- In [D98783](https://reviews.llvm.org/D98783), an extra GlobalDCE pass
is inserted before the internalization pass to ensure a global
variable without users could be internalized even if there are dead
users. Instead of inserting a dedicated optimization pass, the
dead user checking, i.e. 'use_empty()', should be preceeded with
constant dead user removal to ensure an accurate result.
Differential Revision: https://reviews.llvm.org/D105590
Additionally, lower the floating point compare SVE intrinsics to
SETCC_MERGE_ZERO ISD nodes to avoid duplicating ISel patterns.
Differential Revision: https://reviews.llvm.org/D105486
WebAssembly's shift instructions implicitly masks the shift count, so optimize
out redundant explicit masks of the shift count. For vector shifts, this
currently only works if the mask is applied before splatting the shift count,
but this should be addressed in a future commit. Resolves PR49655.
Differential Revision: https://reviews.llvm.org/D105600
Lowering for scalar to vector would skip if current subtarget is big
endian and the scalar is larger or equal than 64 bits. However there's
some issue in implementation that SToVRHS may refer to SToVLHS's scalar
size if SToVLHS is present, which leads to some crash.o
Reviewed By: nemanjai, shchenz
Differential Revision: https://reviews.llvm.org/D105094
This commit also makes some slight changes to the scheduling model for AMDGPU to set the RetireOOO flag for all scheduling classes.
This flag is only used by llvm-mca and allows instructions to retire out of order.
See the differential link below for a deeper explanation of everything.
Differential Revision: https://reviews.llvm.org/D104730
This patch prevents GlobalISel from optimizing out redundant branch
instructions when compiling without optimizations.
The motivating example is code like the following common pattern in
Swift, where users expect to be able to set a breakpoint on the early
exit:
public func f(b: Bool) {
guard b else {
return // I would like to set a breakpoint here.
}
...
}
The patch modifies two places in GlobalISEL: The first one is in
IRTranslator.cpp where the removal of redundant branches is made
conditional on the optimization level. The second one is in
AArch64InstructionSelector.cpp where an -O0 *only* optimization is
being removed.
Disabling these optimizations increases code size at -O0 by
~8%. However, doing so improves debuggability, and debug builds are
the primary reason why developers compile without optimizations. We
thus concluded that this is the right trade-off.
rdar://79515454
Differential Revision: https://reviews.llvm.org/D105238
There are some patterns involving the permuted scalar to vector node
for which we don't have patterns without direct moves on little endian
subtargets. This causes selection errors. While we can of course add
the missing patterns, any additional effort to make this work is not
useful since there is no support for any CPU that can run in
little endian mode and does not support direct moves.
Match whats documented in the Intel AOM - almost all the conversion instructions requires BOTH ports (apart from the MMX cvtpi2ps/cvtpi2ps instructions which we already override) - this was being incorrectly modelled as EITHER port.
Now that we can use in-order models in llvm-mca, the atom model is a good "worst case scenario" analysis for x86.
Adding usage of VSSRC and VSFRC when adding the live in registers on AIX.
This matches the behaviour of the rest of PPC Subtargets.
Reviewed By: nemanjai, #powerpc
Differential Revision: https://reviews.llvm.org/D104396
Update costs based on the worst case costs from the script in D103695.
Move to using legalized types wherever possible, which allows us to prune the cost tables.
Update (mainly) vXi8/vXi16 -> vXf32/vXf64 sitofp/uitofp costs based on the worst case costs from the script in D103695.
Move to using legalized types wherever possible, which allows us to prune the cost tables.
We have several checks for both cl::opt and OptLevel over our
pass config, although these checks do not properly work if
default value of a cl::opt will be false. Create a helper to
use instead and properly handle it. NFC for now.
Differential Revision: https://reviews.llvm.org/D105517
The combine was disabled in 4e22c7265d as it caused failures in
the ppc64be-multistage (bootstrap) bot.
It turns out that the combine did not correctly update the MMO for
the high load which caused aliased stores to be reported as unaliased.
This patch fixes that problem and re-enables the combine.
There are cases where infer address spaces pass cannot yet
infer an address space in the opt pipeline and then in the
llc pipeline it runs too late for atomic expand pass to
benefit from a specific address space.
Move atomic expand pass past the infer address spaces.
