[Mesa-dev] [PATCH 2/2] radeonsi: Always pre-load separate VGPRs for centroid vs. center interpolation

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

The LLVM R600 backend currently always uses separate VGPRs for these.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68162
(Centroid interpolation is identical to center interpolation without
multisampling, so the shader hardware was only pre-loading one set of
interpolation coefficients, and the pixel shader code was using
uninitialized values as the centroid interpolation coefficients)

Cc: mesa-stable at lists.freedesktop.org
Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 src/gallium/drivers/radeonsi/si_state_draw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index 7ecaf77..15cb87f 100644
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -183,7 +183,8 @@ static void si_pipe_shader_ps(struct pipe_context *ctx, struct si_pipe_shader *s
 		exports_ps = 2;
 	}
 
-	spi_ps_in_control = S_0286D8_NUM_INTERP(shader->shader.ninterp);
+	spi_ps_in_control = S_0286D8_NUM_INTERP(shader->shader.ninterp) |
+		S_0286D8_BC_OPTIMIZE_DISABLE(1);
 
 	si_pm4_set_reg(pm4, R_0286E0_SPI_BARYC_CNTL, spi_baryc_cntl);
 	spi_ps_input_ena = shader->spi_ps_input_ena;
-- 
1.8.4.rc3