i965/vec4: Add wrapper functions for vec4_instruction::regs_read and ::regs_written.

This is in preparation for dropping vec4_instruction::regs_read and
::regs_written in favor of more accurate alternatives expressed in
byte units.  The main reason these wrappers are useful is that a
number of optimization passes implement dataflow analysis with
register granularity, so these helpers will come in handy once we've
switched register offsets and sizes to the byte representation.  The
wrapper functions will also make sure that GRF misalignment (currently
neglected by most of the back-end) is taken into account correctly in
the calculation of regs_read and regs_written.

Reviewed-by: Iago Toral Quiroga <[email protected]>

6 files changed, 42 insertions, 16 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_ir_vec4.h b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
index 4f49428ef3f..a1a201b8b5f 100644
--- a/src/mesa/drivers/dri/i965/brw_ir_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_ir_vec4.h
@@ -254,6 +254,32 @@ set_saturate(bool saturate, vec4_instruction *inst)
    return inst;
 }
 
+/**
+ * Return the number of dataflow registers written by the instruction (either
+ * fully or partially) counted from 'floor(reg_offset(inst->dst) /
+ * register_size)'.  The somewhat arbitrary register size unit is 16B for the
+ * UNIFORM and IMM files and 32B for all other files.
+ */
+inline unsigned
+regs_written(const vec4_instruction *inst)
+{
+   /* XXX - Take into account register-misaligned offsets correctly. */
+   return inst->regs_written;
+}
+
+/**
+ * Return the number of dataflow registers read by the instruction (either
+ * fully or partially) counted from 'floor(reg_offset(inst->src[i]) /
+ * register_size)'.  The somewhat arbitrary register size unit is 16B for the
+ * UNIFORM and IMM files and 32B for all other files.
+ */
+inline unsigned
+regs_read(const vec4_instruction *inst, unsigned i)
+{
+   /* XXX - Take into account register-misaligned offsets correctly. */
+   return inst->regs_read(i);
+}
+
 } /* namespace brw */
 
 #endif
diff --git a/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp b/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
index 0d3a07cad5b..c12bf09e835 100644
--- a/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
+++ b/src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp
@@ -1269,7 +1269,7 @@ vec4_instruction_scheduler::calculate_deps()
       /* read-after-write deps. */
       for (int i = 0; i < 3; i++) {
          if (inst->src[i].file == VGRF) {
-            for (unsigned j = 0; j < inst->regs_read(i); ++j)
+            for (unsigned j = 0; j < regs_read(inst, i); ++j)
                add_dep(last_grf_write[inst->src[i].nr + j], n);
          } else if (inst->src[i].file == FIXED_GRF) {
             add_dep(last_fixed_grf_write, n);
@@ -1303,7 +1303,7 @@ vec4_instruction_scheduler::calculate_deps()
 
       /* write-after-write deps. */
       if (inst->dst.file == VGRF) {
-         for (unsigned j = 0; j < inst->regs_written; ++j) {
+         for (unsigned j = 0; j < regs_written(inst); ++j) {
             add_dep(last_grf_write[inst->dst.nr + j], n);
             last_grf_write[inst->dst.nr + j] = n;
          }
@@ -1351,7 +1351,7 @@ vec4_instruction_scheduler::calculate_deps()
       /* write-after-read deps. */
       for (int i = 0; i < 3; i++) {
          if (inst->src[i].file == VGRF) {
-            for (unsigned j = 0; j < inst->regs_read(i); ++j)
+            for (unsigned j = 0; j < regs_read(inst, i); ++j)
                add_dep(n, last_grf_write[inst->src[i].nr + j]);
          } else if (inst->src[i].file == FIXED_GRF) {
             add_dep(n, last_fixed_grf_write);
@@ -1384,7 +1384,7 @@ vec4_instruction_scheduler::calculate_deps()
        * can mark this as WAR dependency.
        */
       if (inst->dst.file == VGRF) {
-         for (unsigned j = 0; j < inst->regs_written; ++j)
+         for (unsigned j = 0; j < regs_written(inst); ++j)
             last_grf_write[inst->dst.nr + j] = n;
       } else if (inst->dst.file == MRF) {
          last_mrf_write[inst->dst.nr] = n;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index de5b5d6c838..3e57addb7a4 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -1335,11 +1335,11 @@ vec4_visitor::split_virtual_grfs()
     * to split.
     */
    foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
-      if (inst->dst.file == VGRF && inst->regs_written > 1)
+      if (inst->dst.file == VGRF && regs_written(inst) > 1)
          split_grf[inst->dst.nr] = false;
 
       for (int i = 0; i < 3; i++) {
-         if (inst->src[i].file == VGRF && inst->regs_read(i) > 1)
+         if (inst->src[i].file == VGRF && regs_read(inst, i) > 1)
             split_grf[inst->src[i].nr] = false;
       }
    }
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp
index 10898a5917d..f0908b93fc9 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_cse.cpp
@@ -178,10 +178,10 @@ vec4_visitor::opt_cse_local(bblock_t *block)
             bool no_existing_temp = entry->tmp.file == BAD_FILE;
             if (no_existing_temp && !entry->generator->dst.is_null()) {
                entry->tmp = retype(src_reg(VGRF, alloc.allocate(
-                                              entry->generator->regs_written),
+                                              regs_written(entry->generator)),
                                            NULL), inst->dst.type);
 