Fixes: SWDEV-293410
Differential Revision: https://reviews.llvm.org/D105511
This applies to memory accesses to (compile-time) constant addresses
(such as memory-mapped registers). Currently when a misaligned access
to such an address is detected, a fatal error is reported. This change
will emit a remark, and the compilation will continue with a trap,
and "undef" (for loads) emitted.
This fixes https://llvm.org/PR50838.
Differential Revision: https://reviews.llvm.org/D50524
These are fp->int conversions using either RMM or dynamic rounding modes.
The lround and lrint opcodes have a return type of either i32 or
i64 depending on sizeof(long) in the frontend which should follow
xlen. llround/llrint should always return i64 so we'll need a libcall
for those on rv32.
The frontend will only emit the intrinsics if -fno-math-errno is in
effect otherwise a libcall will be emitted which will not use
these ISD opcodes.
gcc also does this optimization.
Reviewed By: arcbbb
Differential Revision: https://reviews.llvm.org/D105206
The odd register of a (128 bit) register pair is accessed with the 'N' code
with an inline assembly operand.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D105502
This adds a DAG combine to detect sext/zext inputs and emit a
new ISD opcode. The extends will either be removed or replaced
with narrower extends.
Isel patterns are used to match add and widening mul to vwmacc
similar to the recently added vmacc patterns.
There's still some work to be to match vmulsu.
We should also rewrite splats that were extended as scalars and
then splatted.
Reviewed By: arcbbb
Differential Revision: https://reviews.llvm.org/D104802
Provide a generic fallback that performs the fptosi to i32 types, then truncates to sub-i32 scalars.
These numbers can be tweaked for specific sse levels, but we should get the default handling in place first.
Benchmarking has shown that it is worthwhile to implement a variable length
memset of 0 with XC (exclusive or) like gcc does, instead of using a libcall.
This requires the use of the EXecute Relative Long (EXRL) instruction which
can now be done in a framework that can also be used with other target
instructions (not just XC).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D103865
Provide a generic fallback that extends sub-i32 scalars before using the existing sitofp instructions.
These numbers can be tweaked for specific sse levels, but we should get the default handling in place first.
We get the extension for free for non-vector loads.
This patch adds a TTI function, isElementTypeLegalForScalableVector, to query
whether it is possible to vectorize a given element type. This is called by
isLegalToVectorizeInstTypesForScalable to reject scalable vectorization if
any of the instruction types in the loop are unsupported, e.g:
int foo(__int128_t* ptr, int N)
#pragma clang loop vectorize_width(4, scalable)
for (int i=0; i<N; ++i)
ptr[i] = ptr[i] + 42;
This example currently crashes if we attempt to vectorize since i128 is not a
supported type for scalable vectorization.
Reviewed By: sdesmalen, david-arm
Differential Revision: https://reviews.llvm.org/D102253
This avoids the use of the vector unit for copying from scalar to
vector. There is an extra ptrue instruction, but a predicate register
with the ptrue pattern populated is likely to be free in the context of
real code.
Tests were generated from a template to cover the axes mentioned at the
top of the test file.
Co-authored-by: Francesco Petrogalli <francesco.petrogalli@arm.com>
Differential Revision: https://reviews.llvm.org/D103170
Set informational fields in the .shader_functions table.
Also correct the documentation, .scratch_memory_size and .lds_size are
integers.
Differential Revision: https://reviews.llvm.org/D105116
This patch implaments the load and reserve and store conditional
builtins for the PowerPC target, in order to have feature parody with
xlC on AIX.
Differential revision: https://reviews.llvm.org/D105236
For the following case:
t8: i32 = or t7, t4
t10: i32 = ORRWrs t8, t8, TargetConstant:i32<73>
Current code wrongly returns (t8 >> shiftConstant) as the
UsefulBits of t8, which in fact is (t8 | (t8 >> shiftConstant)).
Reviewed by: sdesmalen, mdchen
Differential Revision: https://reviews.llvm.org/D102759
This patch adds a new ShuffleKind SK_Splice and then handle the cost in
getShuffleCost, as in experimental.vector.reverse.
Differential Revision: https://reviews.llvm.org/D104630
This patch fixes PR50823.
