1 ; RUN: opt -jump-threading -S %s | FileCheck %s 2 3 ; Check that we thread arg2neg -> checkpos -> end. 4 ; 5 ; LazyValueInfo would previously fail to analyze the value of %arg in arg2neg 6 ; because its predecessing blocks (checkneg) hadn't been processed yet (PR21238) 7 8 ; CHECK-LABEL: @test_jump_threading 9 ; CHECK: arg2neg: 10 ; CHECK-NEXT: br i1 %arg1, label %end, label %checkpos.thread 11 ; CHECK: checkpos.thread: 12 ; CHECK-NEXT: br label %end 13 14 define i32 @test_jump_threading(i1 %arg1, i32 %arg2) { 15 checkneg: 16 %cmp = icmp slt i32 %arg2, 0 17 br i1 %cmp, label %arg2neg, label %checkpos 18 19 arg2neg: 20 br i1 %arg1, label %end, label %checkpos 21 22 checkpos: 23 %cmp2 = icmp sgt i32 %arg2, 0 24 br i1 %cmp2, label %arg2pos, label %end 25 26 arg2pos: 27 br label %end 28 29 end: 30 %0 = phi i32 [ 1, %arg2neg ], [ 2, %checkpos ], [ 3, %arg2pos ] 31 ret i32 %0 32 } 33 34 35 ; arg2neg has an edge back to itself. If LazyValueInfo is not careful when 36 ; visiting predecessors, it could get into an infinite loop. 37 38 ; CHECK-LABEL: test_infinite_loop 39 40 define i32 @test_infinite_loop(i1 %arg1, i32 %arg2) { 41 checkneg: 42 %cmp = icmp slt i32 %arg2, 0 43 br i1 %cmp, label %arg2neg, label %checkpos 44 45 arg2neg: 46 br i1 %arg1, label %arg2neg, label %checkpos 47 48 checkpos: 49 %cmp2 = icmp sgt i32 %arg2, 0 50 br i1 %cmp2, label %arg2pos, label %end 51 52 arg2pos: 53 br label %end 54 55 end: 56 %0 = phi i32 [ 2, %checkpos ], [ 3, %arg2pos ] 57 ret i32 %0 58 } 59
