| /* |
| * 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 "nir.h" |
| #include "nir_builder.h" |
| |
| #include <math.h> |
| #include <float.h> |
| |
| /* |
| * Lowers some unsupported double operations, using only: |
| * |
| * - pack/unpackDouble2x32 |
| * - conversion to/from single-precision |
| * - double add, mul, and fma |
| * - conditional select |
| * - 32-bit integer and floating point arithmetic |
| */ |
| |
| /* Creates a double with the exponent bits set to a given integer value */ |
| static nir_ssa_def * |
| set_exponent(nir_builder *b, nir_ssa_def *src, nir_ssa_def *exp) |
| { |
| /* Split into bits 0-31 and 32-63 */ |
| nir_ssa_def *lo = nir_unpack_64_2x32_split_x(b, src); |
| nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src); |
| |
| /* The exponent is bits 52-62, or 20-30 of the high word, so set the exponent |
| * to 1023 |
| */ |
| nir_ssa_def *new_hi = nir_bitfield_insert(b, hi, exp, |
| nir_imm_int(b, 20), |
| nir_imm_int(b, 11)); |
| /* recombine */ |
| return nir_pack_64_2x32_split(b, lo, new_hi); |
| } |
| |
| static nir_ssa_def * |
| get_exponent(nir_builder *b, nir_ssa_def *src) |
| { |
| /* get bits 32-63 */ |
| nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src); |
| |
| /* extract bits 20-30 of the high word */ |
| return nir_ubitfield_extract(b, hi, nir_imm_int(b, 20), nir_imm_int(b, 11)); |
| } |
| |
| /* Return infinity with the sign of the given source which is +/-0 */ |
| |
| static nir_ssa_def * |
| get_signed_inf(nir_builder *b, nir_ssa_def *zero) |
| { |
| nir_ssa_def *zero_hi = nir_unpack_64_2x32_split_y(b, zero); |
| |
| /* The bit pattern for infinity is 0x7ff0000000000000, where the sign bit |
| * is the highest bit. Only the sign bit can be non-zero in the passed in |
| * source. So we essentially need to OR the infinity and the zero, except |
| * the low 32 bits are always 0 so we can construct the correct high 32 |
| * bits and then pack it together with zero low 32 bits. |
| */ |
| nir_ssa_def *inf_hi = nir_ior(b, nir_imm_int(b, 0x7ff00000), zero_hi); |
| return nir_pack_64_2x32_split(b, nir_imm_int(b, 0), inf_hi); |
| } |
| |
| /* |
| * Generates the correctly-signed infinity if the source was zero, and flushes |
| * the result to 0 if the source was infinity or the calculated exponent was |
| * too small to be representable. |
| */ |
| |
| static nir_ssa_def * |
| fix_inv_result(nir_builder *b, nir_ssa_def *res, nir_ssa_def *src, |
| nir_ssa_def *exp) |
| { |
| /* If the exponent is too small or the original input was infinity/NaN, |
| * force the result to 0 (flush denorms) to avoid the work of handling |
| * denorms properly. Note that this doesn't preserve positive/negative |
| * zeros, but GLSL doesn't require it. |
| */ |
| res = nir_bcsel(b, nir_ior(b, nir_ige(b, nir_imm_int(b, 0), exp), |
| nir_feq(b, nir_fabs(b, src), |
| nir_imm_double(b, INFINITY))), |
| nir_imm_double(b, 0.0f), res); |
| |
| /* If the original input was 0, generate the correctly-signed infinity */ |
| res = nir_bcsel(b, nir_fneu(b, src, nir_imm_double(b, 0.0f)), |
