Commit Graph

22 Commits

Author SHA1 Message Date
Matt Arsenault 24f14993e8 GlobalISel: Combine g_extract with g_merge_values
Try to use the underlying source registers.

This enables legalization in more cases where some irregular
operations are widened and others narrowed.

This seems to make the test_combines_2 AArch64 test worse, since the
MERGE_VALUES has multiple uses. Since this should be required for
legalization, a hasOneUse check is probably inappropriate (or maybe
should only be used if the merge is legal?).

llvm-svn: 353121
2019-02-04 23:41:59 +00:00
Daniel Sanders acc008cb0c [globalisel] Remove redundant -global-isel option from tests that use -run-pass. NFC
As Roman Tereshin pointed out in https://reviews.llvm.org/D45541, the
-global-isel option is redundant when -run-pass is given. -global-isel sets up
the GlobalISel passes in the pass manager but -run-pass skips that entirely and
configures it's own pipeline.

llvm-svn: 331603
2018-05-05 21:19:59 +00:00
Roman Tereshin 3c6ea7e28c [GlobalISel][Legalizer] Look thro copies while combining G_UNMERGE's
As we're becoming stricter w/ respect to not allowing vregs having LLTs
and regclasses assigned both mid-globalisel pipeline, the number of
extra copies grows, some of which separate G_UNMERGE's from their
corresponding G_MERGE's, becoming a performance concern.

It's worth mentioning that we're already looking through copies while
combining legalization artifacts for every kind of artifact but
G_UNMERGE.

Reviewed By: aditya_nandakumar

Reviewers: ab, t.p.northover, volkan, javed.absar

Subscribers: rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45644

llvm-svn: 330660
2018-04-23 22:28:36 +00:00
Amara Emerson f542355942 [GlobalISel] Fix legalizer combine to not use illegal input G_EXTRACT.
This was being masked because GISel is enabled by default for -O0 and
the abort was disabled. Modified test to explicitly enable abort.

llvm-svn: 328311
2018-03-23 12:48:57 +00:00
Aditya Nandakumar b14fd2608c [GISel]: Verify COPIES involving generic registers.
Add verification for copies involving generic registers if they are
compatible - ie if it is a generic copy, then the types are the
same, and if a COPY b/w generic and target virtual register, then
the sizes should be the same. Only checks if there are no sub registers
involved for now.

https://reviews.llvm.org/D37775

llvm-svn: 324696
2018-02-09 01:27:23 +00:00
Puyan Lotfi 43e94b15ea Followup on Proposal to move MIR physical register namespace to '$' sigil.
Discussed here:

http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html

In preparation for adding support for named vregs we are changing the sigil for
physical registers in MIR to '$' from '%'. This will prevent name clashes of
named physical register with named vregs.

llvm-svn: 323922
2018-01-31 22:04:26 +00:00
Volkan Keles a32ff00b00 GlobalISel: Enable the legalization of G_MERGE_VALUES and G_UNMERGE_VALUES
Summary: LegalizerInfo assumes all G_MERGE_VALUES and G_UNMERGE_VALUES instructions are legal, so it is not possible to legalize vector operations on illegal vector types. This patch fixes the problem by removing the related check and adding default actions for G_MERGE_VALUES and G_UNMERGE_VALUES.

Reviewers: qcolombet, ab, dsanders, aditya_nandakumar, t.p.northover, kristof.beyls

Reviewed By: dsanders

Subscribers: rovka, javed.absar, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39823

llvm-svn: 319524
2017-12-01 08:19:10 +00:00
Aditya Nandakumar e6201c8724 [GISel]: Rework legalization algorithm for better elimination of
artifacts along with DCE

Legalization Artifacts are all those insts that are there to make the
type system happy. Currently, the target needs to say all combinations
of extends and truncs are legal and there's no way of verifying that
post legalization, we only have *truly* legal instructions. This patch
changes roughly the legalization algorithm to process all illegal insts
at one go, and then process all truncs/extends that were added to
satisfy the type constraints separately trying to combine trivial cases
until they converge. This has the added benefit that, the target
legalizerinfo can only say which truncs and extends are okay and the
artifact combiner would combine away other exts and truncs.

Updated legalization algorithm to roughly the following pseudo code.

WorkList Insts, Artifacts;
collect_all_insts_and_artifacts(Insts, Artifacts);

do {
  for (Inst in Insts)
         legalizeInstrStep(Inst, Insts, Artifacts);
  for (Artifact in Artifacts)
         tryCombineArtifact(Artifact, Insts, Artifacts);
} while(!Insts.empty());

Also, wrote a simple wrapper equivalent to SetVector, except for
erasing, it avoids moving all elements over by one and instead just
nulls them out.

llvm-svn: 318210
2017-11-14 22:42:19 +00:00
Justin Bogner 6c452834a1 MIR: Print the register class or bank in vreg defs
This updates the MIRPrinter to include the regclass when printing
virtual register defs, which is already valid syntax for the
parser. That is, given 64 bit %0 and %1 in a "gpr" regbank,

  %1(s64) = COPY %0(s64)

would now be written as

  %1:gpr(s64) = COPY %0(s64)

While this change alone introduces a bit of redundancy with the
registers block, it allows us to update the tests to be more concise
and understandable and brings us closer to being able to remove the
registers block completely.

