| /* pngtarget.h - target configuration file for libpng |
| * |
| * libpng version 1.6.44.git |
| * |
| * Copyright (c) 2024 John Bowler |
| * |
| * This code is released under the libpng license. |
| * For conditions of distribution and use, see the disclaimer |
| * and license in png.h |
| * |
| * [[Added to libpng1.8]] |
| * |
| * This header file discovers whether the target machine has support for target |
| * (normally CPU) specific code such as SIMD instructions. It is included by |
| * pngpriv.h immediately after pnglibconf.h to establish compile-time (as |
| * opposed to configuration time) requirements for the build of libpng |
| * |
| * The header only defines a very limited number of macros and it only defines |
| * macros; no functions are declared, no types etc. |
| * |
| * Every target architecture <arch> must have the following file: |
| * |
| * <arch>/check.h |
| * |
| * This file contains checks based on compiler flags to determine if |
| * target-specific code can be implemented for this architecture with this set |
| * of compiler options. Define |
| * |
| * PNG_TARGET_CODE_IMPLEMENTATION |
| * |
| * To the quoted relative path name of a single C file to include to obtain the |
| * implementation of the the target specific code. For example: |
| * |
| * "arm/arm_init.c" |
| * "intel/intel_init.c" |
| * |
| * This file will be included by pngsmid.c so the string must be a valid |
| * relative path name from that file. See the file pngsmid.c for the definition |
| * of what the C file must do. |
| * |
| * When it defines PNG_TARGET_CODE_IMPLEMENTATION the check file may also |
| * define: |
| * |
| * PNG_TARGET_STORES_DATA |
| * If set a png_voidp pointer called "target_data" will be defined in |
| * pngstruct.h. The initialization code included in pngsimd.c must then |
| * also implement a function to free the data called png_target_free_data, |
| * see png_simd.c. |
| * |
| * PNG_TARGET_ROW_ALIGNMENT |
| * If set this defines a power-of-2 required memory alignment for rows |
| * passed to the read "filter". If not set this defaults to 1. |
| * |
| * PNG_TARGET_IMPLEMENTS_FILTERS |
| * If defined this indicates to the system that target specific |
| * implementations of the read filters may be available. This must be set |
| * to cause a target specific filter implementation to be used. |
| * |
| * PNG_TARGET_IMPLEMENTS_EXPAND_PALETTE |
| * If defined this indicates to the system that target specific |
| * code for rgb_do_expand_palette is available. This must be defined to |
| * cause such implementations to be used. |
| * |
| * It MUST NOT define these macros unless it also defines |
| * PNG_TARGET_CODE_IMPLEMENTATION. At least one of the 'IMPLEMENTS' macros must |
| * be defined; this file will produce an error diagnostic if not. |
| * |
| * If the check.h file needs to define other macros, for example for use in the |
| * PNG_TARGET_CODE_IMPLEMENTATION file macros must have the form: |
| * |
| * PNG_TARGET_<ARCH>_... |
| * |
| * Where ARCH the architecture directory (the directory containing check.h) in |
| * upper case. See pngsimd.c for more information about function definitions |
| * used to implement the code. |
| */ |
| #ifndef PNGTARGET_H |
| #define PNGTARGET_H |
| |
| #ifdef PNG_TARGET_SPECIFIC_CODE_SUPPORTED /* from pnglibconf.h */ |
| # ifdef PNG_READ_SUPPORTED /* checked here as a convenience */ |
| # include "arm/check.h" |
| # include "intel/check.h" |
| # include "mips/check.h" |
| # include "powerpc/check.h" |
| #endif |
| #endif /* PNG_TARGET_SPECIFIC_CODE_SUPPORTED */ |
| |
| /* This is also a convenience to avoid checking in every check.h: */ |
| #ifndef PNG_READ_EXPAND_SUPPORTED |
| # undef PNG_TARGET_IMPLEMENTS_EXPAND_PALETTE |
| #endif |
| |
| /* Now check the condition above. Note that these checks consider the composite |
| * result of all the above includes; if errors are preceded by warnings about |
| * redefinition of the macros those need to be fixed first. |
| */ |
| #ifdef PNG_TARGET_CODE_IMPLEMENTATION /* There is target-specific code */ |
| /* List all the supported target specific code types here: */ |
| # if !defined(PNG_TARGET_IMPLEMENTS_FILTERS) &&\ |
| !defined(PNG_TARGET_IMPLEMENTS_EXPAND_PALETTE) |
| # error PNG_TARGET_CODE_IMPLEMENTATION without any implementations. |
| |
| /* Currently only row alignments which are a power of 2 and less than 17 are |
| * supported: the current code always aligns to 16 bytes (but may not in the |
| * future). |
| */ |
| # if defined(PNG_TARGET_ROW_ALIGNMENT) && (\ |
| PNG_TARGET_ROW_ALIGNMENT > 16 /*too big*/ ||\ |
| PNG_TARGET_ROW_ALIGNMENT !=\ |
| (PNG_TARGET_ROW_ALIGNMENT & -PNG_TARGET_ROW_ALIGNMENT)) /*!power of 2*/ |
| # error unsupported TARGET_ROW_ALIGNMENT |
| # endif /* PNG_TARGET_ROW_ALIGNMENT check */ |
| #endif /* Target specific code macro checks. */ |
| #endif /* PNG_TARGET_SPECIFIC_CODE_SUPPORTED */ |
| |
| #ifndef PNG_TARGET_CODE_IMPLEMENTATION |
| # if defined(PNG_TARGET_STORES_DATA) ||\ |
| defined(PNG_TARGET_ROW_ALIGNMENT) ||\ |
| defined(PNG_TARGET_IMPLEMENTS_FILTERS) ||\ |
| defined(PNG_TARGET_IMPLEMENTS_EXPAND_PALETTE) |
| # error PNG_TARGET_ macro defined without target specfic code. |
| # endif /* Check PNG_TARGET_ macros are not defined. */ |
| #endif /* PNG_TARGET_CODE_IMPLEMENTATION */ |
| |
| #ifndef PNG_TARGET_ROW_ALIGNMENT |
| # define PNG_TARGET_ROW_ALIGNMENT 1 |
| #endif |
| #endif /* PNGTARGET_H */ |