| res, get_signed_inf(b, src)); |
| |
| return res; |
| |
| } |
| |
| static nir_ssa_def * |
| lower_rcp(nir_builder *b, nir_ssa_def *src) |
| { |
| /* normalize the input to avoid range issues */ |
| nir_ssa_def *src_norm = set_exponent(b, src, nir_imm_int(b, 1023)); |
| |
| /* cast to float, do an rcp, and then cast back to get an approximate |
| * result |
| */ |
| nir_ssa_def *ra = nir_f2f64(b, nir_frcp(b, nir_f2f32(b, src_norm))); |
| |
| /* Fixup the exponent of the result - note that we check if this is too |
| * small below. |
| */ |
| nir_ssa_def *new_exp = nir_isub(b, get_exponent(b, ra), |
| nir_isub(b, get_exponent(b, src), |
| nir_imm_int(b, 1023))); |
| |
| ra = set_exponent(b, ra, new_exp); |
| |
| /* Do a few Newton-Raphson steps to improve precision. |
| * |
| * Each step doubles the precision, and we started off with around 24 bits, |
| * so we only need to do 2 steps to get to full precision. The step is: |
| * |
| * x_new = x * (2 - x*src) |
| * |
| * But we can re-arrange this to improve precision by using another fused |
| * multiply-add: |
| * |
| * x_new = x + x * (1 - x*src) |
| * |
| * See https://en.wikipedia.org/wiki/Division_algorithm for more details. |
| */ |
| |
| ra = nir_ffma(b, nir_fneg(b, ra), nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra); |
| ra = nir_ffma(b, nir_fneg(b, ra), nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra); |
| |
| return fix_inv_result(b, ra, src, new_exp); |
| } |
| |
| static nir_ssa_def * |
| lower_sqrt_rsq(nir_builder *b, nir_ssa_def *src, bool sqrt) |
| { |
| /* We want to compute: |
| * |
| * 1/sqrt(m * 2^e) |
| * |
| * When the exponent is even, this is equivalent to: |
| * |
| * 1/sqrt(m) * 2^(-e/2) |
| * |
| * and then the exponent is odd, this is equal to: |
| * |
| * 1/sqrt(m * 2) * 2^(-(e - 1)/2) |
| * |
| * where the m * 2 is absorbed into the exponent. So we want the exponent |
| * inside the square root to be 1 if e is odd and 0 if e is even, and we |
| * want to subtract off e/2 from the final exponent, rounded to negative |
| * infinity. We can do the former by first computing the unbiased exponent, |
| * and then AND'ing it with 1 to get 0 or 1, and we can do the latter by |
| * shifting right by 1. |
| */ |
| |
| nir_ssa_def *unbiased_exp = nir_isub(b, get_exponent(b, src), |
| nir_imm_int(b, 1023)); |
| nir_ssa_def *even = nir_iand_imm(b, unbiased_exp, 1); |
| nir_ssa_def *half = nir_ishr_imm(b, unbiased_exp, 1); |
| |
| nir_ssa_def *src_norm = set_exponent(b, src, |
| nir_iadd(b, nir_imm_int(b, 1023), |
| even)); |
| |
| nir_ssa_def *ra = nir_f2f64(b, nir_frsq(b, nir_f2f32(b, src_norm))); |
| nir_ssa_def *new_exp = nir_isub(b, get_exponent(b, ra), half); |
| ra = set_exponent(b, ra, new_exp); |
| |
| /* |
| * The following implements an iterative algorithm that's very similar |
| * between sqrt and rsqrt. We start with an iteration of Goldschmit's |
| * algorithm, which looks like: |
| * |
| * a = the source |
| * y_0 = initial (single-precision) rsqrt estimate |
| * |
| * h_0 = .5 * y_0 |
| * g_0 = a * y_0 |
| * r_0 = .5 - h_0 * g_0 |
