[Mesa-dev] [PATCH 4/5] i965: Remove some dead code optimization passes.
Kenneth Graunke
kenneth at whitecape.org
Tue Nov 13 21:09:37 PST 2012
The old brw_remove_grf_to_mrf_moves() pass is obsolete and replaced by
fs_visitor::compute_to_mrf().
The old brw_remove_duplicate_mrf_moves() pass is obsolete and replaced
by fs_visitor::remove_duplicate_mrf_writes().
The remaining pass, brw_set_dp4_dependency_control(), is currently
unused, but could be, so I'm leaving it for now.
---
src/mesa/drivers/dri/i965/brw_optimize.c | 544 -------------------------------
1 file changed, 544 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_optimize.c b/src/mesa/drivers/dri/i965/brw_optimize.c
index 1e3f4d9..bb6e837 100644
--- a/src/mesa/drivers/dri/i965/brw_optimize.c
+++ b/src/mesa/drivers/dri/i965/brw_optimize.c
@@ -86,550 +86,6 @@ const struct brw_instruction_info brw_opcodes[128] = {
[BRW_OPCODE_ENDIF] = { .name = "endif", .nsrc = 2, .ndst = 0 },
};
-static INLINE
-bool brw_is_arithmetic_inst(const struct brw_instruction *inst)
-{
- return brw_opcodes[inst->header.opcode].is_arith;
-}
-
-static const GLuint inst_stride[7] = {
- [0] = 0,
- [1] = 1,
- [2] = 2,
- [3] = 4,
- [4] = 8,
- [5] = 16,
- [6] = 32
-};
-
-static const GLuint inst_type_size[8] = {
- [BRW_REGISTER_TYPE_UD] = 4,
- [BRW_REGISTER_TYPE_D] = 4,
- [BRW_REGISTER_TYPE_UW] = 2,
- [BRW_REGISTER_TYPE_W] = 2,
- [BRW_REGISTER_TYPE_UB] = 1,
- [BRW_REGISTER_TYPE_B] = 1,
- [BRW_REGISTER_TYPE_F] = 4
-};
-
-static INLINE bool
-brw_is_grf_written(const struct brw_instruction *inst,
- int reg_index, int size,
- int gen)
-{
- if (brw_opcodes[inst->header.opcode].ndst == 0)
- return false;
-
- if (inst->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT)
- if (inst->bits1.ia1.dest_reg_file == BRW_GENERAL_REGISTER_FILE)
- return true;
-
- if (inst->bits1.da1.dest_reg_file != BRW_GENERAL_REGISTER_FILE)
- return false;
-
- const int reg_start = reg_index * REG_SIZE;
- const int reg_end = reg_start + size;
-
- const int type_size = inst_type_size[inst->bits1.da1.dest_reg_type];
- const int write_start = inst->bits1.da1.dest_reg_nr*REG_SIZE
- + inst->bits1.da1.dest_subreg_nr;
- int length, write_end;
-
- /* SEND is specific */
- if (inst->header.opcode == BRW_OPCODE_SEND) {
- if (gen >= 5)
- length = inst->bits3.generic_gen5.response_length*REG_SIZE;
- else
- length = inst->bits3.generic.response_length*REG_SIZE;
- }
- else {
- length = 1 << inst->header.execution_size;
- length *= type_size;
- length *= inst->bits1.da1.dest_horiz_stride;
- }
-
- /* If the two intervals intersect, we overwrite the register */
- write_end = write_start + length;
- const int left = MAX2(write_start, reg_start);
- const int right = MIN2(write_end, reg_end);
-
- return left < right;
-}
-
-static bool
-brw_is_mrf_written_alu(const struct brw_instruction *inst,
- int reg_index, int size)
-{
- if (brw_opcodes[inst->header.opcode].ndst == 0)
- return false;
-
- if (inst->bits1.da1.dest_reg_file != BRW_MESSAGE_REGISTER_FILE)
- return false;
-
- if (inst->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT)
- return true;
-
- const int reg_start = reg_index * REG_SIZE;
- const int reg_end = reg_start + size;
-
- const int mrf_index = inst->bits1.da1.dest_reg_nr & 0x0f;
- const int is_compr4 = inst->bits1.da1.dest_reg_nr & BRW_MRF_COMPR4;
- const int type_size = inst_type_size[inst->bits1.da1.dest_reg_type];
-
- /* We use compr4 with a size != 16 elements. Strange, we conservatively
- * consider that we are writing the register.
