i965/nir: Replace fs_reg(GRF, virtual_grf_alloc(...)) with vgrf(...).

brw_fs_nir.cpp creates almost all of its registers via:

   fs_reg reg = fs_reg(GRF, virtual_grf_alloc(num_components));

When we add SIMD16 support, we'll need to set reg->width = 16 and
double the VGRF size...on pretty much every VGRF it allocates.

This patch replaces that pattern with a new "vgrf" helper method:

   fs_reg reg = vgrf(num_components);

The new function correctly takes reg_width into account.  For now,
reg_width is always 1, so this should have no functional change.

v2: Just make vgrf() account for reg_width right away, rather than
    changing the behavior in the next patch.

v3: Replace one last virtual_grf_alloc I missed.  It's used in code
    that only runs for dispatch_width == 8, so it doesn't matter,
    but consistency is nice.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Matt Turner <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>

3 files changed, 23 insertions, 13 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 817ca2e860f..6490788118b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1040,6 +1040,14 @@ fs_visitor::vgrf(const glsl_type *const type)
                  brw_type_for_base_type(type), dispatch_width);
 }
 
+fs_reg
+fs_visitor::vgrf(int num_components)
+{
+   int reg_width = dispatch_width / 8;
+   return fs_reg(GRF, virtual_grf_alloc(num_components * reg_width),
+                 BRW_REGISTER_TYPE_F, dispatch_width);
+}
+
 /** Fixed HW reg constructor. */
 fs_reg::fs_reg(enum register_file file, int reg)
 {
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 466f90f476c..1de10bb4b85 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -323,6 +323,7 @@ public:
    fs_reg *variable_storage(ir_variable *var);
    int virtual_grf_alloc(int size);
    fs_reg vgrf(const glsl_type *const type);
+   fs_reg vgrf(int num_components);
    void import_uniforms(fs_visitor *v);
    void setup_uniform_clipplane_values();
    void compute_clip_distance();
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 7d7c04cedc7..c4c7d60608b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -95,12 +95,12 @@ fs_visitor::emit_nir_code()
     */
 
    if (nir->num_inputs > 0) {
-      nir_inputs = fs_reg(GRF, virtual_grf_alloc(nir->num_inputs));
+      nir_inputs = vgrf(nir->num_inputs);
       nir_setup_inputs(nir);
    }
 
    if (nir->num_outputs > 0) {
-      nir_outputs = fs_reg(GRF, virtual_grf_alloc(nir->num_outputs));
+      nir_outputs = vgrf(nir->num_outputs);
       nir_setup_outputs(nir);
    }
 
@@ -116,7 +116,7 @@ fs_visitor::emit_nir_code()
       unsigned array_elems =
          reg->num_array_elems == 0 ? 1 : reg->num_array_elems;
       unsigned size = array_elems * reg->num_components;
-      nir_globals[reg->index] = fs_reg(GRF, virtual_grf_alloc(size));
+      nir_globals[reg->index] = vgrf(size);
    }
 
    /* get the main function and emit it */
@@ -356,7 +356,7 @@ fs_visitor::nir_emit_impl(nir_function_impl *impl)
       unsigned array_elems =
          reg->num_array_elems == 0 ? 1 : reg->num_array_elems;
       unsigned size = array_elems * reg->num_components;
-      nir_locals[reg->index] = fs_reg(GRF, virtual_grf_alloc(size));
+      nir_locals[reg->index] = vgrf(size);
    }
 
