From 843855bbf0da2204ce536623ba957bfa83fdbd52 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nicolai=20H=C3=A4hnle?= Date: Tue, 19 Jan 2016 14:59:22 -0500 Subject: [PATCH] radeonsi: fix discard-only fragment shaders (v2) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When a fragment shader is used that has no outputs but does conditional discard (KILL_IF), all fragments are killed without this patch. By comparing various register settings, my conclusion is that the exec mask is either not properly forwarded to the DB by NULL exports or ends up being unused, at least when there is _only_ a NULL export (the ISA documentation claims that NULL exports can be used to override a previously exported exec mask). Of the various approaches I have tried to work around the problem, this one seems to be the least invasive one. v2: take discard by alpha test into account as well Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93761 Reviewed-by: Marek Olšák --- src/gallium/drivers/radeonsi/si_state_shaders.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c index 79f2335..fae804c 100644 --- a/src/gallium/drivers/radeonsi/si_state_shaders.c +++ b/src/gallium/drivers/radeonsi/si_state_shaders.c @@ -438,6 +438,7 @@ static void si_shader_ps(struct si_shader *shader) unsigned spi_baryc_cntl = S_0286E0_FRONT_FACE_ALL_BITS(1); uint64_t va; bool has_centroid; + bool writes_execmask; pm4 = shader->pm4 = CALLOC_STRUCT(si_pm4_state); @@ -492,10 +493,13 @@ static void si_shader_ps(struct si_shader *shader) si_pm4_set_reg(pm4, R_0286E0_SPI_BARYC_CNTL, spi_baryc_cntl); si_pm4_set_reg(pm4, R_0286D8_SPI_PS_IN_CONTROL, spi_ps_in_control); + writes_execmask = info->uses_kill || + shader->key.ps.alpha_func != PIPE_FUNC_ALWAYS; si_pm4_set_reg(pm4, R_028710_SPI_SHADER_Z_FORMAT, info->writes_samplemask ? V_028710_SPI_SHADER_32_ABGR : info->writes_stencil ? V_028710_SPI_SHADER_32_GR : info->writes_z ? V_028710_SPI_SHADER_32_R : + (writes_execmask && !info->num_outputs) ? V_028710_SPI_SHADER_32_R : V_028710_SPI_SHADER_ZERO); si_pm4_set_reg(pm4, R_028714_SPI_SHADER_COL_FORMAT, spi_shader_col_format); -- 2.7.4