Commit Graph

195 Commits

Author SHA1 Message Date
Owen Anderson 3c84ecb067 More cleanups of my JumpThreading transforms, including extracting some duplicated code into a helper function.
llvm-svn: 112634
2010-08-31 20:26:04 +00:00
Owen Anderson 6fdcb172a9 Add an RAII helper to make cleanup of the RecursionSet more fool-proof.
llvm-svn: 112628
2010-08-31 19:24:27 +00:00
Owen Anderson cd4de7f399 Refactor my fix for PR5652 to terminate the predecessor lookups after the first failure.
llvm-svn: 112620
2010-08-31 18:48:48 +00:00
Owen Anderson 3997a07fb9 More Chris-inspired JumpThreading fixes: use ConstantExpr to correctly constant-fold undef, and be more careful with its return value.
This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's
handling of and/or of i1's), but never manifested before.  This patch adds a tracking set to prevent this case.

llvm-svn: 112589
2010-08-31 07:36:34 +00:00
Owen Anderson c910acb54a Re-apply r112539, being more careful to respect the return values of the constant folding methods. Additionally,
use the ConstantExpr::get*() methods to simplify some constant folding.

llvm-svn: 112550
2010-08-30 23:22:36 +00:00
Owen Anderson 1ddcbbe49c Revert r112539. It accidentally introduced a miscompilation.
llvm-svn: 112543
2010-08-30 22:33:41 +00:00
Owen Anderson 75f6037c7c Fixes and cleanups pointed out by Chris. In general, be careful to handle 0 results from ComputeValueKnownInPredecessors
(indicating undef), and re-use existing constant folding APIs.

llvm-svn: 112539
2010-08-30 22:07:52 +00:00
Owen Anderson 99d4cb861b Fix typos in comments.
llvm-svn: 112286
2010-08-27 20:32:56 +00:00
Owen Anderson 6ebbd92380 Use LVI to eliminate conditional branches where we've tested a related condition previously. Update tests for this change.
This fixes PR5652.

llvm-svn: 112270
2010-08-27 17:12:29 +00:00
Owen Anderson bd2ecc7e68 Make JumpThreading smart enough to properly thread StrSwitch when it's compiled with clang++.
llvm-svn: 112198
2010-08-26 17:40:24 +00:00
Owen Anderson 7c853e877e Turn LVI on, previously detected failures should be fixed now.
llvm-svn: 111923
2010-08-24 17:21:18 +00:00
Owen Anderson 6ffa3f2aea Turn LVI back off, I have a testcase now.
llvm-svn: 111834
2010-08-23 19:59:27 +00:00
Owen Anderson 630add39a6 Re-enable LazyValueInfo. Monitoring for failures.
llvm-svn: 111816
2010-08-23 18:12:23 +00:00
Owen Anderson aac8cbb261 Disable LVI while I evaluate a failure.
llvm-svn: 111551
2010-08-19 19:47:08 +00:00
Owen Anderson 5c87dd55d3 Tentatively enabled LVI by default. I'll be monitoring for any failures.
llvm-svn: 111543
2010-08-19 19:04:40 +00:00
Owen Anderson 208636fa33 Inform LazyValueInfo whenever a block is deleted, to avoid dangling pointer issues.
llvm-svn: 111382
2010-08-18 18:39:01 +00:00
Chris Lattner 3c603024bb Fix PR7755: knowing something about an inval for a pred
from the LHS should disable reconsidering that pred on the
RHS.  However, knowing something about the pred on the RHS
shouldn't disable subsequent additions on the RHS from
happening.

llvm-svn: 111349
2010-08-18 03:14:36 +00:00
Owen Anderson a7aed18624 Reapply r110396, with fixes to appease the Linux buildbot gods.
llvm-svn: 110460
2010-08-06 18:33:48 +00:00
Owen Anderson bda59bd247 Revert r110396 to fix buildbots.
llvm-svn: 110410
2010-08-06 00:23:35 +00:00
Owen Anderson 755aceb5d0 Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396
2010-08-05 23:42:04 +00:00
Owen Anderson 4674dd6cf5 Give JumpThreading+LVI a long-form cl::opt so that it's easier to toggle the default.
llvm-svn: 110384
2010-08-05 22:11:31 +00:00
Owen Anderson aa7f66ba67 Add an initial implementation of LazyValueInfo updating for JumpThreading. Disabled for now.
llvm-svn: 109424
2010-07-26 18:48:03 +00:00
Owen Anderson a57b97e7e7 Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
llvm-svn: 109045
2010-07-21 22:09:45 +00:00
Gabor Greif a5fa885d47 cache results of operator*
llvm-svn: 108142
2010-07-12 14:10:24 +00:00
Chris Lattner bbc25ff5cc if jump threading is able to infer interesting values on both
the LHS and RHS of an and/or instruction, don't multiply add
known predecessor values.  This fixes the crash on testcase
from PR7498

