Commit Graph

15 Commits

Author SHA1 Message Date
Matt Arsenault 1af53a91c0 DivergenceAnalysis: Fix crash with no return blocks
The post dominator tree does not have a root node in this case.

llvm-svn: 268933
2016-05-09 16:57:08 +00:00
Matt Arsenault 790eb1c490 DivergenceAnalysis: Fix crash with unreachable blocks
Unreachable blocks may not be in the dominator tree,
so don't crash on them.

llvm-svn: 268001
2016-04-29 06:17:47 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Nicolai Haehnle 13d90f324c [DivergenceAnalysis] Treat PHI with incoming undef as constant
Summary:
If a PHI has an incoming undef, we can pretend that it is equal to one
non-undef, non-self incoming value.

This is particularly relevant in combination with the StructurizeCFG
pass, which introduces PHI nodes with undefs. Previously, this lead to
branch conditions that were uniform before StructurizeCFG to become
non-uniform afterwards, which confused the SIAnnotateControlFlow
pass.

This fixes a crash when Mesa radeonsi compiles a shader from
dEQP-GLES3.functional.shaders.switch.switch_in_for_loop_dynamic_vertex

Reviewers: arsenm, tstellarAMD, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19013

llvm-svn: 266347
2016-04-14 17:42:47 +00:00
Hongbin Zheng 3f97840721 Introduce analysis pass to compute PostDominators in the new pass manager. NFC
Differential Revision: http://reviews.llvm.org/D17537

llvm-svn: 261902
2016-02-25 17:54:07 +00:00
Hongbin Zheng 66b19fbc4e Revert "Introduce analysis pass to compute PostDominators in the new pass manager. NFC"
This reverts commit a3e5cc6a51ab5ad88d1760c63284294a4e34c018.

llvm-svn: 261891
2016-02-25 16:45:53 +00:00
Hongbin Zheng a0273a04f5 Introduce analysis pass to compute PostDominators in the new pass manager. NFC
Differential Revision: http://reviews.llvm.org/D17537

llvm-svn: 261882
2016-02-25 16:33:06 +00:00
Benjamin Kramer 820f7548a1 Make some headers self-contained, remove unused includes that violate layering.
llvm-svn: 258937
2016-01-27 16:05:37 +00:00
Jingyue Wu 3f422280f5 [DivergenceAnalysis] fix a bug in computing influence regions
Fixes PR25864

llvm-svn: 256036
2015-12-18 21:44:26 +00:00
Duncan P. N. Exon Smith 5a82c916b0 Analysis: Remove implicit ilist iterator conversions
Remove implicit ilist iterator conversions from LLVMAnalysis.

I came across something really scary in `llvm::isKnownNotFullPoison()`
which relied on `Instruction::getNextNode()` being completely broken
(not surprising, but scary nevertheless).  This function is documented
(and coded to) return `nullptr` when it gets to the sentinel, but with
an `ilist_half_node` as a sentinel, the sentinel check looks into some
other memory and we don't recognize we've hit the end.

Rooting out these scary cases is the reason I'm removing the implicit
conversions before doing anything else with `ilist`; I'm not at all
surprised that clients rely on badness.

I found another scary case -- this time, not relying on badness, just
bad (but I guess getting lucky so far) -- in
`ObjectSizeOffsetEvaluator::compute_()`.  Here, we save out the
insertion point, do some things, and then restore it.  Previously, we
let the iterator auto-convert to `Instruction*`, and then set it back
using the `Instruction*` version:

    Instruction *PrevInsertPoint = Builder.GetInsertPoint();

    /* Logic that may change insert point */

    if (PrevInsertPoint)
      Builder.SetInsertPoint(PrevInsertPoint);

The check for `PrevInsertPoint` doesn't protect correctly against bad
accesses.  If the insertion point has been set to the end of a basic
block (i.e., `SetInsertPoint(SomeBB)`), then `GetInsertPoint()` returns
an iterator pointing at the list sentinel.  The version of
`SetInsertPoint()` that's getting called will then call
`PrevInsertPoint->getParent()`, which explodes horribly.  The only
reason this hasn't blown up is that it's fairly unlikely the builder is
adding to the end of the block; usually, we're adding instructions
somewhere before the terminator.

llvm-svn: 249925
2015-10-10 00:53:03 +00:00
Marcello Maggioni ab58c74d98 [DivergenceAnalysis] Separated definition of class into header.
The definition of the DivergenceAnalysis pass was in a CPP
file and wasn't accessible to users of the analysis to get it
through "getAnalysis<>()".
This patch extracts the definition into a separate header that
can be used by users of the analysis to fetch the results.

Patch by Volkan Keles (vkeles@apple.com)

llvm-svn: 248186
2015-09-21 17:58:14 +00:00
Nico Rieck 78199518c4 Rename inst_range() to instructions() for consistency. NFC
llvm-svn: 244248
2015-08-06 19:10:45 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Jingyue Wu 5da831cc31 Divergence analysis for GPU programs
Summary:
Some optimizations such as jump threading and loop unswitching can negatively
affect performance when applied to divergent branches. The divergence analysis
added in this patch conservatively estimates which branches in a GPU program
can diverge. This information can then help LLVM to run certain optimizations
selectively.

Test Plan: test/Analysis/DivergenceAnalysis/NVPTX/diverge.ll

Reviewers: resistor, hfinkel, eliben, meheff, jholewinski

Subscribers: broune, bjarke.roune, madhur13490, tstellarAMD, dberlin, echristo, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8576

llvm-svn: 234567
2015-04-10 05:03:50 +00:00