1*9880d681SAndroid Build Coastguard Worker; RUN: opt -jump-threading -S %s | FileCheck %s 2*9880d681SAndroid Build Coastguard Worker 3*9880d681SAndroid Build Coastguard Worker; Check that we thread arg2neg -> checkpos -> end. 4*9880d681SAndroid Build Coastguard Worker; 5*9880d681SAndroid Build Coastguard Worker; LazyValueInfo would previously fail to analyze the value of %arg in arg2neg 6*9880d681SAndroid Build Coastguard Worker; because its predecessing blocks (checkneg) hadn't been processed yet (PR21238) 7*9880d681SAndroid Build Coastguard Worker 8*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @test_jump_threading 9*9880d681SAndroid Build Coastguard Worker; CHECK: arg2neg: 10*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: br i1 %arg1, label %end, label %checkpos.thread 11*9880d681SAndroid Build Coastguard Worker; CHECK: checkpos.thread: 12*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: br label %end 13*9880d681SAndroid Build Coastguard Worker 14*9880d681SAndroid Build Coastguard Workerdefine i32 @test_jump_threading(i1 %arg1, i32 %arg2) { 15*9880d681SAndroid Build Coastguard Workercheckneg: 16*9880d681SAndroid Build Coastguard Worker %cmp = icmp slt i32 %arg2, 0 17*9880d681SAndroid Build Coastguard Worker br i1 %cmp, label %arg2neg, label %checkpos 18*9880d681SAndroid Build Coastguard Worker 19*9880d681SAndroid Build Coastguard Workerarg2neg: 20*9880d681SAndroid Build Coastguard Worker br i1 %arg1, label %end, label %checkpos 21*9880d681SAndroid Build Coastguard Worker 22*9880d681SAndroid Build Coastguard Workercheckpos: 23*9880d681SAndroid Build Coastguard Worker %cmp2 = icmp sgt i32 %arg2, 0 24*9880d681SAndroid Build Coastguard Worker br i1 %cmp2, label %arg2pos, label %end 25*9880d681SAndroid Build Coastguard Worker 26*9880d681SAndroid Build Coastguard Workerarg2pos: 27*9880d681SAndroid Build Coastguard Worker br label %end 28*9880d681SAndroid Build Coastguard Worker 29*9880d681SAndroid Build Coastguard Workerend: 30*9880d681SAndroid Build Coastguard Worker %0 = phi i32 [ 1, %arg2neg ], [ 2, %checkpos ], [ 3, %arg2pos ] 31*9880d681SAndroid Build Coastguard Worker ret i32 %0 32*9880d681SAndroid Build Coastguard Worker} 33*9880d681SAndroid Build Coastguard Worker 34*9880d681SAndroid Build Coastguard Worker 35*9880d681SAndroid Build Coastguard Worker; arg2neg has an edge back to itself. If LazyValueInfo is not careful when 36*9880d681SAndroid Build Coastguard Worker; visiting predecessors, it could get into an infinite loop. 37*9880d681SAndroid Build Coastguard Worker 38*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: test_infinite_loop 39*9880d681SAndroid Build Coastguard Worker 40*9880d681SAndroid Build Coastguard Workerdefine i32 @test_infinite_loop(i1 %arg1, i32 %arg2) { 41*9880d681SAndroid Build Coastguard Workercheckneg: 42*9880d681SAndroid Build Coastguard Worker %cmp = icmp slt i32 %arg2, 0 43*9880d681SAndroid Build Coastguard Worker br i1 %cmp, label %arg2neg, label %checkpos 44*9880d681SAndroid Build Coastguard Worker 45*9880d681SAndroid Build Coastguard Workerarg2neg: 46*9880d681SAndroid Build Coastguard Worker br i1 %arg1, label %arg2neg, label %checkpos 47*9880d681SAndroid Build Coastguard Worker 48*9880d681SAndroid Build Coastguard Workercheckpos: 49*9880d681SAndroid Build Coastguard Worker %cmp2 = icmp sgt i32 %arg2, 0 50*9880d681SAndroid Build Coastguard Worker br i1 %cmp2, label %arg2pos, label %end 51*9880d681SAndroid Build Coastguard Worker 52*9880d681SAndroid Build Coastguard Workerarg2pos: 53*9880d681SAndroid Build Coastguard Worker br label %end 54*9880d681SAndroid Build Coastguard Worker 55*9880d681SAndroid Build Coastguard Workerend: 56*9880d681SAndroid Build Coastguard Worker %0 = phi i32 [ 2, %checkpos ], [ 3, %arg2pos ] 57*9880d681SAndroid Build Coastguard Worker ret i32 %0 58*9880d681SAndroid Build Coastguard Worker} 59