Commit Graph

64 Commits

Author SHA1 Message Date
Aditya Nandakumar f75d4f329c [GISel]: Provide standard interface to observe changes in GISel passes
https://reviews.llvm.org/D54980

This provides a standard API across GISel passes to observe and notify
passes about changes (insertions/deletions/mutations) to MachineInstrs.
This patch also removes the recordInsertion method in MachineIRBuilder
and instead provides method to setObserver.

Reviewed by: vkeles.

llvm-svn: 348406
2018-12-05 20:14:52 +00:00
Daniel Sanders a464ffd52c [globalisel][combine] When placing truncates, handle the case when the BB is empty
GlobalISel uses MIR with implicit fallthrough on each basic block. As a result,
getFirstNonPhi() can return end().

llvm-svn: 343829
2018-10-04 23:47:37 +00:00
Daniel Sanders ab358bfd09 [globalisel][combine] Fix a rare crash when encountering an instruction whose op0 isn't a reg
The simplest instance of this is an intrinsic with no results which will have the
intrinsic ID as operand 0.

Also fix some benign incorrectness when op0 is a reg but isn't a def that was
guarded against by checking for the extension opcodes.

llvm-svn: 343821
2018-10-04 21:44:32 +00:00
Daniel Sanders a05c7583c9 [globalisel][combine] Improve the truncate placement for the extending-loads combine
This brings the extending loads patch back to the original intent but minus the
PHI bug and with another small improvement to de-dupe truncates that are
inserted into the same block.

The truncates are sunk to their uses unless this would require inserting before a
phi in which case it sinks to the _beginning_ of the predecessor block for that
path (but no earlier than the def).

The reason for choosing the beginning of the predecessor is that it makes de-duping
multiple truncates in the same block simple, and optimized code is going to run a
scheduler at some point which will likely change the position anyway.

llvm-svn: 343804
2018-10-04 18:44:58 +00:00
Daniel Sanders fb9b99b26e [globalisel][combines] Don't sink G_TRUNC down to use if that use is a G_PHI
This fixes a problem where the register allocator fails to eliminate a PHI
because there's a non-PHI in the middle of the PHI instructions at the start
of a BB.

This G_TRUNC can be better placed but this at least fixes the correctness issue
quickly. I'll follow up with a patch to the verifier to catch this kind of bug
in future.

llvm-svn: 343693
2018-10-03 15:43:39 +00:00
Jonas Toth 602e3a640f [CodeGen] NFC fix pedantic warning from extra semicolon
llvm-svn: 343674
2018-10-03 10:59:19 +00:00
Daniel Sanders c973ad1878 Re-commit: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

The previous commit failed portions of the test-suite on GreenDragon due to
duplicate COPY instructions and iterator invalidation. Both issues have now
been fixed. To assist with this, a helper (cloneVirtualRegister) has been added
to MachineRegisterInfo that can be used to get another register that has the same
type and class/bank as an existing one.

llvm-svn: 343654
2018-10-03 02:12:17 +00:00
Daniel Sanders 33f42f97af Revert: r343521 and r343541: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
There's a strange assertion on two of the Green Dragon bots that goes away when
this is reverted. The assertion is in RegBankAlloc and if it is this commit then
-verify-machine-instrs should have caught it earlier in the pipeline.

llvm-svn: 343546
2018-10-01 22:32:08 +00:00
Reid Kleckner 7a6966ec27 Fix the Windows build in GlobalISel
Clang-cl was complaining about some sort of constexpr narrowing bug:

C:\src\llvm-project\llvm\lib\CodeGen\GlobalISel\CombinerHelper.cpp(136,31):  error: non-constant-expression cannot be narrowed from type 'llvm::TargetOpcode::(anonymous enum at C:\src\llvm-project\llvm\include\llvm/CodeGen/TargetOpcodes.h:22:1)' to 'unsigned int' in initializer list [-Wc++11-narrowing]
                              unsigned(MI.getOpcode()) == unsigned(TargetOpcode::G_LOAD)
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\src\llvm-project\llvm\lib\CodeGen\GlobalISel\CombinerHelper.cpp(136,31):  note: insert an explicit cast to silence this issue
                              unsigned(MI.getOpcode()) == unsigned(TargetOpcode::G_LOAD)
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                              static_cast<unsigned int>(

llvm-svn: 343541
2018-10-01 21:39:39 +00:00
Daniel Sanders 9659bfda5a [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 343521
2018-10-01 18:56:47 +00:00
Daniel Sanders 618437459c Revert r331816 and r331820 - [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Reverting this to see if the clang-cmake-aarch64-global-isel and
clang-cmake-aarch64-quick bots are failing because of this commit.
We know it wasn't r331819.

llvm-svn: 331846
2018-05-09 05:00:17 +00:00
Daniel Sanders ec17920da1 [globalisel] Correct r331816 to check the opcode before calling getOperand().
Fix a silly mistake in my pre-commit changes for r331816. It should check what
opcode the insn is before extracting the operands.

NFC at the moment since the caller already checked the opcode.

llvm-svn: 331820
2018-05-08 22:58:35 +00:00
Daniel Sanders d24dcdd1f7 [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64
Summary: Depends on D45541

Reviewers: ab, aditya_nandakumar, bogner, rtereshin, volkan, rovka, javed.absar, aemerson

Reviewed By: aemerson

Subscribers: aemerson, rengolin, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D45543

llvm-svn: 331816
2018-05-08 22:26:39 +00:00
Aditya Nandakumar 81c81b6426 [GISel]: Implement GlobalISel combiner API.
https://reviews.llvm.org/D41373

The various components are

GICombinerHelper contains transformations that are common to all
targets. Targets can pick and choose which transformations (at
function/opcode granularity) each pass uses via configuring a
GICombinerInfo.

GICombiner contains some common code and it does the traversal,
driving of combines, worklist management and iterating until
convergence.

GICombinerInfo is an interface with a virtual method called combine.
The combiner info will allow targets to pick and choose (or
implement their own specific combines). CombineInfos can make
use of available combines in GICombineHelper to configure the
transformations for a particular pass. Currently this approach allows
cherry picking transformations from helpers (at function/opcode
granularity) and also allows early returning on specific
transformations. Targets also get to prioritize whether target specific
combines run before/after the opt-in generic combines. Ideally we would
like this part to be configured by both C++ and Tablegen. The
CombinerInfo also has a field which indicates how to deal with
IllegalOps (ie - should we allow to create them/or legalize them?).

A CombinerPass would configure a CombinerInfo, create the GICombiner
with the Info, and call
GICombiner::combineMachineInstrs(MachineFunction&).
This organization is very similar to the GISelLegalizer.

llvm-svn: 323392
2018-01-25 00:41:58 +00:00