.
Specify LHS/RHS operands in matchShuffleWithUNPCK's calls to isTargetShuffleEquivalent, and handle VBROADCAST/VBROADCAST_LOAD matching in IsElementEquivalent
If this will help us fold shuffles together, then push the shuffle through the merged binops.
Ideally this would be performed in DAGCombiner::visitVECTOR_SHUFFLE but getting an efficient+legal merged shuffle can be tricky - on SSE we can be confident that for 32/64-bit elements vectors shuffles should easily fold.
See if we can remove the shuffle by resorting a HOP chain so that the HOP args are pre-shuffled.
This initial version just handles (the most common) v4i32/v4f32 hadd/hsub reduction patterns - future work can extend this to v8i16 types plus PACK chains (2f64 HADD/HSUB should already be handled in the half-lane combine code later on).
canonicalizeShuffleMaskWithHorizOp currently only supports shuffles with 1 or 2 sources, but PR41813 will require us to support higher numbers of sources.
This patch just generalizes the initial setup stages to ensure all src ops are the same type and opcode and then will continue to early out if we have more than 2 sources.
rG73a44f437bf1 result in 256-bit packss/packus ops with additional shuffles that shuffle combining can sometimes try to convert back into a truncation.
Adapted from D54696 by @nikic.
This patch improves lowering of saturating float to
int conversions, FP_TO_[SU]INT_SAT, for X86.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D86079
We can't easily treat ASHR a faux shuffle, but if it was just feeding a PACKSS then it was likely being used as sign-extension for a truncation, so just peek through and adjust the mask accordingly.
v16i32 -> v16i16/v8i16 truncation is now good enough using PACKSS/PACKUS + shuffle combining that its no longer necessary to early-out on pre-AVX512BW targets.
This was noticed while looking at completing PR40111 and moving combineSubToSubus to DAGCombine entirely.
SSE2 truncation codegen has improved over the past few years (mainly due to better shuffle lowering/combining and computeKnownBits) - its no longer necessary to early-out from v8i32/v8i64 truncations.
This was noticed while looking at completing PR40111 and moving combineSubToSubus to DAGCombine entirely.
If vpermf128/vpermi128 is acting on 2 similar 'inlane' ops, then try to perform the vpermf128 first which will allow us to merge the ops.
This will help us fix one of the regressions in D56387
This reapplies commit rG80dee7965dffdfb866afa9d74f3a4a97453708b2.
[X86][SSE] Fold unpack(hop(),hop()) -> permute(hop())
UNPCKL/UNPCKH only uses one op from each hop, so we can merge the hops and then permute the result.
REAPPLIED with a fix for unary unpacks of HOP.
AVX512 has fast truncation ops, but if the truncation source is a concatenation of subvectors then its likely that we can use PACK more efficiently.
This is only guaranteed to work for truncations to 128/256-bit vectors as the PACK works across 128-bit sub-lanes, for now I've just disabled 512-bit truncation cases but we need to get them working eventually for D61129.
When building abseil-cpp `bin/absl_hash_test` with Clang in -fno-pic
mode, an instruction like `movl $foo-2147483648, $eax` may be produced
(subtracting a number from the address of a static variable). If foo's
address is smaller than 2147483648, GNU ld/gold/LLD will error because
R_X86_64_32 cannot represent a negative value.
```
using absl::Hash;
struct NoOp {
template < typename HashCode >
friend HashCode AbslHashValue(HashCode , NoOp );
};
template <typename> class HashIntTest : public testing::Test {};
TYPED_TEST_SUITE_P(HashIntTest);
TYPED_TEST_P(HashIntTest, BasicUsage) {
if (std::numeric_limits< TypeParam >::min )
EXPECT_NE(Hash< NoOp >()({}),
Hash< TypeParam >()(std::numeric_limits< TypeParam >::min()));
}
REGISTER_TYPED_TEST_CASE_P(HashIntTest, BasicUsage);
using IntTypes = testing::Types< int32_t>;
INSTANTIATE_TYPED_TEST_CASE_P(My, HashIntTest, IntTypes);
ld: error: hash_test.cc:(function (anonymous namespace)::gtest_suite_HashIntTest_::BasicUsage<int>::TestBody(): .text+0x4E472): relocation R_X86_64_32 out of range: 18446744071564237392 is not in [0, 4294967295]; references absl::hash_internal::HashState::kSeed
```
Actually any negative offset is not allowed because the symbol address
can be zero (e.g. set by `-Wl,--defsym=foo=0`). So disallow such folding.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D93931
The x86_amx is used for AMX intrisics. <256 x i32> is bitcast to x86_amx when
it is used by AMX intrinsics, and x86_amx is bitcast to <256 x i32> when it
is used by load/store instruction. So amx intrinsics only operate on type x86_amx.
