Commit Graph

23 Commits

Author SHA1 Message Date
Denis Bakhvalov 58f172f05a [MergedLoadStoreMotion] Sink stores to BB with more than 2 predecessors
If we have:

bb5:
  br i1 %arg3, label %bb6, label %bb7

bb6:
  %tmp = getelementptr inbounds i32, i32* %arg1, i64 2
  store i32 3, i32* %tmp, align 4
  br label %bb9

bb7:
  %tmp8 = getelementptr inbounds i32, i32* %arg1, i64 2
  store i32 3, i32* %tmp8, align 4
  br label %bb9

bb9:  ; preds = %bb4, %bb6, %bb7
  ...

We can't sink stores directly into bb9.
This patch creates new BB that is successor of %bb6 and %bb7
and sinks stores into that block.

SplitFooterBB is the parameter to the pass that controls
that behavior.

Change-Id: I7fdf50a772b84633e4b1b860e905bf7e3e29940f
Differential: https://reviews.llvm.org/D66234
llvm-svn: 371089
2019-09-05 17:00:32 +00:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Paul Robinson 96c1f2cd6c Tighten up tests that use -debugify as a shortcut. NFC
These now verify that a given instruction has a specific source
location, rather than any old location. We want to make sure we
propagate the correct locations from one instruction to another.

llvm-svn: 356217
2019-03-14 23:09:17 +00:00
Jordan Rupprecht 80e7e86c29 [DebugInfo][InstMerge] Fix -debugify for phi node created by -mldst-motion
Summary:
-mldst-motion creates a new phi node without any debug info. Use the merged debug location from the incoming stores to fix this.

Fixes PR38177. The test case here is (somewhat) simplified from:

```
struct S {
  int foo;
  void fn(int bar);
};
void S::fn(int bar) {
  if (bar)
    foo = 1;
  else
    foo = 0;
}
```

Reviewers: dblaikie, gbedwell, aprantl, vsk

Reviewed By: vsk

Subscribers: vsk, JDevlieghere, llvm-commits

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D54019

llvm-svn: 346027
2018-11-02 18:25:41 +00:00
Bjorn Pettersson 9f953cdd7c [MergedLoadStoreMotion] Fix a debug invariant bug in mergeStores
Summary:
MergedLoadStoreMotion::mergeStores is using some heuristics
to limit the amount of stores that it tries to sink (see
MagicCompileTimeControl in MergedLoadStoreMotion.cpp). The
heuristic involves counting the number of instructions in
one of the basic blocks that is part of the transformation.

We now ignore dbg intrinsics when counting instruction for
the MagicCompileTimeControl heuristic. This to make sure that
the amount of stores that are sunk doesn't depend on the amount
of debug information (if -g is used or not).

Reviewers: Gerolf, davide, majnemer

Reviewed By: davide

Subscribers: dberlin, bjope, aprantl, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D46600

llvm-svn: 331852
2018-05-09 06:52:12 +00:00
Daniel Berlin 390dfde0f3 Remove the load hoisting code of MLSM, it is completely subsumed by GVNHoist
Summary:
GVNHoist performs all the optimizations that MLSM does to loads, in a
more general way, and in a faster time bound (MLSM is N^3 in most
cases, N^4 in a few edge cases).

This disables the load portion.

Note that the way ld_hoist_st_sink.ll is written makes one think that
the loads should be moved to the while.preheader block, but

1. Neither MLSM nor GVNHoist do it (they both move them to identical places).

2. MLSM couldn't possibly do it anyway, as the while.preheader block
is not the head of the diamond, while.body is.  (GVNHoist could do it
if it was legal).

3. At a glance, it's not legal anyway because the in-loop load
conflict with the in-loop store, so the loads must stay in-loop.

I am happy to update the test to use update_test_checks so that
checking is tighter, just was going to do it as a followup.

Note that i can find no particular benefit to the store portion on any
real testcase/benchmark i have (even size-wise).  If we really still
want it, i am happy to commit to writing a targeted store sinker, just
taking the code from the MemorySSA port of MergedLoadStoreMotion
(which is N^2 worst case, and N most of the time).

