Commit Graph

86 Commits

Author SHA1 Message Date
Dan Gohman
c2695eba57 Revert 72493 and replace it with a more conservative fix, for now: don't
rewrite the comparison if there is any implicit extension or truncation
on the induction variable. I'm planning for IVUsers to eventually take
over some of the work of this code, and for it to be generalized.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72496 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 21:10:47 +00:00
Dan Gohman
ead28bd04b In ChangeCompareStride, when the stride to be reused is truncated to
a smaller type, promoted its offset back up to the type of the new
comparison. This fixes PR4222.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72493 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-27 20:00:18 +00:00
Dan Gohman
513fae2db5 Suppress the IV reversal transformation in the case that the RHS
of the comparison is defined inside the loop. This fixes a
use-before-def problem, because the transformation puts a use
of the RHS outside the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72149 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-20 00:34:08 +00:00
Dan Gohman
5be18e8476 Teach SCEVExpander to expand arithmetic involving pointers into GEP
instructions. It attempts to create high-level multi-operand GEPs,
though in cases where this isn't possible it falls back to casting
the pointer to i8* and emitting a GEP with that. Using GEP instructions
instead of ptrtoint+arithmetic+inttoptr helps pointer analyses that
don't use ScalarEvolution, such as BasicAliasAnalysis.

Also, make the AddrModeMatcher more aggressive in handling GEPs.
Previously it assumed that operand 0 of a GEP would require a register
in almost all cases. It now does extra checking and can do more
matching if operand 0 of the GEP is foldable. This fixes a problem
that was exposed by SCEVExpander using GEPs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72093 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19 02:15:55 +00:00
Dan Gohman
81db61a2e6 Factor the code for collecting IV users out of LSR into an IVUsers class,
and generalize it so that it can be used by IndVarSimplify. Implement the
base IndVarSimplify transformation code using IVUsers. This removes
TestOrigIVForWrap and associated code, as ScalarEvolution now has enough
builtin overflow detection and folding logic to handle all the same cases,
and more. Run "opt -iv-users -analyze -disable-output" on your favorite
loop for an example of what IVUsers does.

This lets IndVarSimplify eliminate IV casts and compute trip counts in
more cases. Also, this happens to finally fix the remaining testcases
in PR1301.

Now that IndVarSimplify is being more aggressive, it occasionally runs
into the problem where ScalarEvolutionExpander's code for avoiding
duplicate expansions makes it difficult to ensure that all expanded
instructions dominate all the instructions that will use them. As a
temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function
to fix up instructions inserted by SCEVExpander. Fortunately, this code
is contained, and can be easily removed once a more comprehensive
solution is available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71535 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-12 02:17:14 +00:00
Bill Wendling
a48941087b Temporarily reverting r71008. It was causing this failure:
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/change-compare-stride-1.ll
Failed with exit(1) at line 2
while running: grep {cmpq       $-478,} change-compare-stride-1.ll.tmp
child process exited abnormally



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71013 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-05 20:49:46 +00:00
David Greene
58deef5559 Handle overflow of 64-bit loop conditions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71008 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-05 20:22:36 +00:00
Dan Gohman
afc36a9520 Previously, RecursivelyDeleteDeadInstructions provided an option
of returning a list of pointers to Values that are deleted. This was
unsafe, because the pointers in the list are, by nature of what
RecursivelyDeleteDeadInstructions does, always dangling. Replace this
with a simple callback mechanism. This may eventually be removed if
all clients can reasonably be expected to use CallbackVH.

Use this to factor out the dead-phi-cycle-elimination code from LSR
utility function, and generalize it to use the
RecursivelyDeleteTriviallyDeadInstructions utility function.

This makes LSR more aggressive about eliminating dead PHI cycles;
adjust tests to either be less trivial or to simply expect fewer
instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70636 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-02 18:29:22 +00:00
Dan Gohman
4acd12a0cb Don't try to mix integers and pointers in an icmp instruction
in getSCEVAtScope.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70495 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-30 16:40:30 +00:00
Dale Johannesen
c9cf35055f Fix recent regression in gcc.dg/pr26719.c (6835035).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70386 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 16:38:47 +00:00
Dan Gohman
01ecca20bf Teach getZeroExtendExpr and getSignExtendExpr to use trip-count
information to simplify [sz]ext({a,+,b}) to {zext(a),+,[zs]ext(b)},
as appropriate.