| * g_1 = g_0 * r_0 + g_0 |
| * h_1 = h_0 * r_0 + h_0 |
| * |
| * Now g_1 ~= sqrt(a), and h_1 ~= 1/(2 * sqrt(a)). We could continue |
| * applying another round of Goldschmit, but since we would never refer |
| * back to a (the original source), we would add too much rounding error. |
| * So instead, we do one last round of Newton-Raphson, which has better |
| * rounding characteristics, to get the final rounding correct. This is |
| * split into two cases: |
| * |
| * 1. sqrt |
| * |
| * Normally, doing a round of Newton-Raphson for sqrt involves taking a |
| * reciprocal of the original estimate, which is slow since it isn't |
| * supported in HW. But we can take advantage of the fact that we already |
| * computed a good estimate of 1/(2 * g_1) by rearranging it like so: |
| * |
| * g_2 = .5 * (g_1 + a / g_1) |
| * = g_1 + .5 * (a / g_1 - g_1) |
| * = g_1 + (.5 / g_1) * (a - g_1^2) |
| * = g_1 + h_1 * (a - g_1^2) |
| * |
| * The second term represents the error, and by splitting it out we can get |
| * better precision by computing it as part of a fused multiply-add. Since |
| * both Newton-Raphson and Goldschmit approximately double the precision of |
| * the result, these two steps should be enough. |
| * |
| * 2. rsqrt |
| * |
| * First off, note that the first round of the Goldschmit algorithm is |
| * really just a Newton-Raphson step in disguise: |
| * |
| * h_1 = h_0 * (.5 - h_0 * g_0) + h_0 |
| * = h_0 * (1.5 - h_0 * g_0) |
| * = h_0 * (1.5 - .5 * a * y_0^2) |
| * = (.5 * y_0) * (1.5 - .5 * a * y_0^2) |
| * |
| * which is the standard formula multiplied by .5. Unlike in the sqrt case, |
| * we don't need the inverse to do a Newton-Raphson step; we just need h_1, |
| * so we can skip the calculation of g_1. Instead, we simply do another |
| * Newton-Raphson step: |
| * |
| * y_1 = 2 * h_1 |
| * r_1 = .5 - h_1 * y_1 * a |
| * y_2 = y_1 * r_1 + y_1 |
| * |
| * Where the difference from Goldschmit is that we calculate y_1 * a |
| * instead of using g_1. Doing it this way should be as fast as computing |
| * y_1 up front instead of h_1, and it lets us share the code for the |
| * initial Goldschmit step with the sqrt case. |
| * |
| * Putting it together, the computations are: |
| * |
| * h_0 = .5 * y_0 |
| * g_0 = a * y_0 |
| * r_0 = .5 - h_0 * g_0 |
| * h_1 = h_0 * r_0 + h_0 |
| * if sqrt: |
| * g_1 = g_0 * r_0 + g_0 |
| * r_1 = a - g_1 * g_1 |
| * g_2 = h_1 * r_1 + g_1 |
| * else: |
| * y_1 = 2 * h_1 |
| * r_1 = .5 - y_1 * (h_1 * a) |
| * y_2 = y_1 * r_1 + y_1 |
| * |
| * For more on the ideas behind this, see "Software Division and Square |
| * Root Using Goldschmit's Algorithms" by Markstein and the Wikipedia page |
| * on square roots |
| * (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots). |
| */ |
| |
| nir_ssa_def *one_half = nir_imm_double(b, 0.5); |
| nir_ssa_def *h_0 = nir_fmul(b, one_half, ra); |
| nir_ssa_def *g_0 = nir_fmul(b, src, ra); |
| nir_ssa_def *r_0 = nir_ffma(b, nir_fneg(b, h_0), g_0, one_half); |
| nir_ssa_def *h_1 = nir_ffma(b, h_0, r_0, h_0); |
| nir_ssa_def *res; |
| if (sqrt) { |
