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path: root/lib/Transforms/Scalar/JumpThreading.cpp
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2008-11-28don't call MergeBasicBlockIntoOnlyPred on a block whose onlyChris Lattner
predecessor is itself. This doesn't make sense, and this is a dead infinite loop anyway. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60210 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27Fix PR3138: if we merge the entry block into another block, make sure toChris Lattner
move the other block back up into the entry position! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60179 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27move FindAvailableLoadedValue from JumpThreading to Transforms/Utils.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60166 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27move MergeBasicBlockIntoOnlyPred to Transforms/Utils.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60162 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27rename ThreadBlock to ProcessBlock, since it does other things thanChris Lattner
just simple threading. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60157 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27Make jump threading substantially more powerful, in the following ways:Chris Lattner
1. Make it fold blocks separated by an unconditional branch. This enables jump threading to see a broader scope. 2. Make jump threading able to eliminate locally redundant loads when they feed the branch condition of a block. This frequently occurs due to reg2mem running. 3. Make jump threading able to eliminate *partially redundant* loads when they feed the branch condition of a block. This is common in code with lots of loads and stores like C++ code and 255.vortex. This implements thread-loads.ll and rdar://6402033. Per the fixme's, several pieces of this should be moved into Transforms/Utils. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60148 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04Tidy up several unbeseeming casts from pointer to intptr_t.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-23Enable first-class aggregates support.Dan Gohman
Remove the GetResultInst instruction. It is still accepted in LLVM assembly and bitcode, where it is now auto-upgraded to ExtractValueInst. Also, remove support for return instructions with multiple values. These are auto-upgraded to use InsertValueInst instructions. The IRBuilder still accepts multiple-value returns, and auto-upgrades them to InsertValueInst instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53941 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-27Fix some constructs that gcc-4.4 warns about.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51591 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23Tidy up BasicBlock::getFirstNonPHI, and change a bunch of places toDan Gohman
use it instead of duplicating its functionality. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51499 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20Fix typo.Matthijs Kooijman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51303 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13Clean up the use of static and anonymous namespaces. This turned upDan Gohman
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
2008-05-09restore doxygen comment.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50881 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-08Improve pass documentation and comments.Gordon Henriksen
Patch by Matthijs Kooijman! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50861 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-06fix typo Duncan noticedChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50699 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-05Fix a crash when threading a block that includes a MRV call result.Chris Lattner
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
2008-04-25Don't infininitely thread branches when a threaded edgeChris Lattner
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
2008-04-22Start doing the significantly useful part of jump threading: handle casesChris Lattner
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
2008-04-22Dig through multiple levels of AND to thread jumps if needed.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50106 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-22Teach jump threading to thread through blocks like:Chris Lattner
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
2008-04-22refactor some code, no functionality change.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50094 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21fix grammar-o, thanks to Duncan for noticing.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50047 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21Use the new SplitBlockPredecessors to implement a todo.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50022 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20finish the first cut of a jump threading pass implementation.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50006 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20we can only thread blocks when there is a pred we can determine the succ of.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50003 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20improve comments, infrastructure, and add some validity checks for threading.Chris Lattner
Add a cost function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50002 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-20Add a new Jump Threading pass, which will handle casesChris Lattner
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
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