forked from OSchip/llvm-project
26 lines
596 B
LLVM
26 lines
596 B
LLVM
; RUN: opt -S -jump-threading < %s | FileCheck %s
|
|
|
|
define i8 @test(i32 %a, i32 %length) {
|
|
; CHECK-LABEL: @test
|
|
entry:
|
|
; CHECK: br label %backedge
|
|
br label %loop
|
|
|
|
loop:
|
|
; CHECK-LABEL: backedge:
|
|
; CHECK: phi i32
|
|
; CHECK: br i1 %cont, label %backedge, label %exit
|
|
%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
|
|
}
|
|
|