test/Transforms/MemCpyOpt/memcpy-zero-size.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -passes=memcpyopt < %s | FileCheck %s

declare void @llvm.memset.p0.i64(ptr, i8, i64, i1)
declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1)

define void @zero_size(ptr %p, ptr %p2) {
; CHECK-LABEL: @zero_size(
; CHECK-NEXT:    ret void
;
  call void @llvm.memcpy.p0.p0.i64(ptr %p, ptr %p2, i64 0, i1 false)
  ret void
}

; The memcpy size is zero in a way that is non-trivial, but understood by AA.
define void @pr54983(ptr %p, ptr noalias %p2) {
; CHECK-LABEL: @pr54983(
; CHECK-NEXT:    call void @llvm.memset.p0.i64(ptr [[P:%.*]], i8 0, i64 1, i1 false)
; CHECK-NEXT:    [[SIZE:%.*]] = shl i64 0, 0
; CHECK-NEXT:    ret void
;
  call void @llvm.memset.p0.i64(ptr %p, i8 0, i64 1, i1 false)
  %size = shl i64 0, 0
  call void @llvm.memcpy.p0.p0.i64(ptr %p, ptr %p2, i64 %size, i1 false)
  ret void
}

define void @pr64886(i64 %len, ptr noalias %p) {
; CHECK-LABEL: @pr64886(
; CHECK-NEXT:    call void @llvm.memset.p0.i64(ptr inttoptr (i64 -1 to ptr), i8 0, i64 [[LEN:%.*]], i1 false)
; CHECK-NEXT:    ret void
;
  call void @llvm.memset.p0.i64(ptr inttoptr (i64 -1 to ptr), i8 0, i64 %len, i1 false)
  call void @llvm.memcpy.p0.p0.i64(ptr inttoptr (i64 -1 to ptr), ptr %p, i64 poison, i1 false)
  ret void
}