reference/shaders-msl/comp/copy-array-of-arrays.comp

#pragma clang diagnostic ignored "-Wmissing-prototypes"

#include <metal_stdlib>
#include <simd/simd.h>

using namespace metal;

struct BUF
{
    int a;
    float b;
    float c;
};

constant float _16[2] = { 1.0, 2.0 };
constant float _19[2] = { 3.0, 4.0 };
constant float _20[2][2] = { { 1.0, 2.0 }, { 3.0, 4.0 } };
constant float _21[2][2][2] = { { { 1.0, 2.0 }, { 3.0, 4.0 } }, { { 1.0, 2.0 }, { 3.0, 4.0 } } };

// Implementation of an array copy function to cover GLSL's ability to copy an array via assignment.
template<typename T, uint N>
void spvArrayCopyFromStack1(thread T (&dst)[N], thread const T (&src)[N])
{
    for (uint i = 0; i < N; dst[i] = src[i], i++);
}

template<typename T, uint N>
void spvArrayCopyFromConstant1(thread T (&dst)[N], constant T (&src)[N])
{
    for (uint i = 0; i < N; dst[i] = src[i], i++);
}

template<typename T, uint A, uint B>
void spvArrayCopyFromStack2(thread T (&dst)[A][B], thread const T (&src)[A][B])
{
    for (uint i = 0; i < A; i++)
    {
        spvArrayCopyFromStack1(dst[i], src[i]);
    }
}

template<typename T, uint A, uint B>
void spvArrayCopyFromConstant2(thread T (&dst)[A][B], constant T (&src)[A][B])
{
    for (uint i = 0; i < A; i++)
    {
        spvArrayCopyFromConstant1(dst[i], src[i]);
    }
}

template<typename T, uint A, uint B, uint C>
void spvArrayCopyFromStack3(thread T (&dst)[A][B][C], thread const T (&src)[A][B][C])
{
    for (uint i = 0; i < A; i++)
    {
        spvArrayCopyFromStack2(dst[i], src[i]);
    }
}

template<typename T, uint A, uint B, uint C>
void spvArrayCopyFromConstant3(thread T (&dst)[A][B][C], constant T (&src)[A][B][C])
{
    for (uint i = 0; i < A; i++)
    {
        spvArrayCopyFromConstant2(dst[i], src[i]);
    }
}

kernel void main0(device BUF& o [[buffer(0)]])
{
    float c[2][2][2];
    spvArrayCopyFromConstant3(c, _21);
    o.a = int(c[1][1][1]);
    float _43[2] = { o.b, o.c };
    float _48[2] = { o.b, o.b };
    float _49[2][2];
    spvArrayCopyFromStack1(_49[0], _43);
    spvArrayCopyFromStack1(_49[1], _48);
    float _54[2] = { o.c, o.c };
    float _59[2] = { o.c, o.b };
    float _60[2][2];
    spvArrayCopyFromStack1(_60[0], _54);
    spvArrayCopyFromStack1(_60[1], _59);
    float _61[2][2][2];
    spvArrayCopyFromStack2(_61[0], _49);
    spvArrayCopyFromStack2(_61[1], _60);
    float d[2][2][2];
    spvArrayCopyFromStack3(d, _61);
    float e[2][2][2];
    spvArrayCopyFromStack3(e, d);
    o.b = e[1][0][1];
}