[Mesa-dev] [PATCH 4/9] glsl, nir: Make ir_triop_bitfield_extract a vectorized operation.

[Matt Turner]

From: Kenneth Graunke <kenneth at whitecape.org>

We would like to be able to combine

   result.x = bitfieldExtract(src0.x, src1.x, src2.x);
   result.y = bitfieldExtract(src0.y, src1.y, src2.y);
   result.z = bitfieldExtract(src0.z, src1.z, src2.z);
   result.w = bitfieldExtract(src0.w, src1.w, src2.w);

into a single ivec4 bitfieldInsert operation.  This should be possible
with most drivers.

This patch changes the offset and bits parameters from scalar ints
to ivecN or uvecN.  The type of all three operands will be the same,
for simplicity.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Matt Turner <mattst88 at gmail.com>
---
[mattst88] v2:
	Use swizzle(expr, SWIZZLE_XXXX, type->vector_elements) instead of
	swizzle_for_size(expr, type->vector_elements). The latter does not
	provide the wanted operation of expanding a scalar.

 src/glsl/builtin_functions.cpp      | 8 +++++++-
 src/glsl/ir.h                       | 4 +---
 src/glsl/ir_constant_expression.cpp | 6 +++---
 src/glsl/ir_validate.cpp            | 5 +++--
 src/glsl/nir/nir_opcodes.py         | 8 ++++----
 5 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/src/glsl/builtin_functions.cpp b/src/glsl/builtin_functions.cpp
index 38383bc..f2e2165 100644
--- a/src/glsl/builtin_functions.cpp
+++ b/src/glsl/builtin_functions.cpp
@@ -4889,12 +4889,18 @@ builtin_builder::_noise4(const glsl_type *type)
 ir_function_signature *
 builtin_builder::_bitfieldExtract(const glsl_type *type)
 {
+   bool is_uint = type->base_type == GLSL_TYPE_UINT;
    ir_variable *value  = in_var(type, "value");
    ir_variable *offset = in_var(glsl_type::int_type, "offset");
    ir_variable *bits   = in_var(glsl_type::int_type, "bits");
    MAKE_SIG(type, gpu_shader5_or_es31, 3, value, offset, bits);
 
-   body.emit(ret(expr(ir_triop_bitfield_extract, value, offset, bits)));
+   operand cast_offset = is_uint ? i2u(offset) : operand(offset);
+   operand cast_bits = is_uint ? i2u(bits) : operand(bits);
+
+   body.emit(ret(expr(ir_triop_bitfield_extract, value,
+      swizzle(cast_offset, SWIZZLE_XXXX, type->vector_elements),
+      swizzle(cast_bits, SWIZZLE_XXXX, type->vector_elements))));
 
    return sig;
 }
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 9af2fc1..5b845c6 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -1708,9 +1708,7 @@ public:
              operation == ir_binop_dot ||
              operation == ir_binop_vector_extract ||
              operation == ir_triop_vector_insert ||
-             operation == ir_quadop_vector ||
-             /* TODO: these can't currently be vectorized */
-             operation == ir_triop_bitfield_extract;
+             operation == ir_quadop_vector;
    }
 
    /**
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index f5b5bd8..7613139 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -1588,10 +1588,10 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
       break;
 
    case ir_triop_bitfield_extract: {
-      int offset = op[1]->value.i[0];
-      int bits = op[2]->value.i[0];
-
       for (unsigned c = 0; c < components; c++) {
+         int offset = op[1]->value.i[c];
+         int bits = op[2]->value.i[c];
+
          if (bits == 0)
             data.u[c] = 0;
          else if (offset < 0 || bits < 0)
diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp
index fea9b76..9481479 100644
--- a/src/glsl/ir_validate.cpp
+++ b/src/glsl/ir_validate.cpp
@@ -632,9 +632,10 @@ ir_validate::visit_leave(ir_expression *ir)
       break;
 
    case ir_triop_bitfield_extract:
+      assert(ir->type->is_integer());
       assert(ir->operands[0]->type == ir->type);
-      assert(ir->operands[1]->type == glsl_type::int_type);
-      assert(ir->operands[2]->type == glsl_type::int_type);
+      assert(ir->operands[1]->type == ir->type);
+      assert(ir->operands[2]->type == ir->type);
       break;
 
    case ir_triop_vector_insert:
diff --git a/src/glsl/nir/nir_opcodes.py b/src/glsl/nir/nir_opcodes.py
index 3780628..855095f 100644
--- a/src/glsl/nir/nir_opcodes.py
+++ b/src/glsl/nir/nir_opcodes.py
@@ -570,9 +570,9 @@ if (mask == 0) {
 """)
 
 opcode("ubitfield_extract", 0, tuint,
-       [0, 1, 1], [tuint, tint, tint], "", """
+       [0, 0, 0], [tuint, tint, tint], "", """
 unsigned base = src0;
-int offset = src1.x, bits = src2.x;
+int offset = src1, bits = src2;
 if (bits == 0) {
    dst = 0;
 } else if (bits < 0 || offset < 0 || offset + bits > 32) {
@@ -582,9 +582,9 @@ if (bits == 0) {
 }
 """)
 opcode("ibitfield_extract", 0, tint,
-       [0, 1, 1], [tint, tint, tint], "", """
+       [0, 0, 0], [tint, tint, tint], "", """
 int base = src0;
-int offset = src1.x, bits = src2.x;
+int offset = src1, bits = src2;
 if (bits == 0) {
    dst = 0;
 } else if (offset < 0 || bits < 0 || offset + bits > 32) {
-- 
2.4.9