blob: 6124aab333851fcde0e1a224029e465b8ba3b783 [file] [log] [blame]
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -jump-threading < %s | FileCheck %s
define i8 @test(i32 %a, i32 %length) {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[BACKEDGE:%.*]]
; CHECK: backedge:
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE]] ]
; CHECK-NEXT: [[IV_NEXT]] = add nsw i32 [[IV]], 1
; CHECK-NEXT: [[CONT:%.*]] = icmp slt i32 [[IV_NEXT]], 400
; CHECK-NEXT: br i1 [[CONT]], label [[BACKEDGE]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: ret i8 0
;
entry:
br label %loop
loop:
%iv = phi i32 [0, %entry], [%iv.next, %backedge]
;; We can use an inductive argument to prove %iv is always positive
%cnd = icmp sge i32 %iv, 0
br i1 %cnd, label %backedge, label %exit
backedge:
%iv.next = add nsw i32 %iv, 1
%cont = icmp slt i32 %iv.next, 400
br i1 %cont, label %loop, label %exit
exit:
ret i8 0
}