[Mesa-dev] [PATCH 1/3] gallium: add TGSI_PROPERTY_MUL_ZERO_WINS

[Ilia Mirkin]

This will be useful for proper D3D9 emulation, where this behavior is
expected by some shaders.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/auxiliary/tgsi/tgsi_strings.c  |  3 ++-
 src/gallium/docs/source/tgsi.rst           | 14 ++++++++++++--
 src/gallium/include/pipe/p_shader_tokens.h |  1 +
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_strings.c b/src/gallium/auxiliary/tgsi/tgsi_strings.c
index 536a4c8..cebc1b4 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_strings.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_strings.c
@@ -148,7 +148,8 @@ const char *tgsi_property_names[TGSI_PROPERTY_COUNT] =
    "NEXT_SHADER",
    "CS_FIXED_BLOCK_WIDTH",
    "CS_FIXED_BLOCK_HEIGHT",
-   "CS_FIXED_BLOCK_DEPTH"
+   "CS_FIXED_BLOCK_DEPTH",
+   "MUL_ZERO_WINS",
 };
 
 const char *tgsi_return_type_names[TGSI_RETURN_TYPE_COUNT] =
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index 4d7ec90..4e71ea6 100644
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -3538,13 +3538,23 @@ Which shader stage will MOST LIKELY follow after this shader when the shader
 is bound. This is only a hint to the driver and doesn't have to be precise.
 Only set for VS and TES.
 
-TGSI_PROPERTY_CS_FIXED_BLOCK_WIDTH / HEIGHT / DEPTH
-"""""""""""""""""""""""""""""""""""""""""""""""""""
+CS_FIXED_BLOCK_WIDTH / HEIGHT / DEPTH
+"""""""""""""""""""""""""""""""""""""
 
 Threads per block in each dimension, if known at compile time. If the block size
 is known all three should be at least 1. If it is unknown they should all be set
 to 0 or not set.
 
+MUL_ZERO_WINS
+"""""""""""""
+
+The MUL TGSI operation (FP32 multiplication) will return 0 if either
+of the operands are equal to 0. That means that 0 * Inf = 0. This
+should be set the same way for an entire pipeline. If there is a
+mismatch between shaders, then it is unspecified whether this behavior
+will be enabled.
+
+
 Texture Sampling and Texture Formats
 ------------------------------------
 
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index f9b658d..27f842c 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -290,6 +290,7 @@ enum tgsi_property_name {
    TGSI_PROPERTY_CS_FIXED_BLOCK_WIDTH,
    TGSI_PROPERTY_CS_FIXED_BLOCK_HEIGHT,
    TGSI_PROPERTY_CS_FIXED_BLOCK_DEPTH,
+   TGSI_PROPERTY_MUL_ZERO_WINS,
    TGSI_PROPERTY_COUNT,
 };
 
-- 
2.10.2