freedreno/a3xx/compiler: highp frag shader

Fixes use of full-precision in fragment shader (ie. don't clobber r0.x
since that can be used by future bary instructions for varying fetch).
And makes use of full-precision the default in fragment shader (but can
be overriden via FD_MESA_DEBUG=fraghalf).

Seems like half precision is often not enough for texture coordinates.
The blob compiler is clever enough to keep texture coords in full
precision registers while using half precision for everything else.  But
we aren't quite that clever yet, so better to default to full precision.

Signed-off-by: Rob Clark <robclark@freedesktop.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/gallium/drivers/freedreno/freedreno_screen.c b/src/gallium/drivers/freedreno/freedreno_screen.c
index b6d37e7e438..20adf21eec6 100644
--- a/src/gallium/drivers/freedreno/freedreno_screen.c
+++ b/src/gallium/drivers/freedreno/freedreno_screen.c
@@ -63,6 +63,7 @@ static const struct debug_named_value debug_options[] = {
 		{"dscis",     FD_DBG_DSCIS,  "Disable scissor optimization"},
 		{"direct",    FD_DBG_DIRECT, "Force inline (SS_DIRECT) state loads"},
 		{"dbypass",   FD_DBG_DBYPASS,"Disable GMEM bypass"},
+		{"fraghalf",  FD_DBG_FRAGHALF, "Use half-precision in fragment shader"},
 		DEBUG_NAMED_VALUE_END
 };