Commit Graph

52 Commits

Author SHA1 Message Date
Andrew Trick
fcf79528da Rotate multi-exit loops even if the latch was simplified.
Test case by Michele Scandale!

Fixes PR10293: Load not hoisted out of loop with multiple exits.

There are few regressions with this patch, now tracked by
rdar:13817079, and a roughly equal number of improvements. The
regressions are almost certainly back luck because LoopRotate has very
little idea of whether rotation is profitable. Doing better requires a
more comprehensive solution.

This checkin is a quick fix that lacks generality (PR10293 has
a counter-example). But it trivially fixes the case in PR10293 without
interfering with other cases, and it does satify the criteria that
LoopRotate is a loop canonicalization pass that should avoid
heuristics and special cases.

I can think of two approaches that would probably be better in
the long run. Ultimately they may both make sense.

(1) LoopRotate should check that the current header would make a good
loop guard, and that the loop does not already has a sufficient
guard. The artifical SimplifiedLoopLatch check would be unnecessary,
and the design would be more general and canonical. Two difficulties:

- We need a strong guarantee that we won't endlessly rotate, so the
  analysis would need to be precise in order to avoid the
  SimplifiedLoopLatch precondition.

- Analysis like this are usually based on SCEV, which we don't want to
  rely on.

(2) Rotate on-demand in late loop passes. This could even be done by
shoving the loop back on the queue after the optimization that needs
it. This could work well when we find LICM opportunities in
multi-branch loops. This requires some work, and it doesn't really
solve the problem of SCEV wanting a loop guard before the analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181230 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-06 17:58:18 +00:00
Dmitri Gribenko
a6542923b8 Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171250 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-30 02:33:22 +00:00
Dmitri Gribenko
b4912b9dcc Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171246 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-30 01:28:40 +00:00
James Molloy
67ae135759 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 16:04:27 +00:00
Benjamin Kramer
7de7078933 LoopRotation: Make the brute force DomTree update more brute force.
We update until we hit a fixpoint. This is probably slow but also
slightly simplifies the code. It should also fix the occasional
invalid domtrees observed when building with expensive checking.

I couldn't find a case where this had a measurable slowdown, but
if someone finds a pathological case where it does we may have
to find a cleverer way of updating dominators here.

Thanks to Duncan for the test case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163091 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-02 11:57:22 +00:00
Benjamin Kramer
86c0d8c92f Fix test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162913 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-30 15:42:45 +00:00
Benjamin Kramer
d70846ec1b LoopRotate: Also rotate loops with multiple exits.
The old PHI updating code in loop-rotate was replaced with SSAUpdater a while
ago, it has no problems with comples PHIs. What had to be fixed is detecting
whether a loop was already rotated and updating dominators when multiple exits
were present.

This change increases overall code size a bit, mostly due to additional loop
unrolling opportunities. Passes test-suite and selfhost with -verify-dom-info.
Fixes PR7447.

Thanks to Andy for the input on the domtree updating code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162912 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-30 15:39:42 +00:00
NAKAMURA Takumi
f30135c519 llvm/test/Transforms/LoopRotate/PhiRename-1.ll: FileCheck-ize. It fixes PR13301.
It began choking since Chandler's r159547, possibly due to improper expression on grep from TclParser to ShParser.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160367 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-17 15:43:17 +00:00
Chandler Carruth
1de43ede89 Fix the remaining TCL-style quotes found in the testsuite. This is
another mechanical change accomplished though the power of terrible Perl
scripts.

I have manually switched some "s to 's to make escaping simpler.

While I started this to fix tests that aren't run in all configurations,
the massive number of tests is due to a really frustrating fragility of
our testing infrastructure: things like 'grep -v', 'not grep', and
'expected failures' can mask broken tests all too easily.

Essentially, I'm deeply disturbed that I can change the testsuite so
radically without causing any change in results for most platforms. =/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159547 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 19:09:46 +00:00
Chandler Carruth
c0d18b6696 Fix ValueTracking to conclude that debug intrinsics are safe to
speculate. Without this, loop rotate (among many other places) would
suddenly stop working in the presence of debug info. I found this
looking at loop rotate, and have augmented its tests with a reduction
out of a very hot loop in yacr2 where failing to do this rotation costs
sometimes more than 10% in runtime performance, perturbing numerous
downstream optimizations.

