--- /dev/null
+/*
+ * Copyright (C) 2020 Google, Inc.
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * 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"
+
+/**
+ * Return the intrinsic if it matches the mask in "modes", else return NULL.
+ */
+static nir_intrinsic_instr *
+get_io_intrinsic(nir_instr *instr, nir_variable_mode modes,
+ nir_variable_mode *out_mode)
+{
+ if (instr->type != nir_instr_type_intrinsic)
+ return NULL;
+
+ nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
+
+ switch (intr->intrinsic) {
+ case nir_intrinsic_load_input:
+ case nir_intrinsic_load_input_vertex:
+ case nir_intrinsic_load_interpolated_input:
+ case nir_intrinsic_load_per_vertex_input:
+ *out_mode = nir_var_shader_in;
+ return modes & nir_var_shader_in ? intr : NULL;
+ case nir_intrinsic_load_output:
+ case nir_intrinsic_load_per_vertex_output:
+ case nir_intrinsic_store_output:
+ case nir_intrinsic_store_per_vertex_output:
+ *out_mode = nir_var_shader_out;
+ return modes & nir_var_shader_out ? intr : NULL;
+ default:
+ return NULL;
+ }
+}
+
+/**
+ * Recompute the IO "base" indices from scratch to remove holes or to fix
+ * incorrect base values due to changes in IO locations by using IO locations
+ * to assign new bases. The mapping from locations to bases becomes
+ * monotonically increasing.
+ */
+bool
+nir_recompute_io_bases(nir_function_impl *impl, nir_variable_mode modes)
+{
+ BITSET_DECLARE(inputs, NUM_TOTAL_VARYING_SLOTS);
+ BITSET_DECLARE(outputs, NUM_TOTAL_VARYING_SLOTS);
+ BITSET_ZERO(inputs);
+ BITSET_ZERO(outputs);
+
+ /* Gather the bitmasks of used locations. */
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ nir_variable_mode mode;
+ nir_intrinsic_instr *intr = get_io_intrinsic(instr, modes, &mode);
+ if (!intr)
+ continue;
+
+ nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
+ unsigned num_slots = sem.num_slots;
+ if (sem.medium_precision)
+ num_slots = (num_slots + sem.high_16bits + 1) / 2;
+
+ if (mode == nir_var_shader_in) {
+ for (unsigned i = 0; i < num_slots; i++)
+ BITSET_SET(inputs, sem.location + i);
+ } else if (!sem.dual_source_blend_index) {
+ for (unsigned i = 0; i < num_slots; i++)
+ BITSET_SET(outputs, sem.location + i);
+ }
+ }
+ }
+
+ /* Renumber bases. */
+ bool changed = false;
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ nir_variable_mode mode;
+ nir_intrinsic_instr *intr = get_io_intrinsic(instr, modes, &mode);
+ if (!intr)
+ continue;
+
+ nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
+ unsigned num_slots = sem.num_slots;
+ if (sem.medium_precision)
+ num_slots = (num_slots + sem.high_16bits + 1) / 2;
+
+ if (mode == nir_var_shader_in) {
+ nir_intrinsic_set_base(intr,
+ BITSET_PREFIX_SUM(inputs, sem.location));
+ } else if (sem.dual_source_blend_index) {
+ nir_intrinsic_set_base(intr,
+ BITSET_PREFIX_SUM(outputs, NUM_TOTAL_VARYING_SLOTS));
+ } else {
+ nir_intrinsic_set_base(intr,
+ BITSET_PREFIX_SUM(outputs, sem.location));
+ }
+ changed = true;
+ }
+ }
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}
+
+/**
+ * Lower mediump inputs and/or outputs to 16 bits.
+ *
+ * \param modes Whether to lower inputs, outputs, or both.
+ * \param varying_mask Determines which varyings to skip (VS inputs,
+ * FS outputs, and patch varyings ignore this mask).
+ * \param use_16bit_slots Remap lowered slots to* VARYING_SLOT_VARn_16BIT.
