Commit Graph

4982 Commits

Author SHA1 Message Date
Dan Gohman 1608df5319 Add a comment about how Imm can be used for loop-variant values.
llvm-svn: 65147
2009-02-20 20:29:04 +00:00
Evan Cheng c380864d2c Factor address mode matcher out of codegen prepare to make it available to other passes, e.g. loop strength reduction.
llvm-svn: 65134
2009-02-20 18:24:38 +00:00
Zhou Sheng 053737e1ae Just roll back the previous change to -mem2reg.
Will re-think about this according to Chris's comments.

llvm-svn: 65126
2009-02-20 17:49:33 +00:00
Zhou Sheng 6a0634d423 patch to update the line number information in pass -mem2reg.
Currently this pass will delete the variable declaration info, 
and keep the line number info. But the kept line number info is not updated, 
and some is redundant or not correct, this patch just updates those info.

llvm-svn: 65123
2009-02-20 16:31:35 +00:00
Dan Gohman 2a12ae7d1f 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.

llvm-svn: 65108
2009-02-20 04:17:46 +00:00
Dan Gohman a34d7adefb Use DEBUG() instead of passing *DOUT to WriteAsOperand,
since the latter just passes a null reference when
debugging is not enabled.

llvm-svn: 65060
2009-02-19 19:32:06 +00:00
Dan Gohman 30a2959367 Make the debug output of LSR less cryptic and more informative.
llvm-svn: 65057
2009-02-19 19:23:27 +00:00
Duncan Sands 7a1db33e77 In theory the aliasee may have dead constant users
here.  Since we only do the transform if there is
one use, strip off any such users in the hope of
making the transform fire more often.

llvm-svn: 64926
2009-02-18 17:55:38 +00:00
Dan Gohman 8078b8bddc Use a sign-extend instead of a zero-extend when promoting a
trip count value when the original loop iteration condition is
signed and the canonical induction variable won't undergo signed
overflow. This isn't required for correctness; it just preserves
more information about original loop iteration values.

Add a getTruncateOrSignExtend method to ScalarEvolution,
following getTruncateOrZeroExtend.

llvm-svn: 64918
2009-02-18 17:22:41 +00:00
Dan Gohman aa0f01929b Simplify by using dyn_cast instead of isa and cast.
llvm-svn: 64917
2009-02-18 16:54:33 +00:00
Dan Gohman 8cab4c44bb Add explicit keywords.
llvm-svn: 64915
2009-02-18 16:37:45 +00:00
Dan Gohman 38a9631d5f Eliminate several more unnecessary intptr_t casts.
llvm-svn: 64888
2009-02-18 05:09:16 +00:00
Dan Gohman 8212ebb5cf Fix a corner case in the new indvars promotion logic: if there
are multiple IV's in a loop, some of them may under go signed
or unsigned wrapping even if the IV that's used in the loop
exit condition doesn't. Restrict sign-extension-elimination
and zero-extension-elimination to only those that operate on
the original loop-controlling IV.

llvm-svn: 64866
2009-02-18 00:52:00 +00:00
Dan Gohman d0b1fbd983 Fix a typo in a comment.
llvm-svn: 64859
2009-02-18 00:08:39 +00:00
Duncan Sands bf3ba5a1e9 If an alias is dead and so is its aliasee, then globaldce would
crash because the alias would still be using the aliasee when the
aliasee was deleted.

llvm-svn: 64844
2009-02-17 23:05:26 +00:00
Dan Gohman d90415555e LoopIndexSplit doesn't actually use ScalarEvolution.
llvm-svn: 64811
2009-02-17 20:50:11 +00:00
Dan Gohman 4330034160 Add a method to ScalarEvolution for telling it when a loop has been
modified in a way that may effect the trip count calculation. Change
IndVars to use this method when it rewrites pointer or floating-point
induction variables instead of using a doInitialization method to
sneak these changes in before ScalarEvolution has a chance to see
the loop. This eliminates the need for LoopPass to depend on
ScalarEvolution.

