gallium/tgsi: Add support for barriers.

src/gallium/auxiliary/tgsi/tgsi_info.c

@@ -201,6 +201,10 @@ static const struct tgsi_opcode_info opcode_info[TGSI_OPCODE_LAST] =
    { 1, 1, 0, 0, 0, 0, COMP, "ISSG", TGSI_OPCODE_ISSG },
    { 1, 2, 0, 0, 0, 0, OTHR, "LOAD", TGSI_OPCODE_LOAD },
    { 1, 2, 0, 0, 0, 0, OTHR, "STORE", TGSI_OPCODE_STORE },
+   { 1, 0, 0, 0, 0, 0, OTHR, "MFENCE", TGSI_OPCODE_MFENCE },
+   { 1, 0, 0, 0, 0, 0, OTHR, "LFENCE", TGSI_OPCODE_LFENCE },
+   { 1, 0, 0, 0, 0, 0, OTHR, "SFENCE", TGSI_OPCODE_SFENCE },
+   { 0, 0, 0, 0, 0, 0, OTHR, "BARRIER", TGSI_OPCODE_BARRIER }
 };
 
 const struct tgsi_opcode_info *

src/gallium/docs/source/tgsi.rst

@@ -1514,6 +1514,55 @@ Resource Access Opcodes
                ignored.
 
 
+.. _threadsyncopcodes:
+
+Inter-thread synchronization opcodes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+These opcodes are intended for communication between threads running
+within the same compute grid.  For now they're only valid in compute
+programs.
+
+.. opcode:: MFENCE - Memory fence
+
+  Syntax: ``MFENCE resource``
+
+  Example: ``MFENCE RES[0]``
+
+  This opcode forces strong ordering between any memory access
+  operations that affect the specified resource.  This means that
+  previous loads and stores (and only those) will be performed and
+  visible to other threads before the program execution continues.
+
+
+.. opcode:: LFENCE - Load memory fence
+
+  Syntax: ``LFENCE resource``
+
+  Example: ``LFENCE RES[0]``
+
+  Similar to MFENCE, but it only affects the ordering of memory loads.
+
+
+.. opcode:: SFENCE - Store memory fence
+
+  Syntax: ``SFENCE resource``
+
+  Example: ``SFENCE RES[0]``
+
+  Similar to MFENCE, but it only affects the ordering of memory stores.
+
+
+.. opcode:: BARRIER - Thread group barrier
+
+  ``BARRIER``
+
+  This opcode suspends the execution of the current thread until all
+  the remaining threads in the working group reach the same point of
+  the program.  Results are unspecified if any of the remaining
+  threads terminates or never reaches an executed BARRIER instruction.
+
+
 Explanation of symbols used
 ------------------------------
 

src/gallium/include/pipe/p_shader_tokens.h

@@ -413,7 +413,12 @@ struct tgsi_property_data {
 #define TGSI_OPCODE_LOAD                161
 #define TGSI_OPCODE_STORE               162
 
-#define TGSI_OPCODE_LAST                163
+#define TGSI_OPCODE_MFENCE              163
+#define TGSI_OPCODE_LFENCE              164
+#define TGSI_OPCODE_SFENCE              165
+#define TGSI_OPCODE_BARRIER             166
+
+#define TGSI_OPCODE_LAST                167
 
 #define TGSI_SAT_NONE            0  /* do not saturate */
 #define TGSI_SAT_ZERO_ONE        1  /* clamp to [0,1] */