+ */
+bool
+nir_lower_mediump_io(nir_shader *nir, nir_variable_mode modes,
+ uint64_t varying_mask, bool use_16bit_slots)
+{
+ bool changed = false;
+ nir_function_impl *impl = nir_shader_get_entrypoint(nir);
+ assert(impl);
+
+ nir_builder b;
+ nir_builder_init(&b, impl);
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ nir_variable_mode mode;
+ nir_intrinsic_instr *intr = get_io_intrinsic(instr, modes, &mode);
+ if (!intr)
+ continue;
+
+ nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
+ nir_ssa_def *(*convert)(nir_builder *, nir_ssa_def *);
+ bool is_varying = !(nir->info.stage == MESA_SHADER_VERTEX &&
+ mode == nir_var_shader_in) &&
+ !(nir->info.stage == MESA_SHADER_FRAGMENT &&
+ mode == nir_var_shader_out);
+
+ if (!sem.medium_precision ||
+ (is_varying && sem.location <= VARYING_SLOT_VAR31 &&
+ !(varying_mask & BITFIELD64_BIT(sem.location))))
+ continue; /* can't lower */
+
+ if (nir_intrinsic_has_src_type(intr)) {
+ /* Stores. */
+ nir_alu_type type = nir_intrinsic_src_type(intr);
+
+ switch (type) {
+ case nir_type_float32:
+ convert = nir_f2fmp;
+ break;
+ case nir_type_int32:
+ case nir_type_uint32:
+ convert = nir_i2imp;
+ break;
+ default:
+ continue; /* already lowered? */
+ }
+
+ /* Convert the 32-bit store into a 16-bit store. */
+ b.cursor = nir_before_instr(&intr->instr);
+ nir_instr_rewrite_src_ssa(&intr->instr, &intr->src[0],
+ convert(&b, intr->src[0].ssa));
+ nir_intrinsic_set_src_type(intr, (type & ~32) | 16);
+ } else {
+ /* Loads. */
+ nir_alu_type type = nir_intrinsic_dest_type(intr);
+
+ switch (type) {
+ case nir_type_float32:
+ convert = nir_f2f32;
+ break;
+ case nir_type_int32:
+ convert = nir_i2i32;
+ break;
+ case nir_type_uint32:
+ convert = nir_u2u32;
+ break;
+ default:
+ continue; /* already lowered? */
+ }
+
+ /* Convert the 32-bit load into a 16-bit load. */
+ b.cursor = nir_after_instr(&intr->instr);
+ intr->dest.ssa.bit_size = 16;
+ nir_intrinsic_set_dest_type(intr, (type & ~32) | 16);
+ nir_ssa_def *dst = convert(&b, &intr->dest.ssa);
+ nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, dst,
+ dst->parent_instr);
+ }
+
+ if (use_16bit_slots && is_varying &&
+ sem.location >= VARYING_SLOT_VAR0 &&
+ sem.location <= VARYING_SLOT_VAR31) {
+ unsigned index = sem.location - VARYING_SLOT_VAR0;
+
+ sem.location = VARYING_SLOT_VAR0_16BIT + index / 2;
+ sem.high_16bits = index % 2;
+ nir_intrinsic_set_io_semantics(intr, sem);
+ }
+ changed = true;
+ }
+ }
+
+ if (changed)
+ nir_recompute_io_bases(impl, modes);
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}
+
+/**
+ * Set the mediump precision bit for those shader inputs and outputs that are
+ * set in the "modes" mask. Non-generic varyings (that GLES3 doesn't have)
+ * are ignored. The "types" mask can be (nir_type_float | nir_type_int), etc.
+ */
+bool
+nir_force_mediump_io(nir_shader *nir, nir_variable_mode modes,
+ nir_alu_type types)
+{
+ bool changed = false;
+ nir_function_impl *impl = nir_shader_get_entrypoint(nir);
+ assert(impl);
+
+ nir_builder b;
+ nir_builder_init(&b, impl);
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ nir_variable_mode mode;
+ nir_intrinsic_instr *intr = get_io_intrinsic(instr, modes, &mode);
+ if (!intr)
+ continue;
+
+ nir_alu_type type;
+ if (nir_intrinsic_has_src_type(intr))
+ type = nir_intrinsic_src_type(intr);
+ else
+ type = nir_intrinsic_dest_type(intr);
+ if (!(type & types))
+ continue;
+
+ nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
+
+ if (nir->info.stage == MESA_SHADER_FRAGMENT &&
+ mode == nir_var_shader_out) {
+ /* Only accept FS outputs. */
+ if (sem.location < FRAG_RESULT_DATA0 &&
+ sem.location != FRAG_RESULT_COLOR)
+ continue;
+ } else if (nir->info.stage == MESA_SHADER_VERTEX &&
+ mode == nir_var_shader_in) {
+ /* Accept all VS inputs. */
+ } else {
+ /* Only accept generic varyings. */
+ if (sem.location < VARYING_SLOT_VAR0 ||
+ sem.location > VARYING_SLOT_VAR31)
+ continue;
+ }
+
+ sem.medium_precision = 1;
+ nir_intrinsic_set_io_semantics(intr, sem);
+ changed = true;
+ }
+ }
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}
+
+/**
+ * Remap 16-bit varying slots to the original 32-bit varying slots.