It can help to separate amx intrinsics from llvm IR instructions (+-*/).
Thank Craig for the idea. This patch depend on https://reviews.llvm.org/D87981.
Differential Revision: https://reviews.llvm.org/D91927
Followup to D92645 - remove the remaining places where we create X86ISD::SUBV_BROADCAST, and fold splatted vector loads to X86ISD::SUBV_BROADCAST_LOAD instead.
Remove all the X86SubVBroadcast isel patterns, including all the fallbacks for if memory folding failed.
This was needed in an earlier version of D92645, but isn't now - and I've just noticed that it was potentially flawed depending on the relevant widths of the broadcasted and extracted subvectors.
Subvector broadcasts are only load instructions, yet X86ISD::SUBV_BROADCAST treats them more generally, requiring a lot of fallback tablegen patterns.
This initial patch replaces constant vector lowering inside lowerBuildVectorAsBroadcast with direct X86ISD::SUBV_BROADCAST_LOAD loads which helps us merge a number of equivalent loads/broadcasts.
As well as general plumbing/analysis additions for SUBV_BROADCAST_LOAD, I needed to wrap SelectionDAG::makeEquivalentMemoryOrdering so it can handle result chains from non generic LoadSDNode nodes.
Later patches will continue to replace X86ISD::SUBV_BROADCAST usage.
Differential Revision: https://reviews.llvm.org/D92645
X86 and AArch64 expand it as libcall inside the target. And PowerPC also
want to expand them as libcall for P8. So, propose an implement in the
legalizer to common the logic and remove the code for X86/AArch64 to
avoid the duplicate code.
Reviewed By: Craig Topper
Differential Revision: https://reviews.llvm.org/D91331
Since these are all working on reduction patterns, actually use that term in the function name to make them easier to search for.
At some point we're likely to start working with the ISD::VECREDUCE_* opcodes directly in the x86 backend, but that is still some way off.
As discussed on D92645, we don't do a good job of recognising when we don't require the full width of a ymm/zmm build vector because the upper elements are undef/zero.
This commit allows us to make use of implicit zeroing of upper elements with AVX instructions, which we emulate in DAG with a INSERT_SUBVECTOR into the bottom of a undef/zero vector of the original type.
This exposed a limitation in getTargetConstantBitsFromNode which didn't extract bits from INSERT_SUBVECTORs of different element widths which I've included as well to prevent a couple of regressions.
The X86-64 ABI defines va_list as
typedef struct {
unsigned int gp_offset;
unsigned int fp_offset;
void *overflow_arg_area;
void *reg_save_area;
} va_list[1];
This means the size, alignment, and reg_save_area offset will depend on
whether we are in LP64 or in ILP32 mode, so this commit adds the checks.
Additionally, the VAARG_64 pseudo-instruction assumed 64-bit pointers, so
this commit adds a VAARG_X32 pseudo-instruction that behaves just like
VAARG_64, except for assuming 32-bit pointers.
Some of these changes were originally done by
Michael Liao <michael.hliao@gmail.com>.
Fixes https://bugs.llvm.org/show_bug.cgi?id=48428.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D93160
If a faux shuffle uses smaller shuffle inputs, try to recursively combine with those inputs directly instead of widening them immediately. Then widen all smaller inputs at the bottom of the recursion.
This will still mean we're generating nodes on the fly (PR45974) even if we don't combine to a new shuffle but it does help AVX2+ targets combine across xmm/ymm/zmm types, mainly as variable shuffles.
Default expansion leads to repeated extensions/truncations to/from vXi16 which shuffle combining and demanded elts can't completely unravel.
Better just to promote (any_extend) the input and perform a vXi16 reduction.
We'll be able to remove a lot of this if we ever get decent legalization support for reduction intrinsics in SelectionDAG.
This patch implements amx programming model that discussed in llvm-dev
(http://lists.llvm.org/pipermail/llvm-dev/2020-August/144302.html).
Thank Hal for the good suggestion in the RA. The fast RA is not in the patch yet.
This patch implemeted 7 components.
1. The c interface to end user.
2. The AMX intrinsics in LLVM IR.
3. Transform load/store <256 x i32> to AMX intrinsics or split the
type into two <128 x i32>.
