[Mesa-dev] [PATCH] RFC: tgsi: Add output_type to struct tgsi_opcode_info

[Tom Stellard]

I've been working more on the TGSI->LLVM converter, and I've found that
it would be useful to be able to look up information about how an opcode
calculates its result.

I'm looking for feedback on whether adding a field to struct
tgsi_opcode_info is the right way to do this, and also if the
enumerations in enum tgsi_output_type make sense.
---
 src/gallium/auxiliary/tgsi/tgsi_info.h     |    1 +
 src/gallium/include/pipe/p_shader_tokens.h |   33 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.h b/src/gallium/auxiliary/tgsi/tgsi_info.h
index 1992d11..4fc19e9 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_info.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_info.h
@@ -43,6 +43,7 @@ struct tgsi_opcode_info
    unsigned is_branch:1;
    int pre_dedent:2;
    int post_indent:2;
+   enum tgsi_output_type output_type:3;
    const char *mnemonic;
    uint opcode;
 };
diff --git a/src/gallium/include/pipe/p_shader_tokens.h b/src/gallium/include/pipe/p_shader_tokens.h
index 330e0ba..8a1d60c 100644
--- a/src/gallium/include/pipe/p_shader_tokens.h
+++ b/src/gallium/include/pipe/p_shader_tokens.h
@@ -216,6 +216,39 @@ struct tgsi_property_data {
    unsigned Data;
 };
 
+/* This enum describes how an opcode calculates its result. */
+enum tgsi_output_type {
+   /** The opcode produces no result. */
+   TGSI_OUTPUT_NONE            = 0,
+
+   /** When this opcode writes to a channel of the destination register,
+    *  it takes as arguments values from the same channel of the source
+    *  register(s).
+    *
+    *  Example: TGSI_OPCODE_ADD
+    */
+   TGSI_OUTPUT_COMPONENTWISE   = 1,
+
+   /** This opcode writes the same value to all enabled channels of the
+    * destination register.
+    *
+    *  Example: TGSI_OPCODE_RSQ
+    */
+   TGSI_OUTPUT_REPLICATE       = 2,
+
+   /** The operation performed by this opcode is dependent on which channel
+    *  of the destination register is being written.
+    *
+    *  Example: TGSI_OPCODE_LOG
+    */
+   TGSI_OUTPUT_CHAN_DEPENDENT  = 3,
+
+   /**
+    * Example: TGSI_OPCODE_TEX
+    */
+   TGSI_OUTPUT_OTHER           = 4
+};
+
 /* TGSI opcodes.  
  * 
  * For more information on semantics of opcodes and
-- 
1.7.6