llvm-svn: 108114
2010-07-12 00:47:34 +00:00
Chris Lattner 329ea064ed jump threading can't split a critical edge from an indirectbr. This
fixes PR7356.

llvm-svn: 105950
2010-06-14 19:45:43 +00:00
Dan Gohman 826bdf8c10 Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of
lib/Transforms/Utils and into lib/Analysis so that Analysis passes
can use them.

llvm-svn: 104949
2010-05-28 16:19:17 +00:00
Chris Lattner 9ae28b141f fix PR6743, a case where we'd delete an instruction before using it
in some cases.

llvm-svn: 100937
2010-04-10 18:26:57 +00:00
Duncan Sands 19d0b47b1f There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Duncan Sands 9dff9bec31 Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!

llvm-svn: 96223
2010-02-15 16:12:20 +00:00
Chris Lattner d924f63692 Make jump threading honor x|undef -> true and x&undef -> false,
instead of considering x|undef -> x, which may not be true.

llvm-svn: 95850
2010-02-11 04:40:44 +00:00
Chris Lattner 29b15c5cfd third bug from PR6119: the xor dupe extension allows
for arbitrary terminators in predecessors, don't assume
it is a conditional or uncond branch.  The testcase shows
an example where they can happen with switches.

llvm-svn: 94323
2010-01-23 19:21:31 +00:00
Chris Lattner ba2d0b89ff add an early out to ProcessBranchOnXOR to speed it up,
handle the case when we can infer an input to the xor
from all inputs that agree, instead of going into an
infinite loop.  Another part of PR6199

llvm-svn: 94321
2010-01-23 19:16:25 +00:00
Chris Lattner de5ab4860f fix a crash in jump threading, PR6119
llvm-svn: 94319
2010-01-23 18:56:07 +00:00
Chris Lattner 573da8ac90 1) Use the new SimplifyInstructionsInBlock routine instead of the copy
in JT.

2) When cloning blocks for PHI or xor conditions, use
instsimplify to simplify the code as we go.  This allows us to 
squish common cases early in JT which opens up opportunities for
subsequent iterations, and allows it to completely simplify the
testcase.

llvm-svn: 93253
2010-01-12 20:41:47 +00:00
Chris Lattner af7855d571 tidy up
llvm-svn: 93222
2010-01-12 02:07:50 +00:00
Chris Lattner eb73bdb2e1 Teach jump threading to duplicate small blocks when the branch
condition is a xor with a phi node.  This eliminates nonsense
like this from 176.gcc in several places:

 LBB166_84:
        testl   %eax, %eax
-       setne   %al
-       xorb    %cl, %al
-       notb    %al
-       testb   $1, %al
-       je      LBB166_85
+       je      LBB166_69
+       jmp     LBB166_85

This is rdar://7391699

llvm-svn: 93221
2010-01-12 02:07:17 +00:00
Chris Lattner 6a19ed0b86 some cleanup, and make it obvious that ProcessJumpOnPHI only works
on branches by renaming it and checking for a branch at the call site.

llvm-svn: 93208
2010-01-11 23:41:09 +00:00
Benjamin Kramer 76e2766442 Use a do-while loop instead of while + boolean.
llvm-svn: 92912
2010-01-07 13:50:07 +00:00
David Greene 1efdb45562 Change errs() to dbgs().
llvm-svn: 92614
2010-01-05 01:27:19 +00:00
Chris Lattner f8d22fc77d Metadata.h doesn't need to include ValueHandle.h anymore.
llvm-svn: 92211
2009-12-28 08:20:46 +00:00
Chris Lattner 6d6f10fe91 fix PR5698
llvm-svn: 90708
2009-12-06 17:17:23 +00:00
Chris Lattner 3c9aca9079 fix PR5640 by tracking whether a block is the header of a loop more
precisely, which prevents us from infinitely peeling the loop.

