forked from OSchip/llvm-project
33 lines
970 B
LLVM
33 lines
970 B
LLVM
; 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
|
|
}
|
|
|