releases-comm-central/third_party/libgcrypt/cipher/sha512-ssse3-amd64.S

468 строки
16 KiB
ArmAsm

/*
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Copyright (c) 2012, Intel Corporation
;
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are
; met:
;
; * Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
;
; * Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the
; distribution.
;
; * Neither the name of the Intel Corporation nor the names of its
; contributors may be used to endorse or promote products derived from
; this software without specific prior written permission.
;
;
; THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION "AS IS" AND ANY
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
; PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL CORPORATION OR
; CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
; EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
; PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
; LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
*/
/*
* Conversion to GAS assembly and integration to libgcrypt
* by Jussi Kivilinna <jussi.kivilinna@iki.fi>
*
* Note: original implementation was named as SHA512-SSE4. However, only SSSE3
* is required.
*/
#ifdef __x86_64
#include <config.h>
#if (defined(HAVE_COMPATIBLE_GCC_AMD64_PLATFORM_AS) || \
defined(HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS)) && \
defined(HAVE_INTEL_SYNTAX_PLATFORM_AS) && \
defined(HAVE_GCC_INLINE_ASM_SSSE3) && defined(USE_SHA512)
#include "asm-common-amd64.h"
.intel_syntax noprefix
.text
/* Virtual Registers */
#define msg rdi /* ARG1 */
#define digest rsi /* ARG2 */
#define msglen rdx /* ARG3 */
#define T1 rcx
#define T2 r8
#define a_64 r9
#define b_64 r10
#define c_64 r11
#define d_64 r12
#define e_64 r13
#define f_64 r14
#define g_64 r15
#define h_64 rbx
#define tmp0 rax
/*
; Local variables (stack frame)
; Note: frame_size must be an odd multiple of 8 bytes to XMM align RSP
*/
#define frame_W 0 /* Message Schedule */
#define frame_W_size (80 * 8)
#define frame_WK ((frame_W) + (frame_W_size)) /* W[t] + K[t] | W[t+1] + K[t+1] */
#define frame_WK_size (2 * 8)
#define frame_GPRSAVE ((frame_WK) + (frame_WK_size))
#define frame_GPRSAVE_size (5 * 8)
#define frame_size ((frame_GPRSAVE) + (frame_GPRSAVE_size))
/* Useful QWORD "arrays" for simpler memory references */
#define MSG(i) msg + 8*(i) /* Input message (arg1) */
#define DIGEST(i) digest + 8*(i) /* Output Digest (arg2) */
#define K_t(i) .LK512 + 8*(i) ADD_RIP /* SHA Constants (static mem) */
#define W_t(i) rsp + frame_W + 8*(i) /* Message Schedule (stack frame) */
#define WK_2(i) rsp + frame_WK + 8*((i) % 2) /* W[t]+K[t] (stack frame) */
/* MSG, DIGEST, K_t, W_t are arrays */
