/* Compile with: * * glsl_compiler --version 140 --dump-builder int64.glsl > builtin_int64.h * * Using version 1.40+ prevents built-in variables from being included. */ #version 400 #extension GL_ARB_gpu_shader_int64: require #extension GL_ARB_shading_language_420pack: require uvec2 umul64(uvec2 a, uvec2 b) { uvec2 result; umulExtended(a.x, b.x, result.y, result.x); result.y += a.x * b.y + a.y * b.x; return result; } ivec2 sign64(ivec2 a) { ivec2 result; result.y = a.y >> 31; result.x = result.y | int((a.x | a.y) != 0); return result; } uvec4 udivmod64(uvec2 n, uvec2 d) { uvec2 quot = uvec2(0U, 0U); int log2_denom = findMSB(d.y) + 32; /* If the upper 32 bits of denom are non-zero, it is impossible for shifts * greater than 32 bits to occur. If the upper 32 bits of the numerator * are zero, it is impossible for (denom << [63, 32]) <= numer unless * denom == 0. */ if (d.y == 0 && n.y >= d.x) { log2_denom = findMSB(d.x); /* Since the upper 32 bits of denom are zero, log2_denom <= 31 and we * don't have to compare log2_denom inside the loop as is done in the * general case (below). */ for (int i = 31; i >= 1; i--) { if (log2_denom <= 31 - i && (d.x << i) <= n.y) { n.y -= d.x << i; quot.y |= 1U << i; } } /* log2_denom is always <= 31, so manually peel the last loop * iteration. */ if (d.x <= n.y) { n.y -= d.x; quot.y |= 1U; } } uint64_t d64 = packUint2x32(d); uint64_t n64 = packUint2x32(n); for (int i = 31; i >= 1; i--) { if (log2_denom <= 63 - i && (d64 << i) <= n64) { n64 -= d64 << i; quot.x |= 1U << i; } } /* log2_denom is always <= 63, so manually peel the last loop * iteration. */ if (d64 <= n64) { n64 -= d64; quot.x |= 1U; } return uvec4(quot, unpackUint2x32(n64)); } uvec2 udiv64(uvec2 n, uvec2 d) { return udivmod64(n, d).xy; } ivec2 idiv64(ivec2 _n, ivec2 _d) { const bool negate = (_n.y < 0) != (_d.y < 0); uvec2 n = unpackUint2x32(uint64_t(abs(packInt2x32(_n)))); uvec2 d = unpackUint2x32(uint64_t(abs(packInt2x32(_d)))); uvec2 quot = udivmod64(n, d).xy; return negate ? unpackInt2x32(-int64_t(packUint2x32(quot))) : ivec2(quot); } uvec2 umod64(uvec2 n, uvec2 d) { return udivmod64(n, d).zw; } ivec2 imod64(ivec2 _n, ivec2 _d) { const bool negate = (_n.y < 0) != (_d.y < 0); uvec2 n = unpackUint2x32(uint64_t(abs(packInt2x32(_n)))); uvec2 d = unpackUint2x32(uint64_t(abs(packInt2x32(_d)))); uvec2 rem = udivmod64(n, d).zw; return negate ? unpackInt2x32(-int64_t(packUint2x32(rem))) : ivec2(rem); }