Instead of inserting everything after the 'root' of the reduction,
insert all instructions as close to their operands as possible. This
can help reduce register pressure.
Differential Revision: https://reviews.llvm.org/D67392
llvm-svn: 374981
Assume that, ModelA has scheduling resource for InstA and ModelB has scheduling resource for InstB. This is what the llvm::MCSchedClassDesc looks like:
llvm::MCSchedClassDesc ModelASchedClasses[] = {
...
InstA, 0, ...
InstB, -1,...
};
llvm::MCSchedClassDesc ModelBSchedClasses[] = {
...
InstA, -1,...
InstB, 0,...
};
The -1 means invalid num of macro ops, while it is valid if it is >=0. This is what we look like now:
llvm::MCSchedClassDesc ModelASchedClasses[] = {
...
InstA, 0, ...
InstB, 0,...
};
llvm::MCSchedClassDesc ModelBSchedClasses[] = {
...
InstA, 0,...
InstB, 0,...
};
And compiler hit the assertion here because the SCDesc is valid now for both InstA and InstB.
Differential Revision: https://reviews.llvm.org/D67950
llvm-svn: 374524
This is an attempt to fill in some of the missing instructions from the
Cortex-M4 schedule, and make it easier to do the same for other ARM cpus.
- Some instructions are marked as hasNoSchedulingInfo as they are pseudos or
otherwise do not require scheduling info
- A lot of features have been marked not supported
- Some WriteRes's have been added for cvt instructions.
- Some extra instruction latencies have been added, notably by relaxing the
regex for dsp instruction to catch more cases, and some fp instructions.
This goes a long way to get the CompleteModel working for this CPU. It does not
go far enough as to get all scheduling info for all output operands correct.
Differential Revision: https://reviews.llvm.org/D67957
llvm-svn: 373163
The incoming accumulator value can be discovered through a sext, in
which case there will be a mismatch between the input and the result.
So sign extend the accumulator input if we're performing a 64-bit mac.
Differential Revision: https://reviews.llvm.org/D67220
llvm-svn: 371370
For any unpaired muls, we accumulate them as an input to the
reduction. Check the type of the mul and perform a sext if the
existing accumlator input type is not the same.
Differential Revision: https://reviews.llvm.org/D66993
llvm-svn: 370851
rL369567 reverted a couple of recent changes made to ARMParallelDSP
because of a miscompilation error: PR43073.
The issue stemmed from an underlying bug that was caused by adding
muls into a reduction before it was proved that they could be executed
in parallel with another mul.
Most of the changes here are from the previously reverted commits.
The additional changes have been made area:
1) The Search function now doesn't insert any muls into the Reduction
object. That now happens once the search has successfully finished.
2) For any muls added into the reduction but that weren't paired, we
accumulate their values as an input into the smlad.
Differential Revision: https://reviews.llvm.org/D66660
llvm-svn: 370171
As loads are combined and widened, we replaced their sext users
operands whereas we should have been replacing the uses of the sext.
I've added a load of tests, with only a few of them originally
causing assertion failures, the rest improve pattern coverage.
Differential Revision: https://reviews.llvm.org/D65740
llvm-svn: 368404
While combining two loads into a single load, we often need to
reorder the pointer operands for the new load. This reordering was
broken in the cases where there was a chain of values that built up
the pointer.
Differential Revision: https://reviews.llvm.org/D65193
llvm-svn: 366881
Two functional changes have been made here:
- Now search up from any add instruction to find the chains of
operations that we may turn into a smlad. This allows the
generation of a smlad which doesn't accumulate into a phi.
- The search function has been corrected to stop it falsely searching
up through an invalid path.
The bulk of the changes have been making the Reduction struct a class
and making it more C++y with getters and setters.
Differential Revision: https://reviews.llvm.org/D61780
llvm-svn: 365740
This patch adds a simple Cortex-M4 schedule, renaming the existing M3
schedule to M4 and filling in the latencies as-per the Cortex-M4 TRM:
https://developer.arm.com/docs/ddi0439/latest
Most of these are 1, with the important exception being loads taking 2
cycles. A few others are also higher, but I don't believe they make a
large difference. I've repurposed the M3 schedule as the latencies are
mostly the same between the two cores, with the M4 having more FP and
DSP instructions. We also turn on MISched and UseAA for the cores that
now use this.
It also adds some schedule Write's to various instruction to make things
simpler.
Differential Revision: https://reviews.llvm.org/D54142
llvm-svn: 360768
When deciding the safety of generating smlad, we checked for any
writes within the block that may alias with any of the loads that
need to be widened. This is overly conservative because it only
matters when there's a potential aliasing write to a location
accessed by a pair of loads.
Now we check for aliasing writes only once, during setup. If two
loads are found to have an aliasing write between them, we don't add
these loads to LoadPairs. This means that later during the transform,
we can safely widened a pair without worrying about aliasing.
However, to maintain correctness, we also need to change the way that
wide loads are inserted because the order is now important.
The MatchSMLAD method has also been changed, absorbing
MatchReductions and AddMACCandidate to hopefully improve readability.
Differential Revision: https://reviews.llvm.org/D6102
llvm-svn: 360567
Bail early when we don't have a preheader and also if the target is
big endian because it's written with only little endian in mind!
Differential Revision: https://reviews.llvm.org/D59368
llvm-svn: 356243
When choosing whether a pair of loads can be combined into a single
wide load, we check that the load only has a sext user and that sext
also only has one user. But this can prevent the transformation in
the cases when parallel macs use the same loaded data multiple times.
To enable this, we need to fix up any other uses after creating the
wide load: generating a trunc and a shift + trunc pair to recreate
the narrow values. We also need to keep a record of which loads have
already been widened.
Differential Revision: https://reviews.llvm.org/D59215
llvm-svn: 356132
Previously reverted in rL343082.
Original commit message:
On failing to find sequences that can be converted into dual macs,
try to find sequential 16-bit loads that are used by muls which we
can then use smultb, smulbt, smultt with a wide load.
Differential Revision: https://reviews.llvm.org/D51983
llvm-svn: 344693
Sam Parker