+ * This only changes IO semantics and bases.
+ */
+bool
+nir_unpack_16bit_varying_slots(nir_shader *nir, nir_variable_mode modes)
+{
+ bool changed = false;
+ nir_function_impl *impl = nir_shader_get_entrypoint(nir);
+ assert(impl);
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ nir_variable_mode mode;
+ nir_intrinsic_instr *intr = get_io_intrinsic(instr, modes, &mode);
+ if (!intr)
+ continue;
+
+ nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
+
+ if (sem.location < VARYING_SLOT_VAR0_16BIT ||
+ sem.location > VARYING_SLOT_VAR15_16BIT)
+ continue;
+
+ sem.location = VARYING_SLOT_VAR0 +
+ (sem.location - VARYING_SLOT_VAR0_16BIT) * 2 +
+ sem.high_16bits;
+ sem.high_16bits = 0;
+ nir_intrinsic_set_io_semantics(intr, sem);
+ changed = true;
+ }
+ }
+
+ if (changed)
+ nir_recompute_io_bases(impl, modes);
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}
+
+static bool
+is_n_to_m_conversion(nir_instr *instr, unsigned n, nir_op m)
+{
+ if (instr->type != nir_instr_type_alu)
+ return false;
+
+ nir_alu_instr *alu = nir_instr_as_alu(instr);
+ return alu->op == m && alu->src[0].src.ssa->bit_size == n;
+}
+
+static bool
+is_f16_to_f32_conversion(nir_instr *instr)
+{
+ return is_n_to_m_conversion(instr, 16, nir_op_f2f32);
+}
+
+static bool
+is_f32_to_f16_conversion(nir_instr *instr)
+{
+ return is_n_to_m_conversion(instr, 32, nir_op_f2f16) ||
+ is_n_to_m_conversion(instr, 32, nir_op_f2f16_rtne) ||
+ is_n_to_m_conversion(instr, 32, nir_op_f2fmp);
+}
+
+static bool
+is_i16_to_i32_conversion(nir_instr *instr)
+{
+ return is_n_to_m_conversion(instr, 16, nir_op_i2i32);
+}
+
+static bool
+is_u16_to_u32_conversion(nir_instr *instr)
+{
+ return is_n_to_m_conversion(instr, 16, nir_op_u2u32);
+}
+
+static bool
+is_i32_to_i16_conversion(nir_instr *instr)
+{
+ return is_n_to_m_conversion(instr, 32, nir_op_i2i16);
+}
+
+static void
+replace_with_mov(nir_builder *b, nir_instr *instr, nir_src *src,
+ nir_alu_instr *alu)
+{
+ nir_ssa_def *mov = nir_mov_alu(b, alu->src[0],
+ nir_dest_num_components(alu->dest.dest));
+ assert(!alu->dest.saturate);
+ nir_instr_rewrite_src_ssa(instr, src, mov);
+}
+
+/**
+ * If texture source operands use f16->f32 conversions or return values are
+ * followed by f16->f32 or f32->f16, remove those conversions. This benefits
+ * drivers that have texture opcodes that can accept and return 16-bit types.
+ *
+ * "tex_src_types" is a mask of nir_tex_src_* operands that should be handled.
+ * It's always done for the destination.
+ *
+ * This should be run after late algebraic optimizations.
+ * Copy propagation and DCE should be run after this.