/* WK_2(t) points to 1 of 2 qwords at frame.WK depdending on t being odd/even */
#define SHA512_Round(t, a, b, c, d, e, f, g, h) \
/* Compute Round %%t */; \
mov T1, f /* T1 = f */; \
mov tmp0, e /* tmp = e */; \
xor T1, g /* T1 = f ^ g */; \
ror tmp0, 23 /* 41 ; tmp = e ror 23 */; \
and T1, e /* T1 = (f ^ g) & e */; \
xor tmp0, e /* tmp = (e ror 23) ^ e */; \
xor T1, g /* T1 = ((f ^ g) & e) ^ g = CH(e,f,g) */; \
add T1, [WK_2(t)] /* W[t] + K[t] from message scheduler */; \
ror tmp0, 4 /* 18 ; tmp = ((e ror 23) ^ e) ror 4 */; \
xor tmp0, e /* tmp = (((e ror 23) ^ e) ror 4) ^ e */; \
mov T2, a /* T2 = a */; \
add T1, h /* T1 = CH(e,f,g) + W[t] + K[t] + h */; \
ror tmp0, 14 /* 14 ; tmp = ((((e ror23)^e)ror4)^e)ror14 = S1(e) */; \
add T1, tmp0 /* T1 = CH(e,f,g) + W[t] + K[t] + S1(e) */; \
mov tmp0, a /* tmp = a */; \
xor T2, c /* T2 = a ^ c */; \
and tmp0, c /* tmp = a & c */; \
and T2, b /* T2 = (a ^ c) & b */; \
xor T2, tmp0 /* T2 = ((a ^ c) & b) ^ (a & c) = Maj(a,b,c) */; \
mov tmp0, a /* tmp = a */; \
ror tmp0, 5 /* 39 ; tmp = a ror 5 */; \
xor tmp0, a /* tmp = (a ror 5) ^ a */; \
add d, T1 /* e(next_state) = d + T1 */; \
ror tmp0, 6 /* 34 ; tmp = ((a ror 5) ^ a) ror 6 */; \
xor tmp0, a /* tmp = (((a ror 5) ^ a) ror 6) ^ a */; \
lea h, [T1 + T2] /* a(next_state) = T1 + Maj(a,b,c) */; \
ror tmp0, 28 /* 28 ; tmp = ((((a ror5)^a)ror6)^a)ror28 = S0(a) */; \
add h, tmp0 /* a(next_state) = T1 + Maj(a,b,c) S0(a) */
#define SHA512_2Sched_2Round_sse_PART1(t, a, b, c, d, e, f, g, h) \
/* \
; Compute rounds %%t-2 and %%t-1 \
; Compute message schedule QWORDS %%t and %%t+1 \
; \
; Two rounds are computed based on the values for K[t-2]+W[t-2] and \
; K[t-1]+W[t-1] which were previously stored at WK_2 by the message \
; scheduler. \
; The two new schedule QWORDS are stored at [W_t(%%t)] and [W_t(%%t+1)]. \
; They are then added to their respective SHA512 constants at \
; [K_t(%%t)] and [K_t(%%t+1)] and stored at dqword [WK_2(%%t)] \
; For brievity, the comments following vectored instructions only refer to \
; the first of a pair of QWORDS. \
; Eg. XMM2=W[t-2] really means XMM2={W[t-2]|W[t-1]} \
; The computation of the message schedule and the rounds are tightly \
; stitched to take advantage of instruction-level parallelism. \
; For clarity, integer instructions (for the rounds calculation) are indented \
; by one tab. Vectored instructions (for the message scheduler) are indented \
; by two tabs. \
*/ \
\
mov T1, f; \
movdqa xmm2, [W_t(t-2)] /* XMM2 = W[t-2] */; \
xor T1, g; \
and T1, e; \
movdqa xmm0, xmm2 /* XMM0 = W[t-2] */; \
xor T1, g; \
add T1, [WK_2(t)]; \
movdqu xmm5, [W_t(t-15)] /* XMM5 = W[t-15] */; \
mov tmp0, e; \
ror tmp0, 23 /* 41 */; \
movdqa xmm3, xmm5 /* XMM3 = W[t-15] */; \
xor tmp0, e; \
ror tmp0, 4 /* 18 */; \
psrlq xmm0, 61 - 19 /* XMM0 = W[t-2] >> 42 */; \