These functions and the trip count code each call into the other, so
this requires careful handling to avoid infinite recursion. During
the initial trip count computation, conservative SCEVs are used,
which are subsequently discarded once the trip count is actually
known.

Among other benefits, this change lets LSR automatically eliminate
some unnecessary zext-inreg and sext-inreg operation where the
operand is an induction variable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70241 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-27 20:16:15 +00:00
Owen Anderson
d92395fe92 Testcase for PR2537.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69866 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 04:26:42 +00:00
Owen Anderson
d49468aa50 Add testcase from PR3086.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69862 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-23 04:14:03 +00:00
Dan Gohman
c17e0cf6c0 Implement "superhero" strength reduction, or full strength
reduction of address calculations down to basic pointer arithmetic.
This is currently off by default, as it needs a few other features
before it becomes generally useful. And even when enabled, full
strength reduction is only performed when it doesn't increase
register pressure, and when several other conditions are true.

This also factors out a bunch of exisiting LSR code out of
StrengthReduceStridedIVUsers into separate functions, and tidies
up IV insertion. This actually decreases register pressure even
in non-superhero mode. The change in iv-users-in-other-loops.ll
is an example of this; there are two more adds because there are
two fewer leas, and there is less spilling.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65108 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-20 04:17:46 +00:00
Evan Cheng
5a6c1a840a Strengthen the "non-constant stride must dominate loop preheader" check.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64703 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-17 00:13:06 +00:00
Evan Cheng
8f40afe62d Fix pr3571: If stride is a value defined by an instruction, make sure it dominates the loop preheader. When IV users are strength reduced, the stride is inserted into the preheader. It could create a use before def situation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64579 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-15 06:06:15 +00:00
Dale Johannesen
1de17d574c Fix PR 3471, and some cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64177 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-09 22:14:15 +00:00
Dale Johannesen
2f46bb8178 Fix the time regression I introduced in 464.h264ref with
my earlier patch to this file.

The issue there was that all uses of an IV inside a loop
are actually references to Base[IV*2], and there was one
use outside that was the same but LSR didn't see the base
or the scaling because it didn't recurse into uses outside
the loop; thus, it used base+IV*scale mode inside the loop
instead of pulling base out of the loop.  This was extra bad
because register pressure later forced both base and IV into
memory.  Doing that recursion, at least enough
to figure out addressing modes, is a good idea in general;
the change in AddUsersIfInteresting does this.  However,
there were side effects....

It is also possible for recursing outside the loop to
introduce another IV where there was only 1 before (if
the refs inside are not scaled and the ref outside is).
I don't think this is a common case, but it's in the testsuite.
It is right to be very aggressive about getting rid of
such introduced IVs (CheckForIVReuse and the handling of
nonzero RewriteFactor in StrengthReduceStridedIVUsers).
In the testcase in question the new IV produced this way
has both a nonconstant stride and a nonzero base, neither
of which was handled before.  And when inserting 
new code that feeds into a PHI, it's right to put such 
code at the original location rather than in the PHI's 
immediate predecessor(s) when the original location is outside 
the loop (a case that couldn't happen before)
(RewriteInstructionToUseNewBase); better to avoid making
multiple copies of it in this case.

Also, the mechanism for keeping SCEV's corresponding to GEP's
no longer works, as the GEP might change after its SCEV
is remembered, invalidating the SCEV, and we might get a bad
SCEV value when looking up the GEP again for a later loop.  
This also couldn't happen before, as we weren't recursing
into GEP's outside the loop.

Also, when we build an expression that involves a (possibly
non-affine) IV from a different loop as well as an IV from
the one we're interested in (containsAddRecFromDifferentLoop),
don't recurse into that.  We can't do much with it and will
get in trouble if we try to create new non-affine IVs or something.