- */
- if (is_compr4 && inst->header.execution_size != BRW_EXECUTE_16)
- return true;
-
- /* Here we write mrf_{i} and mrf_{i+4}. So we read two times 8 elements */
- if (is_compr4) {
- const int length = 8 * type_size * inst->bits1.da1.dest_horiz_stride;
-
- /* First 8-way register */
- const int write_start0 = mrf_index*REG_SIZE
- + inst->bits1.da1.dest_subreg_nr;
- const int write_end0 = write_start0 + length;
-
- /* Second 8-way register */
- const int write_start1 = (mrf_index+4)*REG_SIZE
- + inst->bits1.da1.dest_subreg_nr;
- const int write_end1 = write_start1 + length;
-
- /* If the two intervals intersect, we overwrite the register */
- const int left0 = MAX2(write_start0, reg_start);
- const int right0 = MIN2(write_end0, reg_end);
- const int left1 = MAX2(write_start1, reg_start);
- const int right1 = MIN2(write_end1, reg_end);
-
- if (left0 < right0 || left1 < right1)
- return true;
- }
- else {
- int length;
- length = 1 << inst->header.execution_size;
- length *= type_size;
- length *= inst->bits1.da1.dest_horiz_stride;
-
- /* If the two intervals intersect, we write into the register */
- const int write_start = inst->bits1.da1.dest_reg_nr*REG_SIZE
- + inst->bits1.da1.dest_subreg_nr;
- const int write_end = write_start + length;
- const int left = MAX2(write_start, reg_start);
- const int right = MIN2(write_end, reg_end);
-
- if (left < right)
- return true;
- }
-
- return false;
-}
-
-/* SEND may perform an implicit mov to a mrf register */
-static bool
-brw_is_mrf_written_send(const struct brw_instruction *inst,
- int reg_index, int size)
-{
-
- const int reg_start = reg_index * REG_SIZE;
- const int reg_end = reg_start + size;
- const int mrf_start = inst->header.destreg__conditionalmod;
- const int write_start = mrf_start * REG_SIZE;
- const int write_end = write_start + REG_SIZE;
- const int left = MAX2(write_start, reg_start);
- const int right = MIN2(write_end, reg_end);
-
- if (inst->header.opcode != BRW_OPCODE_SEND ||
- inst->bits1.da1.src0_reg_file == 0)
- return false;
-
- return left < right;
-}
-
-/* Specific path for message register since we need to handle the compr4 case */
-static INLINE bool
-brw_is_mrf_written(const struct brw_instruction *inst, int reg_index, int size)
-{
- return (brw_is_mrf_written_alu(inst, reg_index, size) ||
- brw_is_mrf_written_send(inst, reg_index, size));
-}
-
-static INLINE bool
-brw_is_mrf_read(const struct brw_instruction *inst,
- int reg_index, int size, int gen)
-{
- if (inst->header.opcode != BRW_OPCODE_SEND)
- return false;
- if (inst->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT)
- return true;
-
- const int reg_start = reg_index*REG_SIZE;
- const int reg_end = reg_start + size;
-
- int length, read_start, read_end;
- if (gen >= 5)
- length = inst->bits3.generic_gen5.msg_length*REG_SIZE;
- else
- length = inst->bits3.generic.msg_length*REG_SIZE;
-
- /* Look if SEND uses an implicit mov. In that case, we read one less register
- * (but we write it)
- */
- if (inst->bits1.da1.src0_reg_file != 0)
- read_start = inst->header.destreg__conditionalmod;
- else {
- length--;
- read_start = inst->header.destreg__conditionalmod + 1;
- }
- read_start *= REG_SIZE;
- read_end = read_start + length;
-
- const int left = MAX2(read_start, reg_start);
- const int right = MIN2(read_end, reg_end);
-
- return left < right;
-}
-
-static INLINE bool
