glsl: Add ir_binop_vector_extract

The new opcode is used to get a single field from a vector.  The field
index may not be constant.  This will eventually replace
ir_dereference_array of vectors.  This is similar to the extractelement
instruction in LLVM IR.

http://llvm.org/docs/LangRef.html#extractelement-instruction

v2: Convert tabs to spaces.  Suggested by Eric.

v3: Add array index range checking to ir_binop_vector_extract constant
expression handling.  Suggested by Ken.

v4: Use CLAMP instead of MIN2(MAX2()).  Suggested by Ken.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 6783eca..e3e3b71 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -1136,9 +1136,17 @@ enum ir_expression_operation {
    ir_binop_ubo_load,
 
    /**
+    * Extract a scalar from a vector
+    *
+    * operand0 is the vector
+    * operand1 is the index of the field to read from operand0
+    */
+   ir_binop_vector_extract,
+
+   /**
     * A sentinel marking the last of the binary operations.
     */
-   ir_last_binop = ir_binop_ubo_load,
+   ir_last_binop = ir_binop_vector_extract,
 
    ir_triop_lrp,