4. The Lowering from AMX intrinsics to AMX pseudo instruction.
5. Insert psuedo ldtilecfg and build the def-use between ldtilecfg to amx
intruction.
6. The register allocation for tile register.
7. Morph AMX pseudo instruction to AMX real instruction.
Change-Id: I935e1080916ffcb72af54c2c83faa8b2e97d5cb0
Differential Revision: https://reviews.llvm.org/D87981
Rather than creating a series of associated calls and ensuring that
everything is lined up, use a table driven approach that ensures that
they two always stay in sync.
Adds the ExtensionType flag, which reflects the LoadExtType of a MaskedGatherSDNode.
Also updated SelectionDAGDumper::print_details so that details of the gather
load (is signed, is scaled & extension type) are printed.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D91084
D92346 added TLS_(base_)addrX32 to handle TLS in x32 mode, but missed the
different TLS models. This diff fixes the logic for the local dynamic model
where `RAX` was used when `EAX` should be, and extends the tests to cover
all four TLS models.
Fixes https://bugs.llvm.org/show_bug.cgi?id=26472.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D92737
Sometimes people get minimal crash reports after a UBSAN incident. This change
tags each trap with an integer representing the kind of failure encountered,
which can aid in tracking down the root cause of the problem.
Move fold of (sext (not i1 x)) -> (add (zext i1 x), -1) from X86 to DAGCombiner to improve codegen on other targets.
Differential Revision: https://reviews.llvm.org/D91589
No register can be allocated for indirect call when it use regcall calling
convention and passed 5/5+ args.
For example:
call vreg (ag1, ag2, ag3, ag4, ag5, ...) --> 5 regs (EAX, ECX, EDX, ESI, EDI)
used for pass args, 1 reg (EBX )used for hold GOT point, so no regs can be
allocated to vreg.
The Intel386 architecture provides 8 general purpose 32-bit registers. RA
mostly use 6 of them (EAX, EBX, ECX, EDX, ESI, EDI). 5 of this regs can be
used to pass function arguments (EAX, ECX, EDX, ESI, EDI).
EBX used to hold the GOT pointer when making function calls via the PLT.
ESP and EBP usually be "reserved" in register allocation.
Reviewed By: LuoYuanke
Differential Revision: https://reviews.llvm.org/D91020
LLVM has TLS_(base_)addr32 for 32-bit TLS addresses in 32-bit mode, and
TLS_(base_)addr64 for 64-bit TLS addresses in 64-bit mode. x32 mode wants 32-bit
TLS addresses in 64-bit mode, which were not yet handled. This adds
TLS_(base_)addrX32 as copies of TLS_(base_)addr64, except that they use
tls32(base)addr rather than tls64(base)addr, and then restricts
TLS_(base_)addr64 to 64-bit LP64 mode, TLS_(base_)addrX32 to 64-bit ILP32 mode.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D92346
Its unlikely an undef element in a zero vector will be any use, and SimplifyDemandedVectorElts now calls combineX86ShufflesRecursively so its unlikely we actually have a dependency on these specific elements.
Move the X86 VSELECT->UADDSAT fold to DAGCombiner - there's nothing target specific about these folds.
The SSE42 test diffs are relatively benign - its avoiding an extra constant load in exchange for an extra xor operation - there are extra register moves, which is annoying as all those operations should commute them away.
Differential Revision: https://reviews.llvm.org/D91876
For LP64 mode, this has no effect as pointers are already 64 bits.
For ILP32 mode (x32), this extension is specified by the ABI.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D91338
If usubsat() is legal, this is likely to result in smaller codegen expansion than the default cmp+select codegen expansion.
Allows us to move the x86-specific lowering to the generic expansion code.
Differential Revision: https://reviews.llvm.org/D92183
If usubsat() is legal, this is likely to result in smaller codegen expansion than the default cmp+select codegen expansion.
Allows us to move the x86-specific lowering to the generic expansion code.
This is part of the discussion on D91876 about trying to reduce custom lowering of MIN/MAX ops on older SSE targets - if we can improve generic vector expansion we should be able to relax the limitations in SelectionDAGBuilder when it will let MIN/MAX ops be generated, and avoid having to flag so many ops as 'custom'.
Use the OR(CMP,ADD) / AND(CMP,SUB) patterns like we do on SSE targets.
Enable custom lowering for v8i32/v4i64 and generalize the 128-bit lowering code for any vector size - this also lets us use the slightly cheaper codegen for icmp_ugt instead of umin/umax.