-brw_is_grf_read(const struct brw_instruction *inst, int reg_index, int size)
-{
- int i, j;
- if (brw_opcodes[inst->header.opcode].nsrc == 0)
- return false;
-
- /* Look at first source. We must take into account register regions to
- * monitor carefully the read. Note that we are a bit too conservative here
- * since we do not take into account the fact that some complete registers
- * may be skipped
- */
- if (brw_opcodes[inst->header.opcode].nsrc >= 1) {
-
- if (inst->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT)
- if (inst->bits1.ia1.src0_reg_file == BRW_GENERAL_REGISTER_FILE)
- return true;
- if (inst->bits1.da1.src0_reg_file != BRW_GENERAL_REGISTER_FILE)
- return false;
-
- const int reg_start = reg_index*REG_SIZE;
- const int reg_end = reg_start + size;
-
- /* See if at least one of this element intersects the interval */
- const int type_size = inst_type_size[inst->bits1.da1.src0_reg_type];
- const int elem_num = 1 << inst->header.execution_size;
- const int width = 1 << inst->bits2.da1.src0_width;
- const int row_num = elem_num >> inst->bits2.da1.src0_width;
- const int hs = type_size*inst_stride[inst->bits2.da1.src0_horiz_stride];
- const int vs = type_size*inst_stride[inst->bits2.da1.src0_vert_stride];
- int row_start = inst->bits2.da1.src0_reg_nr*REG_SIZE
- + inst->bits2.da1.src0_subreg_nr;
- for (j = 0; j < row_num; ++j) {
- int write_start = row_start;
- for (i = 0; i < width; ++i) {
- const int write_end = write_start + type_size;
- const int left = write_start > reg_start ? write_start : reg_start;
- const int right = write_end < reg_end ? write_end : reg_end;
- if (left < right)
- return true;
- write_start += hs;
- }
- row_start += vs;
- }
- }
-
- /* Second src register */
- if (brw_opcodes[inst->header.opcode].nsrc >= 2) {
-
- if (inst->bits3.da1.src1_address_mode != BRW_ADDRESS_DIRECT)
- if (inst->bits1.ia1.src1_reg_file == BRW_GENERAL_REGISTER_FILE)
- return true;
- if (inst->bits1.da1.src1_reg_file != BRW_GENERAL_REGISTER_FILE)
- return false;
-
- const int reg_start = reg_index*REG_SIZE;
- const int reg_end = reg_start + size;
-
- /* See if at least one of this element intersects the interval */
- const int type_size = inst_type_size[inst->bits1.da1.src1_reg_type];
- const int elem_num = 1 << inst->header.execution_size;
- const int width = 1 << inst->bits3.da1.src1_width;
- const int row_num = elem_num >> inst->bits3.da1.src1_width;
- const int hs = type_size*inst_stride[inst->bits3.da1.src1_horiz_stride];
- const int vs = type_size*inst_stride[inst->bits3.da1.src1_vert_stride];
- int row_start = inst->bits3.da1.src1_reg_nr*REG_SIZE
- + inst->bits3.da1.src1_subreg_nr;
- for (j = 0; j < row_num; ++j) {
- int write_start = row_start;
- for (i = 0; i < width; ++i) {
- const int write_end = write_start + type_size;
- const int left = write_start > reg_start ? write_start : reg_start;
- const int right = write_end < reg_end ? write_end : reg_end;
- if (left < right)
- return true;
- write_start += hs;
- }
- row_start += vs;
- }
- }
-
- return false;
-}
-
-static INLINE bool
-brw_is_control_done(const struct brw_instruction *mov) {
- return
- mov->header.dependency_control != 0 ||
- mov->header.thread_control != 0 ||
- mov->header.mask_control != 0 ||
- mov->header.saturate != 0 ||
- mov->header.debug_control != 0;
-}
-
-static INLINE bool
-brw_is_predicated(const struct brw_instruction *mov) {
