Commit Graph

29 Commits

Author SHA1 Message Date
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
Sanjay Patel 5b4a003088 [Reassociate] regenerate checks; NFC
llvm-svn: 336211
2018-07-03 16:01:41 +00:00
Fiona Glaser b8a330c42a Reassociate: add global reassociation algorithm
This algorithm (explained more in the source code) takes into account
global redundancies by building a "pair map" to find common subexprs.

The primary motivation of this is to handle situations like

foo = (a * b) * c
bar = (a * d) * c

where we currently don't identify that "a * c" is redundant.

Accordingly, it prioritizes the emission of a * c so that CSE
can remove the redundant calculation later.

Does not change the actual reassociation algorithm -- only the
order in which the reassociated operand chain is reconstructed.

Gives ~1.5% floating point math instruction count reduction on
a large offline suite of graphics shaders.

llvm-svn: 320515
2017-12-12 19:18:02 +00:00
Chad Rosier 95abfa35d6 [Reassociate] Add negated value of negative constant to the Duplicates list.
In OptimizeAdd, we scan the operand list to see if there are any common factors
between operands that can be factored out to reduce the number of multiplies
(e.g., 'A*A+A*B*C+D' -> 'A*(A+B*C)+D'). For each operand of the operand list, we
only consider unique factors (which is tracked by the Duplicate set). Now if we
find a factor that is a negative constant, we add the negated value as a factor
as well, because we can percolate the negate out. However, we mistakenly don't
add this negated constant to the Duplicates set.

Consider the expression A*2*-2 + B. Obviously, nothing to factor.

For the added value A*2*-2 we over count 2 as a factor without this change,
which causes the assert reported in PR30256.  The problem is that this code is
assuming that all the multiply operands of the add are already reassociated.
This change avoids the issue by making OptimizeAdd tolerate multiplies which
haven't been completely optimized; this sort of works, but we're doing wasted
work: we'll end up revisiting the add later anyway.

Another possible approach would be to enforce RPO iteration order more strongly.
If we have RedoInsts, we process them immediately in RPO order, rather than
waiting until we've finished processing the whole function. Intuitively, it
seems like the natural approach: reassociation works on expression trees, so
the optimization only works in one direction. That said, I'm not sure how
practical that is given the current Reassociate; the "optimal" form for an
expression depends on its use list (see all the uses of "user_back()"), so
Reassociate is really an iterative optimization of sorts, so any changes here
would probably get messy.

PR30256

Differential Revision: https://reviews.llvm.org/D30228

llvm-svn: 296003
2017-02-23 18:49:03 +00:00
Justin Bogner c2bf63d29d PM: Port Reassociate to the new pass manager
llvm-svn: 267631
2016-04-26 23:39:29 +00:00
David Majnemer f6e500a0dc [Reassociate] Don't propogate flags when creating negations
Reassociate mutated existing instructions in order to form negations
which would create additional reassociate opportunities.

This fixes PR23926.

llvm-svn: 240593
2015-06-24 21:27:36 +00:00
David Majnemer 587336d2ad [Reassociate] Canonicalizing 'x [+-] (-Constant * y)' isn't always a win
Canonicalizing 'x [+-] (-Constant * y)' is not a win if we don't *know*
we will open up CSE opportunities.

If the multiply was 'nsw', then negating 'y' requires us to clear the
'nsw' flag.  If this is actually worth pursuing, it is probably more
appropriate to do so in GVN or EarlyCSE.

This fixes PR23675.

llvm-svn: 238397
2015-05-28 06:16:39 +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
Chad Rosier 90a2f9b110 Revert "[Reassociate] As the expression tree is rewritten make sure the operands are"
This reverts commit r222142.  This is causing/exposing an execution-time regression
in spec2006/gcc and coremark on AArch64/A57/Ofast.

Conflicts:

	test/Transforms/Reassociate/optional-flags.ll

llvm-svn: 222398
2014-11-19 23:21:20 +00:00
Chad Rosier bc0b869be9 [Reassociate] As the expression tree is rewritten make sure the operands are
emitted in canonical form.

llvm-svn: 222142
2014-11-17 16:33:50 +00:00
Chad Rosier 094ac7735b [Reassociate] Canonicalize negative constants out of expressions.
This is a reapplication of r221171, but we only perform the transformation
on expressions which include a multiplication.  We do not transform rem/div
operations as this doesn't appear to be safe in all cases.

llvm-svn: 221721
2014-11-11 22:58:35 +00:00
Reid Kleckner 941e93e9a8 Revert "[Reassociate] Canonicalize negative constants out of expressions."
This reverts commit r221171.