xor tmp0, e; \
ror tmp0, 14 /* 14 */; \
psrlq xmm3, (8 - 7) /* XMM3 = W[t-15] >> 1 */; \
add T1, tmp0; \
add T1, h; \
pxor xmm0, xmm2 /* XMM0 = (W[t-2] >> 42) ^ W[t-2] */; \
mov T2, a; \
xor T2, c; \
pxor xmm3, xmm5 /* XMM3 = (W[t-15] >> 1) ^ W[t-15] */; \
and T2, b; \
mov tmp0, a; \
psrlq xmm0, 19 - 6 /* XMM0 = ((W[t-2]>>42)^W[t-2])>>13 */; \
and tmp0, c; \
xor T2, tmp0; \
psrlq xmm3, (7 - 1) /* XMM3 = ((W[t-15]>>1)^W[t-15])>>6 */; \
mov tmp0, a; \
ror tmp0, 5 /* 39 */; \
pxor xmm0, xmm2 /* XMM0 = (((W[t-2]>>42)^W[t-2])>>13)^W[t-2] */; \
xor tmp0, a; \
ror tmp0, 6 /* 34 */; \
pxor xmm3, xmm5 /* XMM3 = (((W[t-15]>>1)^W[t-15])>>6)^W[t-15] */; \
xor tmp0, a; \
ror tmp0, 28 /* 28 */; \
psrlq xmm0, 6 /* XMM0 = ((((W[t-2]>>42)^W[t-2])>>13)^W[t-2])>>6 */; \
add T2, tmp0; \
add d, T1; \
psrlq xmm3, 1 /* XMM3 = (((W[t-15]>>1)^W[t-15])>>6)^W[t-15]>>1 */; \
lea h, [T1 + T2]
#define SHA512_2Sched_2Round_sse_PART2(t, a, b, c, d, e, f, g, h) \
movdqa xmm1, xmm2 /* XMM1 = W[t-2] */; \
mov T1, f; \
xor T1, g; \
movdqa xmm4, xmm5 /* XMM4 = W[t-15] */; \
and T1, e; \
xor T1, g; \
psllq xmm1, (64 - 19) - (64 - 61) /* XMM1 = W[t-2] << 42 */; \
add T1, [WK_2(t+1)]; \
mov tmp0, e; \
psllq xmm4, (64 - 1) - (64 - 8) /* XMM4 = W[t-15] << 7 */; \
ror tmp0, 23 /* 41 */; \
xor tmp0, e; \
pxor xmm1, xmm2 /* XMM1 = (W[t-2] << 42)^W[t-2] */; \
ror tmp0, 4 /* 18 */; \
xor tmp0, e; \
pxor xmm4, xmm5 /* XMM4 = (W[t-15]<<7)^W[t-15] */; \
ror tmp0, 14 /* 14 */; \
add T1, tmp0; \
psllq xmm1, (64 - 61) /* XMM1 = ((W[t-2] << 42)^W[t-2])<<3 */; \
add T1, h; \
mov T2, a; \
psllq xmm4, (64 - 8) /* XMM4 = ((W[t-15]<<7)^W[t-15])<<56 */; \
xor T2, c; \
and T2, b; \
pxor xmm0, xmm1 /* XMM0 = s1(W[t-2]) */; \
mov tmp0, a; \
and tmp0, c; \
movdqu xmm1, [W_t(t- 7)] /* XMM1 = W[t-7] */; \
xor T2, tmp0; \
pxor xmm3, xmm4 /* XMM3 = s0(W[t-15]) */; \
mov tmp0, a; \
paddq xmm0, xmm3 /* XMM0 = s1(W[t-2]) + s0(W[t-15]) */; \
ror tmp0, 5 /* 39 */; \
paddq xmm0, [W_t(t-16)] /* XMM0 = s1(W[t-2]) + s0(W[t-15]) + W[t-16] */; \
xor tmp0, a; \
paddq xmm0, xmm1 /* XMM0 = s1(W[t-2]) + W[t-7] + s0(W[t-15]) + W[t-16] */; \
ror tmp0, 6 /* 34 */; \
movdqa [W_t(t)], xmm0 /* Store scheduled qwords */; \
xor tmp0, a; \
paddq xmm0, [K_t(t)] /* Compute W[t]+K[t] */; \
ror tmp0, 28 /* 28 */; \
movdqa [WK_2(t)], xmm0 /* Store W[t]+K[t] for next rounds */; \
add T2, tmp0; \
add d, T1; \
lea h, [T1 + T2]
#define SHA512_2Sched_2Round_sse(t, a, b, c, d, e, f, g, h) \
SHA512_2Sched_2Round_sse_PART1(t, a, b, c, d, e, f, g, h); \
SHA512_2Sched_2Round_sse_PART2(t, h, a, b, c, d, e, f, g)
/*
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; void sha512_sse4(const void* M, void* D, uint64_t L);
; Purpose: Updates the SHA512 digest stored at D with the message stored in M.
