i965: Gen4/5: use IEEE floating point mode for GLSL shaders.

Fixes isinf(), isnan() from GLSL 1.30

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

diff --git a/src/mesa/drivers/dri/i965/brw_vs_state.c b/src/mesa/drivers/dri/i965/brw_vs_state.c
index 54ff754b1ddc4b4126da7d18f2ccef759204d88f..4dda522404277b2dff63aef4850eed166b672acd 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_vs_state.c
+++ b/src/mesa/drivers/dri/i965/brw_vs_state.c
@@ -55,7 +55,14 @@ brw_upload_vs_unit(struct brw_context *brw)
                        brw->vs.prog_offset +
                        (vs->thread0.grf_reg_count << 1)) >> 6;
 
-   vs->thread1.floating_point_mode = BRW_FLOATING_POINT_NON_IEEE_754;
+   /* Use ALT floating point mode for ARB vertex programs, because they
+    * require 0^0 == 1.
+    */
+   if (brw->ctx.Shader.CurrentVertexProgram == NULL)
+      vs->thread1.floating_point_mode = BRW_FLOATING_POINT_NON_IEEE_754;
+   else
+      vs->thread1.floating_point_mode = BRW_FLOATING_POINT_IEEE_754;
+
    /* Choosing multiple program flow means that we may get 2-vertex threads,
     * which will have the channel mask for dwords 4-7 enabled in the thread,
     * and those dwords will be written to the second URB handle when we

diff --git a/src/mesa/drivers/dri/i965/brw_wm_state.c b/src/mesa/drivers/dri/i965/brw_wm_state.c
index f221846f0c88ee164f01a907d388be71c5dc75cc..631f351699b3325edf4f9db93fce0dac66a64fdd 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_state.c
@@ -110,7 +110,15 @@ brw_upload_wm_unit(struct brw_context *brw)
                        (wm->wm9.grf_reg_count_2 << 1)) >> 6;
 
    wm->thread1.depth_coef_urb_read_offset = 1;
-   wm->thread1.floating_point_mode = BRW_FLOATING_POINT_NON_IEEE_754;
+   /* Use ALT floating point mode for ARB fragment programs, because they
+    * require 0^0 == 1.  Even though _CurrentFragmentProgram is used for
+    * rendering, CurrentFragmentProgram is used for this check to
+    * differentiate between the GLSL and non-GLSL cases.
+    */
+   if (ctx->Shader.CurrentFragmentProgram == NULL)
+      wm->thread1.floating_point_mode = BRW_FLOATING_POINT_NON_IEEE_754;
+   else
+      wm->thread1.floating_point_mode = BRW_FLOATING_POINT_IEEE_754;
 
    wm->thread1.binding_table_entry_count = 0;