i965/fs: Remove fs_reg::smear.

The same effect can be achieved using a combination of ::stride and
::subreg_offset.  Remove the less flexible ::smear to keep the data
members of fs_reg orthogonal.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/mesa/drivers/dri/i965/brw_fs.cpp

@@ -380,7 +380,6 @@ void
 fs_reg::init()
 {
    memset(this, 0, sizeof(*this));
-   this->smear = -1;
    stride = 1;
 }
 
@@ -440,7 +439,6 @@ fs_reg::equals(const fs_reg &r) const
            !reladdr && !r.reladdr &&
            memcmp(&fixed_hw_reg, &r.fixed_hw_reg,
                   sizeof(fixed_hw_reg)) == 0 &&
-           smear == r.smear &&
            stride == r.stride &&
            imm.u == r.imm.u);
 }
@@ -463,6 +461,15 @@ fs_reg::apply_stride(unsigned stride)
    return *this;
 }
 
+fs_reg &
+fs_reg::set_smear(unsigned subreg)
+{
+   assert(file != HW_REG && file != IMM);
+   subreg_offset = subreg * type_sz(type);
+   stride = 0;
+   return *this;
+}
+
 bool
 fs_reg::is_contiguous() const
 {
@@ -567,7 +574,7 @@ fs_visitor::get_timestamp()
     * else that might disrupt timing) by setting smear to 2 and checking if
     * that field is != 0.
     */
-   dst.smear = 0;
+   dst.set_smear(0);
 
    return dst;
 }
@@ -602,7 +609,7 @@ fs_visitor::emit_shader_time_end()
     * were the only two timestamp reads that happened).
     */
    fs_reg reset = shader_end_time;
-   reset.smear = 2;
+   reset.set_smear(2);
    fs_inst *test = emit(AND(reg_null_d, reset, fs_reg(1u)));
    test->conditional_mod = BRW_CONDITIONAL_Z;
    emit(IF(BRW_PREDICATE_NORMAL));
@@ -1973,7 +1980,7 @@ fs_visitor::setup_pull_constants()
 	 inst->src[i].file = GRF;
 	 inst->src[i].reg = dst.reg;
 	 inst->src[i].reg_offset = 0;
-	 inst->src[i].smear = pull_index & 3;
+	 inst->src[i].set_smear(pull_index & 3);
       }
    }
 }
@@ -2334,8 +2341,7 @@ fs_visitor::register_coalesce()
 	  inst->src[0].file != GRF ||
 	  inst->src[0].negate ||
 	  inst->src[0].abs ||
-	  inst->src[0].smear != -1 ||
-          !inst->src[0].is_contiguous() ||
+	  !inst->src[0].is_contiguous() ||
 	  inst->dst.file != GRF ||
 	  inst->dst.type != inst->src[0].type) {
 	 continue;
@@ -2496,7 +2502,7 @@ fs_visitor::compute_to_mrf()
 	  inst->dst.file != MRF || inst->src[0].file != GRF ||
 	  inst->dst.type != inst->src[0].type ||
 	  inst->src[0].abs || inst->src[0].negate ||
-          inst->src[0].smear != -1 || !inst->src[0].is_contiguous() ||
+          !inst->src[0].is_contiguous() ||
           inst->src[0].subreg_offset)
 	 continue;
 

src/mesa/drivers/dri/i965/brw_fs.h

@@ -107,7 +107,9 @@ public:
    bool abs;
    bool sechalf;
    struct brw_reg fixed_hw_reg;
-   int smear; /* -1, or a channel of the reg to smear to all channels. */
+
+   /** Smear a channel of the reg to all channels. */
+   fs_reg &set_smear(unsigned subreg);
 
    /** Value for file == IMM */
    union {

src/mesa/drivers/dri/i965/brw_fs_copy_propagation.cpp

@@ -300,7 +300,7 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
    bool has_source_modifiers = entry->src.abs || entry->src.negate;
 
    if ((has_source_modifiers || entry->src.file == UNIFORM ||
-        entry->src.smear != -1 || !entry->src.is_contiguous()) &&
+        !entry->src.is_contiguous()) &&
        !can_do_source_mods(inst))
       return false;
 
