--- /dev/null
+/*
+ * Copyright © 2014 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 "nir.h"
+#include <math.h>
+
+/*
+ * Implements SSA-based constant folding.
+ */
+
+struct constant_fold_state {
+ void *mem_ctx;
+ nir_function_impl *impl;
+ bool progress;
+};
+
+#define SRC_COMP(T, IDX, CMP) src[IDX]->value.T[instr->src[IDX].swizzle[CMP]]
+#define SRC(T, IDX) SRC_COMP(T, IDX, i)
+#define DEST_COMP(T, CMP) dest->value.T[CMP]
+#define DEST(T) DEST_COMP(T, i)
+
+#define FOLD_PER_COMP(EXPR) \
+ for (unsigned i = 0; i < instr->dest.dest.ssa.num_components; i++) { \
+ EXPR; \
+ } \
+
+static bool
+constant_fold_alu_instr(nir_alu_instr *instr, void *void_state)
+{
+ struct constant_fold_state *state = void_state;
+ nir_load_const_instr *src[4], *dest;
+
+ if (!instr->dest.dest.is_ssa)
+ return false;
+
+ for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
+ if (!instr->src[i].src.is_ssa)
+ return false;
+
+ if (instr->src[i].src.ssa->parent_instr->type != nir_instr_type_load_const)
+ return false;
+
+ /* We shouldn't have any source modifiers in the optimization loop. */
+ assert(!instr->src[i].abs && !instr->src[i].negate);
+
+ src[i] = nir_instr_as_load_const(instr->src[i].src.ssa->parent_instr);
+ }
+
+ /* We shouldn't have any saturate modifiers in the optimization loop. */
+ assert(!instr->dest.saturate);
+
+ dest = nir_load_const_instr_create(state->mem_ctx);
+ dest->array_elems = 0;
+ dest->num_components = instr->dest.dest.ssa.num_components;
+
+ switch (instr->op) {
+ case nir_op_ineg:
+ FOLD_PER_COMP(DEST(i) = -SRC(i, 0));
+ break;
+ case nir_op_fneg:
+ FOLD_PER_COMP(DEST(f) = -SRC(f, 0));
+ break;
+ case nir_op_inot:
+ FOLD_PER_COMP(DEST(i) = ~SRC(i, 0));
+ break;
+ case nir_op_fnot:
+ FOLD_PER_COMP(DEST(f) = (SRC(f, 0) == 0.0f) ? 1.0f : 0.0f);
+ break;
+ case nir_op_frcp:
+ FOLD_PER_COMP(DEST(f) = 1.0f / SRC(f, 0));
+ break;
+ case nir_op_frsq:
+ FOLD_PER_COMP(DEST(f) = 1.0f / sqrt(SRC(f, 0)));
+ break;
+ case nir_op_fsqrt:
+ FOLD_PER_COMP(DEST(f) = sqrtf(SRC(f, 0)));
+ break;
+ case nir_op_fexp:
+ FOLD_PER_COMP(DEST(f) = expf(SRC(f, 0)));
+ break;
+ case nir_op_flog:
+ FOLD_PER_COMP(DEST(f) = logf(SRC(f, 0)));
+ break;
+ case nir_op_fexp2:
+ FOLD_PER_COMP(DEST(f) = exp2f(SRC(f, 0)));
+ break;
+ case nir_op_flog2:
+ FOLD_PER_COMP(DEST(f) = log2f(SRC(f, 0)));
+ break;
+ case nir_op_f2i:
+ FOLD_PER_COMP(DEST(i) = SRC(f, 0));
+ break;
+ case nir_op_f2u:
+ FOLD_PER_COMP(DEST(u) = SRC(f, 0));
+ break;
+ case nir_op_i2f:
+ FOLD_PER_COMP(DEST(f) = SRC(i, 0));
+ break;
+ case nir_op_f2b:
+ FOLD_PER_COMP(DEST(u) = (SRC(i, 0) == 0.0f) ? NIR_FALSE : NIR_TRUE);
+ break;
+ case nir_op_b2f:
+ FOLD_PER_COMP(DEST(f) = SRC(u, 0) ? 1.0f : 0.0f);
+ break;
+ case nir_op_i2b:
+ FOLD_PER_COMP(DEST(u) = SRC(i, 0) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_u2f:
+ FOLD_PER_COMP(DEST(f) = SRC(u, 0));
+ break;
+ case nir_op_bany2:
+ DEST_COMP(u, 0) = (SRC_COMP(u, 0, 0) || SRC_COMP(u, 0, 1)) ?
