--- original_noise_math.h +++ noise_math_optimized.h @@ -1490,73 +1490,87 @@ return f; } +/* Unsigned arithmetic preserves the Java long wraparound. */ +static inline __attribute__((const, always_inline)) uint64_t +noiseopt_biome_hash_step(uint64_t v, uint64_t salt) { + return v * (v * UINT64_C(6364136223846793005) + + UINT64_C(1442695040888963407)) + salt; +} + +/* This comparison idiom maps to hardware MINPD for non-NaN inputs. */ +static inline __attribute__((const, always_inline)) double +noiseopt_biome_min(double a, double b) { + return a > b ? b : a; +} + __attribute__((const)) uint32_t math_biome_access_sample(const int64_t theSeed, const int32_t x, const int32_t y, const int32_t z) { - const int32_t var0 = x - 2; - const int32_t var1 = y - 2; - const int32_t var2 = z - 2; - const int32_t var3 = var0 >> 2; - const int32_t var4 = var1 >> 2; - const int32_t var5 = var2 >> 2; - const double var6 = (double) (var0 & 3) / 4.0; - const double var7 = (double) (var1 & 3) / 4.0; - const double var8 = (double) (var2 & 3) / 4.0; - uint32_t var9 = 0; - double var10 = DBL_MAX; + /* Java integer subtraction wraps modulo 2^32. */ + const int32_t xx = (int32_t)((uint32_t)x - 2u); + const int32_t yy = (int32_t)((uint32_t)y - 2u); + const int32_t zz = (int32_t)((uint32_t)z - 2u); + + const int32_t cx = xx >> 2; + const int32_t cy = yy >> 2; + const int32_t cz = zz >> 2; + const double fx = (double)(xx & 3) * 0.25; + const double fy = (double)(yy & 3) * 0.25; + const double fz = (double)(zz & 3) * 0.25; + + const uint64_t seed = (uint64_t)theSeed; + const uint64_t x0 = (uint64_t)(int64_t)cx; + const uint64_t x1 = (uint64_t)(int64_t)(cx + 1); + const uint64_t y0 = (uint64_t)(int64_t)cy; + const uint64_t y1 = (uint64_t)(int64_t)(cy + 1); + const uint64_t z0 = (uint64_t)(int64_t)cz; + const uint64_t z1 = (uint64_t)(int64_t)(cz + 1); - double var28s[8]; + + double distance[8]; #pragma clang loop vectorize_width(NOISEOPT_DOUBLE_LANES) interleave_count(NOISEOPT_BIOME_INTERLEAVE) - for (uint32_t var11 = 0; var11 < 8; ++var11) { - uint32_t var12 = var11 & 4; - uint32_t var13 = var11 & 2; - uint32_t var14 = var11 & 1; - int64_t var15 = var12 ? var3 + 1 : var3; - int64_t var16 = var13 ? var4 + 1 : var4; - int64_t var17 = var14 ? var5 + 1 : var5; - double var18 = var12 ? var6 - 1.0 : var6; - double var19 = var13 ? var7 - 1.0 : var7; - double var20 = var14 ? var8 - 1.0 : var8; - int64_t var21 = theSeed * (theSeed * 6364136223846793005L + 1442695040888963407L) + var15; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + var16; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + var17; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + var15; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + var16; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + var17; - double var22 = (double) ((var21 >> 24) & 1023) / 1024.0; - double var23 = (var22 - 0.5) * 0.9; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + theSeed; - double var24 = (double) ((var21 >> 24) & 1023) / 1024.0; - double var25 = (var24 - 0.5) * 0.9; - var21 = var21 * (var21 * 6364136223846793005L + 1442695040888963407L) + theSeed; - double var26 = (double) ((var21 >> 24) & 1023) / 1024.0; - double var27 = (var26 - 0.5) * 0.9; - double var28 = math_square(var20 + var27) + math_square(var19 + var25) + math_square(var18 + var23); - __builtin_assume(!__builtin_isnan(var28) && !__builtin_signbit(var28)); - var28s[var11] = var28; + for (uint32_t i = 0; i < 8; ++i) { + const uint64_t ix = (i & 4) ? x1 : x0; + const uint64_t iy = (i & 2) ? y1 : y0; + const uint64_t iz = (i & 1) ? z1 : z0; + const double dx = (i & 4) ? fx - 1.0 : fx; + const double dy = (i & 2) ? fy - 1.0 : fy; + const double dz = (i & 1) ? fz - 1.0 : fz; + + uint64_t h = noiseopt_biome_hash_step(noiseopt_biome_hash_step(seed, ix), iy); + h = noiseopt_biome_hash_step(h, iz); + h = noiseopt_biome_hash_step(h, ix); + h = noiseopt_biome_hash_step(h, iy); + h = noiseopt_biome_hash_step(h, iz); + + const double rx = ((double)((h >> 24) & 1023u) / 1024.0 - 0.5) * 0.9; + h = noiseopt_biome_hash_step(h, seed); + const double ry = ((double)((h >> 24) & 1023u) / 1024.0 - 0.5) * 0.9; + h = noiseopt_biome_hash_step(h, seed); + const double rz = ((double)((h >> 24) & 1023u) / 1024.0 - 0.5) * 0.9; + + distance[i] = math_square(dz + rz) + math_square(dy + ry) + math_square(dx + rx); } - // use bmin or use >= produces different asm - double m04 = __builtin_fmin(var28s[0], var28s[4]); - double m15 = __builtin_fmin(var28s[1], var28s[5]); - double m26 = __builtin_fmin(var28s[2], var28s[6]); - double m37 = __builtin_fmin(var28s[3], var28s[7]); - double m0426 = __builtin_fmin(m04, m26); - double m1537 = __builtin_fmin(m15, m37); - double minimum = __builtin_fmin(m0426, m1537); - - uint8_t bitmap = (uint8_t)(var28s[0] == minimum) - | (uint8_t)((var28s[1] == minimum) << 1) - | (uint8_t)((var28s[2] == minimum) << 2) - | (uint8_t)((var28s[3] == minimum) << 3) - | (uint8_t)((var28s[4] == minimum) << 4) - | (uint8_t)((var28s[5] == minimum) << 5) - | (uint8_t)((var28s[6] == minimum) << 6) - | (uint8_t)((var28s[7] == minimum) << 7); - - return __builtin_ctz(bitmap); + const double m04 = noiseopt_biome_min(distance[0], distance[4]); + const double m15 = noiseopt_biome_min(distance[1], distance[5]); + const double m26 = noiseopt_biome_min(distance[2], distance[6]); + const double m37 = noiseopt_biome_min(distance[3], distance[7]); + const double m0426 = noiseopt_biome_min(m04, m26); + const double m1537 = noiseopt_biome_min(m15, m37); + const double minimum = noiseopt_biome_min(m0426, m1537); + + /* Distances are finite and >= +0.0, so at least one lane matches. */ + const unsigned mask = ((unsigned)(distance[0] == minimum) << 0) + | ((unsigned)(distance[1] == minimum) << 1) + | ((unsigned)(distance[2] == minimum) << 2) + | ((unsigned)(distance[3] == minimum) << 3) + | ((unsigned)(distance[4] == minimum) << 4) + | ((unsigned)(distance[5] == minimum) << 5) + | ((unsigned)(distance[6] == minimum) << 6) + | ((unsigned)(distance[7] == minimum) << 7); + return (uint32_t)__builtin_ctz(mask); } - typedef const struct aquifer_data { int32_t startX; int32_t startY;