Commit Graph

35 Commits

Author SHA1 Message Date
Reid Kleckner d80b69fa3b [Constant Hoisting] Avoid inserting instructions before EH pads
Now that terminators can be EH pads, this code needs to iterate over the
immediate dominators of the EH pad to find a valid insertion point.

Fix for PR32107

Patch by Robert Olliff!

Differential Revision: https://reviews.llvm.org/D30511

llvm-svn: 296698
2017-03-01 22:41:12 +00:00
Sjoerd Meijer 38c2cd0c14 This implements a more optimal algorithm for selecting a base constant in
constant hoisting. It not only takes into account the number of uses and the
cost of expressions in which constants appear, but now also the resulting
integer range of the offsets. Thus, the algorithm maximizes the number of uses
within an integer range that will enable more efficient code generation. On
ARM, for example, this will enable code size optimisations because less
negative offsets will be created. Negative offsets/immediates are not supported
by Thumb1 thus preventing more compact instruction encoding.

Differential Revision: http://reviews.llvm.org/D21183

llvm-svn: 275382
2016-07-14 07:44:20 +00:00
Michael Kuperstein 071d8306b0 [PM] Port ConstantHoisting to the new Pass Manager
Differential Revision: http://reviews.llvm.org/D21945

llvm-svn: 274411
2016-07-02 00:16:47 +00:00
Weiming Zhao 5410edddb1 [ARM] Fix 28282: cost computation for constant hoisting
Summary:
This fixes bug: https://llvm.org/bugs/show_bug.cgi?id=28282

Currently the cost model of constant hoisting checks the bit width of the data type of the constants.
However, the actual immediate value is small enough and not need to be hoisted.
This patch checks for the actual bit width needed for the constant.

Reviewers: t.p.northover, rengolin

Subscribers: aemerson, rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D21668

llvm-svn: 274073
2016-06-28 22:30:45 +00:00
Tim Northover 903f81ba18 ARM: don't try to hoist constant RHS out of a division.
Divisions by a constant can be converted into multiplies which are usually
cheaper, but this isn't possible if the constant gets separated (particularly
in loops). Fix this by telling ConstantHoisting that the immediate in a DIV is
cheap.

I considered making the check generic, but neither AArch64 (strangely) nor x86
showed any benefit on the tests I had.

llvm-svn: 266464
2016-04-15 18:17:18 +00:00
Tim Northover 5c02f9ad28 ARM: override cost function to re-enable ConstantHoisting (& fix it).
At some point, ARM stopped getting any benefit from ConstantHoisting because
the pass called a different variant of getIntImmCost. Reimplementing the
correct variant revealed some problems, however:

  + ConstantHoisting was modifying switch statements. This is simply invalid,
    the cases must remain integer constants no matter the notional cost.
  + ConstantHoisting was mangling alloca instructions in the entry block. These
    should be handled by FrameLowering, so constants actually have a cost of 0.
    Worse, the resulting bitcasts meant they became dynamic allocas.

rdar://25707382

llvm-svn: 266260
2016-04-13 23:08:27 +00:00
David Blaikie 23af64846f [opaque pointer type] Add textual IR support for explicit type parameter to the call instruction
See r230786 and r230794 for similar changes to gep and load
respectively.

Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.

When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.

This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.

This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).

No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.

This leaves /only/ the varargs case where the explicit type is required.

Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.

About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.

import fileinput
import sys
import re

pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")

def conv(match, line):
  if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
    return line
  return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]

for line in sys.stdin:
  sys.stdout.write(conv(re.search(pat, line), line))

llvm-svn: 235145
2015-04-16 23:24:18 +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
Juergen Ributzka b2e4edb5c8 [ConstantHoisting][X86] Improve the cost model for small constants with large types (i64 and above).
This improves the X86 cost model for small constants with large types. Before
this commit we would even hoist trivial constants such as i96 2.