This should have no impact on performance without debug info, but the
change in performance when debug info is enabled can be extreme. As
a consequence (and this how I got to this yak) any profiling of
performance problems should be treated with deep suspicion -- they may
have been wildly innacurate of debug info was enabled for profiling. =/
Just a heads up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154263 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-07 19:22:18 +00:00
Eli Bendersky
0f0c411079 Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.
Patch reviewed by Daniel Dunbar. It will be followed by additional cleanup patches.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150664 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16 06:28:33 +00:00
Eli Friedman
5e6162e756 loop-rotate shouldn't hoist alloca instructions out of a loop. Patch by Patrik Hägglund, with slightly modified test. Issue reported by Patrik Hägglund on llvmdev.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150642 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-16 00:41:10 +00:00
Andrew Trick
f6629ab847 Add simplifyLoopLatch to LoopRotate pass.
This folds a simple loop tail into a loop latch. It covers the common (in fortran) case of postincrement loops. It's a "free" way to expose this type of loop to downstream loop optimizations that bail out on non-canonical loops (getLoopLatch is a heavily used check).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150439 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-14 00:00:23 +00:00
Chris Lattner
424545e950 remove asmparser support for the old getresult instruction, which has been subsumed by extractvalue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133247 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 06:57:15 +00:00
Chris Lattner
7a1b9bdd2b Remove support for using "foo" as symbols instead of %"foo". This is ancient
syntax and has been long obsolete.  As usual, updating the tests is the nasty
part of this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133242 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 06:36:20 +00:00
Chris Lattner
f5bf464b70 fix PR9523, a crash in looprotate on a non-canonical loop made out of indirectbr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129203 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-09 07:25:58 +00:00
Devang Patel
3fc178ffda Do not hoist @llvm.dbg.value. Here, @llvm.dbg.value is "referring" a value that is modified inside loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125529 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-14 23:03:23 +00:00
Chris Lattner
86099ba2b5 merge tests into one crash.ll test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123220 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 07:50:07 +00:00
Chris Lattner
93767fdb61 remove a bogus assertion: the latch block of a loop is not
neccesarily an uncond branch to the header.  This fixes 
PR8955 (the assertion tripping).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123219 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 07:47:59 +00:00
Chris Lattner
5d37370a6f When loop rotation happens, it is *very* common for the duplicated condbr
to be foldable into an uncond branch.  When this happens, we can make a
much simpler CFG for the loop, which is important for nested loop cases
where we want the outer loop to be aggressively optimized.

Handle this case more aggressively.  For example, previously on
phi-duplicate.ll we would get this:


define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  %cmp1 = icmp slt i64 1, 1000
  br i1 %cmp1, label %bb.nph, label %for.end

bb.nph:                                           ; preds = %entry
  br label %for.body

for.body:                                         ; preds = %bb.nph, %for.cond
  %j.02 = phi i64 [ 1, %bb.nph ], [ %inc, %for.cond ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.02
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.02, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.02
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.02, 1
  br label %for.cond

for.cond:                                         ; preds = %for.body
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge

for.cond.for.end_crit_edge:                       ; preds = %for.cond
  br label %for.end

for.end:                                          ; preds = %for.cond.for.end_crit_edge, %entry
  ret void
}

Now we get the much nicer:

define void @test(i32 %N, double* %G) nounwind ssp {
entry:
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %j.01 = phi i64 [ 1, %entry ], [ %inc, %for.body ]
  %arrayidx = getelementptr inbounds double* %G, i64 %j.01
  %tmp3 = load double* %arrayidx
  %sub = sub i64 %j.01, 1
  %arrayidx6 = getelementptr inbounds double* %G, i64 %sub
  %tmp7 = load double* %arrayidx6
  %add = fadd double %tmp3, %tmp7
  %arrayidx10 = getelementptr inbounds double* %G, i64 %j.01
  store double %add, double* %arrayidx10
  %inc = add nsw i64 %j.01, 1
  %cmp = icmp slt i64 %inc, 1000
  br i1 %cmp, label %for.body, label %for.end

for.end:                                          ; preds = %for.body
  ret void
}

With all of these recent changes, we are now able to compile:

void foo(char *X) {
 for (int i = 0; i != 100; ++i) 
   for (int j = 0; j != 100; ++j)
     X[j+i*100] = 0;
}

into a single memset of 10000 bytes.  This series of changes
should also be helpful for other nested loop scenarios as well.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123079 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 19:59:06 +00:00
Chris Lattner
0e4a1543ab Three major changes:
1. Rip out LoopRotate's domfrontier updating code.  It isn't
   needed now that LICM doesn't use DF and it is super complex
   and gross.
2. Make DomTree updating code a lot simpler and faster.  The 
   old loop over all the blocks was just to find a block??
3. Change the code that inserts the new preheader to just use
   SplitCriticalEdge instead of doing an overcomplex 
   reimplementation of it.

No behavior change, except for the name of the inserted preheader.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123072 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 18:52:51 +00:00
Chris Lattner
d9ec3572f3 Have loop-rotate simplify instructions (yay instsimplify!) as it clones
them into the loop preheader, eliminating silly instructions like
"icmp i32 0, 100" in fixed tripcount loops.  This also better exposes the 
bigger problem with loop rotate that I'd like to fix: once this has been
folded, the duplicated conditional branch *often* turns into an uncond branch.

Not aggressively handling this is pessimizing later loop optimizations 
somethin' fierce by making "dominates all exit blocks" checks fail.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123060 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-08 08:24:46 +00:00
Chris Lattner
50fb46983c Teach loop rotate to hoist trivially invariant instructions
in the duplicated block instead of duplicating them.  

