Mesa (master): mesa: only check errors when the state change in glClipControl()

[Samuel Pitoiset]

Module: Mesa
Branch: master
Commit: 58acc32a5e29c0c08bc58bd8348c5730db802019
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=58acc32a5e29c0c08bc58bd8348c5730db802019

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Mon Jul 31 14:07:08 2017 +0200

mesa: only check errors when the state change in glClipControl()

When this GL call is a no-op, it should be a little faster in
the errors path only.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

---

 src/mesa/main/viewport.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
index 90c92eadbf..3dce320d1d 100644
--- a/src/mesa/main/viewport.c
+++ b/src/mesa/main/viewport.c
@@ -492,13 +492,25 @@ void _mesa_init_viewport(struct gl_context *ctx)
 }
 
 
-static void
-clip_control(struct gl_context *ctx, GLenum origin, GLenum depth)
+static ALWAYS_INLINE void
+clip_control(struct gl_context *ctx, GLenum origin, GLenum depth, bool no_error)
 {
    if (ctx->Transform.ClipOrigin == origin &&
        ctx->Transform.ClipDepthMode == depth)
       return;
 
+   if (!no_error &&
+       origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
+      return;
+   }
+
+   if (!no_error &&
+       depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
+      _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
+      return;
+   }
+
    /* Affects transform state and the viewport transform */
    FLUSH_VERTICES(ctx, ctx->DriverFlags.NewClipControl ? 0 :
                   _NEW_TRANSFORM | _NEW_VIEWPORT);
@@ -530,7 +542,7 @@ void GLAPIENTRY
 _mesa_ClipControl_no_error(GLenum origin, GLenum depth)
 {
    GET_CURRENT_CONTEXT(ctx);
-   clip_control(ctx, origin, depth);
+   clip_control(ctx, origin, depth, true);
 }
 
 
@@ -551,17 +563,7 @@ _mesa_ClipControl(GLenum origin, GLenum depth)
       return;
    }
 
-   if (origin != GL_LOWER_LEFT && origin != GL_UPPER_LEFT) {
-      _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
-      return;
-   }
-
-   if (depth != GL_NEGATIVE_ONE_TO_ONE && depth != GL_ZERO_TO_ONE) {
-      _mesa_error(ctx, GL_INVALID_ENUM, "glClipControl");
-      return;
-   }
-
-   clip_control(ctx, origin, depth);
+   clip_control(ctx, origin, depth, false);
 }
 
 /**