Signed-off-by: Kenneth Graunke kenn...@whitecape.org
---
src/mesa/drivers/dri/i965/brw_structs.h | 29 +++--
1 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_structs.h
b/src/mesa/drivers/dri/i965/brw_structs.h
index e1947d5..b47be69 100644
--- a/src/mesa/drivers/dri/i965/brw_structs.h
+++ b/src/mesa/drivers/dri/i965/brw_structs.h
@@ -915,7 +915,11 @@ struct brw_instruction
GLuint predicate_control:4;
GLuint predicate_inverse:1;
GLuint execution_size:3;
- GLuint destreg__conditionalmod:4; /* destreg - send, conditionalmod -
others */
+ /**
+ * Conditional Modifier for most instructions. On Gen6+, this is also
+ * used for the SEND instruction's Message Target/SFID.
+ */
+ GLuint destreg__conditionalmod:4;
GLuint acc_wr_control:1;
GLuint cmpt_control:1;
GLuint debug_control:1;
@@ -1060,6 +1064,11 @@ struct brw_instruction
GLuint pad1:6;
} ia16;
+ /* Extended Message Descriptor for Ironlake (Gen5) SEND instruction.
+ *
+ * Does not apply to Gen6+. The SFID/message target moved to bits
+ * 27:24 of the header (destreg__conditionalmod); EOT is in bits3.
+ */
struct
{
GLuint pad:26;
@@ -1373,6 +1382,11 @@ struct brw_instruction
GLuint end_of_thread:1;
} gen7_dp;
+ /**
+ * Message Descriptor for Gen4 SEND instructions (no particular message).
+ *
+ * See the G45 PRM, Volume 4, Table 14-15.
+ */
struct {
GLuint function_control:16;
GLuint response_length:4;
@@ -1382,7 +1396,18 @@ struct brw_instruction
GLuint end_of_thread:1;
} generic;
- /* Of this struct, only end_of_thread is not present for gen6. */
+ /**
+ * Message Descriptor for Gen5-7 SEND instructions.
+ *
+ * See the Sandybridge PRM, Volume 2 Part 2, Table 8-15. (Sadly, most
+ * of the information on the SEND instruction is missing from the public
+ * Ironlake PRM.)
+ *
+ * The table claims that bit 31 is reserved/MBZ on Gen6+, but it lies.
+ * According to the SEND instruction description:
+ * The MSb of the message description, the EOT field, always comes from
+ * bit 127 of the instruction word...which is bit 31 of this field.
+ */
struct {
GLuint function_control:19;
GLuint header_present:1;
--
1.7.7
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