Duplicating them into the end of the loop and the preheader 
means that we got a phi node in the header of the loop, 
which prevented LICM from hoisting them.  GVN would
usually come around later and merge the duplicated 
instructions so we'd get reasonable output... except that
anything dependent on the shoulda-been-hoisted value can't
be hoisted.  In PR5319 (which this fixes), a memory value
didn't get promoted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113134 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-06 01:10:22 +00:00
Dan Gohman
fc8042a122 When rotating loops, put the original header at the bottom of the
loop, making the resulting loop significantly less ugly.  Also, zap
its trivial PHI nodes, since it's easy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111255 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-17 17:39:21 +00:00
Benjamin Kramer
a2938e7e5f Fix some tests that didn't test anything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106954 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-26 20:05:06 +00:00
Dan Gohman
aceba31b7a Delete useless trailing semicolons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92740 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 17:55:26 +00:00
Chris Lattner
4c1e3da0cd fix PR5837 by having SSAUpdate reuse phi nodes for the
'GetValueInMiddleOfBlock' case, instead of inserting 
duplicates.

A similar fix is almost certainly needed by the machine-level
SSAUpdate implementation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91820 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-21 07:16:11 +00:00
Dan Gohman
a58a04921d Make Loop::getLoopLatch() work on loops which don't have preheaders, as
it may be used in contexts where preheader insertion may have failed due
to an indirectbr.

Make LoopSimplify's LoopSimplify::SeparateNestedLoop properly fail in
the case that it would require splitting an indirectbr edge.

These fix PR5502.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89484 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-20 20:51:18 +00:00
Dan Gohman
2b110caabf Make these tests more interesting by using
-verify-dom-info and -verify-loop-info, which enable additional
(expensive) consistency checks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85017 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-24 23:23:04 +00:00
Dan Gohman
c60e0bec11 Add a testcase to help test analysis preservation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83002 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-28 18:40:27 +00:00
Dan Gohman
f2f6ce65b7 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81537 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-11 18:01:28 +00:00
Dan Gohman
3e054fe9ef Use opt -S instead of piping bitcode output through llvm-dis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81257 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 22:34:10 +00:00
Dan Gohman
b1e1e82c54 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81226 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-08 16:50:01 +00:00
Owen Anderson
887fde88ca Testcase for PR2639.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69867 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 04:30:52 +00:00
Chris Lattner
3796a262c5 Fix PR3408 by making a non-obvious assumption very obvious, and
handling the flaw inherent in that assumption.  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62984 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-26 02:11:30 +00:00
Gabor Greif
f6cadc440c sabre brings to my attention that the 'tr' suffix is also obsolete
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51349 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 21:00:03 +00:00
Gabor Greif
722243bd40 Rename the last test with .llx extension to .ll, resolve duplicate test by renaming to isnan2. Now that no test has llx ending there is no need to search for them from dg.exp too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51328 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 19:52:04 +00:00
Dale Johannesen
f1e94f74e5 New test for bug fixed in 50545.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50548 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-01 22:50:14 +00:00
Chris Lattner
69e6317083 remove this testcase. It isn't testing loop rotate, it is testing all
of -std-compile-opts and is now failing because other passes are generating
IR that looks different to input of loop rotate.  Devang, please 
introduce a testcase that only runs loop rotate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50136 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-23 05:36:04 +00:00
Tanya Lattner
6f729d601c Byebye llvm-upgrade!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48762 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-25 04:26:08 +00:00
Duncan Sands
e4dc717585 Ding dong, the DoesntAccessMemoryFns and
OnlyReadsMemoryFns tables are dead!  We
get more, and more accurate, information
from gcc via the readnone and readonly
function attributes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44288 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-23 19:30:27 +00:00
Devang Patel
fee0a9c7ef Bunch of tests to check loop passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40629 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-31 08:04:17 +00:00
Devang Patel
680171f210 New test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39768 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-11 23:54:25 +00:00
John Criswell
e644ef7b09 Convert .cvsignore files
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37801 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-29 16:35:07 +00:00
Reid Spencer
88894b6c40 Add a .cvsignore file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36323 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-21 21:53:04 +00:00
Reid Spencer
eb1d74e0c8 For PR1319:
Remove && from the end of the lines to prevent tests from throwing run
lines into the background. Also, clean up places where the same command
is run multiple times by using a temporary file.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36142 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-16 17:36:08 +00:00
Reid Spencer
2aabd0722d For PR1319:
Upgrade to use new Tcl exec based test harness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36062 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-15 08:30:33 +00:00
Reid Spencer
461637ebde The "implementation" keyword is no more!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35919 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 20:06:03 +00:00
Reid Spencer
0f5aed5648 Make the llvm-runtest function much more amenable by eliminating all the
global variables that needed to be passed in. This makes it possible to
add new global variables with only a couple changes (Makefile and llvm-dg.exp)
instead of touching every single dg.exp file.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35918 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-11 19:56:59 +00:00
Devang Patel
bfe2c9ccf8 Add test case for PR 1154.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35865 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-10 16:57:08 +00:00