llvm/test/Transforms/JumpThreading, branch release_23

Fix a crash when threading a block that includes a MRV call result.

2008-05-05T20:21:22Z

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

Don't infininitely thread branches when a threaded edge

2008-04-25T04:12:29Z

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 ] ; [#uses=2] %tmp39.us = icmp eq i32 %D1361.1.us, 0 ; [#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

Start doing the significantly useful part of jump threading: handle cases

2008-04-22T21:40:39Z

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 ] ; [#uses=2] %done.0 = phi i32 [ %done.2, %bb2231 ], [ 0, %bb2149 ] ; [#uses=1] %tmp2239 = icmp eq i32 %done.0, 0 ; [#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 ] ; [#uses=1] %tmp40.i297 = icmp eq %struct.ibox* %tmp39.i296.rle, null ; [#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

Dig through multiple levels of AND to thread jumps if needed.

2008-04-22T20:46:09Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50106 91177308-0d34-0410-b5e6-96231b3b80d8

Teach jump threading to thread through blocks like:

2008-04-22T07:05:46Z

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 ] ; [#uses=4] %tmp270 = icmp eq %struct.rtx_def* %tmp.0.i, null ; [#uses=1] %bothcond = or i1 %iftmp.251.0, %tmp270 ; [#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 ; [#uses=1] call void @llvm.stackrestore( i8* %savedstack ) nounwind %tmp4389 = icmp eq i32 %added_sets_1.0, 0 ; [#uses=1] %tmp4394 = icmp eq i32 %added_sets_2.0, 0 ; [#uses=1] %bothcond80 = and i1 %tmp4389, %tmp4394 ; [#uses=1] %bothcond81 = and i1 %bothcond80, %tmp.0.i420 ; [#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 ] ; [#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 ] ; [#uses=3] %tmp292.i.i = load i8* %tmp16.i.i100, align 1 ; [#uses=1] %tmp293.not.i.i = icmp ne i8 %tmp292.i.i, 0 ; [#uses=1] %bothcond.i.i = and i1 %tmp293.not.i.i, %myEOF.1.i.i ; [#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

add a basic testcase.

2008-04-22T06:35:14Z

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50093 91177308-0d34-0410-b5e6-96231b3b80d8