Recommiting after fixing X86 inc/dec chain bug.
* Simplify Consecutive Merge Store Candidate Search
Now that address aliasing is much less conservative, push through
simplified store merging search and chain alias analysis which only
checks for parallel stores through the chain subgraph. This is cleaner
as the separation of non-interfering loads/stores from the
store-merging logic.
When merging stores search up the chain through a single load, and
finds all possible stores by looking down from through a load and a
TokenFactor to all stores visited.
This improves the quality of the output SelectionDAG and the output
Codegen (save perhaps for some ARM cases where we correctly constructs
wider loads, but then promotes them to float operations which appear
but requires more expensive constant generation).
Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)
Additional Minor Changes:
1. Finishes removing unused AliasLoad code
2. Unifies the chain aggregation in the merged stores across code
paths
3. Re-add the Store node to the worklist after calling
SimplifyDemandedBits.
4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
arbitrary, but seems sufficient to not cause regressions in
tests.
5. Remove Chain dependencies of Memory operations on CopyfromReg
nodes as these are captured by data dependence
6. Forward loads-store values through tokenfactors containing
{CopyToReg,CopyFromReg} Values.
7. Peephole to convert buildvector of extract_vector_elt to
extract_subvector if possible (see
CodeGen/AArch64/store-merge.ll)
8. Store merging for the ARM target is restricted to 32-bit as
some in some contexts invalid 64-bit operations are being
generated. This can be removed once appropriate checks are
added.
This finishes the change Matt Arsenault started in r246307 and
jyknight's original patch.
Many tests required some changes as memory operations are now
reorderable, improving load-store forwarding. One test in
particular is worth noting:
CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
forwarding converts a load-store pair into a parallel store and
a memory-realized bitcast of the same value. However, because we
lose the sharing of the explicit and implicit store values we
must create another local store. A similar transformation
happens before SelectionDAG as well.
Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle
llvm-svn: 293893
This patch moves some helper functions related to interleaved access
vectorization out of LoopVectorize.cpp and into VectorUtils.cpp. We would like
to use these functions in a follow-on patch that improves interleaved load and
store lowering in (ARM/AArch64)ISelLowering.cpp. One of the functions was
already duplicated there and has been removed.
Differential Revision: https://reviews.llvm.org/D29398
llvm-svn: 293788
* Simplify Consecutive Merge Store Candidate Search
Now that address aliasing is much less conservative, push through
simplified store merging search and chain alias analysis which only
checks for parallel stores through the chain subgraph. This is cleaner
as the separation of non-interfering loads/stores from the
store-merging logic.
When merging stores search up the chain through a single load, and
finds all possible stores by looking down from through a load and a
TokenFactor to all stores visited.
This improves the quality of the output SelectionDAG and the output
Codegen (save perhaps for some ARM cases where we correctly constructs
wider loads, but then promotes them to float operations which appear
but requires more expensive constant generation).
Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)
Additional Minor Changes:
1. Finishes removing unused AliasLoad code
2. Unifies the chain aggregation in the merged stores across code
paths
3. Re-add the Store node to the worklist after calling
SimplifyDemandedBits.
4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
arbitrary, but seems sufficient to not cause regressions in
tests.
5. Remove Chain dependencies of Memory operations on CopyfromReg
nodes as these are captured by data dependence
6. Forward loads-store values through tokenfactors containing
{CopyToReg,CopyFromReg} Values.
7. Peephole to convert buildvector of extract_vector_elt to
extract_subvector if possible (see
CodeGen/AArch64/store-merge.ll)
8. Store merging for the ARM target is restricted to 32-bit as
some in some contexts invalid 64-bit operations are being
generated. This can be removed once appropriate checks are
added.
This finishes the change Matt Arsenault started in r246307 and
jyknight's original patch.
Many tests required some changes as memory operations are now
reorderable, improving load-store forwarding. One test in
particular is worth noting:
CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
forwarding converts a load-store pair into a parallel store and
a memory-realized bitcast of the same value. However, because we
lose the sharing of the explicit and implicit store values we
must create another local store. A similar transformation
happens before SelectionDAG as well.
Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle
llvm-svn: 293184
Summary:
This patch aims to generalize matching of the strided store accesses to more general masks.
The more general rule is to have consecutive accesses based on the stride:
[x, y, ... z, x+1, y+1, ...z+1, x+2, y+2, ...z+2, ...]
All elements in the masks need not form a contiguous space, there may be gaps.
As before, undefs are allowed and filled in with adjacent element loads.
Reviewers: HaoLiu, mssimpso
Subscribers: mkuper, delena, llvm-commits
Differential Revision: https://reviews.llvm.org/D23646
llvm-svn: 289573
Instead, expose whether the current type is an array or a struct, if an array
what the upper bound is, and if a struct the struct type itself. This is
in preparation for a later change which will make PointerType derive from
Type rather than SequentialType.
Differential Revision: https://reviews.llvm.org/D26594
llvm-svn: 288458
Summary:
Extend replaceZeroVectorStore to handle more vector type stores,
floating point zero vectors and set alignment more accurately on split
stores.
This is a follow-up change to r286875.
This change fixes PR31038.
Reviewers: MatzeB
Subscribers: mcrosier, aemerson, llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D26682
llvm-svn: 287142
Lower a = b * C where C = (2^n + 1) * 2^m to
add w0, w0, w0, lsl n
lsl w0, w0, m
Differential Revision: https://reviews.llvm.org/D229245
llvm-svn: 287019
Implement the Newton series for square root, its reciprocal and reciprocal
natively using the specialized instructions in AArch64 to perform each
series iteration.