@@ -334,8 +334,6 @@ fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
    inst->src[arg].file = entry->src.file;
    inst->src[arg].reg = entry->src.reg;
    inst->src[arg].reg_offset = entry->src.reg_offset;
-   if (entry->src.smear != -1)
-      inst->src[arg].smear = entry->src.smear;
    inst->src[arg].subreg_offset = entry->src.subreg_offset;
    inst->src[arg].stride *= entry->src.stride;
 

src/mesa/drivers/dri/i965/brw_fs_generator.cpp

@@ -1030,8 +1030,8 @@ brw_reg_from_fs_reg(fs_reg *reg)
    switch (reg->file) {
    case GRF:
    case MRF:
-      if (reg->stride == 0 || reg->smear >= 0) {
-         brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->reg, reg->smear);
+      if (reg->stride == 0) {
+         brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->reg, 0);
       } else {
          brw_reg = brw_vec8_reg(brw_file_from_reg(reg), reg->reg, 0);
          brw_reg = stride(brw_reg, 8 * reg->stride, 8, reg->stride);

src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp

@@ -85,7 +85,7 @@ fs_live_variables::setup_one_read(bblock_t *block, fs_inst *inst,
     * would get stomped by the first decode as well.
     */
    int end_ip = ip;
-   if (v->dispatch_width == 16 && (reg.smear != -1 || reg.stride == 0 ||
+   if (v->dispatch_width == 16 && (reg.stride == 0 ||
                                    (v->pixel_x.reg == reg.reg ||
                                     v->pixel_y.reg == reg.reg))) {
       end_ip++;

src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp

@@ -592,7 +592,7 @@ fs_visitor::choose_spill_reg(struct ra_graph *g)
              * loading pull constants, so spilling them is unlikely to reduce
              * register pressure anyhow.
              */
-            if (inst->src[i].smear >= 0 || !inst->src[i].is_contiguous()) {
+            if (!inst->src[i].is_contiguous()) {
                no_spill[inst->src[i].reg] = true;
             }
 	 }
@@ -601,7 +601,7 @@ fs_visitor::choose_spill_reg(struct ra_graph *g)
       if (inst->dst.file == GRF) {
 	 spill_costs[inst->dst.reg] += inst->regs_written * loop_scale;
 
-         if (inst->dst.smear >= 0 || !inst->dst.is_contiguous()) {
+         if (!inst->dst.is_contiguous()) {
             no_spill[inst->dst.reg] = true;
          }
       }

src/mesa/drivers/dri/i965/brw_fs_visitor.cpp

@@ -744,8 +744,14 @@ fs_visitor::visit(ir_expression *ir)
          emit(fs_inst(FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD,
                       packed_consts, surf_index, const_offset_reg));
 
-         packed_consts.smear = const_offset->value.u[0] % 16 / 4;
          for (int i = 0; i < ir->type->vector_elements; i++) {
+            packed_consts.set_smear(const_offset->value.u[0] % 16 / 4 + i);
+
+            /* The std140 packing rules don't allow vectors to cross 16-byte
+             * boundaries, and a reg is 32 bytes.
+             */
+            assert(packed_consts.subreg_offset < 32);
+
             /* UBO bools are any nonzero value.  We consider bools to be
              * values with the low bit set to 1.  Convert them using CMP.
              */
@@ -755,13 +761,7 @@ fs_visitor::visit(ir_expression *ir)
                emit(MOV(result, packed_consts));
             }
 
-            packed_consts.smear++;
             result.reg_offset++;
-
-            /* The std140 packing rules don't allow vectors to cross 16-byte
-             * boundaries, and a reg is 32 bytes.
-             */
-            assert(packed_consts.smear < 8);
          }
       } else {
          /* Turn the byte offset into a dword offset. */