Commit Graph

19 Commits

Author SHA1 Message Date
David Green 25312b2b6c [GlobalMerge] Set the alignment on merged global structs
If no alignment is set, the abi/preferred alignment of structs will be
used which may be higher than required. This can lead to extra padding
and in the end an increase in data size.

Differential Revision: https://reviews.llvm.org/D47633

llvm-svn: 334099
2018-06-06 14:48:32 +00:00
Haicheng Wu 69ba0613f2 [GlobalMerge] Exit early if only one global is to be merged
To save some compilation time and prevent some unnecessary changes.

Differential Revision: https://reviews.llvm.org/D46640

llvm-svn: 332813
2018-05-19 18:00:02 +00:00
Peter Collingbourne 5ab4a4793e Reland r329956, "AArch64: Introduce a DAG combine for folding offsets into addresses.", with a fix for the bot failure.
This reland includes a check to prevent the DAG combiner from folding an
offset that is smaller than the existing one. This can cause oscillations
between two possible DAGs, which was the cause of the hang and later assertion
failure observed on the lnt-ctmark-aarch64-O3-flto bot.
http://green.lab.llvm.org/green/job/lnt-ctmark-aarch64-O3-flto/2024/

Original commit message:
> This is a code size win in code that takes offseted addresses
> frequently, such as C++ constructors that typically need to compute
> an offseted address of a vtable. This reduces the size of Chromium
> for Android's .text section by 108KB.

Differential Revision: https://reviews.llvm.org/D45199

llvm-svn: 330630
2018-04-23 19:09:34 +00:00
Peter Collingbourne ab40e44ba1 Revert r329956, "AArch64: Introduce a DAG combine for folding offsets into addresses."
Caused a hang and eventually an assertion failure in LTO builds
of 7zip-benchmark on aarch64 iOS targets.
http://green.lab.llvm.org/green/job/lnt-ctmark-aarch64-O3-flto/2024/

llvm-svn: 330063
2018-04-13 20:21:00 +00:00
Peter Collingbourne 00db326b0d AArch64: Introduce a DAG combine for folding offsets into addresses.
This is a code size win in code that takes offseted addresses
frequently, such as C++ constructors that typically need to compute
an offseted address of a vtable. This reduces the size of Chromium
for Android's .text section by 108KB.

Differential Revision: https://reviews.llvm.org/D45199

llvm-svn: 329956
2018-04-12 21:23:55 +00:00
Krzysztof Parzyszek 52396bb9c5 Use .set instead of = when printing assignment in assembly output
On Hexagon "x = y" is a syntax used in most instructions, and is not
treated as a directive.

Differential Revision: https://reviews.llvm.org/D44256

llvm-svn: 328635
2018-03-27 16:44:41 +00:00
Adrian Prantl 554fd99dd5 Revert "Use private linkage for MergedGlobals variables" on Darwin.
This is a partial revert of r244615 (http://reviews.llvm.org/D11942),
which caused a major regression in debug info quality.

Turning the artificial __MergedGlobal symbols into private symbols
(l__MergedGlobal) means that the linker will not include them in the
symbol table of the final executable. Without a symbol table entry
dsymutil is not be able to process the debug info for any of the
merged globals and thus drops the debug info for all of them.

This patch is enabling the old behavior for all MachO targets while
leaving all other targets unaffected.

rdar://problem/29160481
https://reviews.llvm.org/D26531

llvm-svn: 286607
2016-11-11 17:50:09 +00:00
Diana Picus 850043b25a [AArch64] Register passes so they can be run by llc
Initialize all AArch64-specific passes in the TargetMachine so they can be run
by llc. This can lead to conflicts in opt with some command line options that
share the same name as the pass, so I took this opportunity to do some cleanups:
* rename all relevant command line options from "aarch64-blah" to
  "aarch64-enable-blah" and update the tests accordingly
* run clang-format on their declarations
* move all these declarations to a common place (the TargetMachine) as opposed
  to having them scattered around (AArch64BranchRelaxation and
  AArch64AddressTypePromotion were the only offenders)

llvm-svn: 277322
2016-08-01 05:56:57 +00:00
Dan Gohman 61d15ae4f5 [MC] Use .p2align instead of .align
For historic reasons, the behavior of .align differs between targets.
Fortunately, there are alternatives, .p2align and .balign, which make the
interpretation of the parameter explicit, and which behave consistently across
targets.

