third_party/llvm-7.0/llvm/test/Transforms/MemCpyOpt/align.ll

; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"

declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i1) nounwind
declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i1) nounwind

; The resulting memset is only 4-byte aligned, despite containing
; a 16-byte aligned store in the middle.

define void @foo(i32* %p) {
; CHECK-LABEL: @foo(
; CHECK: call void @llvm.memset.p0i8.i64(i8* align 4 {{.*}}, i8 0, i64 16, i1 false)
  %a0 = getelementptr i32, i32* %p, i64 0
  store i32 0, i32* %a0, align 4
  %a1 = getelementptr i32, i32* %p, i64 1
  store i32 0, i32* %a1, align 16
  %a2 = getelementptr i32, i32* %p, i64 2
  store i32 0, i32* %a2, align 4
  %a3 = getelementptr i32, i32* %p, i64 3
  store i32 0, i32* %a3, align 4
  ret void
}

; Replacing %a8 with %a4 in the memset requires boosting the alignment of %a4.

define void @bar() {
; CHECK-LABEL: @bar(
; CHECK: %a4 = alloca i32, align 8
; CHECK-NOT: memcpy
  %a4 = alloca i32, align 4
  %a8 = alloca i32, align 8
  %a8.cast = bitcast i32* %a8 to i8*
  %a4.cast = bitcast i32* %a4 to i8*
  call void @llvm.memset.p0i8.i64(i8* align 8 %a8.cast, i8 0, i64 4, i1 false)
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %a4.cast, i8* align 4 %a8.cast, i64 4, i1 false)
  ret void
}