; The size of the message pointed to by M must be an integer multiple of SHA512
; message blocks.
; L is the message length in SHA512 blocks.
*/
.globl _gcry_sha512_transform_amd64_ssse3
ELF(.type _gcry_sha512_transform_amd64_ssse3,@function;)
.align 16
_gcry_sha512_transform_amd64_ssse3:
CFI_STARTPROC()
xor eax, eax
cmp msglen, 0
je .Lnowork
/* Allocate Stack Space */
sub rsp, frame_size
CFI_ADJUST_CFA_OFFSET(frame_size);
/* Save GPRs */
mov [rsp + frame_GPRSAVE + 8 * 0], rbx
mov [rsp + frame_GPRSAVE + 8 * 1], r12
mov [rsp + frame_GPRSAVE + 8 * 2], r13
mov [rsp + frame_GPRSAVE + 8 * 3], r14
mov [rsp + frame_GPRSAVE + 8 * 4], r15
CFI_REL_OFFSET(rbx, frame_GPRSAVE + 8 * 0);
CFI_REL_OFFSET(r12, frame_GPRSAVE + 8 * 1);
CFI_REL_OFFSET(r13, frame_GPRSAVE + 8 * 2);
CFI_REL_OFFSET(r14, frame_GPRSAVE + 8 * 3);
CFI_REL_OFFSET(r15, frame_GPRSAVE + 8 * 4);
.Lupdateblock:
/* Load state variables */
mov a_64, [DIGEST(0)]
mov b_64, [DIGEST(1)]
mov c_64, [DIGEST(2)]
mov d_64, [DIGEST(3)]
mov e_64, [DIGEST(4)]
mov f_64, [DIGEST(5)]
mov g_64, [DIGEST(6)]
mov h_64, [DIGEST(7)]
/* BSWAP 2 QWORDS */
movdqa xmm1, [.LXMM_QWORD_BSWAP ADD_RIP]
movdqu xmm0, [MSG(0)]
pshufb xmm0, xmm1 /* BSWAP */
movdqa [W_t(0)], xmm0 /* Store Scheduled Pair */
paddq xmm0, [K_t(0)] /* Compute W[t]+K[t] */
movdqa [WK_2(0)], xmm0 /* Store into WK for rounds */
#define T_2_14(t, a, b, c, d, e, f, g, h) \
/* BSWAP 2 QWORDS; Compute 2 Rounds */; \
movdqu xmm0, [MSG(t)]; \
pshufb xmm0, xmm1 /* BSWAP */; \
SHA512_Round(((t) - 2), a##_64, b##_64, c##_64, d##_64, \
e##_64, f##_64, g##_64, h##_64); \
movdqa [W_t(t)], xmm0 /* Store Scheduled Pair */; \
paddq xmm0, [K_t(t)] /* Compute W[t]+K[t] */; \
SHA512_Round(((t) - 1), h##_64, a##_64, b##_64, c##_64, \
d##_64, e##_64, f##_64, g##_64); \
movdqa [WK_2(t)], xmm0 /* Store W[t]+K[t] into WK */
#define T_16_78(t, a, b, c, d, e, f, g, h) \
SHA512_2Sched_2Round_sse((t), a##_64, b##_64, c##_64, d##_64, \
e##_64, f##_64, g##_64, h##_64)
#define T_80(t, a, b, c, d, e, f, g, h) \
/* Compute 2 Rounds */; \
SHA512_Round((t - 2), a##_64, b##_64, c##_64, d##_64, \
e##_64, f##_64, g##_64, h##_64); \
SHA512_Round((t - 1), h##_64, a##_64, b##_64, c##_64, \
d##_64, e##_64, f##_64, g##_64)
