/* * 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. * * Authors: * Jason Ekstrand (jason@jlekstrand.net) * */ #include #include "nir/nir_builtin_builder.h" #include "vtn_private.h" #include "GLSL.std.450.h" #define M_PIf ((float) M_PI) #define M_PI_2f ((float) M_PI_2) #define M_PI_4f ((float) M_PI_4) static nir_ssa_def * build_mat2_det(nir_builder *b, nir_ssa_def *col[2]) { unsigned swiz[2] = {1, 0 }; nir_ssa_def *p = nir_fmul(b, col[0], nir_swizzle(b, col[1], swiz, 2, true)); return nir_fsub(b, nir_channel(b, p, 0), nir_channel(b, p, 1)); } static nir_ssa_def * build_mat3_det(nir_builder *b, nir_ssa_def *col[3]) { unsigned yzx[3] = {1, 2, 0 }; unsigned zxy[3] = {2, 0, 1 }; nir_ssa_def *prod0 = nir_fmul(b, col[0], nir_fmul(b, nir_swizzle(b, col[1], yzx, 3, true), nir_swizzle(b, col[2], zxy, 3, true))); nir_ssa_def *prod1 = nir_fmul(b, col[0], nir_fmul(b, nir_swizzle(b, col[1], zxy, 3, true), nir_swizzle(b, col[2], yzx, 3, true))); nir_ssa_def *diff = nir_fsub(b, prod0, prod1); return nir_fadd(b, nir_channel(b, diff, 0), nir_fadd(b, nir_channel(b, diff, 1), nir_channel(b, diff, 2))); } static nir_ssa_def * build_mat4_det(nir_builder *b, nir_ssa_def **col) { nir_ssa_def *subdet[4]; for (unsigned i = 0; i < 4; i++) { unsigned swiz[3]; for (unsigned j = 0; j < 3; j++) swiz[j] = j + (j >= i); nir_ssa_def *subcol[3]; subcol[0] = nir_swizzle(b, col[1], swiz, 3, true); subcol[1] = nir_swizzle(b, col[2], swiz, 3, true); subcol[2] = nir_swizzle(b, col[3], swiz, 3, true); subdet[i] = build_mat3_det(b, subcol); } nir_ssa_def *prod = nir_fmul(b, col[0], nir_vec(b, subdet, 4)); return nir_fadd(b, nir_fsub(b, nir_channel(b, prod, 0), nir_channel(b, prod, 1)), nir_fsub(b, nir_channel(b, prod, 2), nir_channel(b, prod, 3))); } static nir_ssa_def * build_mat_det(struct vtn_builder *b, struct vtn_ssa_value *src) { unsigned size = glsl_get_vector_elements(src->type); nir_ssa_def *cols[4]; for (unsigned i = 0; i < size; i++) cols[i] = src->elems[i]->def; switch(size) { case 2: return build_mat2_det(&b->nb, cols); case 3: return build_mat3_det(&b->nb, cols); case 4: return build_mat4_det(&b->nb, cols); default: vtn_fail("Invalid matrix size"); } } /* Computes the determinate of the submatrix given by taking src and * removing the specified row and column. */ static nir_ssa_def * build_mat_subdet(struct nir_builder *b, struct vtn_ssa_value *src, unsigned size, unsigned row, unsigned col) { assert(row < size && col < size); if (size == 2) { return nir_channel(b, src->elems[1 - col]->def, 1 - row); } else { /* Swizzle to get all but the specified row */ unsigned swiz[3]; for (unsigned j = 0; j < 3; j++) swiz[j] = j + (j >= row); /* Grab all but the specified column */ nir_ssa_def *subcol[3]; for (unsigned j = 0; j < size; j++) { if (j != col) { subcol[j - (j > col)] = nir_swizzle(b, src->elems[j]->def, swiz, size - 1, true); } } if (size == 3) { return build_mat2_det(b, subcol); } else { assert(size == 4); return build_mat3_det(b, subcol); } } } static struct vtn_ssa_value * matrix_inverse(struct vtn_builder *b, struct vtn_ssa_value *src) { nir_ssa_def *adj_col[4]; unsigned size = glsl_get_vector_elements(src->type); /* Build