We currently miss a number of opportunities to emit single-instruction
VMRG[LH][BHW] instructions for shuffles on little endian subtargets. Although
this in itself is not a huge performance opportunity since loading the permute
vector for a VPERM can always be pulled out of loops, producing such merge
instructions is useful to downstream optimizations.
Since VPERM is essentially opaque to all subsequent optimizations, we want to
avoid it as much as possible. Other permute instructions have semantics that can
be reasoned about much more easily in later optimizations.
This patch does the following:
- Canonicalize shuffles so that the first element comes from the first vector
(since that's what most of the mask matching functions want)
- Switch the elements that come from splat vectors so that they match the
corresponding elements from the other vector (to allow for merges)
- Adds debugging messages for when a shuffle is matched to a VPERM so that
anyone interested in improving this further can get the info for their code
Differential revision: https://reviews.llvm.org/D77448
Summary:
When doing the conversion: MachineInst -> MCInst, we should ignore the
implicit operands, it will expose more opportunity for InstiAlias.
Reviewed By: steven.zhang
Differential Revision: https://reviews.llvm.org/D77118
There are a few patterns where we use a superclass for inputs to this
instruction rather than the correct class. This can sometimes lead to
unncessary copies.
An analysis of real world code turned up a number of patterns with BUILD_VECTOR
of nodes resulting from operations on extracted vector elements for which we
produce poor code. This addresses those cases. No attempt is made for
completeness as that would entail a large amount of work for something that
there is no evidence of in real code.
Differential revision: https://reviews.llvm.org/D72660
Summary:
This is found during review of https://reviews.llvm.org/D67088.
CHECK-DAG is non-overlapping after https://reviews.llvm.org/D47106.
-allow-deprecated-dag-overlap was introduced to temporary accept old
behavior.
But it actually hide some broken tests, eg: `test/CodeGen/PowerPC/swaps-le-1.ll`
The codegen has changed, but the CHECK-DAG still PASS due to allowing `overlap`.
This patch remove the deprecated options, and fix the broken tests.
Reviewers: #powerpc, hfinkel, nemanjai, steven.zhang, shchenz
Reviewed By: shchenz
Subscribers: shchenz, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69733
We currently produce a load, followed by (possibly a move for integers and) a
splat as separate instructions. VSX has always had a splatting load for
doublewords, but as of Power9, we have it for words as well. This patch just
exploits these instructions.
Differential revision: https://reviews.llvm.org/D63624
llvm-svn: 372139
In PowerPC, there is instruction to load vector in big endian element order when it's in little endian target.
So we can combine vector load + reverse into big endian load to eliminate the swap instruction.
Also combine vector reverse + store into big endian store.
Differential Revision: https://reviews.llvm.org/D65063
llvm-svn: 367516
In PowerPC, there is instruction to load vector in big endian element order when it's in little endian target.
So we can combine vector load + reverse into big endian load to eliminate the swap instruction.
Also combine vector reverse + store into big endian store.
llvm-svn: 367382
When we call checkResourceLimit in bumpCycle or bumpNode, and we
know the resource count has just reached the limit (the equations
are equal). We should return true to mark that we are resource
limited for next schedule, or else we might continue to schedule
in favor of latency for 1 more schedule and create a schedule that
actually overbook the resource.
When we call checkResourceLimit to estimate the resource limite before
scheduling, we don't need to return true even if the equations are
equal, as it shouldn't limit the schedule for it .
Differential Revision: https://reviews.llvm.org/D62345
llvm-svn: 362805
This is to address some of the problems in existing P9 resource modeling,
especially about the dispatching rules.
Instead of using a hypothetical DISPATCHER , we try to use the number of
actual dispatch slots, and define SchedWriteRes to model dispatch rules,
then update instruction classes according to dispatch rules.
All the dispatch rules and instruction classes update are made according
to POWER9 User Manual.
Differential Revision: https://reviews.llvm.org/D61873
llvm-svn: 362509
build-vector-tests.ll is a huge testcase, it is hard to maintain: eg:
any fundamental changes might need to update hundreds of lines. We should
leverage the script to maintain it.
This patch simply run utils/update_llc_test_checks.py on it. There
should be no missing test points.
llvm-svn: 360175
When switched to the MI scheduler for P9, the hardware is modeled as out of order.
However, inside the MI Scheduler algorithm, we still use the in-order scheduling model
as the MicroOpBufferSize isn't set. The MI scheduler take it as the hw cannot buffer
the op. So, only when all the available instructions issued, the pending instruction
could be scheduled. That is not true for our P9 hw in fact.
This patch is trying to enable the Out-of-Order scheduling model. The buffer size 44 is
picked from the P9 hw spec, and the perf test indicate that, its value won't hurt the cpu2017.
With this patch, there are 3 specs improved over 3% and 1 spec deg over 3%. The detail is as follows:
x264_r: +6.95%
cactuBSSN_r: +6.94%
lbm_r: +4.11%
xz_r: -3.85%
And the GEOMEAN for all the C/C++ spec in spec2017 is about 0.18% improved.
Reviewer: Nemanjai
Differential Revision: https://reviews.llvm.org/D55810
llvm-svn: 350285
Currently, for this node:
vector int test(int a, int b, int c, int d) {
return (vector int) { a, b, c, d };
}
we get this on Power9:
mtvsrdd 34, 5, 3
mtvsrdd 35, 6, 4
vmrgow 2, 3, 2
and this on Power8:
mtvsrwz 0, 3
mtvsrwz 1, 5
mtvsrwz 2, 4
mtvsrwz 3, 6
xxmrghd 34, 1, 0
xxmrghd 35, 3, 2
vmrgow 2, 3, 2
This can be improved to this on LE Power9:
rldimi 3, 4, 32, 0
rldimi 5, 6, 32, 0
mtvsrdd 34, 5, 3
and this on LE Power8
rldimi 3, 4, 32, 0
rldimi 5, 6, 32, 0
mtvsrd 34, 3
mtvsrd 35, 5
xxpermdi 34, 35, 34, 0
This patch updates the TD pattern to generate the optimized sequence for both
Power8 and Power9 on LE and BE.