| nir_ssa_def *g_1 = nir_ffma(b, g_0, r_0, g_0); |
| nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, g_1), g_1, src); |
| res = nir_ffma(b, h_1, r_1, g_1); |
| } else { |
| nir_ssa_def *y_1 = nir_fmul(b, nir_imm_double(b, 2.0), h_1); |
| nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, y_1), nir_fmul(b, h_1, src), |
| one_half); |
| res = nir_ffma(b, y_1, r_1, y_1); |
| } |
| |
| if (sqrt) { |
| /* Here, the special cases we need to handle are |
| * 0 -> 0 and |
| * +inf -> +inf |
| */ |
| const bool preserve_denorms = |
| b->shader->info.float_controls_execution_mode & |
| FLOAT_CONTROLS_DENORM_PRESERVE_FP64; |
| nir_ssa_def *src_flushed = src; |
| if (!preserve_denorms) { |
| src_flushed = nir_bcsel(b, |
| nir_flt(b, nir_fabs(b, src), |
| nir_imm_double(b, DBL_MIN)), |
| nir_imm_double(b, 0.0), |
| src); |
| } |
| res = nir_bcsel(b, nir_ior(b, nir_feq(b, src_flushed, nir_imm_double(b, 0.0)), |
| nir_feq(b, src, nir_imm_double(b, INFINITY))), |
| src_flushed, res); |
| } else { |
| res = fix_inv_result(b, res, src, new_exp); |
| } |
| |
| return res; |
| } |
| |
| static nir_ssa_def * |
| lower_trunc(nir_builder *b, nir_ssa_def *src) |
| { |
| nir_ssa_def *unbiased_exp = nir_isub(b, get_exponent(b, src), |
| nir_imm_int(b, 1023)); |
| |
| nir_ssa_def *frac_bits = nir_isub(b, nir_imm_int(b, 52), unbiased_exp); |
| |
| /* |
| * Decide the operation to apply depending on the unbiased exponent: |
| * |
| * if (unbiased_exp < 0) |
| * return 0 |
| * else if (unbiased_exp > 52) |
| * return src |
| * else |
| * return src & (~0 << frac_bits) |
| * |
| * Notice that the else branch is a 64-bit integer operation that we need |
| * to implement in terms of 32-bit integer arithmetics (at least until we |
| * support 64-bit integer arithmetics). |
| */ |
| |
| /* Compute "~0 << frac_bits" in terms of hi/lo 32-bit integer math */ |
| nir_ssa_def *mask_lo = |
| nir_bcsel(b, |
| nir_ige(b, frac_bits, nir_imm_int(b, 32)), |
| nir_imm_int(b, 0), |
| nir_ishl(b, nir_imm_int(b, ~0), frac_bits)); |
| |
| nir_ssa_def *mask_hi = |
| nir_bcsel(b, |
| nir_ilt(b, frac_bits, nir_imm_int(b, 33)), |
| nir_imm_int(b, ~0), |
| nir_ishl(b, |
| nir_imm_int(b, ~0), |
| nir_isub(b, frac_bits, nir_imm_int(b, 32)))); |
| |
| nir_ssa_def *src_lo = nir_unpack_64_2x32_split_x(b, src); |
| nir_ssa_def *src_hi = nir_unpack_64_2x32_split_y(b, src); |
| |
| return |
| nir_bcsel(b, |
| nir_ilt(b, unbiased_exp, nir_imm_int(b, 0)), |
| nir_imm_double(b, 0.0), |
| nir_bcsel(b, nir_ige(b, unbiased_exp, nir_imm_int(b, 53)), |
| src, |
| nir_pack_64_2x32_split(b, |
| nir_iand(b, mask_lo, src_lo), |
| nir_iand(b, mask_hi, src_hi)))); |
| } |
| |
| static nir_ssa_def * |
| lower_floor(nir_builder *b, nir_ssa_def *src) |
| { |
| /* |
| * For x >= 0, floor(x) = trunc(x) |
| * For x < 0, |
| * - if x is integer, floor(x) = x |
| * - otherwise, floor(x) = trunc(x) - 1 |
| */ |
| nir_ssa_def *tr = nir_ftrunc(b, src); |
| nir_ssa_def *positive = nir_fge(b, src, nir_imm_double(b, 0.0)); |
| return nir_bcsel(b, |
| nir_ior(b, positive, nir_feq(b, src, tr)), |
| tr, |