This patch teaches MC to use .p2align instead of .align, so that people reading
code for multiple architectures don't have to remember which way each platform
does its .align directive.

Differential Revision: http://reviews.llvm.org/D16549

llvm-svn: 258750
2016-01-26 00:03:25 +00:00
Chad Rosier d016574df8 [AArch64] Enable PostRAScheduler for AArch64 generic build.
Disable post-ra scheduler for perturbed tests to appease the bots and to
preserve the history of the tests.

http://reviews.llvm.org/D15652

llvm-svn: 256158
2015-12-21 14:43:45 +00:00
John Brawn 75fc09ddba Redo "Make global aliases have symbol size equal to their type"
r242520 was reverted in r244313 as the expected behaviour of the alias
attribute in C is that the alias has the same size as the aliasee. However
we can re-introduce adding the size on the alias when the aliasee does not,
from a source code or object perspective, exist as a discrete entity. This
happens when the aliasee is not a symbol, or when that symbol is private.

Differential Revision: http://reviews.llvm.org/D11943

llvm-svn: 244752
2015-08-12 15:05:39 +00:00
John Brawn 0bef27d836 [GlobalMerge] Only emit aliases for internal linkage variables for non-Mach-O
On Mach-O emitting aliases for the variables that make up a MergedGlobals
variable can cause problems when linking with dead stripping enabled so don't
do that, except for external variables where we must emit an alias.

llvm-svn: 244748
2015-08-12 13:36:48 +00:00
John Brawn 863bfdbfb4 [GlobalMerge] Use private linkage for MergedGlobals variables
Other objects can never reference the MergedGlobals symbol so external linkage
is never needed. Using private instead of internal linkage means the object is
more similar to what it looks like when global merging is not enabled, with
the only difference being that the merged variables are addressed indirectly
relative to the start of the section they are in.

Also add aliases for merged variables with internal linkage, as this also makes
the object be more like what it is when they are not merged.

Differential Revision: http://reviews.llvm.org/D11942

llvm-svn: 244615
2015-08-11 15:48:04 +00:00
John Brawn 64e5a66794 Revert "Make global aliases have symbol size equal to their type"
This reverts r242520, as it caused pr24379. Also removes part of the test added
by r243874 that checks the size of alias symbols.

llvm-svn: 244313
2015-08-07 10:56:21 +00:00
John Brawn 9ca9ca2805 Make global aliases have symbol size equal to their type
This is mainly for the benefit of GlobalMerge, so that an alias into a
MergedGlobals variable has the same size as the original non-merged
variable.

Differential Revision: http://reviews.llvm.org/D10837

llvm-svn: 242520
2015-07-17 12:12:03 +00:00
Ahmed Bougacha b96444efd1 [CodeGen] Split -enable-global-merge into ARM and AArch64 options.
Currently, there's a single flag, checked by the pass itself.
It can't force-enable the pass (and is on by default), because it
might not even have been created, as that's the targets decision.
Instead, have separate explicit flags, so that the decision is
consistently made in the target.

Keep the flag as a last-resort "force-disable GlobalMerge" for now,
for backwards compatibility.

llvm-svn: 234666
2015-04-11 00:06:36 +00:00
Ahmed Bougacha d1655cb1c0 [AArch64, ARM] Enable GlobalMerge with -O3 rather than -O1.
The pass used to be enabled by default with CodeGenOpt::Less (-O1).
This is too aggressive, considering the pass indiscriminately merges
all globals together.

Currently, performance doesn't always improve, and, on code that uses
few globals (e.g., the odd file- or function- static), more often than
not is degraded by the optimization.  Lengthy discussion can be found
on llvmdev (AArch64-focused;  ARM has similar problems):
  http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-February/082800.html
Also, it makes tooling and debuggers less useful when dealing with
globals and data sections.

GlobalMerge needs to better identify those cases that benefit, and this
will be done separately.  In the meantime, move the pass to run with
-O3 rather than -O1, on both ARM and AArch64.

llvm-svn: 233024
2015-03-23 21:17:36 +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
Jiangning Liu 96e92c1d75 Move GlobalMerge from Transform to CodeGen.
This patch is to move GlobalMerge pass from Transform/Scalar                                                           
to CodeGen, because GlobalMerge depends on TargetMachine.
In the mean time, the macro INITIALIZE_TM_PASS is also moved
to CodeGen/Passes.h. With this fix we can avoid making
libScalarOpts depend on libCodeGen.

llvm-svn: 210951
2014-06-13 22:57:59 +00:00