The shuffle mask should be twisted twice before gotten the correct one due to the difference between inner HOP and outer.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D104903
Improve codegen when lowering the common vector shuffle case from the
vectorizer (op1[last]:op2[0:last-1]). This patch only handles this
common case as it is difficult to handle this more generally when using
fixed length vectors, due to being unable to use the SVE ext instruction.
Differential Revision: https://reviews.llvm.org/D105289
Loads of <4 x i8> vectors were modeled as extremely expensive. And while we
don't have a load instruction that supports this, it isn't that expensive to
create a vector of i8 elements. The codegen for this was fixed/optimised in
D105110. This now tweaks the cost model and enables SLP vectorisation of my
motivating case loadi8.ll.
Differential Revision: https://reviews.llvm.org/D103629
Added support to check if architecture supports s_mulhi which is used as part of
the decision whether or not to use valu 24 bit mul (if the mulhi gets
transformed to a valu op anyway, then may as well use it).
This is an extension of the work in D97063
Differential Revision: https://reviews.llvm.org/D103321
Change-Id: I80b1323de640a52623d69ac005a97d06a5d42a14
FeatureBitset is 4 64-bit values in an array. It's better passed by
reference rather than copying it.
I may be adding FeatureBitset as an argument to another function
and noticed this while working on that.
This API is not compatible with opaque pointers, the method
accepting an explicit pointer element type should be used instead.
Thankfully there were few in-tree users. The BPF case still ends
up using the pointer element type for now and needs something like
D105407 to avoid doing so.
Same as other CreateLoad-style APIs, these need an explicit type
argument to support opaque pointers.
Differential Revision: https://reviews.llvm.org/D105395
This adds simple patterns for signed and unsigned saturating extract
narrow instructions. They combine a min/max/truncate into a single
instruction, providing that the immediates on the min/max are correct
for the saturation type. This is just handled in tablegen with some
extra patterns.
v2i64->v2i32 is not handled here as the min/max nodes are not legal,
making the lowering quite different.
Differential Revision: https://reviews.llvm.org/D103263
Allocate non-volatile registers in order to be compatible with ABI, regarding gpr_save.
Quoted from https://www.ibm.com/docs/en/ssw_aix_72/assembler/assembler_pdf.pdf page55,
> The preferred method of using GPRs is to use the volatile registers first. Next, use the nonvolatile registers
> in descending order, starting with GPR31.
This patch is based on @jsji 's initial draft.
Tested on test-suite and SPEC, found no degradation.
Reviewed By: jsji, ZarkoCA, xingxue
Differential Revision: https://reviews.llvm.org/D100167
The SLM model is inconsistent about where it kept its 'unsupported' schedule classes - better to keep them close to similar classes.
I'm not sure why some ymm classes are defined and others are unsupported though (but I haven't altered them) - the only SLM-like CPU supporting any ymm is KNL and that currently uses the HSW model.
Update v4i64 -> v4f32/v4f64 uitofp costs based on the worst case costs from the script in D103695.
Fixes a few regressions before we start adding AVX costs for legalized types.
Reland of 31859f896.
This change implements new DAG notes GLOBAL_GET/GLOBAL_SET, and
lowering methods for load and stores of reference types from IR
globals. Once the lowering creates the new nodes, tablegen pattern
matches those and converts them to Wasm global.get/set.
Differential Revision: https://reviews.llvm.org/D104797
Target-independent code only knows how to spill to the stack; instead,
use AArch64ISD::REINTERPRET_CAST.
Differential Revision: https://reviews.llvm.org/D104573
D104868 removed an (incorrect) fold for distributing BFI instructions in
a chain, combining them into a single instruction. BFIs like that are
hard to test, as the patterns are often destroyed before they become
BFIs. But it can come up in places, with chains of BFIs that can be
combined.
This patch adds a replacement, which reassociates BFI instructions with
non-overlapping insertion masks so that low bits are inserted first.
This can end up sorting the nodes so that adjacent inserts are next to
one another, allowing the existing folds to combine into a single BFI.
Differential Revision: https://reviews.llvm.org/D105096
Inserting into a smaller-than-legal scalable vector would result in an
internal compiler error. For example, inserting a <vscale x 4 x i8> into
a <vscale x 8 x i8> (both illegal vector types for SVE) would cause a
crash.
This crash was happening because there was no code to promote (legalise)
the result of an INSERT_SUBVECTOR node.
