/* * Copyright © 2018 Red Hat Inc. * Copyright © 2015 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include #include "nir.h" #include "nir_builtin_builder.h" nir_ssa_def* nir_cross3(nir_builder *b, nir_ssa_def *x, nir_ssa_def *y) { unsigned yzx[3] = { 1, 2, 0 }; unsigned zxy[3] = { 2, 0, 1 }; return nir_fsub(b, nir_fmul(b, nir_swizzle(b, x, yzx, 3), nir_swizzle(b, y, zxy, 3)), nir_fmul(b, nir_swizzle(b, x, zxy, 3), nir_swizzle(b, y, yzx, 3))); } nir_ssa_def* nir_cross4(nir_builder *b, nir_ssa_def *x, nir_ssa_def *y) { nir_ssa_def *cross = nir_cross3(b, x, y); return nir_vec4(b, nir_channel(b, cross, 0), nir_channel(b, cross, 1), nir_channel(b, cross, 2), nir_imm_intN_t(b, 0, cross->bit_size)); } nir_ssa_def* nir_length(nir_builder *b, nir_ssa_def *vec) { nir_ssa_def *finf = nir_imm_floatN_t(b, INFINITY, vec->bit_size); nir_ssa_def *abs = nir_fabs(b, vec); if (vec->num_components == 1) return abs; nir_ssa_def *maxc = nir_fmax_abs_vec_comp(b, abs); abs = nir_fdiv(b, abs, maxc); nir_ssa_def *res = nir_fmul(b, nir_fsqrt(b, nir_fdot(b, abs, abs)), maxc); return nir_bcsel(b, nir_feq(b, maxc, finf), maxc, res); } nir_ssa_def* nir_fast_length(nir_builder *b, nir_ssa_def *vec) { switch (vec->num_components) { case 1: return nir_fsqrt(b, nir_fmul(b, vec, vec)); case 2: return nir_fsqrt(b, nir_fdot2(b, vec, vec)); case 3: return nir_fsqrt(b, nir_fdot3(b, vec, vec)); case 4: return nir_fsqrt(b, nir_fdot4(b, vec, vec)); default: unreachable("Invalid number of components"); } } nir_ssa_def* nir_nextafter(nir_builder *b, nir_ssa_def *x, nir_ssa_def *y) { nir_ssa_def *zero = nir_imm_intN_t(b, 0, x->bit_size); nir_ssa_def *one = nir_imm_intN_t(b, 1, x->bit_size); nir_ssa_def *condeq = nir_feq(b, x, y); nir_ssa_def *conddir = nir_flt(b, x, y); nir_ssa_def *condzero = nir_feq(b, x, zero); /* beware of: +/-0.0 - 1 == NaN */ nir_ssa_def *xn = nir_bcsel(b, condzero, nir_imm_intN_t(b, (1 << (x->bit_size - 1)) + 1, x->bit_size), nir_isub(b, x, one)); /* beware of -0.0 + 1 == -0x1p-149 */ nir_ssa_def *xp = nir_bcsel(b, condzero, one, nir_iadd(b, x, one)); /* nextafter can be implemented by just +/- 1 on the int value */ nir_ssa_def *res = nir_bcsel(b, nir_ixor(b, conddir, nir_flt(b, x, zero)), xp, xn); return nir_nan_check2(b, x, y, nir_bcsel(b, condeq, x, res)); } nir_ssa_def* nir_normalize(nir_builder *b, nir_ssa_def *vec) { if (vec->num_components == 1) return nir_fsign(b, vec); nir_ssa_def *f0 = nir_imm_floatN_t(b, 0.0, vec->bit_size); nir_ssa_def *f1 = nir_imm_floatN_t(b, 1.0, vec->bit_size); nir_ssa_def *finf = nir_imm_floatN_t(b, INFINITY, vec->bit_size); /* scale the input to increase precision */ nir_ssa_def *maxc = nir_fmax_abs_vec_comp(b, vec); nir_ssa_def *svec = nir_fdiv(b, vec, maxc); /* for inf */ nir_ssa_def *finfvec = nir_copysign(b, nir_bcsel(b, nir_feq(b, vec, finf), f1, f0), f1); nir_ssa_def *temp = nir_bcsel(b, nir_feq(b, maxc, finf), finfvec, svec); nir_ssa_def *res = nir_fmul(b, temp, nir_frsq(b, nir_fdot(b, temp, temp))); return nir_bcsel(b, nir_feq(b, maxc, f0), vec, res); } nir_ssa_def* nir_rotate(nir_builder *b, nir_ssa_def *x, nir_ssa_def *y) { nir_ssa_def *shift_mask = nir_imm_int(b, x->bit_size - 1); if (y->bit_size != 32) y = nir_u2u32(b, y); nir_ssa_def *lshift = nir_iand(b, y, shift_mask); nir_ssa_def *rshift = nir_isub(b, nir_imm_int(b, x->bit_size), lshift); nir_ssa_def *hi = nir_ishl(b, x, lshift); nir_ssa_def *lo = nir_ushr(b, x, rshift); return nir_ior(b, hi, lo); } nir_ssa_def* nir_smoothstep(nir_builder *b, nir_ssa_def *edge0, nir_ssa_def *edge1, nir_ssa_def *x) { nir_ssa_def *f2 = nir_imm_floatN_t(b, 2.0, x->bit_size); nir_ssa_def *f3 = nir_imm_floatN_t(b, 3.0, x->bit_size); /* t = clamp((x - edge0) / (edge1 - edge0), 0, 1) */ nir_ssa_def *t = nir_fsat(b, nir_fdiv(b, nir_fsub(b, x, edge0), nir_fsub(b, edge1, edge0))); /* result = t * t * (3 - 2 * t) */ return nir_fmul(b, t, nir_fmul(b, t, nir_fsub(b, f3, nir_fmul(b, f2, t)))); } nir_ssa_def* nir_upsample(nir_builder *b, nir_ssa_def *hi, nir_ssa_def *lo) { assert(lo->num_components == hi->num_components); assert(lo->bit_size == hi->bit_size); nir_ssa_def *res[NIR_MAX_VEC_COMPONENTS]; for (unsigned i = 0; i < lo->num_components; ++i) { nir_ssa_def *vec = nir_vec2(b, nir_channel(b, lo, i), nir_channel(b, hi, i)); res[i] = nir_pack_bits(b, vec, vec->bit_size * 2); } return nir_vec(b, res, lo->num_components); } /** * Compute xs[0] + xs[1] + xs[2] + ... using fadd. */ static nir_ssa_def * build_fsum(nir_builder *b, nir_ssa_def **xs, int terms) { nir_ssa_def *accum = xs[0]; for (int i = 1; i < terms; i++) accum = nir_fadd(b, accum, xs[i]); return accum; } nir_ssa_def * nir_atan(nir_builder *b, nir_ssa_def *y_over_x) { const uint32_t bit_size = y_over_x->bit_size; nir_ssa_def *abs_y_over_x = nir_fabs(b, y_over_x); nir_ssa_def *one = nir_imm_floatN_t(b, 1.0f, bit_size); /* * range-reduction, first step: * * / y_over_x if |y_over_x| <= 1.0; * x = < * \ 1.0 / y_over_x otherwise */ nir_ssa_def *x = nir_fdiv(b, nir_fmin(b, abs_y_over_x, one), nir_fmax(b, abs_y_over_x, one)); /* * approximate atan by evaluating polynomial: * * x * 0.9999793128310355 - x^3 * 0.3326756418091246 + * x^5 * 0.1938924977115610 - x^7 * 0.1173503194786851 + * x^9 * 0.0536813784310406 - x^11 * 0.0121323213173444 */ nir_ssa_def *x_2 = nir_fmul(b, x, x); nir_ssa_def *x_3 = nir_fmul(b, x_2, x); nir_ssa_def *x_5 = nir_fmul(b, x_3, x_2); nir_ssa_def *x_7 = nir_fmul(b, x_5, x_2); nir_ssa_def *x_9 = nir_fmul(b, x_7, x_2); nir_ssa_def *x_11 = nir_fmul(b, x_9, x_2); nir_ssa_def *polynomial_terms[] = { nir_fmul_imm(b, x, 0.9999793128310355f), nir_fmul_imm(b, x_3, -0.3326756418091246f), nir_fmul_imm(b, x_5, 0.1938924977115610f), nir_fmul_imm(b, x_7, -0.1173503194786851f), nir_fmul_imm(b, x_9, 0.0536813784310406f), nir_fmul_imm(b, x_11, -0.0121323213173444f), }; nir_ssa_def *tmp = build_fsum(b, polynomial_terms, ARRAY_SIZE(polynomial_terms)); /* range-reduction fixup */ tmp = nir_fadd(b, tmp, nir_fmul(b, nir_b2f(b, nir_flt(b, one, abs_y_over_x), bit_size), nir_fadd_imm(b, nir_fmul_imm(b, tmp, -2.0f), M_PI_2))); /* sign fixup */ return nir_fmul(b, tmp, nir_fsign(b, y_over_x)); } nir_ssa_def * nir_atan2(nir_builder *b, nir_ssa_def *y, nir_ssa_def *x) { assert(y->bit_size == x->bit_size); const uint32_t bit_size = x->bit_size; nir_ssa_def *zero = nir_imm_floatN_t(b, 0, bit_size); nir_ssa_def *one = nir_imm_floatN_t(b, 1, bit_size); /* If we're on the left half-plane rotate the coordinates π/2 clock-wise * for the y=0 discontinuity to end up aligned with the vertical * discontinuity of atan(s/t) along t=0. This also makes sure that we * don't attempt to divide by zero along the vertical line, which may give * unspecified results on non-GLSL 4.1-capable hardware. */ nir_ssa_def *flip = nir_fge(b, zero, x); nir_ssa_def *s = nir_bcsel(b, flip, nir_fabs(b, x), y); nir_ssa_def *t = nir_bcsel(b, flip, y, nir_fabs(b, x)); /* If the magnitude of the denominator exceeds some huge value, scale down * the arguments in order to prevent the reciprocal operation from flushing * its result to zero, which would cause precision problems, and for s * infinite would cause us to return a NaN instead of the correct finite * value. * * If fmin and fmax are respectively the smallest and largest positive * normalized floating point values representable by the implementation, * the constants below should be in agreement with: * * huge <= 1 / fmin * scale <= 1 / fmin / fmax (for |t| >= huge) * * In addition scale should be a negative power of two in order to avoid * loss of precision. The values chosen below should work for most usual * floating point representations with at least the dynamic range of ATI's * 24-bit representation. */ const double huge_val = bit_size >= 32 ? 1e18 : 16384; nir_ssa_def *huge = nir_imm_floatN_t(b, huge_val, bit_size); nir_ssa_def *scale = nir_bcsel(b, nir_fge(b, nir_fabs(b, t), huge), nir_imm_floatN_t(b, 0.25, bit_size), one); nir_ssa_def *rcp_scaled_t = nir_frcp(b, nir_fmul(b, t, scale)); nir_ssa_def *s_over_t = nir_fmul(b, nir_fmul(b, s, scale), rcp_scaled_t); /* For |x| = |y| assume tan = 1 even if infinite (i.e. pretend momentarily * that ∞/∞ = 1) in order to comply with the rather artificial rules * inherited from IEEE 754-2008, namely: * * "atan2(±∞, −∞) is ±3π/4 * atan2(±∞, +∞) is ±π/4" * * Note that this is inconsistent with the rules for the neighborhood of * zero that are based on iterated limits: * * "atan2(±0, −0) is ±π * atan2(±0, +0) is ±0" * * but GLSL specifically allows implementations to deviate from IEEE rules * at (0,0), so we take that license (i.e. pretend that 0/0 = 1 here as * well). */ nir_ssa_def *tan = nir_bcsel(b, nir_feq(b, nir_fabs(b, x), nir_fabs(b, y)), one, nir_fabs(b, s_over_t)); /* Calculate the arctangent and fix up the result if we had flipped the * coordinate system. */ nir_ssa_def *arc = nir_fadd(b, nir_fmul_imm(b, nir_b2f(b, flip, bit_size), M_PI_2), nir_atan(b, tan)); /* Rather convoluted calculation of the sign of the result. When x < 0 we * cannot use fsign because we need to be able to distinguish between * negative and positive zero. We don't use bitwise arithmetic tricks for * consistency with the GLSL front-end. When x >= 0 rcp_scaled_t will * always be non-negative so this won't be able to distinguish between * negative and positive zero, but we don't care because atan2 is * continuous along the whole positive y = 0 half-line, so it won't affect * the result significantly. */ return nir_bcsel(b, nir_flt(b, nir_fmin(b, y, rcp_scaled_t), zero), nir_fneg(b, arc), arc); }