This is related to <rdar://problem/17070936>

llvm-svn: 210504
2014-06-10 00:32:29 +00:00
Alp Toker d3d017cf00 Reduce verbiage of lit.local.cfg files
We can just split targets_to_build in one place and make it immutable.

llvm-svn: 210496
2014-06-09 22:42:55 +00:00
Tim Northover 3b0846e8f7 AArch64/ARM64: move ARM64 into AArch64's place
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.

"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.

This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.

llvm-svn: 209577
2014-05-24 12:50:23 +00:00
Juergen Ributzka 431761771c [ConstantHoisting][X86] Change the cost model to never hoist constants for types larger than i128.
Currently the X86 backend doesn't support types larger than i128 very well. For
example an i192 multiply will assert in codegen when the 2nd argument is a constant and the constant got hoisted.

This fix changes the cost model to never hoist constants for types larger than
i128. Once the codegen issues have been resolved, the cost model can be updated
to allow also larger types.

This is related to <rdar://problem/16954938>

llvm-svn: 209162
2014-05-19 21:00:53 +00:00
Michael Zolotukhin e37f33c466 Move test from r207969 to another folder and rename it.
llvm-svn: 207984
2014-05-05 18:10:15 +00:00
Michael Zolotukhin 4e030e8fb4 Fix test from r207966 and add a comment there.
llvm-svn: 207969
2014-05-05 14:46:53 +00:00
Michael Zolotukhin 0c380a30d8 Add regression test for r207692.
llvm-svn: 207966
2014-05-05 14:05:25 +00:00
Michael Zolotukhin 1f4a960ccf [X86] Never hoist the shift value of a shift instruction.
There is no need to check if we want to hoist the immediate value of an
shift instruction. Simply return TCC_Free right away.

This change is like r206101, but for X86.

rdar://problem/16190769

llvm-svn: 207692
2014-04-30 19:17:32 +00:00
Juergen Ributzka 575bcb770a [Constant Hoisting] Materialize the constant before the cloned cast instruction.
In the case where the constant comes from a cloned cast instruction, the
materialization code has to go before the cloned cast instruction.

This commit fixes the method that finds the materialization insertion point
by making it aware of this case.

This fixes <rdar://problem/15532441>

llvm-svn: 206913
2014-04-22 18:06:58 +00:00
Hal Finkel 0192cbac66 [PowerPC] [Constant Hoisting] Enable constant hoisting on PPC
Implements the various TTI functions to enable constant hoisting on PPC. The
only significant test-suite change is this:

MultiSource/Benchmarks/VersaBench/bmm/bmm - 20% speedup
(which essentially reverses the slowdown from r206120).

llvm-svn: 206141
2014-04-13 23:02:40 +00:00
Juergen Ributzka cf03068d91 [ARM64] Never hoist the shift value of a shift instruction.
There is no need to check if we want to hoist the immediate value of an
shift instruction. Simply return TCC_Free right away.

llvm-svn: 206101
2014-04-12 02:53:51 +00:00
Juergen Ributzka 6e17aa45a3 [ARM64] Fix the cost model for cheap large constants.
Originally the cost model would give up for large constants and just return the
maximum cost. This is not what we want for constant hoisting, because some of
these constants are large in bitwidth, but are still cheap to materialize.

This commit fixes the cost model to either return TCC_Free if the cost cannot be
determined, or accurately calculate the cost even for large constants
(bitwidth > 128).

This fixes <rdar://problem/16591573>.

llvm-svn: 206100
2014-04-12 02:36:28 +00:00
Juergen Ributzka 48c8c07d0a [ARM64] Fix immediate cost calculation for types larger than i64.
The immediate cost calculation code was hitting an assertion in the included
test case, because APInt was still internally 128-bits. Truncating it to 64-bits
fixed the issue.

Fixes <rdar://problem/16572521>.

llvm-svn: 205947
2014-04-10 01:36:59 +00:00
Juergen Ributzka c11e8b67bb [Constant Hoisting][ARM64] Enable constant hoisting for ARM64.
This implements the target-hooks for ARM64 to enable constant hoisting.