T_2_14(2, a, b, c, d, e, f, g, h)
T_2_14(4, g, h, a, b, c, d, e, f)
T_2_14(6, e, f, g, h, a, b, c, d)
T_2_14(8, c, d, e, f, g, h, a, b)
T_2_14(10, a, b, c, d, e, f, g, h)
T_2_14(12, g, h, a, b, c, d, e, f)
T_2_14(14, e, f, g, h, a, b, c, d)
T_16_78(16, c, d, e, f, g, h, a, b)
T_16_78(18, a, b, c, d, e, f, g, h)
T_16_78(20, g, h, a, b, c, d, e, f)
T_16_78(22, e, f, g, h, a, b, c, d)
T_16_78(24, c, d, e, f, g, h, a, b)
T_16_78(26, a, b, c, d, e, f, g, h)
T_16_78(28, g, h, a, b, c, d, e, f)
T_16_78(30, e, f, g, h, a, b, c, d)
T_16_78(32, c, d, e, f, g, h, a, b)
T_16_78(34, a, b, c, d, e, f, g, h)
T_16_78(36, g, h, a, b, c, d, e, f)
T_16_78(38, e, f, g, h, a, b, c, d)
T_16_78(40, c, d, e, f, g, h, a, b)
T_16_78(42, a, b, c, d, e, f, g, h)
T_16_78(44, g, h, a, b, c, d, e, f)
T_16_78(46, e, f, g, h, a, b, c, d)
T_16_78(48, c, d, e, f, g, h, a, b)
T_16_78(50, a, b, c, d, e, f, g, h)
T_16_78(52, g, h, a, b, c, d, e, f)
T_16_78(54, e, f, g, h, a, b, c, d)
T_16_78(56, c, d, e, f, g, h, a, b)
T_16_78(58, a, b, c, d, e, f, g, h)
T_16_78(60, g, h, a, b, c, d, e, f)
T_16_78(62, e, f, g, h, a, b, c, d)
T_16_78(64, c, d, e, f, g, h, a, b)
T_16_78(66, a, b, c, d, e, f, g, h)
T_16_78(68, g, h, a, b, c, d, e, f)
T_16_78(70, e, f, g, h, a, b, c, d)
T_16_78(72, c, d, e, f, g, h, a, b)
T_16_78(74, a, b, c, d, e, f, g, h)
T_16_78(76, g, h, a, b, c, d, e, f)
T_16_78(78, e, f, g, h, a, b, c, d)
T_80(80, c, d, e, f, g, h, a, b)
/* Update digest */
add [DIGEST(0)], a_64
add [DIGEST(1)], b_64
add [DIGEST(2)], c_64
add [DIGEST(3)], d_64
add [DIGEST(4)], e_64
add [DIGEST(5)], f_64
add [DIGEST(6)], g_64
add [DIGEST(7)], h_64
/* Advance to next message block */
add msg, 16*8
dec msglen
jnz .Lupdateblock
/* Restore GPRs */
mov rbx, [rsp + frame_GPRSAVE + 8 * 0]
mov r12, [rsp + frame_GPRSAVE + 8 * 1]
mov r13, [rsp + frame_GPRSAVE + 8 * 2]
mov r14, [rsp + frame_GPRSAVE + 8 * 3]
mov r15, [rsp + frame_GPRSAVE + 8 * 4]
CFI_RESTORE(rbx)
CFI_RESTORE(r12)
CFI_RESTORE(r13)
CFI_RESTORE(r14)
CFI_RESTORE(r15)
pxor xmm0, xmm0
pxor xmm1, xmm1
pxor xmm2, xmm2
pxor xmm3, xmm3
pxor xmm4, xmm4
pxor xmm5, xmm5
/* Burn stack */
mov eax, 0
.Lerase_stack:
movdqu [rsp + rax], xmm0
add eax, 16
cmp eax, frame_W_size
