This patch includes the following updates to the load/store refactoring effort introduced in D93370:
- Update various VSX patterns that use to "force" an XForm, to instead just XForm.
This allows the ability for the patterns to compute the most optimal addressing
mode (and to produce a DForm instruction when possible)
- Update pattern and test case for the LXVD2X/STXVD2X intrinsics
- Update LIT test cases that use to use the XForm instruction to use the DForm instruction
Differential Revision: https://reviews.llvm.org/D95115
Extend shuffle canonicalization and conversion of shuffles fed by vectorized
scalars to big endian subtargets. For big endian subtargets, loads and direct
moves of scalars into vector registers put the data in the correct element for
SCALAR_TO_VECTOR if the data type is 8 bytes wide. However, if the data type is
narrower, the value still ends up in the wrong place - althouth a different
wrong place than on little endian targets.
This patch extends the combine that keeps values where they are if they feed a
shuffle to big endian targets.
Differential revision: https://reviews.llvm.org/D100478
The VSX tablegen file has some rather eggregious uses of
COPY_TO_REGCLASS even in situations where it needs to use
SUBREG_TO_REG. While this produces correct code, it often doesn't
allow the register coalescer to coalesce copies and the resulting
code ends up being suboptimal. This patch just changes over
patterns that should use SUBREG_TO_REG.
tryLatency compares two sched candidates. For the top zone it prefers
the one with lesser depth, but only if that depth is greater than the
total latency of the instructions we've already scheduled -- otherwise
its latency would be hidden and there would be no stall.
Unfortunately it only tests the depth of one of the candidates. This can
lead to situations where the TopDepthReduce heuristic does not kick in,
but a lower priority heuristic chooses the other candidate, whose depth
*is* greater than the already scheduled latency, which causes a stall.
The fix is to apply the heuristic if the depth of *either* candidate is
greater than the already scheduled latency.
All this also applies to the BotHeightReduce heuristic in the bottom
zone.
Differential Revision: https://reviews.llvm.org/D72392
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.
We can only report the knownbits for a SCALAR_TO_VECTOR node if we only demand the 0'th element - the upper elements are undefined and shouldn't be trusted.
This is causing a number of regressions that need addressing but we need to get the bugfix in first.
Summary:
If we didn't set the value for hasSideEffects bit in our td file, `llvm-tblgen`
will set it as true for those instructions which has no match pattern.
Below 6 instructions don't set the hasSideEffects flag and don't have match
pattern, so their hasSideEffects flag will be set true by llvm-tblgen.
But in fact below instructions don't modify any special register and don't have
other SideEffects, they shouldn't have SideEffects.
This patch is to modify the hasSideEffects of below instructions from 1 to 0.
```
VEXTUHLX
VEXTUHRX
VEXTUWLX
VEXTUWRX
VSPLTBs
VSPLTHs
```
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D71391
Change the PPCISelLowering.cpp function that decides to avoid update form in
favor of partial vector loads to know about newer load types and to not be
confused by the chain operand.
Differential Revision: https://reviews.llvm.org/D60102
llvm-svn: 359504
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
Improve the current vec_abs support on P9, generate ISD::ABS node for vector types,
combine ABS node to VABSD node for some special cases to make use of P9 VABSD* insns,
do custom lowering to vsub(vneg later)+vmax if it has no combination opportunity.
Differential Revision: https://reviews.llvm.org/D54783
llvm-svn: 349437
With some patch adopted for Power9 vabsd* insns, some CHECKs can't get the expected results.
But it's false alarm, we should update the case more robust.
llvm-svn: 349325
This patch addresses:
- Implementation within PPCISelLowering.cpp to check if we should use direct
load into vector instructions (such as lxsd/lfd ) when the scalar_to_vector
function is used; which will allow us to catch as many cases of the
scalar_to_vector uses as possible to translate the ld->mtvsrd sequence into
lxsd.
- Test cases to exhibit the behaviour of emitting lxsd/lfd.
Patch by amyk
Differential revision: https://reviews.llvm.org/D49698
llvm-svn: 340037
Amy Kwan