up an adjugate matrix */ for (unsigned c = 0; c < size; c++) { nir_ssa_def *elem[4]; for (unsigned r = 0; r < size; r++) { elem[r] = build_mat_subdet(&b->nb, src, size, c, r); if ((r + c) % 2) elem[r] = nir_fneg(&b->nb, elem[r]); } adj_col[c] = nir_vec(&b->nb, elem, size); } nir_ssa_def *det_inv = nir_frcp(&b->nb, build_mat_det(b, src)); struct vtn_ssa_value *val = vtn_create_ssa_value(b, src->type); for (unsigned i = 0; i < size; i++) val->elems[i]->def = nir_fmul(&b->nb, adj_col[i], det_inv); return val; } /** * Return e^x. */ static nir_ssa_def * build_exp(nir_builder *b, nir_ssa_def *x) { return nir_fexp2(b, nir_fmul_imm(b, x, M_LOG2E)); } /** * Return ln(x) - the natural logarithm of x. */ static nir_ssa_def * build_log(nir_builder *b, nir_ssa_def *x) { return nir_fmul_imm(b, nir_flog2(b, x), 1.0 / M_LOG2E); } /** * Approximate asin(x) by the formula: * asin~(x) = sign(x) * (pi/2 - sqrt(1 - |x|) * (pi/2 + |x|(pi/4 - 1 + |x|(p0 + |x|p1)))) * * which is correct to first order at x=0 and x=±1 regardless of the p * coefficients but can be made second-order correct at both ends by selecting * the fit coefficients appropriately. Different p coefficients can be used * in the asin and acos implementation to minimize some relative error metric * in each case. */ static nir_ssa_def * build_asin(nir_builder *b, nir_ssa_def *x, float p0, float p1) { if (x->bit_size == 16) { /* The polynomial approximation isn't precise enough to meet half-float * precision requirements. Alternatively, we could implement this using * the formula: * * asin(x) = atan2(x, sqrt(1 - x*x)) * * But that is very expensive, so instead we just do the polynomial * approximation in 32-bit math and then we convert the result back to * 16-bit. */ return nir_f2f16(b, build_asin(b, nir_f2f32(b, x), p0, p1)); } nir_ssa_def *one = nir_imm_floatN_t(b, 1.0f, x->bit_size); nir_ssa_def *abs_x = nir_fabs(b, x); nir_ssa_def *p0_plus_xp1 = nir_fadd_imm(b, nir_fmul_imm(b, abs_x, p1), p0); nir_ssa_def *expr_tail = nir_fadd_imm(b, nir_fmul(b, abs_x, nir_fadd_imm(b, nir_fmul(b, abs_x, p0_plus_xp1), M_PI_4f - 1.0f)), M_PI_2f); return nir_fmul(b, nir_fsign(b, x), nir_fsub(b, nir_imm_floatN_t(b, M_PI_2f, x->bit_size), nir_fmul(b, nir_fsqrt(b, nir_fsub(b, one, abs_x)), expr_tail))); } /** * 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; } static nir_ssa_def * build_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_2f))); /* sign fixup */ return nir_fmul(b, tmp, nir_fsign(b, y_over_x)); } static nir_ssa_def * build_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_2f), build_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); } static nir_ssa_def * build_frexp16(nir_builder *b, nir_ssa_def *x, nir_ssa_def **exponent) { assert(x->bit_size == 16); nir_ssa_def *abs_x = nir_fabs(b, x); nir_ssa_def *zero = nir_imm_floatN_t(b, 0, 16); /* Half-precision floating-point values are stored as * 1 sign bit; * 5 exponent bits; * 10 mantissa bits. * * An exponent shift of 10 will shift the mantissa out, leaving only the * exponent and sign bit (which itself may be zero, if the absolute value * was taken before the bitcast and shift). */ nir_ssa_def *exponent_shift = nir_imm_int(b, 10); nir_ssa_def *exponent_bias = nir_imm_intN_t(b, -14, 16); nir_ssa_def *sign_mantissa_mask = nir_imm_intN_t(b, 0x83ffu, 16); /* Exponent of floating-point values in the range [0.5, 1.0). */ nir_ssa_def *exponent_value = nir_imm_intN_t(b, 0x3800u, 16); nir_ssa_def *is_not_zero = nir_fne(b, abs_x, zero); /* Significand return must be of the same type as the input, but the * exponent must be a 32-bit integer. */ *exponent = nir_i2i32(b, nir_iadd(b, nir_ushr(b, abs_x, exponent_shift), nir_bcsel(b, is_not_zero, exponent_bias, zero))); return nir_ior(b, nir_iand(b, x, sign_mantissa_mask), nir_bcsel(b, is_not_zero, exponent_value, zero)); } static nir_ssa_def * build_frexp32(nir_builder *b, nir_ssa_def *x, nir_ssa_def **exponent) { nir_ssa_def *abs_x = nir_fabs(b, x); nir_ssa_def *zero = nir_imm_float(b, 0.0f); /* Single-precision floating-point values are stored as * 1 sign bit; * 8 exponent bits; * 23 mantissa bits. * * An exponent shift of 23 will shift the mantissa out, leaving only the * exponent and sign bit (which itself may be zero, if the absolute value * was taken before the bitcast and shift. */ nir_ssa_def *exponent_shift = nir_imm_int(b, 23); nir_ssa_def *exponent_bias = nir_imm_int(b, -126); nir_ssa_def *sign_mantissa_mask = nir_imm_int(b, 0x807fffffu); /* Exponent of floating-point values in the range [0.5, 1.0). */ nir_ssa_def *exponent_value = nir_imm_int(b, 0x3f000000u); nir_ssa_def *is_not_zero = nir_fne(b, abs_x, zero); *exponent = nir_iadd(b, nir_ushr(b, abs_x, exponent_shift), nir_bcsel(b, is_not_zero, exponent_bias, zero)); return nir_ior(b, nir_iand(b, x, sign_mantissa_mask), nir_bcsel(b, is_not_zero, exponent_value, zero)); } static nir_ssa_def * build_frexp64(nir_builder *b, nir_ssa_def *x, nir_ssa_def **exponent) { nir_ssa_def *abs_x = nir_fabs(b, x); nir_ssa_def *zero = nir_imm_double(b, 0.0); nir_ssa_def *zero32 = nir_imm_float(b, 0.0f); /* Double-precision floating-point values are stored as * 1 sign bit; * 11 exponent bits; * 52 mantissa bits. * * We only need to deal with the exponent so first we extract the upper 32 * bits using nir_unpack_64_2x32_split_y. */ nir_ssa_def *upper_x = nir_unpack_64_2x32_split_y(b, x); nir_ssa_def *abs_upper_x = nir_unpack_64_2x32_split_y(b, abs_x); /* An exponent shift of 20 will shift the remaining mantissa bits out, * leaving only the exponent and sign bit (which itself may be zero, if the * absolute value was taken before the bitcast and shift. */ nir_ssa_def *exponent_shift = nir_imm_int(b, 20); nir_ssa_def *exponent_bias = nir_imm_int(b, -1022); nir_ssa_def *sign_mantissa_mask = nir_imm_int(b, 0x800fffffu); /* Exponent of floating-point values in the range [0.5, 1.0). */ nir_ssa_def *exponent_value = nir_imm_int(b, 0x3fe00000u); nir_ssa_def *is_not_zero = nir_fne(b, abs_x, zero); *exponent = nir_iadd(b, nir_ushr(b, abs_upper_x, exponent_shift), nir_bcsel(b, is_not_zero, exponent_bias, zero32)); nir_ssa_def *new_upper = nir_ior(b, nir_iand(b, upper_x, sign_mantissa_mask), nir_bcsel(b, is_not_zero, exponent_value, zero32)); nir_ssa_def *lower_x = nir_unpack_64_2x32_split_x(b, x); return