jne .Lerase_stack
movdqu [rsp + frame_WK], xmm0
xor eax, eax
/* Restore Stack Pointer */
add rsp, frame_size
CFI_ADJUST_CFA_OFFSET(-frame_size);
.Lnowork:
ret
CFI_ENDPROC()
/*
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Binary Data
*/
.align 16
/* Mask for byte-swapping a couple of qwords in an XMM register using (v)pshufb. */
.LXMM_QWORD_BSWAP:
.octa 0x08090a0b0c0d0e0f0001020304050607
/* K[t] used in SHA512 hashing */
.LK512:
.quad 0x428a2f98d728ae22,0x7137449123ef65cd
.quad 0xb5c0fbcfec4d3b2f,0xe9b5dba58189dbbc
.quad 0x3956c25bf348b538,0x59f111f1b605d019
.quad 0x923f82a4af194f9b,0xab1c5ed5da6d8118
.quad 0xd807aa98a3030242,0x12835b0145706fbe
.quad 0x243185be4ee4b28c,0x550c7dc3d5ffb4e2
.quad 0x72be5d74f27b896f,0x80deb1fe3b1696b1
.quad 0x9bdc06a725c71235,0xc19bf174cf692694
.quad 0xe49b69c19ef14ad2,0xefbe4786384f25e3
.quad 0x0fc19dc68b8cd5b5,0x240ca1cc77ac9c65
.quad 0x2de92c6f592b0275,0x4a7484aa6ea6e483
.quad 0x5cb0a9dcbd41fbd4,0x76f988da831153b5
.quad 0x983e5152ee66dfab,0xa831c66d2db43210
.quad 0xb00327c898fb213f,0xbf597fc7beef0ee4
.quad 0xc6e00bf33da88fc2,0xd5a79147930aa725
.quad 0x06ca6351e003826f,0x142929670a0e6e70
.quad 0x27b70a8546d22ffc,0x2e1b21385c26c926
.quad 0x4d2c6dfc5ac42aed,0x53380d139d95b3df
.quad 0x650a73548baf63de,0x766a0abb3c77b2a8
.quad 0x81c2c92e47edaee6,0x92722c851482353b
.quad 0xa2bfe8a14cf10364,0xa81a664bbc423001
.quad 0xc24b8b70d0f89791,0xc76c51a30654be30
.quad 0xd192e819d6ef5218,0xd69906245565a910
.quad 0xf40e35855771202a,0x106aa07032bbd1b8
.quad 0x19a4c116b8d2d0c8,0x1e376c085141ab53
.quad 0x2748774cdf8eeb99,0x34b0bcb5e19b48a8
.quad 0x391c0cb3c5c95a63,0x4ed8aa4ae3418acb
.quad 0x5b9cca4f7763e373,0x682e6ff3d6b2b8a3
.quad 0x748f82ee5defb2fc,0x78a5636f43172f60
.quad 0x84c87814a1f0ab72,0x8cc702081a6439ec
.quad 0x90befffa23631e28,0xa4506cebde82bde9
.quad 0xbef9a3f7b2c67915,0xc67178f2e372532b
.quad 0xca273eceea26619c,0xd186b8c721c0c207
.quad 0xeada7dd6cde0eb1e,0xf57d4f7fee6ed178
.quad 0x06f067aa72176fba,0x0a637dc5a2c898a6
.quad 0x113f9804bef90dae,0x1b710b35131c471b
.quad 0x28db77f523047d84,0x32caab7b40c72493
.quad 0x3c9ebe0a15c9bebc,0x431d67c49c100d4c
.quad 0x4cc5d4becb3e42b6,0x597f299cfc657e2a
.quad 0x5fcb6fab3ad6faec,0x6c44198c4a475817
#endif
#endif