llvm-svn: 64810
2009-02-17 20:49:49 +00:00
Chris Lattner 24f31a0e59 commit a tweaked version of Daniel's patch for PR3599. We now
eliminate all the extensions and all but the one required truncate
from the testcase, but the or/and/shift stuff still isn't zapped.

llvm-svn: 64809
2009-02-17 20:47:23 +00:00
Dan Gohman f84d42f282 Delete trailing whitespace.
llvm-svn: 64784
2009-02-17 19:13:57 +00:00
Duncan Sands f974c5703c This transform also applies to private linkage.
llvm-svn: 64773
2009-02-17 17:50:04 +00:00
Dan Gohman efe65e547b Fix 80-column violation.
llvm-svn: 64766
2009-02-17 15:57:39 +00:00
Evan Cheng 161861deb0 Strengthen the "non-constant stride must dominate loop preheader" check.
llvm-svn: 64703
2009-02-17 00:13:06 +00:00
Dan Gohman 2cd8982002 Simplify; fix some 80-column violations.
llvm-svn: 64702
2009-02-17 00:10:53 +00:00
Dan Gohman f68d29edd5 Fix EnforceKnownAlignment so that it doesn't ever reduce the alignment
of an alloca or global variable.

llvm-svn: 64693
2009-02-16 23:02:21 +00:00
Nick Lewycky 0f269cfdee Fix typo caused by too much surfing, dudes...
llvm-svn: 64626
2009-02-16 04:26:53 +00:00
Dan Gohman 136aa1fb96 Delete this long-commented-out code. The situation it seems to have
been written for is no longer relevant with the elimination of
signed and unsigned types.

llvm-svn: 64625
2009-02-16 02:57:42 +00:00
Dan Gohman 9cdfd44521 Change these tests to use regular loads instead of llvm.x86.sse2.loadu.dq.
Enhance instcombine to use the preferred field of
GetOrEnforceKnownAlignment in more cases, so that regular IR operations are
optimized in the same way that the intrinsics currently are.

llvm-svn: 64623
2009-02-16 00:44:23 +00:00
Nick Lewycky 8f4a097f15 Update the list of function annotations for nocapture. All of these came up
when I was looking at functions used by python.

Highlights include, better largefile support (64-bit file sizes on 32-bit
systems), fputs string is nocapture, popen/pclose added (popen being noalias
return), modf and frexp and friends. Also added some missing 'break' statements
and combined identical sections.

llvm-svn: 64615
2009-02-15 22:47:25 +00:00
Duncan Sands 46196aef82 Make this more useful for cleaning up after the
one-definition-rule llvm-gcc changes (coming soon
to a tree near you!).

llvm-svn: 64588
2009-02-15 11:54:49 +00:00
Duncan Sands b3f27881a9 If the target of an alias has internal linkage, then the
alias can be morphed into the target.  Implement this
transform, and fix a crash in the existing transform at
the same time.

llvm-svn: 64583
2009-02-15 09:56:08 +00:00
Evan Cheng e79841adbb 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.
llvm-svn: 64579
2009-02-15 06:06:15 +00:00
Evan Cheng fe151ba135 ifdef out unneeded if statement.
llvm-svn: 64575
2009-02-15 03:20:37 +00:00
Dan Gohman 671f2c085f Extend the IndVarSimplify support for promoting induction variables:
- Test for signed and unsigned wrapping conditions, instead of just
   testing for non-negative induction ranges. 
 - Handle loops with GT comparisons, in addition to LT comparisons.
 - Support more cases of induction variables that don't start at 0.

llvm-svn: 64532
2009-02-14 02:31:09 +00:00
Dan Gohman 47ff6aad23 Clarify debug output.
llvm-svn: 64531
2009-02-14 02:26:50 +00:00
Dan Gohman 4bfa1d4c63 Simplify some code. hasComputableLoopEvolution is overkill in this case.
No functionality change.

llvm-svn: 64530
2009-02-14 02:25:19 +00:00
Dan Gohman 55ea72179c In CodeGenPrepare's debug output, use WriteAsOperand instead of
printing getName(), so that unnamed values are printed correctly.