The default version only works if the returned node has a single
result. The X86 and PowerPC versions support multiple results
and allow a single result to be returned from a node with
multiple outputs. And allow a single result that is not result 0
of the node.
Also replace the Mips version since the new version should work
for it. The original version handled multiple results, but only
if the new node and original node had the same number of results.
Differential Revision: https://reviews.llvm.org/D91846
Use the OR(CMP,ADD) / AND(CMP,SUB) patterns like we do on pre-SSE4 targets.
We're still using X86ISD::BLENDV on some AVX targets as we don't do custom lowering for >= 256-bit vectors.
Really this (and combineVSelectWithAllOnesOrZeros) needs moving to DAGCombiner, but pre-SSE42 we see the vXi64 comparison type as a 2 x 32-bits result so we can't just rely on ComputeNumSignBits to give us the 'all bits' result we need.
D57663 allowed us to reuse broadcasts of the same scalar value by extracting low subvectors from the widest type.
Unfortunately we weren't ensuring the broadcasts were from the same SDValue, just the same SDNode - which failed on multiple-value nodes like ISD::SDIVREM
FYI: I intend to request this be merged into the 11.x release branch.
Differential Revision: https://reviews.llvm.org/D91709
We can use GF2P8AFFINEQB to reverse bits in a byte. Shuffles are needed to reverse the bytes in elements larger than i8. LegalizeVectorOps takes care of inserting the shuffle for the larger element size.
We already have Custom lowering for v16i8 with SSSE3, v32i8 with AVX, and v64i8 with AVX512BW.
I think we might be able to use this for scalars too by moving into a vector and back. But I'll save that for a follow up as its a little more involved.
Reviewed By: RKSimon, pengfei
Differential Revision: https://reviews.llvm.org/D91515
We unconditionally marked i64 as Custom, but did not install a
handler in ReplaceNodeResults when i64 isn't legal type. This
leads to ReplaceNodeResults asserting.
We have two options to fix this. Only mark i64 as Custom on
64-bit targets and let it expand to two i32 bitreverses which
each need a VPPERM. Or the other option is to add the Custom
handling to ReplaceNodeResults. This is what I went with.
This was a mistake introduced in D91294. I'm not sure how to
exercise this with the existing code, but I hit it while trying
some follow up experiments.
We can't store garbage in the unused bits. It possible that something like zextload from i1/i2/i4 is created to read the memory. Those zextloads would be legalized assuming the extra bits are 0.
I'm not sure that the code in lowerStore is executed for the v1i1/v2i1/v4i1 case. It looks like the DAG combine in combineStore may have converted them to v8i1 first. And I think we're missing some cases to avoid going to the stack in the first place. But I don't have time to investigate those things at the moment so I wanted to focus on the correctness issue.
Should fix PR48147.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D91294
We have a frequent pattern where we're merging two KnownBits to get the common/shared bits, and I just fell for the gotcha where I tried to use the & operator to merge them........
This patch adds the IsTruncatingStore flag to MaskedScatterSDNode, set by getMaskedScatter().
Updated SelectionDAGDumper::print_details for MaskedScatterSDNode to print
the details of masked scatters (is truncating, signed or scaled).
This is the first in a series of patches which adds support for scalable masked scatters
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D90939
Invert the select condition when masking in the sign bit of a fptoui operation. Also, rather than lowering the sign mask to select/xor and expecting the select to get cleaned up later, directly lower to shift/xor.
Patch by Layton Kifer!
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D90658
Replace the X86 specific isSplatZeroExtended helper with a generic BuildVectorSDNode method.
I've just used this to simplify the X86ISD::BROADCASTM lowering so far (and remove isSplatZeroExtended), but we should be able to use this in more places to lower to complex broadcast patterns.
Differential Revision: https://reviews.llvm.org/D87930
Add the MVT equivalent handling for EVT changeTypeToInteger/changeVectorElementType/changeVectorElementTypeToInteger.
All the SimpleVT code already exists inside the EVT equivalents, but by splitting this out we can use these directly inside MVT types without converting to/from EVT.
Some of our conversion algorithms produce -0.0 when converting unsigned i64 to double when the rounding mode is round toward negative. This switches them to other algorithms that don't have this problem. Since it is undefined behavior to change rounding mode with the non-strict nodes, this patch only changes the behavior for strict nodes.
There are still problems with unsigned i32 conversions too which I'll try to fix in another patch.
Fixes part of PR47393
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87115
extract_vector_elt will turn type vxi1 into i8, which triggers the assertion fail.
