1*9880d681SAndroid Build Coastguard Worker; RUN: opt -S -jump-threading < %s | FileCheck %s 2*9880d681SAndroid Build Coastguard Worker 3*9880d681SAndroid Build Coastguard Workerdefine i8 @test(i32 %a, i32 %length) { 4*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @test 5*9880d681SAndroid Build Coastguard Workerentry: 6*9880d681SAndroid Build Coastguard Worker; CHECK: br label %backedge 7*9880d681SAndroid Build Coastguard Worker br label %loop 8*9880d681SAndroid Build Coastguard Worker 9*9880d681SAndroid Build Coastguard Workerloop: 10*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: backedge: 11*9880d681SAndroid Build Coastguard Worker; CHECK: phi i32 12*9880d681SAndroid Build Coastguard Worker; CHECK: br i1 %cont, label %backedge, label %exit 13*9880d681SAndroid Build Coastguard Worker %iv = phi i32 [0, %entry], [%iv.next, %backedge] 14*9880d681SAndroid Build Coastguard Worker ;; We can use an inductive argument to prove %iv is always positive 15*9880d681SAndroid Build Coastguard Worker %cnd = icmp sge i32 %iv, 0 16*9880d681SAndroid Build Coastguard Worker br i1 %cnd, label %backedge, label %exit 17*9880d681SAndroid Build Coastguard Worker 18*9880d681SAndroid Build Coastguard Workerbackedge: 19*9880d681SAndroid Build Coastguard Worker %iv.next = add nsw i32 %iv, 1 20*9880d681SAndroid Build Coastguard Worker %cont = icmp slt i32 %iv.next, 400 21*9880d681SAndroid Build Coastguard Worker br i1 %cont, label %loop, label %exit 22*9880d681SAndroid Build Coastguard Workerexit: 23*9880d681SAndroid Build Coastguard Worker ret i8 0 24*9880d681SAndroid Build Coastguard Worker} 25*9880d681SAndroid Build Coastguard Worker 26