| nir_fsub(b, tr, nir_imm_double(b, 1.0))); |
| } |
| |
| static nir_ssa_def * |
| lower_ceil(nir_builder *b, nir_ssa_def *src) |
| { |
| /* if x < 0, ceil(x) = trunc(x) |
| * else if (x - trunc(x) == 0), ceil(x) = x |
| * else, ceil(x) = trunc(x) + 1 |
| */ |
| nir_ssa_def *tr = nir_ftrunc(b, src); |
| nir_ssa_def *negative = nir_flt(b, src, nir_imm_double(b, 0.0)); |
| return nir_bcsel(b, |
| nir_ior(b, negative, nir_feq(b, src, tr)), |
| tr, |
| nir_fadd(b, tr, nir_imm_double(b, 1.0))); |
| } |
| |
| static nir_ssa_def * |
| lower_fract(nir_builder *b, nir_ssa_def *src) |
| { |
| return nir_fsub(b, src, nir_ffloor(b, src)); |
| } |
| |
| static nir_ssa_def * |
| lower_round_even(nir_builder *b, nir_ssa_def *src) |
| { |
| /* Add and subtract 2**52 to round off any fractional bits. */ |
| nir_ssa_def *two52 = nir_imm_double(b, (double)(1ull << 52)); |
| nir_ssa_def *sign = nir_iand(b, nir_unpack_64_2x32_split_y(b, src), |
| nir_imm_int(b, 1ull << 31)); |
| |
| b->exact = true; |
| nir_ssa_def *res = nir_fsub(b, nir_fadd(b, nir_fabs(b, src), two52), two52); |
| b->exact = false; |
| |
| return nir_bcsel(b, nir_flt(b, nir_fabs(b, src), two52), |
| nir_pack_64_2x32_split(b, nir_unpack_64_2x32_split_x(b, res), |
| nir_ior(b, nir_unpack_64_2x32_split_y(b, res), sign)), src); |
| } |
| |
| static nir_ssa_def * |
| lower_mod(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1) |
| { |
| /* mod(x,y) = x - y * floor(x/y) |
| * |
| * If the division is lowered, it could add some rounding errors that make |
| * floor() to return the quotient minus one when x = N * y. If this is the |
| * case, we should return zero because mod(x, y) output value is [0, y). |
| * But fortunately Vulkan spec allows this kind of errors; from Vulkan |
| * spec, appendix A (Precision and Operation of SPIR-V instructions: |
| * |
| * "The OpFRem and OpFMod instructions use cheap approximations of |
| * remainder, and the error can be large due to the discontinuity in |
| * trunc() and floor(). This can produce mathematically unexpected |
| * results in some cases, such as FMod(x,x) computing x rather than 0, |
| * and can also cause the result to have a different sign than the |
| * infinitely precise result." |
| * |
| * In practice this means the output value is actually in the interval |
| * [0, y]. |
| * |
| * While Vulkan states this behaviour explicitly, OpenGL does not, and thus |
| * we need to assume that value should be in range [0, y); but on the other |
| * hand, mod(a,b) is defined as "a - b * floor(a/b)" and OpenGL allows for |
| * some error in division, so a/a could actually end up being 1.0 - 1ULP; |
| * so in this case floor(a/a) would end up as 0, and hence mod(a,a) == a. |
| * |
| * In summary, in the practice mod(a,a) can be "a" both for OpenGL and |
| * Vulkan. |
| */ |
| nir_ssa_def *floor = nir_ffloor(b, nir_fdiv(b, src0, src1)); |
| |
| return nir_fsub(b, src0, nir_fmul(b, src1, floor)); |
| } |
| |
| static nir_ssa_def * |
| lower_doubles_instr_to_soft(nir_builder *b, nir_alu_instr *instr, |
| const nir_shader *softfp64, |