Since we don't really handle vxi1 cases in below code, we can just return from here.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D89096
In most of lib/Target we know that we are not dealing with scalable
types so it's perfectly fine to replace TypeSize comparison operators
with their fixed width equivalents, making use of getFixedSize()
and so on.
Differential Revision: https://reviews.llvm.org/D89101
This passes existing X86 test but I'm not sure if it handles all type
legalization cases it needs to.
Alternative to D89200
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D89222
This is my first LLVM patch, so please tell me if there are any process issues.
The main observation for this patch is that we can lower UMIN/UMAX with v8i16 by using unsigned saturated subtractions in a clever way. Previously this operation was lowered by turning the signbit of both inputs and the output which turns the unsigned minimum/maximum into a signed one.
We could use this trick in reverse for lowering SMIN/SMAX with v16i8 instead. In terms of latency/throughput this is the needs one large move instruction. It's just that the sign bit turning has an increased chance of being optimized further. This is particularly apparent in the "reduce" test cases. However due to the slight regression in the single use case, this patch no longer proposes this.
Unfortunately this argument also applies in reverse to the new lowering of UMIN/UMAX with v8i16 which regresses the "horizontal-reduce-umax", "horizontal-reduce-umin", "vector-reduce-umin" and "vector-reduce-umax" test cases a bit with this patch. Maybe some extra casework would be possible to avoid this. However independent of that I believe that the benefits in the common case of just 1 to 3 chained min/max instructions outweighs the downsides in that specific case.
Patch By: @TomHender (Tom Hender) ActuallyaDeviloper
Differential Revision: https://reviews.llvm.org/D87236
The bextri intrinsic has a ImmArg attribute which will be converted
in SelectionDAG using TargetConstant. We previously converted this
to a plain Constant to allow X86ISD::BEXTR to call SimplifyDemandedBits
on it.
But while trying to decide if D89178 was safe, I realized that
this conversion of TargetConstant to Constant would be one case
where that would break.
So this patch adds a new opcode specifically for the immediate case.
And then teaches computeKnownBits and SimplifyDemandedBits to also
handle it, but not try to SimplifyDemandedBits on it. To make up
for that, I immediately masked the constant to 16 bits when
converting from the intrinsic node to the X86ISD node.
The notrack prefix is a relaxation of CET policies which makes it possible to indirectly call targets which do not have an ENDBR instruction in the landing address. To emit a call with this prefix, the special attribute "nocf_check" is used. When used as a function attribute, a CallInst targeting the respective function will return true for the method "doesNoCfCheck()", no matter if it is a direct call (and such should remain like this, as the information that the to-be-called function won't perform control-flow checks is useful in other contexts). Yet, when emitting an X86ISD::NT_CALL, the respective CallInst should be verified for its indirection, allowing that the prefixed calls are only emitted in the right situations.
Update the respective testing unit to also verify for direct calls to functions with ''nocf_check'' attributes.
The bug can also be reproduced through compiling the following C code using the -fcf-protection=full flag.
int __attribute__((nocf_check)) foo(int a) {};
int main() {
foo(42);
}
Differential Revision: https://reviews.llvm.org/D87320
I suspect getAddressFromInstr and addFullAddress are not handling
all addresses cases properly based on a report from MaskRay.
So just copy the operands directly. This should be more efficient
anyway.
We need to use LCMPXCHG16B_SAVE_RBX if RBX/EBX is being used as
the frame pointer. We previously checked for this during type
legalization, but that's too early to know for sure if the base
pointer is needed.
This patch adds a new pseudo instruction to emit from isel that
uses a virtual register for the RBX input. Then we use the custom
inserter hook to emit LCMPXCHG16B if RBX isn't needed as a base
pointer or LCMPXCHG16B_SAVE_RBX if it is.
Fixes PR42064.
Reviewed By: pengfei
Differential Revision: https://reviews.llvm.org/D88808
As part of PR45974, we're getting closer to not creating 'padded' vectors on-the-fly in combineX86ShufflesRecursively, and only pad the source inputs if we have a definite match inside combineX86ShuffleChain.
At the moment combineX86ShuffleChain just has to bitcast an input to the correct shuffle type, but eventually we'll need to pad them as well. So, move the bitcast into a 'CanonicalizeShuffleInput helper for now, making the diff for future padding support a lot smaller.
