| /* |
| * Copyright © 2018 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 "util/fast_idiv_by_const.h" |
| #include "util/u_math.h" |
| |
| static nir_ssa_def * |
| build_udiv(nir_builder *b, nir_ssa_def *n, uint64_t d) |
| { |
| if (d == 0) { |
| return nir_imm_intN_t(b, 0, n->bit_size); |
| } else if (util_is_power_of_two_or_zero64(d)) { |
| return nir_ushr_imm(b, n, util_logbase2_64(d)); |
| } else { |
| struct util_fast_udiv_info m = |
| util_compute_fast_udiv_info(d, n->bit_size, n->bit_size); |
| |
| if (m.pre_shift) |
| n = nir_ushr_imm(b, n, m.pre_shift); |
| if (m.increment) |
| n = nir_uadd_sat(b, n, nir_imm_intN_t(b, m.increment, n->bit_size)); |
| n = nir_umul_high(b, n, nir_imm_intN_t(b, m.multiplier, n->bit_size)); |
| if (m.post_shift) |
| n = nir_ushr_imm(b, n, m.post_shift); |
| |
| return n; |
| } |
| } |
| |
| static nir_ssa_def * |
| build_umod(nir_builder *b, nir_ssa_def *n, uint64_t d) |
| { |
| if (d == 0) { |
| return nir_imm_intN_t(b, 0, n->bit_size); |
| } else if (util_is_power_of_two_or_zero64(d)) { |
| return nir_iand(b, n, nir_imm_intN_t(b, d - 1, n->bit_size)); |
| } else { |
| return nir_isub(b, n, nir_imul(b, build_udiv(b, n, d), |
| nir_imm_intN_t(b, d, n->bit_size))); |
| } |
| } |
| |
| static nir_ssa_def * |
| build_idiv(nir_builder *b, nir_ssa_def *n, int64_t d) |
| { |
| uint64_t abs_d = d < 0 ? -d : d; |
| |
| if (d == 0) { |
| return nir_imm_intN_t(b, 0, n->bit_size); |
| } else if (d == 1) { |
| return n; |
| } else if (d == -1) { |
| return nir_ineg(b, n); |
| } else if (util_is_power_of_two_or_zero64(abs_d)) { |
| nir_ssa_def *uq = nir_ushr_imm(b, nir_iabs(b, n), util_logbase2_64(abs_d)); |
| nir_ssa_def *n_neg = nir_ilt(b, n, nir_imm_intN_t(b, 0, n->bit_size)); |
| nir_ssa_def *neg = d < 0 ? nir_inot(b, n_neg) : n_neg; |
| return nir_bcsel(b, neg, nir_ineg(b, uq), uq); |
| } else { |
| struct util_fast_sdiv_info m = |
| util_compute_fast_sdiv_info(d, n->bit_size); |
| |
| nir_ssa_def *res = |
| nir_imul_high(b, n, nir_imm_intN_t(b, m.multiplier, n->bit_size)); |
| if (d > 0 && m.multiplier < 0) |
| res = nir_iadd(b, res, n); |
| if (d < 0 && m.multiplier > 0) |
| res = nir_isub(b, res, n); |
| if (m.shift) |
| res = nir_ishr_imm(b, res, m.shift); |
| res = nir_iadd(b, res, nir_ushr_imm(b, res, n->bit_size - 1)); |
| |
| return res; |
| } |
| } |
| |
| static bool |
| nir_opt_idiv_const_instr(nir_builder *b, nir_alu_instr *alu) |
| { |
| assert(alu->dest.dest.is_ssa); |
| assert(alu->src[0].src.is_ssa && alu->src[1].src.is_ssa); |
| |
| if (!nir_src_is_const(alu->src[1].src)) |
| return false; |
| |
| unsigned bit_size = alu->src[1].src.ssa->bit_size; |
| |
| b->cursor = nir_before_instr(&alu->instr); |
| |
| nir_ssa_def *q[NIR_MAX_VEC_COMPONENTS]; |
| for (unsigned comp = 0; comp < alu->dest.dest.ssa.num_components; comp++) { |
| /* Get the numerator for the channel */ |
| nir_ssa_def *n = nir_channel(b, alu->src[0].src.ssa, |
| alu->src[0].swizzle[comp]); |
| |
| /* Get the denominator for the channel */ |
| int64_t d = nir_src_comp_as_int(alu->src[1].src, |
| alu->src[1].swizzle[comp]); |
| |
| nir_alu_type d_type = nir_op_infos[alu->op].input_types[1]; |
| if (nir_alu_type_get_base_type(d_type) == nir_type_uint) { |
| /* The code above sign-extended. If we're lowering an unsigned op, |
| * we need to mask it off to the correct number of bits so that a |
| * cast to uint64_t will do the right thing. |
| */ |
| if (bit_size < 64) |
| d &= (1ull << bit_size) - 1; |
| } |
| |
| switch (alu->op) { |
| case nir_op_udiv: |
| q[comp] = build_udiv(b, n, d); |
| break; |
| case nir_op_idiv: |
| q[comp] = build_idiv(b, n, d); |
| break; |
| case nir_op_umod: |
| q[comp] = build_umod(b, n, d); |
| break; |
| default: |
| unreachable("Unknown integer division op"); |
| } |
| } |
| |
| nir_ssa_def *qvec = nir_vec(b, q, alu->dest.dest.ssa.num_components); |
| nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa, nir_src_for_ssa(qvec)); |
| nir_instr_remove(&alu->instr); |
| |
| return true; |
| } |
| |
| static bool |
| nir_opt_idiv_const_impl(nir_function_impl *impl, unsigned min_bit_size) |
| { |
| bool progress = false; |
| |
| nir_builder b; |
| nir_builder_init(&b, impl); |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type != nir_instr_type_alu) |
| continue; |
| |
| nir_alu_instr *alu = nir_instr_as_alu(instr); |
| if (alu->op != nir_op_udiv && |
| alu->op != nir_op_idiv && |
| alu->op != nir_op_umod) |
| continue; |
| |
| assert(alu->dest.dest.is_ssa); |
| if (alu->dest.dest.ssa.bit_size < min_bit_size) |
| continue; |
| |
| progress |= nir_opt_idiv_const_instr(&b, alu); |
| } |
| } |
| |
| 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_opt_idiv_const(nir_shader *shader, unsigned min_bit_size) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl) |
| progress |= nir_opt_idiv_const_impl(function->impl, min_bit_size); |
| } |
| |
| return progress; |
| } |