It performs this invalid transformation:
-  %div.i = urem i64 -1, %add
-  %sub.i = sub i64 -2, %div.i
+  %div.i = urem i64 1, %add
+  %sub.i1 = add i64 %div.i, -2

llvm-svn: 221317
2014-11-04 23:42:45 +00:00
Chad Rosier 005505b027 [Reassociate] Canonicalize negative constants out of expressions.
This gives CSE/GVN more options to eliminate duplicate expressions.
This is a follow up patch to http://reviews.llvm.org/D4904.

http://reviews.llvm.org/D5363

llvm-svn: 221171
2014-11-03 19:11:30 +00:00
Chad Rosier 5ea14e09e9 [Reassociate] FileCheckize and cleanup a few testcases. No functional change
intended.

llvm-svn: 210685
2014-06-11 18:28:45 +00:00
Stephen Lin c1c7a1309c Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done

llvm-svn: 186268
2013-07-14 01:42:54 +00:00
Bob Wilson a10e65c852 Add a test for my change to disable reassociation for i1 types.
llvm-svn: 95465
2010-02-06 01:16:25 +00:00
Chris Lattner 0c59ac3f41 When factoring multiply expressions across adds, factor both
positive and negative forms of constants together.  This 
allows us to compile:

int foo(int x, int y) {
    return (x-y) + (x-y) + (x-y);
}

into:

_foo:                                                       ## @foo
	subl	%esi, %edi
	leal	(%rdi,%rdi,2), %eax
	ret

instead of (where the 3 and -3 were not factored):

_foo:
        imull   $-3, 8(%esp), %ecx
        imull   $3, 4(%esp), %eax
        addl    %ecx, %eax
        ret

this started out as:
    movl    12(%ebp), %ecx
    imull   $3, 8(%ebp), %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    subl    %ecx, %eax
    ret

This comes from PR5359.

llvm-svn: 92381
2010-01-01 01:13:15 +00:00
Chris Lattner 2f03e64094 test case we alredy get right.
llvm-svn: 92380
2010-01-01 00:50:00 +00:00
Chris Lattner fed3397654 reuse negates where possible instead of always creating them from scratch.
This allows us to optimize test12 into:

define i32 @test12(i32 %X) {
  %factor = mul i32 %X, -3                        ; <i32> [#uses=1]
  %Z = add i32 %factor, 6                         ; <i32> [#uses=1]
  ret i32 %Z
}

instead of:

define i32 @test12(i32 %X) {
  %Y = sub i32 6, %X                              ; <i32> [#uses=1]
  %C = sub i32 %Y, %X                             ; <i32> [#uses=1]
  %Z = sub i32 %C, %X                             ; <i32> [#uses=1]
  ret i32 %Z
}

llvm-svn: 92373
2009-12-31 20:34:32 +00:00
Chris Lattner 60b71b5c4d teach reassociate to factor x+x+x -> x*3. While I'm at it,
fix RemoveDeadBinaryOp to actually do something.

llvm-svn: 92368
2009-12-31 19:24:52 +00:00
Chris Lattner 4e3a5678af simple fix for an incorrect factoring which causes a
miscompilation, PR5458.

llvm-svn: 92354
2009-12-31 08:33:49 +00:00
Chris Lattner 2d3b53a68c merge some more tests in.
llvm-svn: 92353
2009-12-31 08:32:22 +00:00
Chris Lattner 19a4baa201 filecheckize
llvm-svn: 92352
2009-12-31 08:29:56 +00:00
Dan Gohman 1880092722 Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.

llvm-svn: 81537
2009-09-11 18:01:28 +00:00
Dan Gohman 72a13d2476 Use opt -S instead of piping bitcode output through llvm-dis.
llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Dan Gohman 9737a63ed8 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.

llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Tanya Lattner 0ea4c8d706 Upgrade tests to not use llvm-upgrade.
llvm-svn: 48530
2008-03-19 04:36:04 +00:00
Reid Spencer 83b3d82672 Regression is gone, don't try to find it on clean target.
llvm-svn: 33296
2007-01-17 07:59:14 +00:00