Commit Graph

19 Commits

Author SHA1 Message Date
Duncan Sands
43e2a03530 Fix some constructs that gcc-4.4 warns about.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51591 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-27 11:50:51 +00:00
Dan Gohman
02dea8b39f Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places to
use it instead of duplicating its functionality.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 21:05:58 +00:00
Matthijs Kooijman
6e7b322d36 Fix typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 07:26:45 +00:00
Dan Gohman
844731a7f1 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:00:25 +00:00
Chris Lattner
94019f8e06 restore doxygen comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50881 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-09 04:43:13 +00:00
Gordon Henriksen
a8a118b68f Improve pass documentation and comments.
Patch by Matthijs Kooijman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50861 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-08 17:46:35 +00:00
Chris Lattner
9b34849a6b fix typo Duncan noticed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50699 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-06 02:31:18 +00:00
Chris Lattner
8554cc2ea7 Fix a crash when threading a block that includes a MRV call result.
DemoteRegToStack doesn't work with MRVs yet, because it relies on the
ability to load/store things.

This fixes PR2285.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50667 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-05 20:21:22 +00:00
Chris Lattner
eede65ce6c Don't infininitely thread branches when a threaded edge
goes back to the block, e.g.:

  Threading edge through bool from 'bb37.us.thread3829' to 'bb37.us' with cost: 1, across block:

bb37.us:		; preds = %bb37.us.thread3829, %bb37.us, %bb33
	%D1361.1.us = phi i32 [ %tmp36, %bb33 ], [ %D1361.1.us, %bb37.us ], [ 0, %bb37.us.thread3829 ]		; <i32> [#uses=2]
	%tmp39.us = icmp eq i32 %D1361.1.us, 0		; <i1> [#uses=1]
	br i1 %tmp39.us, label %bb37.us, label %bb42.us



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50251 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-25 04:12:29 +00:00
Chris Lattner
a5ddb59a13 Start doing the significantly useful part of jump threading: handle cases
where a comparison has a phi input and that phi is a constant.  For example,
stuff like:

  Threading edge through bool from 'bb2149' to 'bb2231' with cost: 1, across block:
bb2237:		; preds = %bb2231, %bb2149
	%tmp2328.rle = phi i32 [ %tmp2232, %bb2231 ], [ %tmp2232439, %bb2149 ]		; <i32> [#uses=2]
	%done.0 = phi i32 [ %done.2, %bb2231 ], [ 0, %bb2149 ]		; <i32> [#uses=1]
	%tmp2239 = icmp eq i32 %done.0, 0		; <i1> [#uses=1]
	br i1 %tmp2239, label %bb2231, label %bb2327

or

bb38.i298:		; preds = %bb33.i295, %bb1693
	%tmp39.i296.rle = phi %struct.ibox* [ null, %bb1693 ], [ %tmp39.i296.rle1109, %bb33.i295 ]		; <%struct.ibox*> [#uses=2]
	%minspan.1.i291.reg2mem.1 = phi i32 [ 32000, %bb1693 ], [ %minspan.0.i288, %bb33.i295 ]		; <i32> [#uses=1]
	%tmp40.i297 = icmp eq %struct.ibox* %tmp39.i296.rle, null		; <i1> [#uses=1]
	br i1 %tmp40.i297, label %implfeeds.exit311, label %bb43.i301

This triggers thousands of times in spec.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50110 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 21:40:39 +00:00
Chris Lattner
ae65b3c791 Dig through multiple levels of AND to thread jumps if needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50106 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 20:46:09 +00:00
Chris Lattner
6bf77500c6 Teach jump threading to thread through blocks like:
br (and X, phi(Y, Z, false)), label L1, label L2

This triggers once on 252.eon and 6 times on 176.gcc.  Blocks 
in question often look like this:

bb262:		; preds = %bb261, %bb248
	%iftmp.251.0 = phi i1 [ true, %bb261 ], [ false, %bb248 ]		; <i1> [#uses=4]
	%tmp270 = icmp eq %struct.rtx_def* %tmp.0.i, null		; <i1> [#uses=1]
	%bothcond = or i1 %iftmp.251.0, %tmp270		; <i1> [#uses=1]
	br i1 %bothcond, label %bb288, label %bb273

In this case, it is clear that it doesn't matter if tmp.0.i is null when coming from bb261.  When coming from bb248, it is all that matters.


Another random example:

check_asm_operands.exit:		; preds = %check_asm_operands.exit.thr_comm, %bb30.i, %bb12.i, %bb6.i413
	%tmp.0.i420 = phi i1 [ true, %bb6.i413 ], [ true, %bb12.i ], [ true, %bb30.i ], [ false, %check_asm_operands.exit.thr_comm ; <i1> [#uses=1]
	call void @llvm.stackrestore( i8* %savedstack ) nounwind 
	%tmp4389 = icmp eq i32 %added_sets_1.0, 0		; <i1> [#uses=1]
	%tmp4394 = icmp eq i32 %added_sets_2.0, 0		; <i1> [#uses=1]
	%bothcond80 = and i1 %tmp4389, %tmp4394		; <i1> [#uses=1]
	%bothcond81 = and i1 %bothcond80, %tmp.0.i420		; <i1> [#uses=1]
	br i1 %bothcond81, label %bb4398, label %bb4397

Here is the case from 252.eon:

bb290.i.i:		; preds = %bb23.i57.i.i, %bb8.i39.i.i, %bb100.i.i, %bb100.i.i, %bb85.i.i110
	%myEOF.1.i.i = phi i1 [ true, %bb100.i.i ], [ true, %bb100.i.i ], [ true, %bb85.i.i110 ], [ true, %bb8.i39.i.i ], [ false, %bb23.i57.i.i ]		; <i1> [#uses=2]
	%i.4.i.i = phi i32 [ %i.1.i.i, %bb85.i.i110 ], [ %i.0.i.i, %bb100.i.i ], [ %i.0.i.i, %bb100.i.i ], [ %i.3.i.i, %bb8.i39.i.i ], [ %i.3.i.i, %bb23.i57.i.i ]		; <i32> [#uses=3]
	%tmp292.i.i = load i8* %tmp16.i.i100, align 1		; <i8> [#uses=1]
	%tmp293.not.i.i = icmp ne i8 %tmp292.i.i, 0		; <i1> [#uses=1]
	%bothcond.i.i = and i1 %tmp293.not.i.i, %myEOF.1.i.i		; <i1> [#uses=1]
	br i1 %bothcond.i.i, label %bb202.i.i, label %bb301.i.i
  Factoring out 3 common predecessors.

On the path from any blocks other than bb23.i57.i.i, the load and compare 
are dead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50096 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 07:05:46 +00:00
Chris Lattner
d38c14e6ed refactor some code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22 06:36:15 +00:00
Chris Lattner
037c781de7 fix grammar-o, thanks to Duncan for noticing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50047 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 18:25:01 +00:00
Chris Lattner
2cc675180b Use the new SplitBlockPredecessors to implement a todo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50022 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 02:57:57 +00:00
Chris Lattner
bd3401fa98 finish the first cut of a jump threading pass implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50006 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 22:39:42 +00:00
Chris Lattner
f9065a904f we can only thread blocks when there is a pred we can determine the succ of.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50003 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 21:18:09 +00:00
Chris Lattner
177480b7ed improve comments, infrastructure, and add some validity checks for threading.
Add a cost function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50002 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 21:13:06 +00:00
Chris Lattner
8383a7b7a6 Add a new Jump Threading pass, which will handle cases
such as those in PR2235.  Right now the pass is not very
effective. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50000 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20 20:35:01 +00:00