Commit Graph

13 Commits

Author SHA1 Message Date
Reid Kleckner 0c2b09a9b6 [IR] Lazily number instructions for local dominance queries
Essentially, fold OrderedBasicBlock into BasicBlock, and make it
auto-invalidate the instruction ordering when new instructions are
added. Notably, we don't need to invalidate it when removing
instructions, which is helpful when a pass mostly delete dead
instructions rather than transforming them.

The downside is that Instruction grows from 56 bytes to 64 bytes.  The
resulting LLVM code is substantially simpler and automatically handles
invalidation, which makes me think that this is the right speed and size
tradeoff.

The important change is in SymbolTableTraitsImpl.h, where the numbering
is invalidated. Everything else should be straightforward.

We probably want to implement a fancier re-numbering scheme so that
local updates don't invalidate the ordering, but I plan for that to be
future work, maybe for someone else.

Reviewed By: lattner, vsk, fhahn, dexonsmith

Differential Revision: https://reviews.llvm.org/D51664
2020-02-18 14:44:24 -08:00
Reid Kleckner 4c1a1d3cf9 Add missing includes needed to prune LLVMContext.h include, NFC
These are a pre-requisite to removing #include "llvm/Support/Options.h"
from LLVMContext.h: https://reviews.llvm.org/D70280
2019-11-14 15:23:15 -08:00
Max Kazantsev 24383cd7bb Make widenable condition transparent for MemoryWriteTracking
Side effects of widenable condition intrinsic are modelled via
InaccessibleMemOnly, and there is no way to say that it isn't
really writing any memory. This patch teaches MemoryWriteTracking
ignore this intrinsic.

llvm-svn: 354021
2019-02-14 11:10:29 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Max Kazantsev 4615a505f8 [IPT] Drop cache less eagerly in GVN and LoopSafetyInfo
Current strategy of dropping `InstructionPrecedenceTracking` cache is to
invalidate the entire basic block whenever we change its contents. In fact,
`InstructionPrecedenceTracking` has 2 internal strictures: `OrderedInstructions`
that is needed to be invalidated whenever the contents changes, and the map
with first special instructions in block. This second map does not need an
update if we add/remove a non-special instuction because it cannot
affect the contents of this map.

This patch changes API of `InstructionPrecedenceTracking` so that it now
accounts for reasons under which we invalidate blocks. This should lead
to much less recalculations of the map and should save us some compile time
because in practice we don't typically add/remove special instructions.

Differential Revision: https://reviews.llvm.org/D54462
Reviewed By: efriedma

llvm-svn: 350694
2019-01-09 07:28:13 +00:00
Max Kazantsev 7d49a3a816 [LICM] Hoist guards from non-header blocks
This patch relaxes overconservative checks on whether or not we could write
memory before we execute an instruction. This allows us to hoist guards out of
loops even if they are not in the header block.

Differential Revision: https://reviews.llvm.org/D50891
Reviewed By: fedor.sergeev

llvm-svn: 346643
2018-11-12 09:29:58 +00:00
Max Kazantsev 90edc98c58 [NFC] Rename variable
llvm-svn: 341901
2018-09-11 05:10:01 +00:00
Max Kazantsev 6afebe1d30 [NFC] Simplify inner structure of InstructionPrecedenceTracking
Currently it has a set KnownBlocks that marks blocks as having cached
answers and a map FirstSpecialInsts that maps these blocks to first
special instructions in them. The value in the map is always non-null,
and for blocks that are known to have no special instructions the map
does not have an instance.

This patch removes KnownBlocks as obsolete. Instead, for blocks that
are known to have no special instructions, we just put a nullptr value.
This makes the code much easier to read.

llvm-svn: 341531
2018-09-06 09:29:42 +00:00
Max Kazantsev 8a9e059e5c Return "[NFC] Add severe validation of InstructionPrecedenceTracking"
This validation patch has been reverted as rL341147 because of conserns raised by
@reames. This revision returns it as is to raise a discussion and address the concerns.

Differential Revision: https://reviews.llvm.org/D51523
Reviewed By: reames

llvm-svn: 341526
2018-09-06 08:33:02 +00:00
Max Kazantsev c683d643c9 Revert "[NFC] Add severe validation of InstructionPrecedenceTracking" for discussion
llvm-svn: 341147
2018-08-31 00:01:54 +00:00
Max Kazantsev ec9b386820 [NFC] Add severe validation of InstructionPrecedenceTracking
llvm-svn: 341051
2018-08-30 10:26:06 +00:00
Max Kazantsev d3487bdb61 [NFC] Rename map to make the naming consistent
llvm-svn: 341043
2018-08-30 09:24:33 +00:00
Max Kazantsev d3a4cbe153 [NFC] Move OrderedInstructions and InstructionPrecedenceTracking to Analysis
These classes don't make any changes to IR and have no reason to be in
Transform/Utils. This patch moves them to Analysis folder. This will allow
us reusing these classes in some analyzes, like MustExecute.

llvm-svn: 341015
2018-08-30 04:49:03 +00:00