Note: We generally only print the class in defs, but there is one
exception. If there are uses without any defs whatsoever, we'll print
the class on all uses. I'm not completely convinced this comes up in
meaningful machine IR, but for now the MIRParser and MachineVerifier
both accept that kind of stuff, so we don't want to have a situation
where we can print something we can't parse.

llvm-svn: 316479
2017-10-24 18:04:54 +00:00
Justin Bogner d45849f703 Canonicalize a large number of mir tests using update_mir_test_checks
This converts a large and somewhat arbitrary set of tests to use
update_mir_test_checks. I ran the script on all of the tests I expect
to need to modify for an upcoming mir syntax change and kept the ones
that obviously didn't change the tests in ways that might make it
harder to understand.

llvm-svn: 316137
2017-10-18 23:18:12 +00:00
Tim Northover c2d5e6d637 AArch64: legalize G_EXTRACT operations.
This is the dual problem to legalizing G_INSERTs so most of the code and
testing was cribbed from there.

llvm-svn: 306328
2017-06-26 20:34:13 +00:00
Tim Northover 4b4eec7009 GlobalISel: remove G_SEQUENCE instruction.
It was trying to do too many things. The basic lumping together of values for
legalization purposes is now handled by G_MERGE_VALUES. More complex things
involving gaps and odd sizes are handled by G_INSERT sequences.

llvm-svn: 306120
2017-06-23 16:15:55 +00:00
Tim Northover c2c545b8f7 GlobalISel: restrict G_EXTRACT instruction to just one operand.
A bit more painful than G_INSERT because it was more widely used, but this
should simplify the handling of extract operations in most locations.

llvm-svn: 297100
2017-03-06 23:50:28 +00:00
Ahmed Bougacha 67d1c7c3c2 [GlobalISel] Replace all combined G_EXTRACT uses.
Iterating on the use-list we're modifying doesn't work: after the first
iteration, the use-list iterator will point to a MachineOperand
referencing the new register.  This caused us to skip the other uses to
replace.

Instead, use MRI.replaceRegWith(), which accounts for this behavior.

llvm-svn: 296551
2017-03-01 00:43:39 +00:00
Matthias Braun f1141285eb MIRTests: Remove unnecessary 2>&1 redirection
llc mir output goes to stdout nowadays, so the 2>&1 is not necessary
anymore for most tests.

llvm-svn: 295859
2017-02-22 18:47:41 +00:00
Ahmed Bougacha b0de0d1bfc [AArch64][GlobalISel] Split legalizer combine tests. NFC.
Big functions with large vreg # are quite unwieldy to update.  This test
also relied on legal s8 operations which we're considering removing.

Change it to have one function per test (it does increase boilerplate,
but makes the core hopefully more readable and maintanable), and use
100% legal operations throughout.

llvm-svn: 292551
2017-01-20 00:30:06 +00:00
Tim Northover 69fa84a6e9 GlobalISel: rename legalizer components to match others.
The previous names were both misleading (the MachineLegalizer actually
contained the info tables) and inconsistent with the selector & translator (in
having a "Machine") prefix. This should make everything sensible again.

The only functional change is the name of a couple of command-line options.

llvm-svn: 284287
2016-10-14 22:18:18 +00:00
Diana Picus 68c7b04e8d [GlobalISel] Get the AArch64 tests to work on Linux
Mostly this just means changing the triple from aarch64-apple-ios to the generic
aarch64--. Only one test needs more significant changes, but GlobalISel already
does the right thing so it's ok to just change the checks.

Differential Revision: https://reviews.llvm.org/D25532

llvm-svn: 284223
2016-10-14 10:19:40 +00:00
Tim Northover d28d3cc079 GlobalISel: disambiguate types when printing MIR
Some generic instructions have multiple types. While in theory these always be
discovered by inspecting the single definition of each generic vreg, in
practice those definitions won't always be local and traipsing through a big
function to find them will not be fun.

So this changes MIRPrinter to print out the type of uses as well as defs, if
they're known to be different or not known to be the same.

On the parsing side, we're a little more flexible: provided each register is
given a type in at least one place it's mentioned (and all types are
consistent) we accept the MIR. This doesn't introduce ambiguity but makes
writing tests manually a bit less painful.

llvm-svn: 281204
2016-09-12 11:20:10 +00:00
Tim Northover 0f140c769a GlobalISel: move type information to MachineRegisterInfo.
We want each register to have a canonical type, which means the best place to
store this is in MachineRegisterInfo rather than on every MachineInstr that
happens to use or define that register.

Most changes following from this are pretty simple (you need an MRI anyway if
you're going to be doing any transformations, so just check the type there).
But legalization doesn't really want to check redundant operands (when, for
example, a G_ADD only ever has one type) so I've made use of MCInstrDesc's
operand type field to encode these constraints and limit legalization's work.

As an added bonus, more validation is possible, both in MachineVerifier and
MachineIRBuilder (coming soon).

llvm-svn: 281035
2016-09-09 11:46:34 +00:00
Tim Northover 11a2354670 GlobalISel: use G_TYPE to annotate physregs with a type.
More preparation for dropping source types from MachineInstrs: regsters coming
out of already-selected code (i.e. non-generic instructions) don't have a type,
but that information is needed so we must add it manually.

This is done via a new G_TYPE instruction.

llvm-svn: 280292
2016-08-31 21:24:02 +00:00
Tim Northover 991b12bf09 GlobalISel: combine extracts & sequences created for legalization
Legalization ends up creating many G_SEQUENCE/G_EXTRACT pairs which leads to
inefficient codegen (even for -O0), so add a quick pass over the function to
remove them again.

llvm-svn: 280155
2016-08-30 20:51:25 +00:00