This fixes <rdar://problem/14774662> and <rdar://problem/16381500>.

llvm-svn: 205791
2014-04-08 20:39:59 +00:00
Juergen Ributzka 9dff139025 Update the test to use FileCheck.
llvm-svn: 205647
2014-04-04 19:57:01 +00:00
Juergen Ributzka b0abeb0984 Add test case for [Constant Hoisting] Erase dead cast instructions (r204538).
llvm-svn: 205484
2014-04-02 23:06:22 +00:00
Adrian Prantl fd43f6ba3b typo
llvm-svn: 205473
2014-04-02 22:17:30 +00:00
Juergen Ributzka 27435b3b8a Add comments and test case for [X86TTI] Make constant base pointers for GetElementPtr opaque (r204739).
llvm-svn: 205468
2014-04-02 21:45:36 +00:00
Juergen Ributzka ab6f44efaf Add test case for [Stackmaps][X86TTI] Fix think-o in getIntImmCost calculation (r204738).
llvm-svn: 205464
2014-04-02 21:15:36 +00:00
Juergen Ributzka e802d507b0 [Constant Hoisting] Fix multiple entries for the same basic block in PHI nodes.
A PHI node usually has only one value/basic block pair per incoming basic block.
In the case of a switch statement it is possible that a following PHI node may
have more than one such pair per incoming basic block. E.g.:
%0 = phi i64 [ 123456, %case2 ], [ 654321, %Entry ], [ 654321, %Entry ]
This is valid and the verfier doesn't complain, because both values are the
same.

Constant hoisting materializes the constant for each operand separately and the
value is still the same, but the variable names have changed. As a result the
verfier can't recognize anymore that they are the same value and complains.

This fix adds special update code for PHI node in constant hoisting to prevent
this corner case.

This fixes <rdar://problem/16394449>

llvm-svn: 204537
2014-03-22 01:49:27 +00:00
Juergen Ributzka f0dff49ad0 [Constant Hoisting] Make the constant materialization cost operand dependent
Extend the target hook to take also the operand index into account when
calculating the cost of the constant materialization.

Related to <rdar://problem/16381500>

llvm-svn: 204435
2014-03-21 06:04:45 +00:00
Juergen Ributzka 5429c06b90 [Constant Hoisting] Change the algorithm to only track constants for instructions.
Originally the algorithm would search for expensive constants and track their
users, which could be instructions and constant expressions. This change only
tracks the constants for instructions, but constant expressions are indirectly
covered too. If an operand is an constant expression, then we look through the
expression to find anny expensive constants.

The algorithm keep now track of the instruction and the operand index where the
constant is used. This allows more precise hoisting of constant materialization
code for PHI instructions, because we only hoist to the basic block of the
incoming operand. Before we had to find the idom of all PHI operands and hoist
the materialization code there.

This also makes updating of instructions easier. Before we had to keep track of
the original constant, find it in the instructions, and then replace it. Now we
can just simply update the operand.

Related to <rdar://problem/16381500>

llvm-svn: 204433
2014-03-21 06:04:36 +00:00
Juergen Ributzka 46357931ab Revert "[Constant Hoisting] Extend coverage of the constant hoisting pass."
I will break this up into smaller pieces for review and recommit.

llvm-svn: 204393
2014-03-20 20:17:13 +00:00
Juergen Ributzka 6dab520c70 [Constant Hoisting] Extend coverage of the constant hoisting pass.
This commit extends the coverage of the constant hoisting pass, adds additonal
debug output and updates the function names according to the style guide.

Related to <rdar://problem/16381500>

llvm-svn: 204389
2014-03-20 19:55:52 +00:00
Juergen Ributzka 9479b31f97 [Constant Hoisting] Fix insertion point for constant materialization.
The bitcast instruction during constant materialization was not placed correcly
in the presence of phi nodes. This commit fixes the insertion point to be in the
idom instead.

This fixes PR18768

llvm-svn: 201009
2014-02-08 00:20:49 +00:00
Benjamin Kramer 9e709bce86 ConstantHoisting: We can't insert instructions directly in front of a PHI node.
Insert before the terminating instruction of the dominating block instead.

llvm-svn: 200218
2014-01-27 13:11:43 +00:00