| nir_lower_doubles_options options) |
| { |
| if (!(options & nir_lower_fp64_full_software)) |
| return NULL; |
| |
| |
| assert(instr->dest.dest.is_ssa); |
| |
| const char *name; |
| const char *mangled_name; |
| const struct glsl_type *return_type = glsl_uint64_t_type(); |
| |
| switch (instr->op) { |
| case nir_op_f2i64: |
| if (instr->src[0].src.ssa->bit_size != 64) |
| return false; |
| name = "__fp64_to_int64"; |
| mangled_name = "__fp64_to_int64(u641;"; |
| return_type = glsl_int64_t_type(); |
| break; |
| case nir_op_f2u64: |
| if (instr->src[0].src.ssa->bit_size != 64) |
| return false; |
| name = "__fp64_to_uint64"; |
| mangled_name = "__fp64_to_uint64(u641;"; |
| break; |
| case nir_op_f2f64: |
| name = "__fp32_to_fp64"; |
| mangled_name = "__fp32_to_fp64(f1;"; |
| break; |
| case nir_op_f2f32: |
| name = "__fp64_to_fp32"; |
| mangled_name = "__fp64_to_fp32(u641;"; |
| return_type = glsl_float_type(); |
| break; |
| case nir_op_f2i32: |
| name = "__fp64_to_int"; |
| mangled_name = "__fp64_to_int(u641;"; |
| return_type = glsl_int_type(); |
| break; |
| case nir_op_f2u32: |
| name = "__fp64_to_uint"; |
| mangled_name = "__fp64_to_uint(u641;"; |
| return_type = glsl_uint_type(); |
| break; |
| case nir_op_f2b1: |
| case nir_op_f2b32: |
| name = "__fp64_to_bool"; |
| mangled_name = "__fp64_to_bool(u641;"; |
| return_type = glsl_bool_type(); |
| break; |
| case nir_op_b2f64: |
| name = "__bool_to_fp64"; |
| mangled_name = "__bool_to_fp64(b1;"; |
| break; |
| case nir_op_i2f64: |
| if (instr->src[0].src.ssa->bit_size == 64) { |
| name = "__int64_to_fp64"; |
| mangled_name = "__int64_to_fp64(i641;"; |
| } |
| else { |
| name = "__int_to_fp64"; |
| mangled_name = "__int_to_fp64(i1;"; |
| } |
| break; |
| case nir_op_u2f64: |
| if (instr->src[0].src.ssa->bit_size == 64) { |
| name = "__uint64_to_fp64"; |
| mangled_name = "__uint64_to_fp64(u641;"; |
| } |
| else { |
| name = "__uint_to_fp64"; |
| mangled_name = "__uint_to_fp64(u1;"; |
| } |
| break; |
| case nir_op_fabs: |
| name = "__fabs64"; |
| mangled_name = "__fabs64(u641;"; |
| break; |
| case nir_op_fneg: |
| name = "__fneg64"; |
| mangled_name = "__fneg64(u641;"; |
| break; |
| case nir_op_fround_even: |
| name = "__fround64"; |
| mangled_name = "__fround64(u641;"; |
| break; |
| case nir_op_ftrunc: |
| name = "__ftrunc64"; |
| mangled_name = "__ftrunc64(u641;"; |
| break; |
| case nir_op_ffloor: |
| name = "__ffloor64"; |
| mangled_name = "__ffloor64(u641;"; |
| break; |
| case nir_op_ffract: |
| name = "__ffract64"; |
| mangled_name = "__ffract64(u641;"; |
| break; |
| case nir_op_fsign: |
| name = "__fsign64"; |
| mangled_name = "__fsign64(u641;"; |
| break; |
| case nir_op_feq: |
| name = "__feq64"; |
| mangled_name = "__feq64(u641;u641;"; |
| return_type = glsl_bool_type(); |
| break; |
| case nir_op_fneu: |
| name = "__fneu64"; |
| mangled_name = "__fneu64(u641;u641;"; |
| return_type = glsl_bool_type(); |
| break; |
| case nir_op_flt: |
| name = "__flt64"; |
| mangled_name = "__flt64(u641;u641;"; |
| return_type = glsl_bool_type(); |
| break; |
| case nir_op_fge: |