llvm-svn: 90211
2009-12-01 06:04:43 +00:00
Chris Lattner 9d9812a636 make PRE of loads preserve the alignment of the moved load instruction.
llvm-svn: 88865
2009-11-15 19:58:31 +00:00
Chris Lattner 5f037b6439 fix a bug handling 'not x' when x is undef.
llvm-svn: 88864
2009-11-15 19:57:43 +00:00
Chris Lattner 5f6b8b2bcb use getPredicateOnEdge to fold comparisons through PHI nodes,
which implements GCC PR18046.  This also gets us 360 more
jump threads on 176.gcc.

llvm-svn: 86953
2009-11-12 05:24:05 +00:00
Chris Lattner 22db4b5e0c various fixes to the lattice transfer functions.
llvm-svn: 86952
2009-11-12 04:57:13 +00:00
Chris Lattner c893c4ed10 switch jump threading to use getPredicateOnEdge in one place
making the new LVI stuff smart enough to subsume some special
cases in the old code.  Disable them when LVI is around, the
testcase still passes.

llvm-svn: 86951
2009-11-12 04:37:50 +00:00
Chris Lattner ba45616958 with the new code we can thread non-instruction values. This
allows us to handle the test10 testcase.

llvm-svn: 86924
2009-11-12 01:41:34 +00:00
Chris Lattner 3f80d85191 this argument can be an arbitrary value, it doesn't need to be an instruction.
llvm-svn: 86923
2009-11-12 01:37:43 +00:00
Chris Lattner d5e25436a1 expose edge information and switch j-t to use it.
llvm-svn: 86920
2009-11-12 01:29:10 +00:00
Chris Lattner 67146695b6 pass TD into a SimplifyCmpInst call. Add another case that
uses LVI info when -enable-jump-threading-lvi is passed.

llvm-svn: 86886
2009-11-11 22:31:38 +00:00
Chris Lattner fde1f8d0d8 stub out some LazyValueInfo interfaces, and have JumpThreading
start using them in a trivial way when -enable-jump-threading-lvi
is passed.  enable-jump-threading-lvi will be my playground for 
awhile.

llvm-svn: 86789
2009-11-11 02:08:33 +00:00
Chris Lattner 3a2ae908fe add a fixme
llvm-svn: 86766
2009-11-11 00:21:58 +00:00
Chris Lattner 9518fbb54e implement a TODO by teaching jump threading about "xor x, 1".
llvm-svn: 86739
2009-11-10 22:39:16 +00:00
Chris Lattner 852d6d64ff move some generally useful functions out of jump threading
into libanalysis and transformutils.

llvm-svn: 86735
2009-11-10 22:26:15 +00:00
Chris Lattner 40b15f220d improve comment.
llvm-svn: 86723
2009-11-10 21:45:09 +00:00
Chris Lattner 80e7e5a429 Make jump threading eliminate blocks that just contain phi nodes,
debug intrinsics, and an unconditional branch when possible.  This
reuses the TryToSimplifyUncondBranchFromEmptyBlock function split
out of simplifycfg.

llvm-svn: 86722
2009-11-10 21:40:01 +00:00
Chris Lattner 38c44ea6b0 make jump threading recursively simplify expressions instead of doing it
just one level deep.  On the testcase we go from getting this:

F1:                                               ; preds = %T2
  %F = and i1 true, %cond                         ; <i1> [#uses=1]
  br i1 %F, label %X, label %Y

to a fully threaded:

F1:                                               ; preds = %T2
  br label %Y


This changes gets us to the point where we're forming (too many) switch 
instructions on doug's strswitch testcase.

llvm-svn: 86646
2009-11-10 01:57:31 +00:00
Chris Lattner be11db6894 don't invalidate PN, rewrite of this code is in progress anyway.
llvm-svn: 86639
2009-11-10 01:19:06 +00:00
Chris Lattner fb7f87d5a3 add a new SimplifyInstruction API, which is like ConstantFoldInstruction,
except that the result may not be a constant.  Switch jump threading to 
use it so that it gets things like (X & 0) -> 0, which occur when phi preds
are deleted and the remaining phi pred was a zero.