llvm-svn: 64468
2009-02-13 17:45:12 +00:00
Dan Gohman a2730abaaa Complete the sentance in this comment. I have reservations
about the code it describes, but at least now the comment
is right.

llvm-svn: 64465
2009-02-13 17:36:42 +00:00
Nick Lewycky d234a845f9 Mark strto* as readonly when the endptr is null.
llvm-svn: 64460
2009-02-13 17:08:33 +00:00
Nick Lewycky a0e83a0952 On strtod and friends, mark 'endptr' nocapture in the function prototype, and
mark the first argument nocapture if endptr=NULL for each particular call.

llvm-svn: 64453
2009-02-13 15:31:46 +00:00
Dan Gohman f71a473720 Fix the code that checked if a SCEVAddRecExpr Start contains an
addrec in a different loop to check the value being added to
the accumulated Start value, not the Start value before it has
the new value added to it. This prevents LSR from going crazy
on the included testcase. Dale, please review.

llvm-svn: 64440
2009-02-13 03:58:31 +00:00
Dan Gohman ba83228cdb Fix LSR's IV sorting function to explicitly sort by bitwidth
after sorting by stride value. This prevents it from missing
IV reuse opportunities in a host-sensitive manner.

llvm-svn: 64415
2009-02-13 00:26:43 +00:00
Dan Gohman eb6be650ce Teach IndVarSimplify to optimize code using the C "int" type for
loop induction on LP64 targets. When the induction variable is
used in addressing, IndVars now is usually able to inserst a
64-bit induction variable and eliminates the sign-extending cast.
This is also useful for code using C "short" types for
induction variables on targets with 32-bit addressing.

Inserting a wider induction variable is easy; the tricky part is
determining when trunc(sext(i)) expressions are no-ops. This
requires range analysis of the loop trip count. A common case is
when the original loop iteration starts at 0 and exits when the
induction variable is signed-less-than a fixed value; this case
is now handled.

This replaces IndVarSimplify's OptimizeCanonicalIVType. It was
doing the same optimization, but it was limited to loops with
constant trip counts, because it was running after the loop
rewrite, and the information about the original induction
variable is lost by that point.

Rename ScalarEvolution's executesAtLeastOnce to
isLoopGuardedByCond, generalize it to be able to test for
ICMP_NE conditions, and move it to be a public function so that
IndVars can use it.

llvm-svn: 64407
2009-02-12 22:19:27 +00:00
Dan Gohman 656b097b8a Add a utility function to LoopInfo to return the exit block
when the loop has exactly one exit, and make use of it in
LoopIndexSplit.

llvm-svn: 64388
2009-02-12 18:08:24 +00:00
Dan Gohman e0d32c490a This code doesn't actually use the ExitingBlocks list.
llvm-svn: 64376
2009-02-12 16:36:26 +00:00
Chris Lattner feb129e813 Fix a nasty bug (PR3550) where the inline pass could incorrectly mark
calls with the tail marker when inlining them through an invoke.  Patch,
testcase, and perfect analysis by Jay Foad!

llvm-svn: 64364
2009-02-12 07:06:42 +00:00
Chris Lattner 096f44de61 improve naming of values in GVN, patch by Jay Foad!
llvm-svn: 64363
2009-02-12 07:00:35 +00:00
Chris Lattner 5297c63565 fix PR3537: if resetting bbi back to the start of a block, we need to
forget about already inserted expressions.

llvm-svn: 64362
2009-02-12 06:56:08 +00:00
Nick Lewycky b92c4d72a7 Don't mark all args to strtod and friends as nocapture.
llvm-svn: 64352
2009-02-12 03:18:34 +00:00
Nate Begeman 318aea93bf the two non-mask arguments to a shufflevector must be the same width, but they do not have to be the same
width as the result value.

llvm-svn: 64335
2009-02-11 22:36:25 +00:00
Devang Patel 316705027b If llvm.dbg.region.end is disappearing then remove corresponding llvm.dbg.func.start also.
llvm-svn: 64278
2009-02-11 01:29:06 +00:00