[Mesa-dev] [PATCH 10/23] i965/fs: Remove fs_reg::sechalf.

[Francisco Jerez]

The same effect can be achieved using ::subreg_offset.  Remove the
less flexible alternative and define a convenience function to keep
the fs_reg interface sane.
---
 src/mesa/drivers/dri/i965/brw_fs.cpp           |  9 ++-------
 src/mesa/drivers/dri/i965/brw_fs.h             | 11 ++++++++++-
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp |  2 --
 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp   |  4 +---
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index e6e32fc..6b9c9b5 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1186,22 +1186,18 @@ fs_visitor::emit_samplepos_setup(ir_variable *ir)
 
    emit(MOV(int_sample_x, fs_reg(sample_pos_reg)));
    if (dispatch_width == 16) {
-      int_sample_x.sechalf = true;
-      fs_inst *inst = emit(MOV(int_sample_x,
+      fs_inst *inst = emit(MOV(half(int_sample_x, 1),
                                fs_reg(suboffset(sample_pos_reg, 16))));
       inst->force_sechalf = true;
-      int_sample_x.sechalf = false;
    }
    /* Compute gl_SamplePosition.x */
    compute_sample_position(pos, int_sample_x);
    pos.reg_offset++;
    emit(MOV(int_sample_y, fs_reg(suboffset(sample_pos_reg, 1))));
    if (dispatch_width == 16) {
-      int_sample_y.sechalf = true;
-      fs_inst *inst = emit(MOV(int_sample_y,
+      fs_inst *inst = emit(MOV(half(int_sample_y, 1),
                                fs_reg(suboffset(sample_pos_reg, 17))));
       inst->force_sechalf = true;
-      int_sample_y.sechalf = false;
    }
    /* Compute gl_SamplePosition.y */
    compute_sample_position(pos, int_sample_y);
@@ -2446,7 +2442,6 @@ fs_visitor::register_coalesce()
                   new_src.abs = 1;
                }
 	       new_src.negate ^= scan_inst->src[i].negate;
-	       new_src.sechalf = scan_inst->src[i].sechalf;
                new_src.subreg_offset +=
                   scan_inst->src[i].subreg_offset * new_src.stride;
                new_src.stride *= scan_inst->src[i].stride;
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index e36943c..2c36d9f 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -86,7 +86,6 @@ public:
 
    bool negate;
    bool abs;
-   bool sechalf;
    int subreg_offset; /**< Offset in bytes from the start of the register. */
    int stride; /**< Register region horizontal stride */
 
@@ -101,6 +100,16 @@ byte_offset(fs_reg reg, unsigned delta)
    return reg;
 }
 
+/**
+ * Get either of the 8-component halves of a 16-component register.
+ */
+static inline fs_reg
+half(const fs_reg &reg, unsigned idx)
+{
+   assert(idx == 0 || (reg.file != HW_REG && reg.file != IMM));
+   return byte_offset(reg, 8 * idx * reg.stride * type_sz(reg.type));
+}
+
 static const fs_reg reg_undef;
 static const fs_reg reg_null_f(retype(brw_null_reg(), BRW_REGISTER_TYPE_F));
 static const fs_reg reg_null_d(retype(brw_null_reg(), BRW_REGISTER_TYPE_D));
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 3972fda..8d310a1 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -996,8 +996,6 @@ brw_reg_from_fs_reg(fs_reg *reg)
       }
 
       brw_reg = retype(brw_reg, reg->type);
-      if (reg->sechalf)
-	 brw_reg = sechalf(brw_reg);
       brw_reg = byte_offset(brw_reg, reg->subreg_offset);
       break;
    case IMM:
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 8a76094..5693dbc 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -2598,12 +2598,10 @@ fs_visitor::emit_color_write(int target, int index, int first_color_mrf)
 	 inst->saturate = c->key.clamp_fragment_color;
 	 pop_force_uncompressed();
 
-	 color.sechalf = true;
 	 inst = emit(MOV(fs_reg(MRF, first_color_mrf + index + 4, color.type),
-                         color));
+                         half(color, 1)));
 	 inst->force_sechalf = true;
 	 inst->saturate = c->key.clamp_fragment_color;
-	 color.sechalf = false;
       }
    }
 }
-- 
1.8.3.4