[Mesa-dev] [PATCH 12/19] i965/fs: Pass fs_regs by constant reference where possible.

[Matt Turner]

These functions (modulo emit_lrp, necessitating the small fix-up) pass
these arguments by value unmodified to other functions. No point in
making an additional copy.
---
 src/mesa/drivers/dri/i965/brw_fs.cpp         |  7 ++++---
 src/mesa/drivers/dri/i965/brw_fs.h           | 14 ++++++++------
 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 12 +++++++-----
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 37b5bb0..7dc83ad 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -238,8 +238,9 @@ fs_visitor::CMP(fs_reg dst, fs_reg src0, fs_reg src1, uint32_t condition)
 }
 
 exec_list
-fs_visitor::VARYING_PULL_CONSTANT_LOAD(fs_reg dst, fs_reg surf_index,
-                                       fs_reg varying_offset,
+fs_visitor::VARYING_PULL_CONSTANT_LOAD(const fs_reg &dst,
+                                       const fs_reg &surf_index,
+                                       const fs_reg &varying_offset,
                                        uint32_t const_offset)
 {
    exec_list instructions;
@@ -3191,7 +3192,7 @@ fs_visitor::dump_instruction(backend_instruction *be_inst)
 fs_inst *
 fs_visitor::get_instruction_generating_reg(fs_inst *start,
 					   fs_inst *end,
-					   fs_reg reg)
+					   const fs_reg &reg)
 {
    if (end == start ||
        end->is_partial_write() ||
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index a1f33e7..da4ef2a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -317,10 +317,11 @@ public:
    int type_size(const struct glsl_type *type);
    fs_inst *get_instruction_generating_reg(fs_inst *start,
 					   fs_inst *end,
-					   fs_reg reg);
+					   const fs_reg &reg);
 
-   exec_list VARYING_PULL_CONSTANT_LOAD(fs_reg dst, fs_reg surf_index,
-                                        fs_reg varying_offset,
+   exec_list VARYING_PULL_CONSTANT_LOAD(const fs_reg &dst,
+                                        const fs_reg &surf_index,
+                                        const fs_reg &varying_offset,
                                         uint32_t const_offset);
 
    bool run();
@@ -399,9 +400,10 @@ public:
    fs_reg fix_math_operand(fs_reg src);
    fs_inst *emit_math(enum opcode op, fs_reg dst, fs_reg src0);
    fs_inst *emit_math(enum opcode op, fs_reg dst, fs_reg src0, fs_reg src1);
-   void emit_lrp(fs_reg dst, fs_reg x, fs_reg y, fs_reg a);
-   void emit_minmax(uint32_t conditionalmod, fs_reg dst,
-                    fs_reg src0, fs_reg src1);
+   void emit_lrp(const fs_reg &dst, const fs_reg &x, const fs_reg &y,
+                 const fs_reg &a);
+   void emit_minmax(uint32_t conditionalmod, const fs_reg &dst,
+                    const fs_reg &src0, const fs_reg &src1);
    bool try_emit_saturate(ir_expression *ir);
    bool try_emit_mad(ir_expression *ir, int mul_arg);
    void try_replace_with_sel();
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 172ad6e..0c376a7 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -212,7 +212,8 @@ fs_visitor::visit(ir_dereference_array *ir)
 }
 
 void
-fs_visitor::emit_lrp(fs_reg dst, fs_reg x, fs_reg y, fs_reg a)
+fs_visitor::emit_lrp(const fs_reg &dst, const fs_reg &x, const fs_reg &y,
+                     const fs_reg &a)
 {
    if (brw->gen < 6 ||
        !x.is_valid_3src() ||
@@ -225,8 +226,9 @@ fs_visitor::emit_lrp(fs_reg dst, fs_reg x, fs_reg y, fs_reg a)
 
       emit(MUL(y_times_a, y, a));
 
-      a.negate = !a.negate;
-      emit(ADD(one_minus_a, a, fs_reg(1.0f)));
+      fs_reg negative_a = a;
+      negative_a.negate = !a.negate;
+      emit(ADD(one_minus_a, negative_a, fs_reg(1.0f)));
       emit(MUL(x_times_one_minus_a, x, one_minus_a));
 
       emit(ADD(dst, x_times_one_minus_a, y_times_a));
@@ -239,8 +241,8 @@ fs_visitor::emit_lrp(fs_reg dst, fs_reg x, fs_reg y, fs_reg a)
 }
 
 void
-fs_visitor::emit_minmax(uint32_t conditionalmod, fs_reg dst,
-                        fs_reg src0, fs_reg src1)
+fs_visitor::emit_minmax(uint32_t conditionalmod, const fs_reg &dst,
+                        const fs_reg &src0, const fs_reg &src1)
 {
    fs_inst *inst;
 
-- 
1.8.3.2