i965/hsw: Apply gather4 RG32F w/a using SCS instead of shader.

The new surface channel select bits allow us to avoid having to
recompile the shader for this workaround.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-and-tested-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c
index 3d1ed447cc836d8dd0ac86b46b8ea778feea9b36..6ce58dda35a9e2848ea5e22d8a08b1a6630a9fc4 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm.c
+++ b/src/mesa/drivers/dri/i965/brw_wm.c
@@ -346,8 +346,9 @@ brw_populate_sampler_prog_key_data(struct gl_context *ctx,
               key->gl_clamp_mask[2] |= 1 << s;
         }
 
-         /* gather4's channel select for green from RG32F is broken */
-         if (brw->gen >= 7 && prog->UsesGather) {
+         /* gather4's channel select for green from RG32F is broken;
+          * requires a shader w/a on IVB; fixable with just SCS on HSW. */
+         if (brw->gen >= 7 && !brw->is_haswell && prog->UsesGather) {
             if (img->InternalFormat == GL_RG32F && GET_SWZ(t->_Swizzle, 0) == 1)
                key->gather_channel_quirk_mask |= 1 << s;
          }

diff --git a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
index 7f934f89e834e4f70ff6715994f808cae1c4a76b..564ac7616587578f0b0f6e352febaeecc5446c8f 100644 (file)
--- a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
@@ -42,13 +42,13 @@
  * "Shader Channel Select" enumerations (i.e. HSW_SCS_RED)
  */
 static unsigned
-swizzle_to_scs(GLenum swizzle)
+swizzle_to_scs(GLenum swizzle, bool need_green_to_blue)
 {
    switch (swizzle) {
    case SWIZZLE_X:
       return HSW_SCS_RED;
    case SWIZZLE_Y:
-      return HSW_SCS_GREEN;
+      return need_green_to_blue ? HSW_SCS_BLUE : HSW_SCS_GREEN;
    case SWIZZLE_Z:
       return HSW_SCS_BLUE;
    case SWIZZLE_W:
@@ -369,11 +369,13 @@ gen7_update_texture_surface(struct gl_context *ctx,
       const int swizzle = unlikely(alpha_depth)
          ? SWIZZLE_XYZW : brw_get_texture_swizzle(ctx, tObj);
 
+      const bool need_scs_green_to_blue = for_gather && tex_format == BRW_SURFACEFORMAT_R32G32_FLOAT_LD;
+
       surf[7] =
-         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 0)), GEN7_SURFACE_SCS_R) |
-         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 1)), GEN7_SURFACE_SCS_G) |
-         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 2)), GEN7_SURFACE_SCS_B) |
-         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 3)), GEN7_SURFACE_SCS_A);
+         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 0), need_scs_green_to_blue), GEN7_SURFACE_SCS_R) |
+         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 1), need_scs_green_to_blue), GEN7_SURFACE_SCS_G) |
+         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 2), need_scs_green_to_blue), GEN7_SURFACE_SCS_B) |
+         SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 3), need_scs_green_to_blue), GEN7_SURFACE_SCS_A);
    }
 
    /* Emit relocation to surface contents */