4 Commits

Author SHA1 Message Date
James Molloy
d50104d677 [ModuloSchedule] Fix no-asserts build
Apologies, due to a git SNAFU this fix (dump doesn't exist and silence unused variables) stayed in my index rather than applying to rL370893.

llvm-svn: 370894
2019-09-04 12:57:23 +00:00
James Molloy
74913a772f [ModuloSchedule] Introduce PeelingModuloScheduleExpander
This is the beginnings of a reimplementation of ModuloScheduleExpander. It works
by generating a single-block correct pipelined kernel and then peeling out the
prolog and epilogs.

This patch implements kernel generation as well as a validator that will
confirm the number of phis added is the same as the ModuloScheduleExpander.

Prolog and epilog peeling will come in a different patch.

Differential Revision: https://reviews.llvm.org/D67081

llvm-svn: 370893
2019-09-04 12:54:24 +00:00
James Molloy
33edb0a6f1 [MachinePipeliner] Add a way to unit-test the schedule emitter
Emitting a schedule is really hard. There are lots of corner cases to take care of; in fact, of the 60+ SWP-specific testcases in the Hexagon backend most of those are testing codegen rather than the schedule creation itself.

One issue is that to test an emission corner case we must craft an input such that the generated schedule uses that corner case; sometimes this is very hard and convolutes testcases. Other times it is impossible but we want to test it anyway.

This patch adds a simple test pass that will consume a module containing a loop and generate pipelined code from it. We use post-instr-symbols as a way to annotate instructions with the stage and cycle that we want to schedule them at.

We also provide a flag that causes the MachinePipeliner to generate these annotations instead of actually emitting code; this allows us to generate an input testcase with:

  llc < %s -stop-after=pipeliner -pipeliner-annotate-for-testing -o test.mir

And run the emission in isolation with:

  llc < test.mir -run-pass=modulo-schedule-test

llvm-svn: 370705
2019-09-03 08:20:31 +00:00
James Molloy
e93cbbf303 [MachinePipeliner] Separate schedule emission, NFC
This is the first stage in refactoring the pipeliner and making it more
accessible for backends to override and control. This separates the logic and
state required to *emit* a scheudule from the logic that *computes* and
validates a schedule.

This will enable (a) new schedule emitters and (b) new modulo scheduling
implementations to coexist.

NFC.

Differential Revision: https://reviews.llvm.org/D67006

llvm-svn: 370500
2019-08-30 18:49:50 +00:00