[Mesa-dev] [PATCH 3/7] gallium: add FBFETCH opcode to retrieve the current sample value

[Ilia Mirkin]

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/auxiliary/tgsi/tgsi_info.c     |  2 +-
 src/gallium/docs/source/tgsi.rst           | 11 +++++++++++
 src/gallium/include/pipe/p_shader_tokens.h |  2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.c b/src/gallium/auxiliary/tgsi/tgsi_info.c
index 37549aa..e34b8c7 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_info.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_info.c
@@ -106,7 +106,7 @@ static const struct tgsi_opcode_info opcode_info[TGSI_OPCODE_LAST] =
    { 1, 3, 0, 0, 0, 0, 0, COMP, "CMP", TGSI_OPCODE_CMP },
    { 1, 1, 0, 0, 0, 0, 0, CHAN, "SCS", TGSI_OPCODE_SCS },
    { 1, 2, 1, 0, 0, 0, 0, OTHR, "TXB", TGSI_OPCODE_TXB },
-   { 0, 1, 0, 0, 0, 0, 1, NONE, "", 69 },      /* removed */
+   { 1, 1, 0, 0, 0, 0, 0, OTHR, "FBFETCH", TGSI_OPCODE_FBFETCH },
    { 1, 2, 0, 0, 0, 0, 0, COMP, "DIV", TGSI_OPCODE_DIV },
    { 1, 2, 0, 0, 0, 0, 0, REPL, "DP2", TGSI_OPCODE_DP2 },
    { 1, 2, 1, 0, 0, 0, 0, OTHR, "TXL", TGSI_OPCODE_TXL },
diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index d2d30b4..accbe1d 100644
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -2561,6 +2561,17 @@ Resource Access Opcodes
   image, while .w will contain the number of samples for multi-sampled
   images.
 
+.. opcode:: FBFETCH - Load data from framebuffer
+
+  Syntax: ``FBFETCH dst, output``
+
+  Example: ``FBFETCH TEMP[0], OUT[0]``
+
+  Returns the color of the current position in the framebuffer from
+  before this fragment shader invocation. Always returns the same
+  value from multiple calls for a particular output within a single
+  invocation.
+
 
 .. _threadsyncopcodes:
 
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index ee59df0..328768f 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -397,7 +397,7 @@ struct tgsi_property_data {
 #define TGSI_OPCODE_CMP                 66
 #define TGSI_OPCODE_SCS                 67
 #define TGSI_OPCODE_TXB                 68
-                                /* gap */
+#define TGSI_OPCODE_FBFETCH             69
 #define TGSI_OPCODE_DIV                 70
 #define TGSI_OPCODE_DP2                 71
 #define TGSI_OPCODE_TXL                 72
-- 
2.10.2