mesa: use fi_type in vertex attribute code

For 32-bit builds, floating point operations use x86 FPU registers,
not SSE registers.  If we're actually storing an integer in a float
variable, the value might get modified when written to memory.  This
patch changes the VBO code to use the fi_type (float/int union) to
store/copy vertex attributes.

Also, this can improve performance on x86 because moving floats with
integer registers instead of FP registers is faster.

Neil Roberts review:
- include changes on all places that are storing attribute values.
- check with and without -O3 compiler flag.
Brian Paul review:
- use fi_type type instead gl_constant_value type
- fix a bunch of nit-picks.
- fix compiler warnings

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82668
Signed-off-by: Marius Predut <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 13 insertions, 11 deletions

diff --git a/src/mesa/vbo/vbo_exec_eval.c b/src/mesa/vbo/vbo_exec_eval.c
index 82f89b95f74..409f31abf88 100644
--- a/src/mesa/vbo/vbo_exec_eval.c
+++ b/src/mesa/vbo/vbo_exec_eval.c
@@ -130,11 +130,12 @@ void vbo_exec_do_EvalCoord1f(struct vbo_exec_context *exec, GLfloat u)
       struct gl_1d_map *map = exec->eval.map1[attr].map;
       if (map) {
 	 GLfloat uu = (u - map->u1) * map->du;
-	 GLfloat data[4];
+	 fi_type data[4];
 
-	 ASSIGN_4V(data, 0, 0, 0, 1);
+	 ASSIGN_4V(data, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
+		   FLOAT_AS_UNION(0), FLOAT_AS_UNION(1));
 
-	 _math_horner_bezier_curve(map->Points, data, uu, 
+	 _math_horner_bezier_curve(map->Points, &data[0].f, uu,
 				   exec->eval.map1[attr].sz, 
 				   map->Order);
 
@@ -176,12 +177,13 @@ void vbo_exec_do_EvalCoord2f( struct vbo_exec_context *exec,
       if (map) {
 	 GLfloat uu = (u - map->u1) * map->du;
 	 GLfloat vv = (v - map->v1) * map->dv;
-	 GLfloat data[4];
+	 fi_type data[4];
 
-	 ASSIGN_4V(data, 0, 0, 0, 1);
+	 ASSIGN_4V(data, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
+		   FLOAT_AS_UNION(0), FLOAT_AS_UNION(1));
 
 	 _math_horner_bezier_surf(map->Points, 
-				  data, 
+				  &data[0].f,
 				  uu, vv, 
 				  exec->eval.map2[attr].sz, 
 				  map->Uorder, map->Vorder);
@@ -203,7 +205,7 @@ void vbo_exec_do_EvalCoord2f( struct vbo_exec_context *exec,
       ASSIGN_4V(vertex, 0, 0, 0, 1);
 
       if (exec->ctx->Eval.AutoNormal) {
-	 GLfloat normal[4];
+	 fi_type normal[4];
          GLfloat du[4], dv[4];
 
          _math_de_casteljau_surf(map->Points, vertex, du, dv, uu, vv, 
@@ -221,11 +223,11 @@ void vbo_exec_do_EvalCoord2f( struct vbo_exec_context *exec,
 	 }
 
 
-         CROSS3(normal, du, dv);
-         NORMALIZE_3FV(normal);
-	 normal[3] = 1.0;
+         CROSS3(&normal[0].f, du, dv);
+         NORMALIZE_3FV(&normal[0].f);
+	 normal[3] = FLOAT_AS_UNION(1.0);
 
-	 COPY_SZ_4V( exec->vtx.attrptr[VBO_ATTRIB_NORMAL],
+ 	 COPY_SZ_4V( exec->vtx.attrptr[VBO_ATTRIB_NORMAL],
 		     exec->vtx.attrsz[VBO_ATTRIB_NORMAL],
 		     normal );