| name = "__fge64"; |
| mangled_name = "__fge64(u641;u641;"; |
| return_type = glsl_bool_type(); |
| break; |
| case nir_op_fmin: |
| name = "__fmin64"; |
| mangled_name = "__fmin64(u641;u641;"; |
| break; |
| case nir_op_fmax: |
| name = "__fmax64"; |
| mangled_name = "__fmax64(u641;u641;"; |
| break; |
| case nir_op_fadd: |
| name = "__fadd64"; |
| mangled_name = "__fadd64(u641;u641;"; |
| break; |
| case nir_op_fmul: |
| name = "__fmul64"; |
| mangled_name = "__fmul64(u641;u641;"; |
| break; |
| case nir_op_ffma: |
| name = "__ffma64"; |
| mangled_name = "__ffma64(u641;u641;u641;"; |
| break; |
| case nir_op_fsat: |
| name = "__fsat64"; |
| mangled_name = "__fsat64(u641;"; |
| break; |
| default: |
| return false; |
| } |
| |
| assert(softfp64 != NULL); |
| nir_function *func = nir_shader_get_function_for_name(softfp64, name); |
| |
| /* Another attempt, but this time with mangled names if softfp64 |
| * shader is taken from SPIR-V. |
| */ |
| if (!func) |
| func = nir_shader_get_function_for_name(softfp64, mangled_name); |
| |
| if (!func || !func->impl) { |
| fprintf(stderr, "Cannot find function \"%s\"\n", name); |
| assert(func); |
| } |
| |
| nir_ssa_def *params[4] = { NULL, }; |
| |
| nir_variable *ret_tmp = |
| nir_local_variable_create(b->impl, return_type, "return_tmp"); |
| nir_deref_instr *ret_deref = nir_build_deref_var(b, ret_tmp); |
| params[0] = &ret_deref->dest.ssa; |
| |
| assert(nir_op_infos[instr->op].num_inputs + 1 == func->num_params); |
| for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) { |
| assert(i + 1 < ARRAY_SIZE(params)); |
| params[i + 1] = nir_mov_alu(b, instr->src[i], 1); |
| } |
| |
| nir_inline_function_impl(b, func->impl, params, NULL); |
| |
| return nir_load_deref(b, ret_deref); |
| } |
| |
| nir_lower_doubles_options |
| nir_lower_doubles_op_to_options_mask(nir_op opcode) |
| { |
| switch (opcode) { |
| case nir_op_frcp: return nir_lower_drcp; |
| case nir_op_fsqrt: return nir_lower_dsqrt; |
| case nir_op_frsq: return nir_lower_drsq; |
| case nir_op_ftrunc: return nir_lower_dtrunc; |
| case nir_op_ffloor: return nir_lower_dfloor; |
| case nir_op_fceil: return nir_lower_dceil; |
| case nir_op_ffract: return nir_lower_dfract; |
| case nir_op_fround_even: return nir_lower_dround_even; |
| case nir_op_fmod: return nir_lower_dmod; |
| case nir_op_fsub: return nir_lower_dsub; |
| case nir_op_fdiv: return nir_lower_ddiv; |
| default: return 0; |
| } |
| } |
| |
| struct lower_doubles_data { |
| const nir_shader *softfp64; |
| nir_lower_doubles_options options; |
| }; |
| |
| static bool |
| should_lower_double_instr(const nir_instr *instr, const void *_data) |
| { |
| const struct lower_doubles_data *data = _data; |
| const nir_lower_doubles_options options = data->options; |
| |
| if (instr->type != nir_instr_type_alu) |
| return false; |
| |
| const nir_alu_instr *alu = nir_instr_as_alu(instr); |
| |
| assert(alu->dest.dest.is_ssa); |
| bool is_64 = alu->dest.dest.ssa.bit_size == 64; |
| |
| unsigned num_srcs = nir_op_infos[alu->op].num_inputs; |
| for (unsigned i = 0; i < num_srcs; i++) { |