This patch implements PromoteIntRes_INSERT_SUBVECTOR, which legalises
the ISD node. This is currently done by going through memory. This is
necessary because of the requirement that the SubVec parameter of the
INSERT_SUBVECTOR node must be smaller than the Vec parameter, which
means that INSERT_SUBVECTOR cannot always have a legal result/operand
types.
Co-Authored-by: Joe Ellis <joe.ellis@arm.com>
Differential Revision: https://reviews.llvm.org/D102766
Building on rG2a1ef8784ad9a, adjust the SSE cost tables to use the legalized types based on the worst case costs from the script in D103695.
To account for different numbers of src/dst legalized type registers we must scale the cost by maximum of the src/dst, not just use src
Much like fixed-point to floating-point conversion, the converse can
also be transformed into a fixed-point VCVT. This patch transforms
multiplications of floating point numbers by 2^n into a VCVT_fix. The
exception is that a float to fixed conversion with 1 fractional bit
ends up being an FADD (FADD(x, x) emulates FMUL(x, 2)) rather than an FMUL so there is a special case for that. This patch also moves the code from https://reviews.llvm.org/D103903 into a separate function as fixed to float and float to fixed are very similar.
Differential Revision: https://reviews.llvm.org/D104793
Since gather lowering can now lower to nodes that may need expansion via
the vector legalizer, do MGATHER lowering via vector legalizer.
Additionally, as part of adding passthru support for fixed typed
gathers, fix passthru support for scalable types.
Depends on D104910
Differential Revision: https://reviews.llvm.org/D104217
Move the (SSE-only) generic, legalized type conversion matching after the specific,custom conversion cases, allowing us to properly provide cost overrides.
The next step will be to clean up some of the weird existing costs and then to enable AVX+ legalized costs, which will let us strip out a lot of the cost tables entries.
Very late in compilation, backends like X86 will perform optimisations like
this:
$cx = MOV16rm $rax, ...
->
$rcx = MOV64rm $rax, ...
Widening the load from 16 bits to 64 bits. SEeing how the lower 16 bits
remain the same, this doesn't affect execution. However, any debug
instruction reference to the defined operand now refers to a 64 bit value,
nto a 16 bit one, which might be unexpected. Elsewhere in codegen, there's
often this pattern:
CALL64pcrel32 @foo, implicit-def $rax
%0:gr64 = COPY $rax
%1:gr32 = COPY %0.sub_32bit
Where we want to refer to the definition of $eax by the call, but don't
want to refer the copies (they don't define values in the way
LiveDebugValues sees it). To solve this, add a subregister field to the
existing "substitutions" facility, so that we can describe a field within
a larger value definition. I would imagine that this would be used most
often when a value is widened, and we need to refer to the original,
narrower definition.
Differential Revision: https://reviews.llvm.org/D88891
This patch changes return type of tryCandidate from void to bool:
1. Methods in some targets already follow this convention.
2. This would help if some target wants to re-use generic code.
3. It looks more intuitive if these try-method returns the same type.
We may need to change return type of them from bool to some enum
further, to make it less confusing.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D103951
This enables proper lowering of non-byte sized loads. We still aren't
faithfully preserving memory types everywhere, so the legality checks
still only consider the size.
Enable the emission of a GNU attributes section by reusing the code for
emitting the ARM build attributes section.
The GNU attributes follow the exact same section format as the ARM
BuildAttributes section, so this can be factored out and reused for GNU
attributes generally.
The immediate motivation for this is to emit a GNU attributes section for the
vector ABI on SystemZ (https://reviews.llvm.org/D105067).
Review: Logan Chien, Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D102894
This is to allow 64 bit constant rematerialization. If a constant
is split into two separate moves initializing sub0 and sub1 like
now RA cannot rematerizalize a 64 bit register.
This gives 10-20% uplift in a set of huge apps heavily using double
precession math.
Fixes: SWDEV-292645
Differential Revision: https://reviews.llvm.org/D104874
This prevents constant gep operands from being hoisted by the Constant
Hoisting pass, leaving them to CodegenPrepare which can usually do a
better job at splitting large offsets. This can, in general, improve
performance and decrease codesize, especially for v6m where many
constants have a high cost.