-               for (unsigned i = 0; i < entry->generator->regs_written; ++i) {
+               for (unsigned i = 0; i < regs_written(entry->generator); ++i) {
                   vec4_instruction *copy = MOV(offset(entry->generator->dst, i),
                                                offset(entry->tmp, i));
                   copy->force_writemask_all =
@@ -196,7 +196,7 @@ vec4_visitor::opt_cse_local(bblock_t *block)
             if (!inst->dst.is_null()) {
                assert(inst->dst.type == entry->tmp.type);
 
-               for (unsigned i = 0; i < inst->regs_written; ++i) {
+               for (unsigned i = 0; i < regs_written(inst); ++i) {
                   vec4_instruction *copy = MOV(offset(inst->dst, i),
                                                offset(entry->tmp, i));
                   copy->force_writemask_all = inst->force_writemask_all;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp b/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
index c643212494b..50706a977cb 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_dead_code_eliminate.cpp
@@ -59,7 +59,7 @@ vec4_visitor::dead_code_eliminate()
             bool result_live[4] = { false };
 
             if (inst->dst.file == VGRF) {
-               for (unsigned i = 0; i < inst->regs_written; i++) {
+               for (unsigned i = 0; i < regs_written(inst); i++) {
                   for (int c = 0; c < 4; c++)
                      result_live[c] |= BITSET_TEST(
                         live, var_from_reg(alloc, offset(inst->dst, i), c));
@@ -110,7 +110,7 @@ vec4_visitor::dead_code_eliminate()
          }
 
          if (inst->dst.file == VGRF && !inst->predicate) {
-            for (unsigned i = 0; i < inst->regs_written; i++) {
+            for (unsigned i = 0; i < regs_written(inst); i++) {
                for (int c = 0; c < 4; c++) {
                   if (inst->dst.writemask & (1 << c)) {
                      BITSET_CLEAR(live, var_from_reg(alloc,
@@ -132,7 +132,7 @@ vec4_visitor::dead_code_eliminate()
 
          for (int i = 0; i < 3; i++) {
             if (inst->src[i].file == VGRF) {
-               for (unsigned j = 0; j < inst->regs_read(i); j++) {
+               for (unsigned j = 0; j < regs_read(inst, i); j++) {
                   for (int c = 0; c < 4; c++) {
                      BITSET_SET(live, var_from_reg(alloc,
                                                    offset(inst->src[i], j), c));
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
index 57d5fbb75dd..20344ed1770 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.cpp
@@ -76,7 +76,7 @@ vec4_live_variables::setup_def_use()
 	 /* Set use[] for this instruction */
 	 for (unsigned int i = 0; i < 3; i++) {
 	    if (inst->src[i].file == VGRF) {
-               for (unsigned j = 0; j < inst->regs_read(i); j++) {
+               for (unsigned j = 0; j < regs_read(inst, i); j++) {
                   for (int c = 0; c < 4; c++) {
                      const unsigned v =
                         var_from_reg(alloc, offset(inst->src[i], j), c);
@@ -99,7 +99,7 @@ vec4_live_variables::setup_def_use()
 	  */
 	 if (inst->dst.file == VGRF &&
 	     (!inst->predicate || inst->opcode == BRW_OPCODE_SEL)) {
-            for (unsigned i = 0; i < inst->regs_written; i++) {
+            for (unsigned i = 0; i < regs_written(inst); i++) {
                for (int c = 0; c < 4; c++) {
                   if (inst->dst.writemask & (1 << c)) {
                      const unsigned v =
@@ -257,7 +257,7 @@ vec4_visitor::calculate_live_intervals()
    foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
       for (unsigned int i = 0; i < 3; i++) {
 	 if (inst->src[i].file == VGRF) {
-            for (unsigned j = 0; j < inst->regs_read(i); j++) {
+            for (unsigned j = 0; j < regs_read(inst, i); j++) {
                for (int c = 0; c < 4; c++) {
                   const unsigned v =
                      var_from_reg(alloc, offset(inst->src[i], j), c);
@@ -269,7 +269,7 @@ vec4_visitor::calculate_live_intervals()
       }
 
       if (inst->dst.file == VGRF) {
-         for (unsigned i = 0; i < inst->regs_written; i++) {
+         for (unsigned i = 0; i < regs_written(inst); i++) {
             for (int c = 0; c < 4; c++) {
                if (inst->dst.writemask & (1 << c)) {
                   const unsigned v =