llvm/lib/Transforms
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
..
Hello Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
Instrumentation Use Intrinsic::getDeclaration in more places. 2008-04-07 13:45:04 +00:00
IPO don't assume that the argument passed to fprintf("%s" is a string. This 2008-04-21 03:18:33 +00:00
Scalar Start doing the significantly useful part of jump threading: handle cases 2008-04-22 21:40:39 +00:00
Utils Move SplitBlockPredecessors out of loopsimplify into BasicBlockUtils.h 2008-04-21 01:28:02 +00:00
Makefile remove attribution from lib Makefiles. 2007-12-29 20:09:26 +00:00