Differential revision: https://reviews.llvm.org/D26518
llvm-svn: 286907
Summary:
Replace a splat of zeros to a vector store by scalar stores of WZR/XZR.
The load store optimizer pass will merge them to store pair stores.
This should be better than a movi to create the vector zero followed by
a vector store if the zero constant is not re-used, since one
instructions and one register live range will be removed.
For example, the final generated code should be:
stp xzr, xzr, [x0]
instead of:
movi v0.2d, #0
str q0, [x0]
Reviewers: t.p.northover, mcrosier, MatzeB, jmolloy
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: https://reviews.llvm.org/D26561
llvm-svn: 286875
Summary:
Fix off-by-one indexing error in loop checking that inserted value was a
splat vector.
Add code to check that INSERT_VECTOR_ELT nodes constructing the splat
vector have the expected constant index values.
Reviewers: t.p.northover, jmolloy, mcrosier
Subscribers: aemerson, llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D26409
llvm-svn: 286616
The generic infrastructure to compute the Newton series for reciprocal and
reciprocal square root was conceived to allow a target to compute the series
itself. However, the original code did not properly consider this condition
if returned by a target. This patch addresses the issues to allow a target
to compute the series on its own.
Differential revision: https://reviews.llvm.org/D22975
llvm-svn: 286523
Under -enable-unsafe-fp-math, SELECT_CC lowering in AArch64
transforms floating point comparisons of the form "a == 0.0 ? 0.0 : x" to
"a == 0.0 ? a : x". But it incorrectly assumes that 'x' and 'a' have
the same type which can lead to a wrong CSEL node that crashes later
due to nonsensical copies.
Differential Revision: https://reviews.llvm.org/D26394
llvm-svn: 286231
Add support for estimating the square root or its reciprocal and division or
reciprocal using the combiner generic Newton series.
Differential revision: https://reviews.llvm.org/D25291
llvm-svn: 284986
Transform `a == 0.0 ? 0.0 : x` to `a == 0.0 ? a : x` and `a != 0.0 ? x : 0.0`
to `a != 0.0 ? x : a` to avoid materializing 0.0 for FCSEL, since it does not
have to be materialized beforehand for FCMP, as it has a form that has 0.0
as an implicit operand.
Differential Revision: https://reviews.llvm.org/D24808
llvm-svn: 284531
Many high-performance processors have a dedicated branch predictor for
indirect branches, commonly used with jump tables. As sophisticated as such
branch predictors are, they tend to have well defined limits beyond which
their effectiveness is hampered or even nullified. One such limit is the
number of possible destinations for a given indirect branches that such
branch predictors can handle.
This patch considers a limit that a target may set to the number of
destination addresses in a jump table.
Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar
<aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>.
Differential revision: https://reviews.llvm.org/D21940
llvm-svn: 282412
This reverts commit b7d42b0048f65346e9fa37fb65defeea7ce8c337 per request by
Eric Christopher <echristo@gmail.com> (v. http://bit.ly/2cmz6kW).
llvm-svn: 282000
This reverts commit ad8ca1528242e2a4cb363e3779309e70eb7a430e per request by
Eric Christopher <echristo@gmail.com> (v. http://bit.ly/2cmz6kW).
llvm-svn: 281999
Cleanup/change the code that checks for possible tailcall conventions to
look the same as the one in the X86 target. This makes the distinction
between calling conventions that can guarnatee tailcalls and the ones
that may tailcall more obvious.
- Add Swift to the mayTailCall list
- PreserveMost seemed to be incorrectly part of the guarnteed tail call
list, move it to the mayTailCall list.
llvm-svn: 281376
Summary:
An IR load can be invariant, dereferenceable, neither, or both. But
currently, MI's notion of invariance is IR-invariant &&
IR-dereferenceable.
This patch splits up the notions of invariance and dereferenceability at
the MI level. It's NFC, so adds some probably-unnecessary
"is-dereferenceable" checks, which we can remove later if desired.
Reviewers: chandlerc, tstellarAMD
Subscribers: jholewinski, arsenm, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D23371
llvm-svn: 281151
In the code to detect fixed-point conversions and make use of AArch64's special
instructions, we weren't prepared for weird types. The fptosi direction got
fixed recently, but not the similar sitofp code.
llvm-svn: 279852
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
Summary:
The DAG combine transformation that was generating the
aarch64_neon_vcvtfp2fxs node was assuming that all
inputs where legal and wasn't accounting that the input
could be a v4f64 if we're trying to do the transformation
before legalization. We now bail out in this case.
All illegal types besides v4f64 were already rejected.
Fixes https://llvm.org/bugs/show_bug.cgi?id=28877.
Reviewers: jmolloy
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: https://reviews.llvm.org/D23261
llvm-svn: 278002
when constraint "w" is used on a 32-bit operand.
This enables compiling the following code, which used to error out in
the backend:
void foo1(int a) {
asm volatile ("sqxtn h0, %s0\n" : : "w"(a):);
}
Fixes PR28633.
llvm-svn: 276344
Inference of the 'returned' attribute was fixed in r276008, lets try
turning the backend support back on.
This reverts commit r275677.
llvm-svn: 276081
r275042 reverted function-attribute inference for the 'returned' attribute
because the feature triggered self-hosting failures on ARM and AArch64. James
Molloy determined that the this-return argument forwarding feature, which
directly ties the returned input argument to the returned value, was the cause.
It seems likely that this forwarding code contains, or triggers, a subtle bug.
Disabling for now until we can track that down.
llvm-svn: 275677