- return mov->header.predicate_control != 0;
-}
-
-static INLINE bool
-brw_is_grf_to_mrf_mov(const struct brw_instruction *mov,
- int *mrf_index,
- int *grf_index,
- bool *is_compr4)
-{
- if (brw_is_predicated(mov) ||
- brw_is_control_done(mov) ||
- mov->header.debug_control != 0)
- return false;
-
- if (mov->bits1.da1.dest_address_mode != BRW_ADDRESS_DIRECT ||
- mov->bits1.da1.dest_reg_file != BRW_MESSAGE_REGISTER_FILE ||
- mov->bits1.da1.dest_reg_type != BRW_REGISTER_TYPE_F ||
- mov->bits1.da1.dest_horiz_stride != BRW_HORIZONTAL_STRIDE_1 ||
- mov->bits1.da1.dest_subreg_nr != 0)
- return false;
-
- if (mov->bits2.da1.src0_address_mode != BRW_ADDRESS_DIRECT ||
- mov->bits1.da1.src0_reg_file != BRW_GENERAL_REGISTER_FILE ||
- mov->bits1.da1.src0_reg_type != BRW_REGISTER_TYPE_F ||
- mov->bits2.da1.src0_width != BRW_WIDTH_8 ||
- mov->bits2.da1.src0_horiz_stride != BRW_HORIZONTAL_STRIDE_1 ||
- mov->bits2.da1.src0_vert_stride != BRW_VERTICAL_STRIDE_8 ||
- mov->bits2.da1.src0_subreg_nr != 0 ||
- mov->bits2.da1.src0_abs != 0 ||
- mov->bits2.da1.src0_negate != 0)
- return false;
-
- *grf_index = mov->bits2.da1.src0_reg_nr;
- *mrf_index = mov->bits1.da1.dest_reg_nr & 0x0f;
- *is_compr4 = (mov->bits1.da1.dest_reg_nr & BRW_MRF_COMPR4) != 0;
- return true;
-}
-
-static INLINE bool
-brw_is_grf_straight_write(const struct brw_instruction *inst, int grf_index)
-{
- /* remark: no problem to predicate a SEL instruction */
- if ((!brw_is_predicated(inst) || inst->header.opcode == BRW_OPCODE_SEL) &&
- brw_is_control_done(inst) == false &&
- inst->header.execution_size == 4 &&
- inst->header.access_mode == BRW_ALIGN_1 &&
- inst->bits1.da1.dest_address_mode == BRW_ADDRESS_DIRECT &&
- inst->bits1.da1.dest_reg_file == BRW_GENERAL_REGISTER_FILE &&
- inst->bits1.da1.dest_reg_type == BRW_REGISTER_TYPE_F &&
- inst->bits1.da1.dest_horiz_stride == BRW_HORIZONTAL_STRIDE_1 &&
- inst->bits1.da1.dest_reg_nr == grf_index &&
- inst->bits1.da1.dest_subreg_nr == 0 &&
- brw_is_arithmetic_inst(inst))
- return true;
-
- return false;
-}
-
-static INLINE bool
-brw_inst_are_equal(const struct brw_instruction *src0,
- const struct brw_instruction *src1)
-{
- const GLuint *field0 = (GLuint *) src0;
- const GLuint *field1 = (GLuint *) src1;
- return field0[0] == field1[0] &&
- field0[1] == field1[1] &&
- field0[2] == field1[2] &&
- field0[3] == field1[3];
-}
-
-static INLINE void
-brw_inst_copy(struct brw_instruction *dst,
- const struct brw_instruction *src)
-{
- GLuint *field_dst = (GLuint *) dst;
- const GLuint *field_src = (GLuint *) src;
- field_dst[0] = field_src[0];
- field_dst[1] = field_src[1];
- field_dst[2] = field_src[2];
- field_dst[3] = field_src[3];
-}
-
-static void brw_remove_inst(struct brw_compile *p, const bool *removeInst)
-{
- int i, nr_insn = 0, to = 0, from = 0;
-
- for (from = 0; from < p->nr_insn; ++from) {
- if (removeInst[from])
- continue;
- if(to != from)
- brw_inst_copy(p->store + to, p->store + from);
- to++;
- }
-
- for (i = 0; i < p->nr_insn; ++i)
- if (removeInst[i] == false)
- nr_insn++;
- p->nr_insn = nr_insn;
-}
-
-/* The gen code emitter generates a lot of duplications in the
- * grf-to-mrf moves, for example when texture sampling with the same
- * coordinates from multiple textures.. Here, we monitor same mov
- * grf-to-mrf instrutions and remove repeated ones where the operands
- * and dst ahven't changed in between.