We can do what it does in a much better time bound.

We also should be both hoisting and sinking stores, not just sinking
them, anyway, since whether we should hoist or sink to merge depends
basically on luck of the draw of where the blockers are placed.

Nonetheless, i have left it alone for now.

Reviewers: chandlerc, davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29079

llvm-svn: 292971
2017-01-24 19:55:36 +00:00
Davide Italiano b49aa5c0c4 [PM] Port MergedLoadStoreMotion to the new pass manager, take two.
This is indeed a much cleaner approach (thanks to Daniel Berlin
for pointing out), and also David/Sean for review.

Differential Revision:  http://reviews.llvm.org/D21454

llvm-svn: 273032
2016-06-17 19:10:09 +00:00
Davide Italiano 41315f7873 [PM] Revert the port of MergeLoadStoreMotion to the new pass manager.
Daniel Berlin expressed some real concerns about the port and proposed
and alternative approach. I'll revert this for now while working on a
new patch, which I hope to put up for review shortly. Sorry for the churn.

llvm-svn: 272925
2016-06-16 17:40:53 +00:00
Davide Italiano 5669ef1efe Placate bots fixing a typo in AA-pipeline description. Sorry.
llvm-svn: 272608
2016-06-14 01:11:12 +00:00
Davide Italiano 89ab89d6cd [PM] Port MergedLoadStoreMotion to the new pass manager.
llvm-svn: 272606
2016-06-14 00:49:23 +00:00
Eli Friedman 9f8031c2da [MergedLoadStoreMotion] Use correct helper for load hoist safety.
It isn't legal to hoist a load past a call which might not return;
even if it doesn't throw, it could, for example, call exit().

Fixes http://llvm.org/PR27953.

llvm-svn: 272495
2016-06-12 02:11:20 +00:00
David Majnemer 474512576e [MergedLoadStoreMotion] Don't transform across may-throw calls
It is unsafe to hoist a load before a function call which may throw, the
throw might prevent a pointer dereference.

Likewise, it is unsafe to sink a store after a call which may throw.
The caller might be able to observe the difference.

This fixes PR27858.

llvm-svn: 270828
2016-05-26 07:11:09 +00:00
Elena Demikhovsky 0053eb9479 fixed typo - CHECK-LABEL
llvm-svn: 264702
2016-03-29 06:49:38 +00:00
David Blaikie f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Elena Demikhovsky 6ddd998589 Minor fix after 229495.
Removed metadata and function attributes from the test.

llvm-svn: 229647
2015-02-18 08:09:28 +00:00
Elena Demikhovsky ef035bb974 Fixed a bug in store sinking.
The problem was in store-sink barrier check.

Store sink barrier should be checked for ModRef (read-write) mode.

http://llvm.org/bugs/show_bug.cgi?id=22613

llvm-svn: 229495
2015-02-17 13:10:05 +00:00
Elena Demikhovsky 028e966a54 Added 5 more tests related to sink store revision 224247
- by Ella Bolshinsky

http://reviews.llvm.org/D6420

llvm-svn: 224418
2014-12-17 08:12:59 +00:00
Elena Demikhovsky bf74736290 Added a test related to 224247 revision
llvm-svn: 224248
2014-12-15 14:14:10 +00:00
Elena Demikhovsky 27152aea88 Use Alias Analysis to hoist 2 loads from diamond to the common predecessor basic block.
Alias Analysis allows to detect real barriers for load hoisting.

Review in http://reviews.llvm.org/D5991

llvm-svn: 221091
2014-11-02 08:03:05 +00:00
Gerolf Hoflehner f27ae6cdcf MergedLoadStoreMotion pass
Merges equivalent loads on both sides of a hammock/diamond
and hoists into into the header.
Merges equivalent stores on both sides of a hammock/diamond
and sinks it to the footer.
Can enable if conversion and tolerate better load misses
and store operand latencies.

llvm-svn: 213396
2014-07-18 19:13:09 +00:00