Commit Graph

210 Commits

Author SHA1 Message Date
972a46c96a 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93253 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 20:41:47 +00:00
797c440caf tidy up
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93222 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 02:07:50 +00:00
2249a0b1bd 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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93221 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-12 02:07:17 +00:00
77beb479f5 some cleanup, and make it obvious that ProcessJumpOnPHI only works
on branches by renaming it and checking for a branch at the call site.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93208 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 23:41:09 +00:00
66b581ef49 Use a do-while loop instead of while + boolean.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92912 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07 13:50:07 +00:00
fe7fe6603f Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92614 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:27:19 +00:00
5660846f15 Metadata.h doesn't need to include ValueHandle.h anymore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92211 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-28 08:20:46 +00:00
08bc2701a2 fix PR5698
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90708 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-06 17:17:23 +00:00
46875c0bfb fix PR5640 by tracking whether a block is the header of a loop more
precisely, which prevents us from infinitely peeling the loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90211 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-01 06:04:43 +00:00
4e447ebc58 make PRE of loads preserve the alignment of the moved load instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88865 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-15 19:58:31 +00:00
1fb5630474 fix a bug handling 'not x' when x is undef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88864 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-15 19:57:43 +00:00
66c04c48de use getPredicateOnEdge to fold comparisons through PHI nodes,
which implements GCC PR18046.  This also gets us 360 more
jump threads on 176.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86953 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 05:24:05 +00:00
f496e79f44 various fixes to the lattice transfer functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86952 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 04:57:13 +00:00
0e0ff29271 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86951 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 04:37:50 +00:00
87e9f59c7a with the new code we can thread non-instruction values. This
allows us to handle the test10 testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86924 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:41:34 +00:00
1c96b4187b this argument can be an arbitrary value, it doesn't need to be an instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86923 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:37:43 +00:00
38392bbeb8 expose edge information and switch j-t to use it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86920 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 01:29:10 +00:00
2ad00bf99d pass TD into a SimplifyCmpInst call. Add another case that
uses LVI info when -enable-jump-threading-lvi is passed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86886 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 22:31:38 +00:00
cc4d3b25f3 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86789 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 02:08:33 +00:00
b14b88a40a add a fixme
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86766 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-11 00:21:58 +00:00
055d046f48 implement a TODO by teaching jump threading about "xor x, 1".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86739 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 22:39:16 +00:00
40d8c28b27 move some generally useful functions out of jump threading
into libanalysis and transformutils.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86735 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 22:26:15 +00:00
6f84a5feee improve comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86723 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 21:45:09 +00:00
f3183f6da6 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86722 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 21:40:01 +00:00
fddcf47a24 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86646 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:57:31 +00:00
e7c90967b1 don't invalidate PN, rewrite of this code is in progress anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86639 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:19:06 +00:00
e34537856a 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86637 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 01:08:51 +00:00
9dbb42944c 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86624 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 23:28:39 +00:00
9819ef7742 use instructionsimplify instead of a weak clone of ad-hoc folding stuff.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86616 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 23:00:14 +00:00
c2c23d03df 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86603 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 22:32:36 +00:00
e7e63fe965 comment typos pointed out by Duncan
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86497 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 00:41:49 +00:00
5729d38c81 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86355 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 08:05:03 +00:00
12d53dba36 Revert following patches to fix llvmgcc bootstrap.
86289, 86278, 86270, 86267, 86266 & 86264
Chris, please take a look.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86321 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 01:32:59 +00:00
9beab3fe6f Avoid "ambiguous 'else'" warning from gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86314 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 00:26:47 +00:00
79f0332c20 Fix a bug where we'd call SplitBlockPredecessors with a pred in the
set only once even if it has multiple edges to BB.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86299 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 23:19:58 +00:00
50591ab1ea Remove function left over from other jump threading cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86289 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 21:24:57 +00:00
82114b98c9 Fix a problem discovered on self host.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86278 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 19:21:48 +00:00
90b9247377 remove more code subsumed by r86264
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86270 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 18:24:32 +00:00
f7807f6b9e eliminate some more code subsumed by r86264
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86267 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 18:22:54 +00:00
90926ab827 remove now redundant code, r86264 handles this case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86266 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 18:20:58 +00:00
785672534d 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.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86264 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 18:15:14 +00:00
7b550ccfc5 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86231 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 04:27:31 +00:00
40dd12e708 improve DSE when TargetData is not around, based on work by
Hans Wennborg!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86067 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-04 23:20:12 +00:00
5a06cf644f when folding duplicate conditions, delete the
now-probably-dead instruction tree feeding it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83778 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 18:39:58 +00:00
78c552ef30 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83759 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 07:24:57 +00:00
6b65f47ad5 restructure some code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83756 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 04:40:21 +00:00
bdbf1a177d factor some code better and move a function, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83755 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 04:33:43 +00:00
e33583b7c2 make jump threading on a phi with undef inputs happen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83754 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-11 04:18:15 +00:00
433a0dbb26 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).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83706 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-10 09:05:58 +00:00
6776064d19 Instruction::clone does not need to take an LLVMContext&. Remove that and
update all the callers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82889 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 07:38:41 +00:00