--- /dev/null
+/*
+ * 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(b, n, nir_imm_int(b, 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(b, n, nir_imm_int(b, 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(b, n, nir_imm_int(b, 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)
+{
+ 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(d)) {
+ uint64_t abs_d = d < 0 ? -d : d;
+ nir_ssa_def *uq = nir_ishr(b, n, nir_imm_int(b, 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(b, res, nir_imm_int(b, m.shift));
+ res = nir_iadd(b, res, nir_ushr(b, res, nir_imm_int(b, 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);
+
+ nir_const_value *const_denom = nir_src_as_const_value(alu->src[1].src);
+ if (!const_denom)
+ return false;
+
+ unsigned bit_size = alu->src[1].src.ssa->bit_size;
+
+ b->cursor = nir_before_instr(&alu->instr);
+
+ nir_ssa_def *q[4];
+ 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;
+ switch (bit_size) {
+ case 8:
+ d = const_denom->i8[alu->src[1].swizzle[comp]];
+ break;
+ case 16:
+ d = const_denom->i16[alu->src[1].swizzle[comp]];
+ break;
+ case 32:
+ d = const_denom->i32[alu->src[1].swizzle[comp]];
+ break;
+ case 64:
+ d = const_denom->i64[alu->src[1].swizzle[comp]];
+ break;
+ default:
+ unreachable("Invalid bit size");
+ }
+
+ 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);
+ }
+
+ 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;
+}
projects / mesa.git / commitdiff