llvm-project/llvm/test/CodeGen/SystemZ/loop-02.ll

39 lines
1016 B
LLVM

; Test BRCTH.
; RUN: llc < %s -verify-machineinstrs -mtriple=s390x-linux-gnu -mcpu=z196 \
; RUN: -no-integrated-as | FileCheck %s
; Test a loop that should be converted into dbr form and then use BRCTH.
define void @f2(i32 *%src, i32 *%dest) {
; CHECK-LABEL: f2:
; CHECK: blah [[REG:%r[0-5]]]
; CHECK: [[LABEL:\.[^:]*]]:{{.*}} %loop
; CHECK: brcth [[REG]], [[LABEL]]
; CHECK: br %r14
entry:
; Force upper bound into a high register in order to encourage the
; register allocator to use a high register for the count variable.
%top = call i32 asm sideeffect "blah $0", "=h"()
br label %loop
loop:
%count = phi i32 [ 0, %entry ], [ %next, %loop.next ]
%next = add i32 %count, 1
%val = load volatile i32 , i32 *%src
%cmp = icmp eq i32 %val, 0
br i1 %cmp, label %loop.next, label %loop.store
loop.store:
%add = add i32 %val, 1
store volatile i32 %add, i32 *%dest
br label %loop.next
loop.next:
%cont = icmp ne i32 %next, %top
br i1 %cont, label %loop, label %exit
exit:
ret void
}