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  1. Apr 23, 2008
  2. Apr 22, 2008
    • Chris Lattner's avatar
      Start doing the significantly useful part of jump threading: handle cases · 37e9c187
      Chris Lattner authored
      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.
      
      llvm-svn: 50110
      37e9c187
    • Chris Lattner's avatar
      Dig through multiple levels of AND to thread jumps if needed. · d5425e8f
      Chris Lattner authored
      llvm-svn: 50106
      d5425e8f
    • Owen Anderson's avatar
      Move MemCpyOpt after GVN. · 7432cbd0
      Owen Anderson authored
      llvm-svn: 50097
      7432cbd0
    • Chris Lattner's avatar
      Teach jump threading to thread through blocks like: · 3df4c15d
      Chris Lattner authored
        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.
      
      llvm-svn: 50096
      3df4c15d
    • Evan Cheng's avatar
      Added command line option -no-lazy to disable JIT lazy compilation. · 0422bef7
      Evan Cheng authored
      llvm-svn: 50095
      0422bef7
    • Chris Lattner's avatar
      refactor some code, no functionality change. · e369c35a
      Chris Lattner authored
      llvm-svn: 50094
      e369c35a
    • Chris Lattner's avatar
      add a basic testcase. · 3cc28ce1
      Chris Lattner authored
      llvm-svn: 50093
      3cc28ce1
    • Nick Lewycky's avatar
      Whoops! Undo r50087, unbreak the build. · 0a7b12bb
      Nick Lewycky authored
      llvm-svn: 50088
      0a7b12bb
    • Nick Lewycky's avatar
      Reverse r47989. Part of removing 'unwinds to' support. · fb6c3499
      Nick Lewycky authored
      llvm-svn: 50087
      fb6c3499
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