+ */
+bool
+nir_fold_16bit_sampler_conversions(nir_shader *nir,
+ unsigned tex_src_types)
+{
+ bool changed = false;
+ nir_function_impl *impl = nir_shader_get_entrypoint(nir);
+ assert(impl);
+
+ nir_builder b;
+ nir_builder_init(&b, impl);
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ if (instr->type != nir_instr_type_tex)
+ continue;
+
+ nir_tex_instr *tex = nir_instr_as_tex(instr);
+ nir_instr *src;
+ nir_alu_instr *src_alu;
+
+ /* Skip because AMD doesn't support 16-bit types with these. */
+ if ((tex->op == nir_texop_txs ||
+ tex->op == nir_texop_query_levels) ||
+ tex->sampler_dim == GLSL_SAMPLER_DIM_CUBE)
+ continue;
+
+ /* Optimize source operands. */
+ for (unsigned i = 0; i < tex->num_srcs; i++) {
+ /* Filter out sources that should be ignored. */
+ if (!(BITFIELD_BIT(tex->src[i].src_type) & tex_src_types))
+ continue;
+
+ src = tex->src[i].src.ssa->parent_instr;
+ if (src->type != nir_instr_type_alu)
+ continue;
+
+ src_alu = nir_instr_as_alu(src);
+ b.cursor = nir_before_instr(src);
+
+ if (src_alu->op == nir_op_mov) {
+ assert(!"The IR shouldn't contain any movs to make this pass"
+ " effective.");
+ continue;
+ }
+
+ /* Handle vector sources that are made of scalar instructions. */
+ if (nir_op_is_vec(src_alu->op)) {
+ /* See if the vector is made of f16->f32 opcodes. */
+ unsigned num = nir_dest_num_components(src_alu->dest.dest);
+ bool is_f16_to_f32 = true;
+ bool is_u16_to_u32 = true;
+
+ for (unsigned comp = 0; comp < num; comp++) {
+ nir_instr *instr = src_alu->src[comp].src.ssa->parent_instr;
+ is_f16_to_f32 &= is_f16_to_f32_conversion(instr);
+ /* Zero-extension (u16) and sign-extension (i16) have
+ * the same behavior here - txf returns 0 if bit 15 is set
+ * because it's out of bounds and the higher bits don't
+ * matter.
+ */
+ is_u16_to_u32 &= is_u16_to_u32_conversion(instr) ||
+ is_i16_to_i32_conversion(instr);
+ }
+
+ if (!is_f16_to_f32 && !is_u16_to_u32)
+ continue;
+
+ nir_alu_instr *new_vec = nir_alu_instr_clone(nir, src_alu);
+ nir_instr_insert_after(&src_alu->instr, &new_vec->instr);
+
+ /* Replace conversions with mov. */
+ for (unsigned comp = 0; comp < num; comp++) {
+ nir_instr *instr = new_vec->src[comp].src.ssa->parent_instr;
+ replace_with_mov(&b, &new_vec->instr,
+ &new_vec->src[comp].src,
+ nir_instr_as_alu(instr));
+ }
+
+ new_vec->dest.dest.ssa.bit_size =
+ new_vec->src[0].src.ssa->bit_size;
+ nir_instr_rewrite_src_ssa(&tex->instr, &tex->src[i].src,
+ &new_vec->dest.dest.ssa);
+ changed = true;
+ } else if (is_f16_to_f32_conversion(&src_alu->instr) ||
+ is_u16_to_u32_conversion(&src_alu->instr) ||
+ is_i16_to_i32_conversion(&src_alu->instr)) {
+ /* Handle scalar sources. */
+ replace_with_mov(&b, &tex->instr, &tex->src[i].src, src_alu);
+ changed = true;
+ }
+ }
+
+ /* Optimize the destination. */
+ bool is_f16_to_f32 = true;
+ bool is_f32_to_f16 = true;
+ bool is_i16_to_i32 = true;
+ bool is_i32_to_i16 = true; /* same behavior for int and uint */
+ bool is_u16_to_u32 = true;
+
+ nir_foreach_use(use, &tex->dest.ssa) {
+ is_f16_to_f32 &= is_f16_to_f32_conversion(use->parent_instr);
+ is_f32_to_f16 &= is_f32_to_f16_conversion(use->parent_instr);
+ is_i16_to_i32 &= is_i16_to_i32_conversion(use->parent_instr);
+ is_i32_to_i16 &= is_i32_to_i16_conversion(use->parent_instr);
+ is_u16_to_u32 &= is_u16_to_u32_conversion(use->parent_instr);
+ }
+
+ if (is_f16_to_f32 || is_f32_to_f16 || is_i16_to_i32 ||
+ is_i32_to_i16 || is_u16_to_u32) {
+ /* All uses are the same conversions. Replace them with mov. */
+ nir_foreach_use(use, &tex->dest.ssa) {
+ nir_alu_instr *conv = nir_instr_as_alu(use->parent_instr);
+ conv->op = nir_op_mov;
+ tex->dest.ssa.bit_size = conv->dest.dest.ssa.bit_size;
+ tex->dest_type = (tex->dest_type & (~16 & ~32 & ~64)) |
+ conv->dest.dest.ssa.bit_size;
+ }
+ changed = true;
+ }
+ }
+ }
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}
+
+/**
+ * Fix types of source operands of texture opcodes according to
+ * the constraints by inserting the appropriate conversion opcodes.