llvm-svn: 86637
2009-11-10 01:08:51 +00:00
Chris Lattner c1f19071f8 rename SimplifyCompare -> SimplifyCmpInst and split it into
Simplify[IF]Cmp pieces.  Add some predicates to CmpInst to 
determine whether a predicate is fp or int.

llvm-svn: 86624
2009-11-09 23:28:39 +00:00
Chris Lattner 800aad3dda use instructionsimplify instead of a weak clone of ad-hoc folding stuff.
llvm-svn: 86616
2009-11-09 23:00:14 +00:00
Chris Lattner 2978ca7b79 stub out a new form of BasicBlock::RemovePredecessorAndSimplify which
simplifies instruction users of PHIs when the phi is eliminated.  This
will be moved to transforms/utils after some other refactoring.

llvm-svn: 86603
2009-11-09 22:32:36 +00:00
Chris Lattner ea465e221e comment typos pointed out by Duncan
llvm-svn: 86497
2009-11-09 00:41:49 +00:00
Chris Lattner 5ff7f5672e reapply 86289, 86278, 86270, 86267, 86266 & 86264 plus a fix
(making pred factoring only happen if threading is guaranteed
to be successful).

This now survives an X86-64 bootstrap of llvm-gcc.

llvm-svn: 86355
2009-11-07 08:05:03 +00:00
Devang Patel 3a42e7ac65 Revert following patches to fix llvmgcc bootstrap.
86289, 86278, 86270, 86267, 86266 & 86264
Chris, please take a look.

llvm-svn: 86321
2009-11-07 01:32:59 +00:00
Jeffrey Yasskin 8f77e948e5 Avoid "ambiguous 'else'" warning from gcc.
llvm-svn: 86314
2009-11-07 00:26:47 +00:00
Chris Lattner eb690feaef Fix a bug where we'd call SplitBlockPredecessors with a pred in the
set only once even if it has multiple edges to BB.

llvm-svn: 86299
2009-11-06 23:19:58 +00:00
Eli Friedman a70917b2f4 Remove function left over from other jump threading cleanup.
llvm-svn: 86289
2009-11-06 21:24:57 +00:00
Chris Lattner a8b9ce3f07 Fix a problem discovered on self host.
llvm-svn: 86278
2009-11-06 19:21:48 +00:00
Chris Lattner d91a7960bf remove more code subsumed by r86264
llvm-svn: 86270
2009-11-06 18:24:32 +00:00
Chris Lattner 899ef22acb eliminate some more code subsumed by r86264
llvm-svn: 86267
2009-11-06 18:22:54 +00:00
Chris Lattner 2f6184f6aa remove now redundant code, r86264 handles this case.
llvm-svn: 86266
2009-11-06 18:20:58 +00:00
Chris Lattner 68d2417e05 Extend jump threading to support much more general threading
predicates.  This allows us to jump thread things like:

_ZN12StringSwitchI5ColorE4CaseILj7EEERS1_RAT__KcRKS0_.exit119:
  %tmp1.i24166 = phi i8 [ 1, %bb5.i117 ], [ %tmp1.i24165, %_Z....exit ], [ %tmp1.i24165, %bb4.i114 ] 
  %toBoolnot.i87 = icmp eq i8 %tmp1.i24166, 0     ; <i1> [#uses=1]
  %tmp4.i90 = icmp eq i32 %tmp2.i, 6              ; <i1> [#uses=1]
  %or.cond173 = and i1 %toBoolnot.i87, %tmp4.i90  ; <i1> [#uses=1]
  br i1 %or.cond173, label %bb4.i96, label %_ZN12...

Where it is "obvious" that when coming from %bb5.i117 that the 'and' is always 
false.  This triggers a surprisingly high number of times in the testsuite, 
and gets us closer to generating good code for doug's strswitch testcase.

