[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibOptDxe / X64 / SetMem.S

#------------------------------------------------------------------------------\r
#\r
# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
# This program and the accompanying materials\r
# are licensed and made available under the terms and conditions of the BSD License\r
# which accompanies this distribution.  The full text of the license may be found at\r
# http://opensource.org/licenses/bsd-license.php.\r
#\r
# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
#\r
# Module Name:\r
#\r
#   SetMem.S\r
#\r
# Abstract:\r
#\r
#   SetMem function\r
#\r
# Notes:\r
#\r
#------------------------------------------------------------------------------\r
#------------------------------------------------------------------------------\r
#  VOID *\r
#  EFIAPI\r
#  InternalMemSetMem (\r
#    IN VOID   *Buffer,\r
#    IN UINTN  Count,\r
#    IN UINT8  Value\r
#    )\r
#------------------------------------------------------------------------------\r
ASM_GLOBAL ASM_PFX(InternalMemSetMem)\r
ASM_PFX(InternalMemSetMem):\r
    pushq   %rdi\r
    pushq   %rbx\r
    pushq   %rcx        # push Buffer\r
    movq    %r8, %rax   # rax = Value\r
    andq    $0xff, %rax # rax = lower 8 bits of r8, upper 56 bits are 0\r
    movb    %al, %ah    # ah  = al\r
    movw    %ax, %bx    # bx  = ax\r
    shlq    $0x10, %rax # rax = ax << 16\r
    movw    %bx,  %ax   # ax  = bx\r
    movq    %rax, %rbx  # ebx = eax\r
    shlq    $0x20, %rax # rax = rax << 32\r
    orq     %rbx, %rax  # eax = ebx\r
    movq    %rcx, %rdi  # rdi = Buffer\r
    movq    %rdx, %rcx  # rcx = Count\r
    shrq    $3, %rcx    # rcx = rcx / 8\r
    cld\r
    rep     stosq\r
    movq    %rdx, %rcx  # rcx = rdx\r
    andq    $7, %rcx    # rcx = rcx & 7\r
    rep     stosb\r
    popq    %rax        # rax = Buffer\r
    popq    %rbx\r
    popq    %rdi\r
    ret\r
Commit	Line	Data
2fb8d3e2	1	#------------------------------------------------------------------------------\r
2fb8d3e2	2	#\r
9095d37b	3	# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
adc29a97	4	# This program and the accompanying materials\r
2fb8d3e2	5	# are licensed and made available under the terms and conditions of the BSD License\r
2fb8d3e2	6	# which accompanies this distribution. The full text of the license may be found at\r
2fc59a00	7	# http://opensource.org/licenses/bsd-license.php.\r
2fb8d3e2	8	#\r
	9	# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	10	# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	11	#\r
	12	# Module Name:\r
	13	#\r
5da37dda	14	# SetMem.S\r
2fb8d3e2	15	#\r
	16	# Abstract:\r
	17	#\r
	18	# SetMem function\r
	19	#\r
	20	# Notes:\r
	21	#\r
	22	#------------------------------------------------------------------------------\r
	23	#------------------------------------------------------------------------------\r
	24	# VOID *\r
	25	# EFIAPI\r
	26	# InternalMemSetMem (\r
	27	# IN VOID *Buffer,\r
	28	# IN UINTN Count,\r
	29	# IN UINT8 Value\r
	30	# )\r
	31	#------------------------------------------------------------------------------\r
132f41f0	32	ASM_GLOBAL ASM_PFX(InternalMemSetMem)\r
2c0bbf43	33	ASM_PFX(InternalMemSetMem):\r
1fef058f	34	pushq %rdi\r
	35	pushq %rbx\r
	36	pushq %rcx # push Buffer\r
	37	movq %r8, %rax # rax = Value\r
	38	andq $0xff, %rax # rax = lower 8 bits of r8, upper 56 bits are 0\r
	39	movb %al, %ah # ah = al\r
	40	movw %ax, %bx # bx = ax\r
	41	shlq $0x10, %rax # rax = ax << 16\r
	42	movw %bx, %ax # ax = bx\r
	43	movq %rax, %rbx # ebx = eax\r
	44	shlq $0x20, %rax # rax = rax << 32\r
	45	orq %rbx, %rax # eax = ebx\r
	46	movq %rcx, %rdi # rdi = Buffer\r
	47	movq %rdx, %rcx # rcx = Count\r
	48	shrq $3, %rcx # rcx = rcx / 8\r
1dc58db3	49	cld\r
9095d37b	50	rep stosq\r
1fef058f	51	movq %rdx, %rcx # rcx = rdx\r
1fef058f	52	andq $7, %rcx # rcx = rcx & 7\r
9095d37b	53	rep stosb\r
1fef058f	54	popq %rax # rax = Buffer\r
	55	popq %rbx\r
	56	popq %rdi\r
1dc58db3	57	ret\r