- */
-void brw_remove_duplicate_mrf_moves(struct brw_compile *p)
-{
- const int gen = p->brw->intel.gen;
- int i, j;
-
- bool *removeInst = calloc(sizeof(bool), p->nr_insn);
- for (i = 0; i < p->nr_insn; i++) {
- if (removeInst[i])
- continue;
-
- const struct brw_instruction *mov = p->store + i;
- int mrf_index, grf_index;
- bool is_compr4;
-
- /* Only consider _straight_ grf-to-mrf moves */
- if (!brw_is_grf_to_mrf_mov(mov, &mrf_index, &grf_index, &is_compr4))
- continue;
-
- const int mrf_index0 = mrf_index;
- const int mrf_index1 = is_compr4 ? mrf_index0+4 : mrf_index0+1;
- const int simd16_size = 2 * REG_SIZE;
-
- for (j = i + 1; j < p->nr_insn; j++) {
- const struct brw_instruction *inst = p->store + j;
-
- if (brw_inst_are_equal(mov, inst)) {
- removeInst[j] = true;
- continue;
- }
-
- if (brw_is_grf_written(inst, grf_index, simd16_size, gen) ||
- brw_is_mrf_written(inst, mrf_index0, REG_SIZE) ||
- brw_is_mrf_written(inst, mrf_index1, REG_SIZE))
- break;
- }
- }
-
- brw_remove_inst(p, removeInst);
- free(removeInst);
-}
-
-/* Replace moves to MRFs where the value moved is the result of a
- * normal arithmetic operation with computation right into the MRF.
- */
-void brw_remove_grf_to_mrf_moves(struct brw_compile *p)
-{
- int i, j, prev;
- struct brw_context *brw = p->brw;
- const int gen = brw->intel.gen;
- const int simd16_size = 2*REG_SIZE;
-
- bool *removeInst = calloc(sizeof(bool), p->nr_insn);
- assert(removeInst);
-
- for (i = 0; i < p->nr_insn; i++) {
- if (removeInst[i])
- continue;
-
- struct brw_instruction *grf_inst = NULL;
- const struct brw_instruction *mov = p->store + i;
- int mrf_index, grf_index;
- bool is_compr4;
-
- /* Only consider _straight_ grf-to-mrf moves */
- if (!brw_is_grf_to_mrf_mov(mov, &mrf_index, &grf_index, &is_compr4))
- continue;
-
- /* Using comp4 enables a stride of 4 for this instruction */
- const int mrf_index0 = mrf_index;
- const int mrf_index1 = is_compr4 ? mrf_index+4 : mrf_index+1;
-
- /* Look where the register has been set */
- prev = i;
- bool potential_remove = false;
- while (prev--) {
-
- /* If _one_ instruction writes the grf, we try to remove the mov */
- struct brw_instruction *inst = p->store + prev;
- if (brw_is_grf_straight_write(inst, grf_index)) {
- potential_remove = true;
- grf_inst = inst;
- break;
- }
-
- }
-
- if (potential_remove == false)
- continue;
- removeInst[i] = true;
-
- /* Monitor first the section of code between the grf computation and the
- * mov. Here we cannot read or write both mrf and grf register
- */
- for (j = prev + 1; j < i; ++j) {
- struct brw_instruction *inst = p->store + j;
- if (removeInst[j])
- continue;
- if (brw_is_grf_written(inst, grf_index, simd16_size, gen) ||
- brw_is_grf_read(inst, grf_index, simd16_size) ||
- brw_is_mrf_written(inst, mrf_index0, REG_SIZE) ||
- brw_is_mrf_written(inst, mrf_index1, REG_SIZE) ||
- brw_is_mrf_read(inst, mrf_index0, REG_SIZE, gen) ||
- brw_is_mrf_read(inst, mrf_index1, REG_SIZE, gen)) {
- removeInst[i] = false;
- break;
- }
- }
-
- /* After the mov, we can read or write the mrf. If the grf is overwritten,
- * we are done
- */
- for (j = i + 1; j < p->nr_insn; ++j) {
- struct brw_instruction *inst = p->store + j;
- if (removeInst[j])
- continue;
-
- if (brw_is_grf_read(inst, grf_index, simd16_size)) {
- removeInst[i] = false;
- break;
- }
-
- if (brw_is_grf_straight_write(inst, grf_index))
- break;
- }
-
- /* Note that with the top down traversal, we can safely pacth the mov
- * instruction
- */
- if (removeInst[i]) {
- grf_inst->bits1.da1.dest_reg_file = mov->bits1.da1.dest_reg_file;
- grf_inst->bits1.da1.dest_reg_nr = mov->bits1.da1.dest_reg_nr;
- }
- }
-
- brw_remove_inst(p, removeInst);
- free(removeInst);
-}
-
static bool
is_single_channel_dp4(struct brw_instruction *insn)
{
--
1.8.0
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