More testcases are coming.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62212 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-14 02:35:31 +00:00
Devang Patel
a009d2ef54 Remove.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56018 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-09 21:41:34 +00:00
Devang Patel
4b3f08bac7 fix overflow check.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56011 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-09 20:54:34 +00:00
Devang Patel
ac8ab789ac xfail
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55914 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-08 16:24:30 +00:00
Devang Patel
a9348dc7ac Check iteration count.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55680 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-03 00:10:56 +00:00
Devang Patel
108f92e376 If all IV uses are extending integer IV then change the type of IV itself, if possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55674 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-02 22:18:08 +00:00
Devang Patel
a0b3909d43 If IV is used in a int-to-float cast inside the loop then try to eliminate the cast operation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55374 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-26 17:57:54 +00:00
Bill Wendling
2dcca3a6d8 XFAIL this test for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54929 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-18 18:29:54 +00:00
Evan Cheng
4e49c80289 Didn't mean to change this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54904 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 19:25:28 +00:00
Evan Cheng
0ac3fc2a61 Fix a (u)comiss intrinsic lowering bug. It was using anyext which can return junk in higher bits. Patch by Nate Begeman.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54903 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 19:22:34 +00:00
Devang Patel
35115f92e4 Reapply 54786. Add overflow and number of mantissa bits checks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54821 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-15 21:21:34 +00:00
Evan Cheng
21066541ae Revert 54786. It's not checking for overflows, etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54813 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-15 08:12:11 +00:00
Devang Patel
79ceb4463e If IV is used in a int-to-float cast inside the loop then try to eliminate the cast opeation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54786 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-14 20:58:31 +00:00
Devang Patel
d16aba22c9 Check sign to detect overflow before changing compare stride.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54710 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 02:05:14 +00:00
Evan Cheng
d756f8820a PR2535, not PR2355.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54416 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 18:06:48 +00:00
Evan Cheng
f5e25f32c7 Fix PR2355: bug in ChangeCompareStride. When the loop termination compare is the only use of its iv stride, the stride can be eliminated by moving it to another stride. If the scale is negative, swap the predicate instead of using a inverse predicate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54415 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 18:04:43 +00:00
Dan Gohman
1d8973b499 Add the PR number to the test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53880 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-21 21:50:25 +00:00
Dan Gohman
7375fbcbf2 Fix a bug in LSR's dead-PHI cleanup. If a PHI has a def-use chain that
leads into a cycle involving a different PHI, LSR got stuck running
around that cycle looking for the original PHI. To avoid this, keep
track of visited PHIs and stop searching if we see one more than once.
This fixes PR2570.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53879 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-21 21:45:02 +00:00
Dan Gohman
cbfe5bbe88 Improve LSR's dead-phi detection to handle use-def cycles
with more than two nodes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52617 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-22 20:44:02 +00:00
Dan Gohman
9b93dd1f1a Refine the change in r52258 for avoiding use-before-def conditions
when changing the stride of a comparison so that it's slightly
more precise, by having it scan the instruction list to determine
if there is a use of the condition after the point where the
condition will be inserted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52371 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-16 22:34:15 +00:00
Dan Gohman
e562b1725e Protect ChangeCompareStride from situations in which it is possible
for it to generate use-before-def IR, such as in this testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52258 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-13 21:43:41 +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
Dan Gohman
fddaa3193c Update old-style syntax in some "not grep" tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50560 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-01 23:50:07 +00:00
Tanya Lattner
e6d5d39c07 Upgrade tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48538 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-19 07:28:33 +00:00
Dan Gohman
28beeeac4d Convert tests using "| wc -l | grep ..." to use the count script.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41097 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-15 13:36:28 +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
Devang Patel
9690809ddd New test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36379 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-23 22:39:53 +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
43b40035ba For PR1319:
Fix syntax of tests to ensure grep pattern is properly quoted.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36134 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-16 15:31:49 +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
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
Reid Spencer
737ec5130e For PR1043:
Bye, Bye Booly. Remove the use of the bool type from non-upgraded test
cases and from grep expressions. The parser doesn't accept it and the
asm writer doesn't produce it any more.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33183 91177308-0d34-0410-b5e6-96231b3b80d8
2007-01-13 05:06:52 +00:00