memmove.ll 2.85 KB
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; This test makes sure that memmove instructions are properly eliminated.
;
; RUN: opt < %s -instcombine -S | FileCheck %s

@S = internal constant [33 x i8] c"panic: restorelist inconsistency\00"		; <[33 x i8]*> [#uses=1]
@h = constant [2 x i8] c"h\00"		; <[2 x i8]*> [#uses=1]
@hel = constant [4 x i8] c"hel\00"		; <[4 x i8]*> [#uses=1]
@hello_u = constant [8 x i8] c"hello_u\00"		; <[8 x i8]*> [#uses=1]

define void @test1(i8* %A, i8* %B, i32 %N) {
; CHECK-LABEL: @test1(
; CHECK-NEXT:    ret void
;
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %A, i8* %B, i32 0, i1 false)
  ret void
}

define void @test2(i8* %A, i32 %N) {
  ;; dest can't alias source since we can't write to source!
; CHECK-LABEL: @test2(
; CHECK-NEXT:    call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 1 [[A:%.*]], i8* align 16 getelementptr inbounds ([33 x i8], [33 x i8]* @S, i64 0, i64 0), i32 [[N:%.*]], i1 false)
; CHECK-NEXT:    ret void
;
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %A, i8* getelementptr inbounds ([33 x i8], [33 x i8]* @S, i32 0, i32 0), i32 %N, i1 false)
  ret void
}

define i32 @test3([1024 x i8]* %target) { ; arg: [1024 x i8]*> [#uses=1]
; CHECK-LABEL: @test3(
; CHECK-NEXT:    [[TMP1:%.*]] = bitcast [1024 x i8]* [[TARGET:%.*]] to i16*
; CHECK-NEXT:    store i16 104, i16* [[TMP1]], align 2
; CHECK-NEXT:    [[TMP2:%.*]] = bitcast [1024 x i8]* [[TARGET]] to i32*
; CHECK-NEXT:    store i32 7103848, i32* [[TMP2]], align 4
; CHECK-NEXT:    [[TMP3:%.*]] = bitcast [1024 x i8]* [[TARGET]] to i64*
; CHECK-NEXT:    store i64 33037504440198504, i64* [[TMP3]], align 8
; CHECK-NEXT:    ret i32 0
;
  %h_p = getelementptr [2 x i8], [2 x i8]* @h, i32 0, i32 0		; <i8*> [#uses=1]
  %hel_p = getelementptr [4 x i8], [4 x i8]* @hel, i32 0, i32 0		; <i8*> [#uses=1]
  %hello_u_p = getelementptr [8 x i8], [8 x i8]* @hello_u, i32 0, i32 0		; <i8*> [#uses=1]
  %target_p = getelementptr [1024 x i8], [1024 x i8]* %target, i32 0, i32 0		; <i8*> [#uses=3]
  call void @llvm.memmove.p0i8.p0i8.i32(i8* align 2 %target_p, i8* align 2 %h_p, i32 2, i1 false)
  call void @llvm.memmove.p0i8.p0i8.i32(i8* align 4 %target_p, i8* align 4 %hel_p, i32 4, i1 false)
  call void @llvm.memmove.p0i8.p0i8.i32(i8* align 8 %target_p, i8* align 8 %hello_u_p, i32 8, i1 false)
  ret i32 0
}

; PR2370
define void @test4(i8* %a) {
; CHECK-LABEL: @test4(
; CHECK-NEXT:    ret void
;
  tail call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %a, i32 100, i1 false)
  ret void
}

@UnknownConstant = external constant i128

define void @memmove_to_constant(i8* %src) {
; CHECK-LABEL: @memmove_to_constant(
; CHECK-NEXT:    ret void
;
  %dest = bitcast i128* @UnknownConstant to i8*
  call void @llvm.memmove.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 16, i1 false)
  ret void
}


declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i1) argmemonly nounwind