libpng/arm/filter_neon.S
John Bowler d7d950e8bd [libpng16] chore: Clean up the leading blank lines from all source files
The leading blank lines are apparently an artefact of an older source
control system.  They are not required and they look like accidents,
because starting a source file with a blank line is not a regular habit
of software developers nowadays.

This is a cherry-pick of commit 37cc20add8fb5b83bb5299a26cd3b41e0f776017
from branch 'libpng18'.

Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
2024-10-11 11:51:04 +03:00

61 lines
2.1 KiB
ArmAsm

/* filter_neon.S - placeholder file
*
* Copyright (c) 2024 Cosmin Truta
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
/* IMPORTANT NOTE:
*
* Historically, the hand-coded assembler implementation of Neon optimizations
* in this module had not been in sync with the intrinsics-based implementation
* in filter_neon_intrinsics.c and palette_neon_intrinsics.c, at least since
* the introduction of riffled palette optimizations. Moreover, the assembler
* code used to work on 32-bit ARM only, and it caused problems, even if empty,
* on 64-bit ARM.
*
* All references to this module from our internal build scripts and projects
* have been removed.
*
* For the external projects that might still expect this module to be present,
* we leave this stub in place, for the remaining lifetime of libpng-1.6.x.
* Everything should continue to function normally, as long as there are no
* deliberate attempts to use the old hand-made assembler code. A build error
* will be raised otherwise.
*/
/* This is required to get the symbol renames, which are #defines, and the
* definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
*/
#define PNG_VERSION_INFO_ONLY
#include "../pngpriv.h"
#ifdef PNG_READ_SUPPORTED
#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
#if PNG_ARM_NEON_OPT > 0
#if defined(__clang__)
#define GNUC_VERSION 0 /* not gcc, although it might pretend to be */
#elif defined(__GNUC__)
#define GNUC_MAJOR (__GNUC__ + 0)
#define GNUC_MINOR (__GNUC_MINOR__ + 0)
#define GNUC_PATCHLEVEL (__GNUC_PATCHLEVEL__ + 0)
#define GNUC_VERSION (GNUC_MAJOR * 10000 + GNUC_MINOR * 100 + GNUC_PATCHLEVEL)
#else
#define GNUC_VERSION 0 /* not gcc */
#endif
#if (GNUC_VERSION > 0) && (GNUC_VERSION < 40300)
#error "PNG_ARM_NEON is not supported with gcc versions earlier than 4.3.0"
#elif GNUC_VERSION == 40504
#error "PNG_ARM_NEON is not supported with gcc version 4.5.4"
#else
#error "Please use 'arm/*_neon_intrinsics.c' for PNG_ARM_NEON support"
#endif
#endif /* PNG_ARM_NEON_OPT > 0 */
#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 */
#endif /* READ */