+ *
+ * For example, if the type of derivatives must be equal to texture
+ * coordinates and the type of the texture bias must be 32-bit, there
+ * will be 2 constraints describing that.
+ */
+bool
+nir_legalize_16bit_sampler_srcs(nir_shader *nir,
+ nir_tex_src_type_constraints constraints)
+{
+ bool changed = false;
+ nir_function_impl *impl = nir_shader_get_entrypoint(nir);
+ assert(impl);
+
+ nir_builder b;
+ nir_builder_init(&b, impl);
+
+ nir_foreach_block_safe (block, impl) {
+ nir_foreach_instr_safe (instr, block) {
+ if (instr->type != nir_instr_type_tex)
+ continue;
+
+ nir_tex_instr *tex = nir_instr_as_tex(instr);
+ int8_t map[nir_num_tex_src_types];
+ memset(map, -1, sizeof(map));
+
+ /* Create a mapping from src_type to src[i]. */
+ for (unsigned i = 0; i < tex->num_srcs; i++)
+ map[tex->src[i].src_type] = i;
+
+ /* Legalize src types. */
+ for (unsigned i = 0; i < tex->num_srcs; i++) {
+ nir_tex_src_type_constraint c = constraints[tex->src[i].src_type];
+
+ if (!c.legalize_type)
+ continue;
+
+ /* Determine the required bit size for the src. */
+ unsigned bit_size;
+ if (c.bit_size) {
+ bit_size = c.bit_size;
+ } else {
+ if (map[c.match_src] == -1)
+ continue; /* e.g. txs */
+
+ bit_size = tex->src[map[c.match_src]].src.ssa->bit_size;
+ }
+
+ /* Check if the type is legal. */
+ if (bit_size == tex->src[i].src.ssa->bit_size)
+ continue;
+
+ /* Fix the bit size. */
+ bool is_sint = i == nir_tex_src_offset;
+ bool is_uint = !is_sint &&
+ (tex->op == nir_texop_txf ||
+ tex->op == nir_texop_txf_ms ||
+ tex->op == nir_texop_txs ||
+ tex->op == nir_texop_samples_identical);
+ nir_ssa_def *(*convert)(nir_builder *, nir_ssa_def *);
+
+ switch (bit_size) {
+ case 16:
+ convert = is_sint ? nir_i2i16 :
+ is_uint ? nir_u2u16 : nir_f2f16;
+ break;
+ case 32:
+ convert = is_sint ? nir_i2i32 :
+ is_uint ? nir_u2u32 : nir_f2f32;
+ break;
+ default:
+ assert(!"unexpected bit size");
+ continue;
+ }
+
+ b.cursor = nir_before_instr(&tex->instr);
+ nir_ssa_def *conv =
+ convert(&b, nir_ssa_for_src(&b, tex->src[i].src,
+ tex->src[i].src.ssa->num_components));
+ nir_instr_rewrite_src_ssa(&tex->instr, &tex->src[i].src, conv);
+ changed = true;
+ }
+ }
+ }
+
+ nir_metadata_preserve(impl, nir_metadata_all);
+ return changed;
+}