This and its friend X86ISD::LCMPXCHG8_SAVE_RBX_DAG are used if we need to avoid clobbering the frame pointer in EBX/RBX. EBX/RBX are only used a frame pointer in 64-bit mode. In 64-bit mode we don't use CMPXCHG8B since we have a GR64 cmpxchg available. So we don't need special handling for LCMPXCHG8B.
Split from D88808
Differential Revision: https://reviews.llvm.org/D88853
getNode handling for ISD:SETCC calls FoldSETCC which can canonicalize
FP constants to the RHS. When this happens we should create the node
with the FMF that was requested. By using FlagInserter when can ensure
any calls to getNode/getSetcc during canonicalization will also get the flags.
Differential Revision: https://reviews.llvm.org/D88063
ebx/rbx only needs to be saved when 64-bit registers are supported
anyway. It should be fine to save/restore the whole rbx register
even in gnux32 where the base is technically just ebx.
This matches what we do for cmpxchg16b where rbx is saved/restored
regardless of gnux32.
Preliminary patch for the next stage of PR45974 - we don't want to be creating 'padded' vectors on-the-fly at all in combineX86ShufflesRecursively, and only pad the source inputs if we have a definite match inside combineX86ShuffleChain.
This means that the inputs to combineX86ShuffleChain might soon be smaller than the final root value type, so we should ensure that isTargetShuffleEquivalent only matches with the inputs if they are the correct size.
We should avoid emitting MachineSDNodes from lowering.
We can use the the implicit def handling in InstrEmitter to avoid
manually copying from each xmm result register. We only need to
manually emit the copies for the implicit uses.
Instead of emitting MachineSDNodes during lowering, emit X86ISD
opcodes. These opcodes will either be selected by tablegen
patterns or custom selection code.
Emitting MachineSDNodes during lowering is uncommon so this makes
things more consistent. It also allows selectAddr to be called to
perform address matching during instruction selection.
I had trouble getting tablegen to accept XMM0-XMM7 as results in
an isel pattern for the WIDE instructions so I had to use custom
instruction selection.
This will be further canonicalized to a compare involving 0
which will enable the use of test instructions. Either using
cmovg for signed for cmovne for unsigned.
Fixes more case for PR47049
Key Locker provides a mechanism to encrypt and decrypt data with an AES key without having access
to the raw key value by converting AES keys into “handles”. These handles can be used to perform the
same encryption and decryption operations as the original AES keys, but they only work on the current
system and only until they are revoked. If software revokes Key Locker handles (e.g., on a reboot),
then any previous handles can no longer be used.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D88398
These instructions are implemented with two port 5 uops and one port 015 uop so they are more complicated that most shuffles.
This patch increases the depth threshold for when we form them during shuffle combining to try to limit increasing the number of uops especially on port 5.
Differential Revision: https://reviews.llvm.org/D88503
We can do several optimizations for PDEP using computeKnownBits and SimplifyDemandedBits
-If the MSBs of the output aren't demanded, those MSBs of the mask input aren't demanded either. We need to keep the most significant demanded bit of the mask and any mask bits before it.
-The number of possible ones in the mask determines how many bits of the lsbs of the other operand are demanded. Any bits of the mask we don't demand by the previous rule should not be counted.
-The result will have zeros in any position that the mask is zero.
-Since non-mask input bits can only be output in the original position or a higher bit position, the result will have at least as many trailing zeroes as the non-mask input.
Differential Revision: https://reviews.llvm.org/D87883
A while ago, we converted isShuffleEquivalent/isTargetShuffleEquivalent to both use IsElementEquivalent internally.
This allows us to make the shuffle args optional like isTargetShuffleEquivalent and update foldShuffleOfHorizOp to use isShuffleEquivalent (which it should as its using a ISD::VECTOR_SHUFFLE mask).
Shuffle combining can now handle this output, and by performing this early in combineVectorTruncation we avoid a scalarization that caused a regression on D87502.
The scalar elements of the vXi1 build_vector will have been type legalized to i8 by padding with 0s. So we can't check for all ones. Instead we should just look at bit 0 of the constant.
Differential Revision: https://reviews.llvm.org/D87863
It should be possible to make this generic, but we're not great at checking legality of *_EXTEND_VECTOR_INREG ops so I'm conservatively putting this inside X86ISelLowering.cpp
It should be possible to make this generic, but we're not great at checking legality of *_EXTEND_VECTOR_INREG ops so I'm conservatively putting this inside X86ISelLowering.cpp
After moving WidenedMask is in an undefined state, so reduce scope of the variable so its reinitialized every iteration - we should still retain any memory allocation savings.
Simon Pilgrim