    nir_emit_cf_list(&impl->body);
@@ -730,7 +730,7 @@ fs_visitor::nir_emit_alu(nir_alu_instr *instr)
    case nir_op_ball_fequal4:
    case nir_op_ball_iequal4: {
       unsigned num_components = nir_op_infos[instr->op].input_sizes[0];
-      fs_reg temp = fs_reg(GRF, virtual_grf_alloc(num_components));
+      fs_reg temp = vgrf(num_components);
       emit_percomp(CMP(temp, op[0], op[1], BRW_CONDITIONAL_Z),
                    (1 << num_components) - 1);
       emit_reduction(BRW_OPCODE_AND, result, temp, num_components);
@@ -744,7 +744,7 @@ fs_visitor::nir_emit_alu(nir_alu_instr *instr)
    case nir_op_bany_fnequal4:
    case nir_op_bany_inequal4: {
       unsigned num_components = nir_op_infos[instr->op].input_sizes[0];
-      fs_reg temp = fs_reg(GRF, virtual_grf_alloc(num_components));
+      fs_reg temp = vgrf(num_components);
       temp.type = BRW_REGISTER_TYPE_UD;
       emit_percomp(CMP(temp, op[0], op[1], BRW_CONDITIONAL_NZ),
                    (1 << num_components) - 1);
@@ -769,7 +769,7 @@ fs_visitor::nir_emit_alu(nir_alu_instr *instr)
    case nir_op_fdot3:
    case nir_op_fdot4: {
       unsigned num_components = nir_op_infos[instr->op].input_sizes[0];
-      fs_reg temp = fs_reg(GRF, virtual_grf_alloc(num_components));
+      fs_reg temp = vgrf(num_components);
       emit_percomp(MUL(temp, op[0], op[1]), (1 << num_components) - 1);
       emit_reduction(BRW_OPCODE_ADD, result, temp, num_components);
       if (instr->dest.saturate) {
@@ -1038,8 +1038,8 @@ fs_visitor::get_nir_src(nir_src src)
    if (src.is_ssa) {
       assert(src.ssa->parent_instr->type == nir_instr_type_load_const);
       nir_load_const_instr *load = nir_instr_as_load_const(src.ssa->parent_instr);
-      fs_reg reg(GRF, virtual_grf_alloc(src.ssa->num_components),
-                 BRW_REGISTER_TYPE_D);
+      fs_reg reg = vgrf(src.ssa->num_components);
+      reg.type = BRW_REGISTER_TYPE_D;
 
       for (unsigned i = 0; i < src.ssa->num_components; ++i)
          emit(MOV(offset(reg, i), fs_reg(load->value.i[i])));
@@ -1091,7 +1091,8 @@ fs_visitor::get_nir_alu_src(nir_alu_instr *instr, unsigned src)
 
    if (needs_swizzle) {
       /* resolve the swizzle through MOV's */
-      fs_reg new_reg = fs_reg(GRF, virtual_grf_alloc(num_components), reg.type);
+      fs_reg new_reg = vgrf(num_components);
+      new_reg.type = reg.type;
 
       for (unsigned i = 0; i < 4; i++) {
          if (!nir_alu_instr_channel_used(instr, src, i))
@@ -1244,7 +1245,7 @@ fs_visitor::emit_reduction(enum opcode op, fs_reg dest, fs_reg src,
       return;
    }
 
-   fs_reg temp1 = fs_reg(GRF, virtual_grf_alloc(1));
+   fs_reg temp1 = vgrf(1);
    temp1.type = src.type;
    emit(op, temp1, src0, src1);
 
@@ -1260,7 +1261,7 @@ fs_visitor::emit_reduction(enum opcode op, fs_reg dest, fs_reg src,
 
    fs_reg src3 = src;
    src3.reg_offset += 3;
-   fs_reg temp2 = fs_reg(GRF, virtual_grf_alloc(1));
+   fs_reg temp2 = vgrf(1);
    temp2.type = src.type;
 
    emit(op, temp2, src2, src3);
@@ -1487,7 +1488,7 @@ fs_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
        */
       no16("interpolate_at_* not yet supported in SIMD16 mode.");
 
-      fs_reg dst_x(GRF, virtual_grf_alloc(2), BRW_REGISTER_TYPE_F);
+      fs_reg dst_x = vgrf(2);
       fs_reg dst_y = offset(dst_x, 1);
 
       /* For most messages, we need one reg of ignored data; the hardware