File: saddo-redundant-add.ll

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llvm-toolchain-3.7 1%3A3.7.1-5
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; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s

define void @redundant_add(i64 %n) {
; Check that we don't create two additions for the sadd.with.overflow.
; CHECK-LABEL: redundant_add
; CHECK-NOT:  leaq
; CHECK-NOT:  addq
; CHECK:      incq
; CHECK-NEXT: jno
entry:
  br label %exit_check

exit_check:
  %i = phi i64 [ 0, %entry ], [ %i.next, %loop ]
  %c = icmp slt i64 %i, %n
  br i1 %c, label %loop, label %exit

loop:
  %i.o = tail call { i64, i1 } @llvm.sadd.with.overflow.i64(i64 %i, i64 1)
  %i.next = extractvalue { i64, i1 } %i.o, 0
  %o = extractvalue { i64, i1 } %i.o, 1
  br i1 %o, label %overflow, label %exit_check

exit:
  ret void

overflow:
  tail call void @llvm.trap()
  unreachable
}

declare { i64, i1 } @llvm.sadd.with.overflow.i64(i64, i64)
declare void @llvm.trap()