+ NIR_TRUE : NIR_FALSE;
+ break;
+ case nir_op_fadd:
+ FOLD_PER_COMP(DEST(f) = SRC(f, 0) + SRC(f, 1));
+ break;
+ case nir_op_iadd:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) + SRC(i, 1));
+ break;
+ case nir_op_fsub:
+ FOLD_PER_COMP(DEST(f) = SRC(f, 0) - SRC(f, 1));
+ break;
+ case nir_op_isub:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) - SRC(i, 1));
+ break;
+ case nir_op_fmul:
+ FOLD_PER_COMP(DEST(f) = SRC(f, 0) * SRC(f, 1));
+ break;
+ case nir_op_imul:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) * SRC(i, 1));
+ break;
+ case nir_op_fdiv:
+ FOLD_PER_COMP(DEST(f) = SRC(f, 0) / SRC(f, 1));
+ break;
+ case nir_op_idiv:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) / SRC(i, 1));
+ break;
+ case nir_op_udiv:
+ FOLD_PER_COMP(DEST(u) = SRC(u, 0) / SRC(u, 1));
+ break;
+ case nir_op_flt:
+ FOLD_PER_COMP(DEST(u) = (SRC(f, 0) < SRC(f, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_fge:
+ FOLD_PER_COMP(DEST(u) = (SRC(f, 0) >= SRC(f, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_feq:
+ FOLD_PER_COMP(DEST(u) = (SRC(f, 0) == SRC(f, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_fne:
+ FOLD_PER_COMP(DEST(u) = (SRC(f, 0) != SRC(f, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ilt:
+ FOLD_PER_COMP(DEST(u) = (SRC(i, 0) < SRC(i, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ige:
+ FOLD_PER_COMP(DEST(u) = (SRC(i, 0) >= SRC(i, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ieq:
+ FOLD_PER_COMP(DEST(u) = (SRC(i, 0) == SRC(i, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ine:
+ FOLD_PER_COMP(DEST(u) = (SRC(i, 0) != SRC(i, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ult:
+ FOLD_PER_COMP(DEST(u) = (SRC(u, 0) < SRC(u, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_uge:
+ FOLD_PER_COMP(DEST(u) = (SRC(u, 0) >= SRC(u, 1)) ? NIR_TRUE : NIR_FALSE);
+ break;
+ case nir_op_ishl:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) << SRC(i, 1));
+ break;
+ case nir_op_ishr:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) >> SRC(i, 1));
+ break;
+ case nir_op_ushr:
+ FOLD_PER_COMP(DEST(u) = SRC(u, 0) >> SRC(u, 1));
+ break;
+ case nir_op_iand:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) & SRC(i, 1));
+ break;
+ case nir_op_ior:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) | SRC(i, 1));
+ break;
+ case nir_op_ixor:
+ FOLD_PER_COMP(DEST(i) = SRC(i, 0) ^ SRC(i, 1));
+ break;
+ default:
+ ralloc_free(dest);
+ return false;
+ }
+
+ dest->dest.is_ssa = true;
+ nir_ssa_def_init(&dest->instr, &dest->dest.ssa,
+ instr->dest.dest.ssa.num_components,
+ instr->dest.dest.ssa.name);
+
+ nir_instr_insert_before(&instr->instr, &dest->instr);
+
+ nir_src new_src = {
+ .is_ssa = true,
+ .ssa = &dest->dest.ssa,
+ };
+
+ nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa, new_src, state->mem_ctx);
+
+ nir_instr_remove(&instr->instr);
+ ralloc_free(instr);
+
+ return true;
+}
+
+static bool
+constant_fold_block(nir_block *block, void *void_state)
+{
+ struct constant_fold_state *state = void_state;
+
+ nir_foreach_instr_safe(block, instr) {
+ if (instr->type != nir_instr_type_alu)
+ continue;
+
+ state->progress |= constant_fold_alu_instr(nir_instr_as_alu(instr), state);
+ }
+
+ return true;
+}
+
+static bool
+nir_opt_constant_folding_impl(nir_function_impl *impl)
+{
+ struct constant_fold_state state;
+
+ state.mem_ctx = ralloc_parent(impl);
+ state.impl = impl;
+ state.progress = false;
+
+ nir_foreach_block(impl, constant_fold_block, &state);
+
+ return state.progress;
+}
+
+bool
+nir_opt_constant_folding(nir_shader *shader)
+{
+ bool progress = false;
+
+ nir_foreach_overload(shader, overload) {
+ if (overload->impl)
+ progress |= nir_opt_constant_folding_impl(overload->impl);
+ }
+
+ return progress;
+}
projects / mesa.git / commitdiff