Differential Revision: https://reviews.llvm.org/D104877
Summary:
in the patch https://reviews.llvm.org/D103651 [AIX][XCOFF] generate eh_info when vector registers are saved according to the traceback table.
when generate eh_info, it switch to other section, when it done, it need to switch back to text section again.
Reviewers: Jason Liu
Differential Revision: https://reviews.llvm.org/105195
This demonstrates a possible fix for PR48760 - for compares with constants, canonicalize the SGT/UGT condition code to use SGE/UGE which should reduce the number of EFLAGs bits we need to read.
As discussed on PR48760, some EFLAG bits are treated independently which can require additional uops to merge together for certain CMOVcc/SETcc/etc. modes.
I've limited this to cases where the constant increment doesn't result in a larger encoding or additional i64 constant materializations.
Differential Revision: https://reviews.llvm.org/D101074
I believe this Changed flag should be initialized to false,
otherwise the if (!Changed) is always dead. This doesn't
manifest in a functional issue because the PHINode checks will
fail if nothing changed. They are identical to the earlier
checks that must have already failed to get into this else block.
While there remove an else after return to reduce indentation.
Differential Revision: https://reviews.llvm.org/D105159
Based off the worse case numbers generated by D103695, the AVX1/2/512 sitofp/uitofp/fptosi/fptoui costs were higher than necessary (based off instruction counts instead of actual throughput).
The SSE costs still need further fixes, but I hit an issue with the order in which SSE costs are checked - we need to check CUSTOM costs (with non-legal types) first, and then fallback to LEGALIZED types. I'm looking at this now, and this should let us start thinning out a lot of the duplicates in the costs tables.
Then we can finally start work on vXi64 / vXi16 / vXi8 / vXi1 integers, which should let us look at sub-128-bit vectorization (D103925).
Details: https://reviews.llvm.org/D96805 changed the GCNTTIImpl::getCFInstrCost to return 1 for the PHI nodes
for the TTI::TCK_CodeSize and TTI::TCK_SizeAndLatency. This is incorrect because the value moves that are the
result of the PHI lowering are inserted into the basic block predecessors - not into the block itself.
As a result of this change LoopRotate and LoopUnroll were broken because of the incorrect Loop header and loop
body size/cost estimation.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D105104
This is a followup patch on D103636 where
it seemed checking on amdgpu-calls and
amdgpu-stack-objects is unnecessary. Removing these
checks didn't regress any tests functionally.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D104513
Looking at PostDominatorTree::dominates, we can see that has the same
logic (with the addition of handling Phi nodes - which are not used as inputs in
this pass) as the helper function.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105141
`ARMInstPrinter::printMveAddrModeQOperand()` was added in D62680, but
was never used. It looks like `printT2AddrModeImm8Operand<false>()` is
used instead.
Differential Revision: https://reviews.llvm.org/D105124
Update AMDGPU gfx90a memory model to make coarse grain memory allocations
consistent when fine grained system scope atomic acquire and release is
performed.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D105137
GlobalISel is relying on regular MachineMemOperands to track all of
the memory properties of accesses. Just the raw byte size is
insufficent to disambiguate all situations. For example, if we need to
split an unaligned extending load, we need to know the number of bits
in the original source value and can't infer it from the result
type. This is also a problem for extending vector loads.
This does decrease the maximum representable size from the full
uint64_t bytes to a maximum of 16-bits. No in tree testcases hit this,
other than places using UINT64_MAX for unknown sizes. This may be an
issue for G_MEMCPY and co., although they can just use unknown size
for large static sizes. This also has potential for backend abuse by
relying on the type when it really shouldn't be relevant after
selection.
This does not include the necessary MIR printer/parser changes to
represent this.
It seems it is possible for DAG combine to create a shl with an
i64 result type and an i32 shift amount. This is ok before type
legalization since the type don't need to match in SelectionDAG.
This results in type legalization calling LowerOperation to
legalize just the amount. We weren't expecting this so we
asserted for not finding a fixed vector shift.
To fix this, I've added a check for the fixed vector case and
returned SDValue() to get the default type legalizer. I've
factored all shifts together and added a fixed vector specific
handler to avoid repeating similar code for each in
LowerOperation.
The particular case I found was exposed by D104581, but the bad
shift is created after that patch triggers.
Michael Liao