Differential Revision: https://reviews.llvm.org/D53494
llvm-svn: 345414
This patch aims to improve the codegen for vector loads involving the
scalar_to_vector (load X) sequence. Initially, ld->mv instructions were used
for scalar_to_vector (load X), so this patch allows scalar_to_vector (load X)
to utilize:
LXSD and LXSDX for i64 and f64
LXSIWAX for i32 (sign extension to i64)
LXSIWZX for i32 and f64
Committing on behalf of Amy Kwan.
Differential Revision: https://reviews.llvm.org/D48950
llvm-svn: 339260
Adding the FP_ROUND nodes when combining FP_TO_[SU]INT of elements
feeding a BUILD_VECTOR into an FP_TO_[SU]INT of the built vector
loses precision. This patch removes the code that adds these nodes
to true f64 operands. It also adds patterns required to ensure
the code is still vectorized rather than converting individual
elements and inserting into a vector.
Fixes https://bugs.llvm.org/show_bug.cgi?id=38342
Differential Revision: https://reviews.llvm.org/D50121
llvm-svn: 338658
See https://reviews.llvm.org/D47106 for details.
Reviewed By: probinson
Differential Revision: https://reviews.llvm.org/D47171
This commit drops that patch's changes to:
llvm/test/CodeGen/NVPTX/f16x2-instructions.ll
llvm/test/CodeGen/NVPTX/param-load-store.ll
For some reason, the dos line endings there prevent me from commiting
via the monorepo. A follow-up commit (not via the monorepo) will
finish the patch.
llvm-svn: 336843
The match pattern in the definition of LXSDX is xoaddr, so the Pseudo
instruction XFLOADf64 never gets selected. XFLOADf64 expands to LXSDX/LFDX post
RA based on the register pressure. To avoid ambiguity, we need to remove the
select pattern for LXSDX, same as what was done for LXSD. STXSDX also have
the same issue.
Patch by Qing Shan Zhang (steven.zhang).
Differential Revision: https://reviews.llvm.org/D47178
llvm-svn: 333150
This patch adds the necessary infrastructure to convert instructions that
take two register operands to those that take a register and immediate if
the necessary operand is produced by a load-immediate. Furthermore, it uses
this infrastructure to perform such conversions twice - first at MachineSSA
and then pre-emit.
There are a number of reasons we may end up with opportunities for this
transformation, including but not limited to:
- X-Form instructions chosen since the exact offset isn't available at ISEL time
- Atomic instructions with constant operands (we will add patterns for this
in the future)
- Tail duplication may duplicate code where one block contains this redundancy
- When emitting compare-free code in PPCDAGToDAGISel, we don't handle constant
comparands specially
Furthermore, this patch moves the initialization of PPCMIPeepholePass so that
it can be used for MIR tests.
llvm-svn: 320791
The VSX versions have the advantage of a full 64-register target whereas the FP
ones have the advantage of lower latency and higher throughput. So what we’re
after is using the faster instructions in low register pressure situations and
using the larger register file in high register pressure situations.
The heuristic chooses between the following 7 pairs of instructions.
PPC::LXSSPX vs PPC::LFSX
PPC::LXSDX vs PPC::LFDX
PPC::STXSSPX vs PPC::STFSX
PPC::STXSDX vs PPC::STFDX
PPC::LXSIWAX vs PPC::LFIWAX
PPC::LXSIWZX vs PPC::LFIWZX
PPC::STXSIWX vs PPC::STFIWX
Differential Revision: https://reviews.llvm.org/D38486
llvm-svn: 318651
This patch just adds printing of CR bit registers in a more human-readable
form akin to that used by the GNU binutils.
Differential Revision: https://reviews.llvm.org/D31494
llvm-svn: 309001
As outlined in the PR, we didn't ensure that displacements for DQ-Form
instructions are multiples of 16. Since the instruction encoding encodes
a quad-word displacement, a sub-16 byte displacement is meaningless and
ends up being encoded incorrectly.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33671.
Differential Revision: https://reviews.llvm.org/D35007
llvm-svn: 307934
For this example:
float test (int *arr) {
return arr[2];
}
We currently generate the following code:
li r4, 8
lxsiwax f0, r3, r4
xscvsxdsp f1, f0
With this patch, we will now generate:
addi r3, r3, 8
lxsiwax f0, 0, r3
xscvsxdsp f1, f0
Originally reported in: https://bugs.llvm.org/show_bug.cgi?id=27204
Differential Revision: https://reviews.llvm.org/D35027
llvm-svn: 307553
Fixes PR30730.
This is a re-commit of a pulled commit. The commit was pulled because some
software projects contained uses of Altivec vectors that violated alignment
requirements. Known issues have now been fixed.
Committing on behalf of Lei Huang.
Differential Revision: https://reviews.llvm.org/D26861
llvm-svn: 301892
Removing sensitivity to scheduling (by using CHECK-DAG instead of CHECK) and
some other minor corrections.
In preparation to commit Power9 processor model.
llvm-svn: 289900
This is the final patch in the series of patches that improves
BUILD_VECTOR handling on PowerPC. This adds a few peephole optimizations
to remove redundant instructions. It also adds a large test case which
encompasses a large set of code patterns that build vectors - this test
case was the motivator for this series of patches.
Differential Revision: https://reviews.llvm.org/D26066
llvm-svn: 288800
Nemanja Ivanovic