[Mesa-dev] [PATCH 1/4] mesa: Add UsesDFdy to struct gl_fragment_program.

[Paul Berry]

The i965 back-end needs to compile dFdy() differently for FBOs and
window system framebuffers, because Y coordinates are flipped between
the two (see commit 82d2596: i965: Compute dFdy() correctly for FBOs).
This boolean will allow it to avoid unnecessarily recompiling shaders
that don't use dFdy().
---
 src/mesa/main/mtypes.h     |    1 +
 src/mesa/program/program.c |    2 ++
 2 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 1f74e6a..4769e10 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -2011,6 +2011,7 @@ struct gl_fragment_program
 {
    struct gl_program Base;   /**< base class */
    GLboolean UsesKill;          /**< shader uses KIL instruction */
+   GLboolean UsesDFdy;          /**< shader uses DDY instruction */
    GLboolean OriginUpperLeft;
    GLboolean PixelCenterInteger;
    enum gl_frag_depth_layout FragDepthLayout;
diff --git a/src/mesa/program/program.c b/src/mesa/program/program.c
index 582cbcc..3ad8377 100644
--- a/src/mesa/program/program.c
+++ b/src/mesa/program/program.c
@@ -551,6 +551,7 @@ _mesa_clone_program(struct gl_context *ctx, const struct gl_program *prog)
             = (const struct gl_fragment_program *) prog;
          struct gl_fragment_program *fpc = (struct gl_fragment_program *) clone;
          fpc->UsesKill = fp->UsesKill;
+         fpc->UsesDFdy = fp->UsesDFdy;
          fpc->OriginUpperLeft = fp->OriginUpperLeft;
          fpc->PixelCenterInteger = fp->PixelCenterInteger;
       }
@@ -772,6 +773,7 @@ _mesa_combine_programs(struct gl_context *ctx,
       newFprog = (struct gl_fragment_program *) newProg;
 
       newFprog->UsesKill = fprogA->UsesKill || fprogB->UsesKill;
+      newFprog->UsesDFdy = fprogA->UsesDFdy || fprogB->UsesDFdy;
 
       /* We'll do a search and replace for instances
        * of progB_colorFile/progB_colorIndex below...
-- 
1.7.7.6