nir_pack_64_2x32_split(b, lower_x, new_upper); } static nir_op vtn_nir_alu_op_for_spirv_glsl_opcode(struct vtn_builder *b, enum GLSLstd450 opcode) { switch (opcode) { case GLSLstd450Round: return nir_op_fround_even; case GLSLstd450RoundEven: return nir_op_fround_even; case GLSLstd450Trunc: return nir_op_ftrunc; case GLSLstd450FAbs: return nir_op_fabs; case GLSLstd450SAbs: return nir_op_iabs; case GLSLstd450FSign: return nir_op_fsign; case GLSLstd450SSign: return nir_op_isign; case GLSLstd450Floor: return nir_op_ffloor; case GLSLstd450Ceil: return nir_op_fceil; case GLSLstd450Fract: return nir_op_ffract; case GLSLstd450Sin: return nir_op_fsin; case GLSLstd450Cos: return nir_op_fcos; case GLSLstd450Pow: return nir_op_fpow; case GLSLstd450Exp2: return nir_op_fexp2; case GLSLstd450Log2: return nir_op_flog2; case GLSLstd450Sqrt: return nir_op_fsqrt; case GLSLstd450InverseSqrt: return nir_op_frsq; case GLSLstd450NMin: return nir_op_fmin; case GLSLstd450FMin: return nir_op_fmin; case GLSLstd450UMin: return nir_op_umin; case GLSLstd450SMin: return nir_op_imin; case GLSLstd450NMax: return nir_op_fmax; case GLSLstd450FMax: return nir_op_fmax; case GLSLstd450UMax: return nir_op_umax; case GLSLstd450SMax: return nir_op_imax; case GLSLstd450FMix: return nir_op_flrp; case GLSLstd450Fma: return nir_op_ffma; case GLSLstd450Ldexp: return nir_op_ldexp; case GLSLstd450FindILsb: return nir_op_find_lsb; case GLSLstd450FindSMsb: return nir_op_ifind_msb; case GLSLstd450FindUMsb: return nir_op_ufind_msb; /* Packing/Unpacking functions */ case GLSLstd450PackSnorm4x8: return nir_op_pack_snorm_4x8; case GLSLstd450PackUnorm4x8: return nir_op_pack_unorm_4x8; case GLSLstd450PackSnorm2x16: return nir_op_pack_snorm_2x16; case GLSLstd450PackUnorm2x16: return nir_op_pack_unorm_2x16; case GLSLstd450PackHalf2x16: return nir_op_pack_half_2x16; case GLSLstd450PackDouble2x32: return nir_op_pack_64_2x32; case GLSLstd450UnpackSnorm4x8: return nir_op_unpack_snorm_4x8; case GLSLstd450UnpackUnorm4x8: return nir_op_unpack_unorm_4x8; case GLSLstd450UnpackSnorm2x16: return nir_op_unpack_snorm_2x16; case GLSLstd450UnpackUnorm2x16: return nir_op_unpack_unorm_2x16; case GLSLstd450UnpackHalf2x16: return nir_op_unpack_half_2x16; case GLSLstd450UnpackDouble2x32: return nir_op_unpack_64_2x32; default: vtn_fail("No NIR equivalent"); } } #define NIR_IMM_FP(n, v) (nir_imm_floatN_t(n, v, src[0]->bit_size)) static void handle_glsl450_alu(struct vtn_builder *b, enum GLSLstd450 entrypoint, const uint32_t *w, unsigned count) { struct nir_builder *nb = &b->nb; const struct glsl_type *dest_type = vtn_value(b, w[1], vtn_value_type_type)->type->type; struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); val->ssa = vtn_create_ssa_value(b, dest_type); /* Collect the various SSA sources */ unsigned num_inputs = count - 5; nir_ssa_def *src[3] = { NULL, }; for (unsigned i = 0; i < num_inputs; i++) { /* These are handled specially below */ if (vtn_untyped_value(b, w[i + 5])->value_type == vtn_value_type_pointer) continue; src[i] = vtn_ssa_value(b, w[i + 5])->def; } switch (entrypoint) { case GLSLstd450Radians: val->ssa->def = nir_radians(nb, src[0]); return; case