| is_64 |= (nir_src_bit_size(alu->src[i].src) == 64); |
| } |
| |
| if (!is_64) |
| return false; |
| |
| if (options & nir_lower_fp64_full_software) |
| return true; |
| |
| return options & nir_lower_doubles_op_to_options_mask(alu->op); |
| } |
| |
| static nir_ssa_def * |
| lower_doubles_instr(nir_builder *b, nir_instr *instr, void *_data) |
| { |
| const struct lower_doubles_data *data = _data; |
| const nir_lower_doubles_options options = data->options; |
| nir_alu_instr *alu = nir_instr_as_alu(instr); |
| |
| nir_ssa_def *soft_def = |
| lower_doubles_instr_to_soft(b, alu, data->softfp64, options); |
| if (soft_def) |
| return soft_def; |
| |
| if (!(options & nir_lower_doubles_op_to_options_mask(alu->op))) |
| return NULL; |
| |
| nir_ssa_def *src = nir_mov_alu(b, alu->src[0], |
| alu->dest.dest.ssa.num_components); |
| |
| switch (alu->op) { |
| case nir_op_frcp: |
| return lower_rcp(b, src); |
| case nir_op_fsqrt: |
| return lower_sqrt_rsq(b, src, true); |
| case nir_op_frsq: |
| return lower_sqrt_rsq(b, src, false); |
| case nir_op_ftrunc: |
| return lower_trunc(b, src); |
| case nir_op_ffloor: |
| return lower_floor(b, src); |
| case nir_op_fceil: |
| return lower_ceil(b, src); |
| case nir_op_ffract: |
| return lower_fract(b, src); |
| case nir_op_fround_even: |
| return lower_round_even(b, src); |
| |
| case nir_op_fdiv: |
| case nir_op_fsub: |
| case nir_op_fmod: { |
| nir_ssa_def *src1 = nir_mov_alu(b, alu->src[1], |
| alu->dest.dest.ssa.num_components); |
| switch (alu->op) { |
| case nir_op_fdiv: |
| return nir_fmul(b, src, nir_frcp(b, src1)); |
| case nir_op_fsub: |
| return nir_fadd(b, src, nir_fneg(b, src1)); |
| case nir_op_fmod: |
| return lower_mod(b, src, src1); |
| default: |
| unreachable("unhandled opcode"); |
| } |
| } |
| default: |
| unreachable("unhandled opcode"); |
| } |
| } |
| |
| static bool |
| nir_lower_doubles_impl(nir_function_impl *impl, |
| const nir_shader *softfp64, |
| nir_lower_doubles_options options) |
| { |
| struct lower_doubles_data data = { |
| .softfp64 = softfp64, |
| .options = options, |
| }; |
| |
| bool progress = |
| nir_function_impl_lower_instructions(impl, |
| should_lower_double_instr, |
| lower_doubles_instr, |
| &data); |
| |
| if (progress && (options & nir_lower_fp64_full_software)) { |
| /* SSA and register indices are completely messed up now */ |
| nir_index_ssa_defs(impl); |
| nir_index_local_regs(impl); |
| |
| nir_metadata_preserve(impl, nir_metadata_none); |
| |
| /* And we have deref casts we need to clean up thanks to function |
| * inlining. |
| */ |
| nir_opt_deref_impl(impl); |
| } else if (progress) { |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| } else { |
| nir_metadata_preserve(impl, nir_metadata_all); |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_lower_doubles(nir_shader *shader, |
| const nir_shader *softfp64, |
| nir_lower_doubles_options options) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) { |
| progress |= nir_lower_doubles_impl(function->impl, softfp64, options); |
| } |
| } |
| |
| return progress; |
| } |