This also make a bunch of other code in jump threading redundant, I'll rip
out in the next patch.  This survived an enable-checking llvm-gcc bootstrap.

llvm-svn: 86264
2009-11-06 18:15:14 +00:00
Chris Lattner 46b5c642b9 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.

llvm-svn: 86231
2009-11-06 04:27:31 +00:00
Chris Lattner a09062758b improve DSE when TargetData is not around, based on work by
Hans Wennborg!

llvm-svn: 86067
2009-11-04 23:20:12 +00:00
Chris Lattner 85c85c5e04 when folding duplicate conditions, delete the
now-probably-dead instruction tree feeding it.

llvm-svn: 83778
2009-10-11 18:39:58 +00:00
Chris Lattner 97b1405207 implement a transformation in jump threading that is currently
done by condprop, but do it in a much more general form.  The
basic idea is that we can do a limited form of tail duplication
in the case when we have a branch on a phi.  Moving the branch
up in to the predecessor block makes instruction selection
much easier and encourages chained jump threadings.

llvm-svn: 83759
2009-10-11 07:24:57 +00:00
Chris Lattner 6ce85e85f5 restructure some code, no functionality change.
llvm-svn: 83756
2009-10-11 04:40:21 +00:00
Chris Lattner f466bc84c9 factor some code better and move a function, no functionality change.
llvm-svn: 83755
2009-10-11 04:33:43 +00:00
Chris Lattner f99a74e24b make jump threading on a phi with undef inputs happen.
llvm-svn: 83754
2009-10-11 04:18:15 +00:00
Chris Lattner 84095071ea Change jump threading to use the new SSAUpdater class instead of
DemoteRegToStack.  This makes it more efficient (because it isn't
creating a ton of load/stores that are eventually removed by a later
mem2reg), and more slightly more effective (because those load/stores
don't get in the way of threading).

llvm-svn: 83706
2009-10-10 09:05:58 +00:00
Nick Lewycky 42fb7452df Instruction::clone does not need to take an LLVMContext&. Remove that and
update all the callers.

llvm-svn: 82889
2009-09-27 07:38:41 +00:00
Chris Lattner 2dd09dbdf7 eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
llvm-svn: 80766
2009-09-02 06:11:42 +00:00
Owen Anderson 55f1c09e31 Push LLVMContexts through the IntegerType APIs.
llvm-svn: 78948
2009-08-13 21:58:54 +00:00
Owen Anderson 23a204d91b Move getTrue() and getFalse() to 2.5-like APIs.
llvm-svn: 77685
2009-07-31 17:39:07 +00:00
Owen Anderson b292b8ce70 Move more code back to 2.5 APIs.
llvm-svn: 77635
2009-07-30 23:03:37 +00:00
Owen Anderson 487375e9a2 Move ConstantExpr to 2.5 API.
llvm-svn: 77494
2009-07-29 18:55:55 +00:00
Daniel Dunbar 6115b39ffd Remove Value::getName{Start,End}, the last of the old Name APIs.
llvm-svn: 77152
2009-07-26 09:48:23 +00:00
Daniel Dunbar 9813b0b025 Eliminate some uses of DOUT, cerr, and getNameStart().
llvm-svn: 77145
2009-07-26 07:49:05 +00:00
Owen Anderson edb4a70325 Revert the ConstantInt constructors back to their 2.5 forms where possible, thanks to contexts-on-types. More to come.
llvm-svn: 77011
2009-07-24 23:12:02 +00:00
Dan Gohman 67243a4bec Convert several more passes to use getAnalysisIfAvailable<TargetData>()
instead of getAnalysis<TargetData>().

llvm-svn: 76982
2009-07-24 18:13:53 +00:00
Owen Anderson 47db941fd3 Get rid of the Pass+Context magic.
llvm-svn: 76702
2009-07-22 00:24:57 +00:00
Owen Anderson c37bc69e91 Rename getConstantInt{True|False} to get{True|False} at Chris' behest.
llvm-svn: 76598
2009-07-21 18:03:38 +00:00
Owen Anderson 4fdeba9706 Revert yesterday's change by removing the LLVMContext parameter to AllocaInst and MallocInst.
llvm-svn: 75863
2009-07-15 23:53:25 +00:00
Owen Anderson b6b2530000 Move EVER MORE stuff over to LLVMContext.
llvm-svn: 75703
2009-07-14 23:09:55 +00:00
Owen Anderson 1e5f00e7a7 This started as a small change, I swear. Unfortunately, lots of things call the [I|F]CmpInst constructors. Who knew!?
llvm-svn: 75200
2009-07-09 23:48:35 +00:00
Owen Anderson 38264b1554 "LLVMContext* " --> "LLVMContext *"
llvm-svn: 74878
2009-07-06 23:00:19 +00:00
Owen Anderson 39f00cc1d4 Thread LLVMContext through the constant folding APIs, which touches a lot of files.
llvm-svn: 74844
2009-07-06 18:42:36 +00:00