GLSLstd450Degrees: val->ssa->def = nir_degrees(nb, src[0]); return; case GLSLstd450Tan: val->ssa->def = nir_fdiv(nb, nir_fsin(nb, src[0]), nir_fcos(nb, src[0])); return; case GLSLstd450Modf: { nir_ssa_def *sign = nir_fsign(nb, src[0]); nir_ssa_def *abs = nir_fabs(nb, src[0]); val->ssa->def = nir_fmul(nb, sign, nir_ffract(nb, abs)); nir_store_deref(nb, vtn_nir_deref(b, w[6]), nir_fmul(nb, sign, nir_ffloor(nb, abs)), 0xf); return; } case GLSLstd450ModfStruct: { nir_ssa_def *sign = nir_fsign(nb, src[0]); nir_ssa_def *abs = nir_fabs(nb, src[0]); vtn_assert(glsl_type_is_struct(val->ssa->type)); val->ssa->elems[0]->def = nir_fmul(nb, sign, nir_ffract(nb, abs)); val->ssa->elems[1]->def = nir_fmul(nb, sign, nir_ffloor(nb, abs)); return; } case GLSLstd450Step: val->ssa->def = nir_sge(nb, src[1], src[0]); return; case GLSLstd450Length: val->ssa->def = nir_fast_length(nb, src[0]); return; case GLSLstd450Distance: val->ssa->def = nir_fast_distance(nb, src[0], src[1]); return; case GLSLstd450Normalize: val->ssa->def = nir_fast_normalize(nb, src[0]); return; case GLSLstd450Exp: val->ssa->def = build_exp(nb, src[0]); return; case GLSLstd450Log: val->ssa->def = build_log(nb, src[0]); return; case GLSLstd450FClamp: case GLSLstd450NClamp: val->ssa->def = nir_fclamp(nb, src[0], src[1], src[2]); return; case GLSLstd450UClamp: val->ssa->def = nir_uclamp(nb, src[0], src[1], src[2]); return; case GLSLstd450SClamp: val->ssa->def = nir_iclamp(nb, src[0], src[1], src[2]); return; case GLSLstd450Cross: { val->ssa->def = nir_cross(nb, src[0], src[1]); return; } case GLSLstd450SmoothStep: { val->ssa->def = nir_smoothstep(nb, src[0], src[1], src[2]); return; } case GLSLstd450FaceForward: val->ssa->def = nir_bcsel(nb, nir_flt(nb, nir_fdot(nb, src[2], src[1]), NIR_IMM_FP(nb, 0.0)), src[0], nir_fneg(nb, src[0])); return; case GLSLstd450Reflect: /* I - 2 * dot(N, I) * N */ val->ssa->def = nir_fsub(nb, src[0], nir_fmul(nb, NIR_IMM_FP(nb, 2.0), nir_fmul(nb, nir_fdot(nb, src[0], src[1]), src[1]))); return; case GLSLstd450Refract: { nir_ssa_def *I = src[0]; nir_ssa_def *N = src[1]; nir_ssa_def *eta = src[2]; nir_ssa_def *n_dot_i = nir_fdot(nb, N, I); nir_ssa_def *one = NIR_IMM_FP(nb, 1.0); nir_ssa_def *zero = NIR_IMM_FP(nb, 0.0); /* According to the SPIR-V and GLSL specs, eta is always a float * regardless of the type of the other operands. However in practice it * seems that if you try to pass it a float then glslang will just * promote it to a double and generate invalid SPIR-V. In order to * support a hypothetical fixed version of glslang we’ll promote eta to * double if the other operands are double also. */ if (I->bit_size != eta->bit_size) { nir_op conversion_op = nir_type_conversion_op(nir_type_float | eta->bit_size, nir_type_float | I->bit_size, nir_rounding_mode_undef); eta = nir_build_alu(nb, conversion_op, eta, NULL, NULL, NULL); } /* k = 1.0 - eta * eta * (1.0 - dot(N, I) * dot(N, I)) */ nir_ssa_def *k = nir_fsub(nb, one, nir_fmul(nb, eta, nir_fmul(nb, eta, nir_fsub(nb, one, nir_fmul(nb, n_dot_i, n_dot_i))))); nir_ssa_def *result = nir_fsub(nb, nir_fmul(nb, eta, I), nir_fmul(nb, nir_fadd(nb, nir_fmul(nb, eta, n_dot_i), nir_fsqrt(nb, k)), N)); /* XXX: bcsel, or if statement? */ val->ssa->def = nir_bcsel(nb, nir_flt(nb, k, zero), zero, result); return; } case GLSLstd450Sinh: /* 0.5 * (e^x - e^(-x)) */ val->ssa->def = nir_fmul_imm(nb, nir_fsub(nb, build_exp(nb, src[0]), build_exp(nb, nir_fneg(nb, src[0]))), 0.5f); return; case GLSLstd450Cosh: /* 0.5 * (e^x + e^(-x)) */ val->ssa->def = nir_fmul_imm(nb, nir_fadd(nb, build_exp(nb, src[0]), build_exp(nb, nir_fneg(nb, src[0]))), 0.5f); return; case GLSLstd450Tanh: { /* tanh(x) := (0.5 * (e^x - e^(-x))) / (0.5 * (e^x + e^(-x))) * * With a little algebra this reduces to (e^2x - 1) / (e^2x + 1) * * We clamp x to (-inf, +10] to avoid precision problems. When x > 10, * e^2x is so much larger than 1.0 that 1.0 gets flushed to zero in the * computation e^2x +/- 1 so it can be ignored. * * For 16-bit precision we clamp x to (-inf, +4.2] since the maximum * representable number is only 65,504 and e^(2*6) exceeds that. Also, * if x > 4.2, tanh(x) will return 1.0 in fp16. */ const uint32_t bit_size = src[0]->bit_size; const double clamped_x = bit_size > 16 ? 10.0 : 4.2; nir_ssa_def *x = nir_fmin(nb, src[0], nir_imm_floatN_t(nb, clamped_x, bit_size)); nir_ssa_def *exp2x = build_exp(nb, nir_fmul_imm(nb, x, 2.0)); val->ssa->def = nir_fdiv(nb, nir_fadd_imm(nb, exp2x, -1.0), nir_fadd_imm(nb, exp2x, 1.0)); return; } case GLSLstd450Asinh: val->ssa->def = nir_fmul(nb, nir_fsign(nb, src[0]), build_log(nb, nir_fadd(nb, nir_fabs(nb, src[0]), nir_fsqrt(nb, nir_fadd_imm(nb, nir_fmul(nb, src[0], src[0]), 1.0f))))); return; case GLSLstd450Acosh: val->ssa->def = build_log(nb, nir_fadd(nb, src[0], nir_fsqrt(nb, nir_fadd_imm(nb, nir_fmul(nb, src[0], src[0]), -1.0f)))); return; case GLSLstd450Atanh: { nir_ssa_def *one = nir_imm_floatN_t(nb, 1.0, src[0]->bit_size); val->ssa->def = nir_fmul_imm(nb, build_log(nb, nir_fdiv(nb, nir_fadd(nb, src[0], one), nir_fsub(nb, one, src[0]))), 0.5f); return; } case GLSLstd450Asin: val->ssa->def = build_asin(nb, src[0], 0.086566724, -0.03102955); return; case GLSLstd450Acos: val->ssa->def = nir_fsub(nb, nir_imm_floatN_t(nb, M_PI_2f, src[0]->bit_size), build_asin(nb, src[0], 0.08132463, -0.02363318)); return; case GLSLstd450Atan: val->ssa->def = build_atan(nb, src[0]); return; case GLSLstd450Atan2: val->ssa->def = build_atan2(nb, src[0], src[1]); return; case GLSLstd450Frexp: { nir_ssa_def *exponent; if (src[0]->bit_size == 64) val->ssa->def = build_frexp64(nb, src[0], &exponent); else if (src[0]->bit_size == 32) val->ssa->def = build_frexp32(nb, src[0], &exponent); else val->ssa->def = build_frexp16(nb, src[0], &exponent); nir_store_deref(nb, vtn_nir_deref(b, w[6]), exponent, 0xf); return; } case GLSLstd450FrexpStruct: { vtn_assert(glsl_type_is_struct(val->ssa->type)); if (src[0]->bit_size == 64) val->ssa->elems[0]->def = build_frexp64(nb, src[0], &val->ssa->elems[1]->def); else if (src[0]->bit_size == 32) val->ssa->elems[0]->def = build_frexp32(nb, src[0], &val->ssa->elems[1]->def); else val->ssa->elems[0]->def = build_frexp16(nb, src[0], &val->ssa->elems[1]->def); return; } default: val->ssa->def = nir_build_alu(&b->nb, vtn_nir_alu_op_for_spirv_glsl_opcode(b, entrypoint), src[0], src[1], src[2], NULL); return; } } static