/*

 * Copyright 2018 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#pragma once

// skcms_internals.h contains APIs shared by skcms' internals and its test tools.

// Please don't use this header from outside the skcms repo.

#include <stdbool.h>

#include <stdint.h>

#ifdef __cplusplus

extern "C" {

#endif

// ~~~~ General Helper Macros ~~~~

// skcms can leverage some C++ extensions when they are present.

#define ARRAY_COUNT(arr) (int)(sizeof((arr)) / sizeof(*(arr)))

#if defined(__clang__) && defined(__has_cpp_attribute)

    #if __has_cpp_attribute(clang::fallthrough)

        #define SKCMS_FALLTHROUGH [[clang::fallthrough]]

    #endif

    #ifndef SKCMS_HAS_MUSTTAIL

        // [[clang::musttail]] is great for performance, but it's not well supported and we run into

        // a variety of problems when we use it. Fortunately, it's an optional feature that doesn't

        // affect correctness, and usually the compiler will generate a tail-call even for us

        // whether or not we force it to do so.

        //

        // Known limitations:

        // - Sanitizers do not work well with [[clang::musttail]], and corrupt src/dst pointers.

        //   (https://github.com/llvm/llvm-project/issues/70849)

        // - Wasm tail-calls were only introduced in 2023 and aren't a mainstream feature yet.

        // - Clang 18 runs into an ICE on armv7/androideabi with [[clang::musttail]].

        //   (http://crbug.com/1504548)

        // - Android RISC-V also runs into an ICE (b/314692534)

        // - LoongArch developers indicate they had to turn it off

        // - Windows builds generate incorrect code with [[clang::musttail]] and crash mysteriously.

        //   (http://crbug.com/1505442)

        #if __has_cpp_attribute(clang::musttail) && !__has_feature(memory_sanitizer) \

                                                 && !__has_feature(address_sanitizer) \

                                                 && !defined(__EMSCRIPTEN__) \

                                                 && !defined(__arm__) \

                                                 && !defined(__riscv) \

                                                 && !defined(__loongarch__) \

                                                 && !defined(_WIN32) && !defined(__SYMBIAN32__)

            #define SKCMS_HAS_MUSTTAIL 1

        #endif

    #endif

#endif

#ifndef SKCMS_FALLTHROUGH

    #define SKCMS_FALLTHROUGH

#endif

#ifndef SKCMS_HAS_MUSTTAIL

    #define SKCMS_HAS_MUSTTAIL 0

#endif

#if defined(__clang__)

    #define SKCMS_MAYBE_UNUSED __attribute__((unused))

    #pragma clang diagnostic ignored "-Wused-but-marked-unused"

#elif defined(__GNUC__)

    #define SKCMS_MAYBE_UNUSED __attribute__((unused))

#elif defined(_MSC_VER)

    #define SKCMS_MAYBE_UNUSED __pragma(warning(suppress:4100))

#else

    #define SKCMS_MAYBE_UNUSED

#endif

// sizeof(x) will return size_t, which is 32-bit on some machines and 64-bit on others.

// We have better testing on 64-bit machines, so force 32-bit machines to behave like 64-bit.

//

// Please do not use sizeof() directly, and size_t only when required.

// (We have no way of enforcing these requests...)

#define SAFE_SIZEOF(x) ((uint64_t)sizeof(x))

// Same sort of thing for _Layout structs with a variable sized array at the end (named "variable").

#define SAFE_FIXED_SIZE(type) ((uint64_t)offsetof(type, variable))

// If this isn't Clang, GCC, or Emscripten with SIMD support, we are in SKCMS_PORTABLE mode.

#if !defined(SKCMS_PORTABLE) && !(defined(__clang__) || \

                                  defined(__GNUC__) || \

                                  (defined(__EMSCRIPTEN__) && defined(__wasm_simd128__)))

    #define SKCMS_PORTABLE 1

#endif

// If we are in SKCMS_PORTABLE mode or running on a non-x86-64 platform, we can't enable HSW or SKX.

// We also disable HSW/SKX on Android, even if it's Android on x64, since it's unlikely to benefit.

#if defined(SKCMS_PORTABLE) || !defined(__x86_64__) || defined(ANDROID) || defined(__ANDROID__)

    #undef SKCMS_FORCE_HSW

    #if !defined(SKCMS_DISABLE_HSW)

        #define SKCMS_DISABLE_HSW 1

    #endif

    #undef SKCMS_FORCE_SKX

    #if !defined(SKCMS_DISABLE_SKX)

        #define SKCMS_DISABLE_SKX 1

    #endif

#endif

// ~~~~ Shared ~~~~

typedef struct skcms_ICCTag {

    uint32_t       signature;

    uint32_t       type;

    uint32_t       size;

    const uint8_t* buf;

} skcms_ICCTag;

typedef struct skcms_ICCProfile skcms_ICCProfile;

typedef struct skcms_TransferFunction skcms_TransferFunction;

typedef union skcms_Curve skcms_Curve;

void skcms_GetTagByIndex    (const skcms_ICCProfile*, uint32_t idx, skcms_ICCTag*);

bool skcms_GetTagBySignature(const skcms_ICCProfile*, uint32_t sig, skcms_ICCTag*);

float skcms_MaxRoundtripError(const skcms_Curve* curve, const skcms_TransferFunction* inv_tf);

// 252 of a random shuffle of all possible bytes.

// 252 is evenly divisible by 3 and 4.  Only 192, 10, 241, and 43 are missing.

// Used for ICC profile equivalence testing.

extern const uint8_t skcms_252_random_bytes[252];

// ~~~~ Portable Math ~~~~

static inline float floorf_(float x) {

    float roundtrip = (float)((int)x);

    return roundtrip > x ? roundtrip - 1 : roundtrip;

}

skcms.cc:floorf_(float)

Line

Count

Source

129

1.28M

static inline float floorf_(float x) {

130

1.28M

    float roundtrip = (float)((int)x);

131

1.28M

    return roundtrip > x ? roundtrip - 1 : roundtrip;

132

1.28M

}

Unexecuted instantiation: skcms_TransformBaseline.cc:floorf_(float)

Unexecuted instantiation: skcms_TransformHsw.cc:floorf_(float)

Unexecuted instantiation: skcms_TransformSkx.cc:floorf_(float)

static inline float fabsf_(float x) { return x < 0 ? -x : x; }

skcms.cc:fabsf_(float)

Line

Count

Source

133

652k

static inline float fabsf_(float x) { return x < 0 ? -x : x; }

Unexecuted instantiation: skcms_TransformBaseline.cc:fabsf_(float)

Unexecuted instantiation: skcms_TransformHsw.cc:fabsf_(float)

Unexecuted instantiation: skcms_TransformSkx.cc:fabsf_(float)

float powf_(float, float);

#ifdef __cplusplus

}

#endif