void handle_glsl450_interpolation(struct vtn_builder *b, enum GLSLstd450 opcode, const uint32_t *w, unsigned count) { const struct glsl_type *dest_type = vtn_value(b, w[1], vtn_value_type_type)->type->type; struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); val->ssa = vtn_create_ssa_value(b, dest_type); nir_intrinsic_op op; switch (opcode) { case GLSLstd450InterpolateAtCentroid: op = nir_intrinsic_interp_deref_at_centroid; break; case GLSLstd450InterpolateAtSample: op = nir_intrinsic_interp_deref_at_sample; break; case GLSLstd450InterpolateAtOffset: op = nir_intrinsic_interp_deref_at_offset; break; default: vtn_fail("Invalid opcode"); } nir_intrinsic_instr *intrin = nir_intrinsic_instr_create(b->nb.shader, op); struct vtn_pointer *ptr = vtn_value(b, w[5], vtn_value_type_pointer)->pointer; nir_deref_instr *deref = vtn_pointer_to_deref(b, ptr); /* If the value we are interpolating has an index into a vector then * interpolate the vector and index the result of that instead. This is * necessary because the index will get generated as a series of nir_bcsel * instructions so it would no longer be an input variable. */ const bool vec_array_deref = deref->deref_type == nir_deref_type_array && glsl_type_is_vector(nir_deref_instr_parent(deref)->type); nir_deref_instr *vec_deref = NULL; if (vec_array_deref) { vec_deref = deref; deref = nir_deref_instr_parent(deref); } intrin->src[0] = nir_src_for_ssa(&deref->dest.ssa); switch (opcode) { case GLSLstd450InterpolateAtCentroid: break; case GLSLstd450InterpolateAtSample: case GLSLstd450InterpolateAtOffset: intrin->src[1] = nir_src_for_ssa(vtn_ssa_value(b, w[6])->def); break; default: vtn_fail("Invalid opcode"); } intrin->num_components = glsl_get_vector_elements(deref->type); nir_ssa_dest_init(&intrin->instr, &intrin->dest, glsl_get_vector_elements(deref->type), glsl_get_bit_size(deref->type), NULL); nir_builder_instr_insert(&b->nb, &intrin->instr); if (vec_array_deref) { assert(vec_deref); if (nir_src_is_const(vec_deref->arr.index)) { val->ssa->def = vtn_vector_extract(b, &intrin->dest.ssa, nir_src_as_uint(vec_deref->arr.index)); } else { val->ssa->def = vtn_vector_extract_dynamic(b, &intrin->dest.ssa, vec_deref->arr.index.ssa); } } else { val->ssa->def = &intrin->dest.ssa; } } bool vtn_handle_glsl450_instruction(struct vtn_builder *b, SpvOp ext_opcode, const uint32_t *w, unsigned count) { switch ((enum GLSLstd450)ext_opcode) { case GLSLstd450Determinant: { struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); val->ssa = rzalloc(b, struct vtn_ssa_value); val->ssa->type = vtn_value(b, w[1], vtn_value_type_type)->type->type; val->ssa->def = build_mat_det(b, vtn_ssa_value(b, w[5])); break; } case GLSLstd450MatrixInverse: { struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa); val->ssa = matrix_inverse(b, vtn_ssa_value(b, w[5])); break; } case GLSLstd450InterpolateAtCentroid: case GLSLstd450InterpolateAtSample: case GLSLstd450InterpolateAtOffset: handle_glsl450_interpolation(b, ext_opcode, w, count); break; default: handle_glsl450_alu(b, (enum GLSLstd450)ext_opcode, w, count); } return true; }