[Mesa-dev] [PATCH v2] glsl: add double support for packing varyings
Ilia Mirkin
imirkin at alum.mit.edu
Fri Feb 20 10:56:25 PST 2015
Doubles are always packed, but a single double will never cross a slot
boundary -- single slots can still be wasted in some situations.
Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
Packing *all* doubles is a bit of a hack... we shouldn't need to do it
for dvec2/dvec4. And yet, here we are. This means that setting
explicit locations on doubles is also unlikely to go well. But this
should be enough to get it mostly going.
v1 -> v2:
- split out variables into a separate list so that it can work for GS
src/glsl/lower_packed_varyings.cpp | 117 ++++++++++++++++++++++++++++---------
1 file changed, 90 insertions(+), 27 deletions(-)
diff --git a/src/glsl/lower_packed_varyings.cpp b/src/glsl/lower_packed_varyings.cpp
index 5e844c7..2c9a1c4 100644
--- a/src/glsl/lower_packed_varyings.cpp
+++ b/src/glsl/lower_packed_varyings.cpp
@@ -146,7 +146,11 @@
#include "glsl_symbol_table.h"
#include "ir.h"
+#include "ir_builder.h"
#include "ir_optimization.h"
+#include "program/prog_instruction.h"
+
+using namespace ir_builder;
namespace {
@@ -163,13 +167,14 @@ public:
lower_packed_varyings_visitor(void *mem_ctx, unsigned locations_used,
ir_variable_mode mode,
unsigned gs_input_vertices,
- exec_list *out_instructions);
+ exec_list *out_instructions,
+ exec_list *out_variables);
void run(exec_list *instructions);
private:
- ir_assignment *bitwise_assign_pack(ir_rvalue *lhs, ir_rvalue *rhs);
- ir_assignment *bitwise_assign_unpack(ir_rvalue *lhs, ir_rvalue *rhs);
+ void bitwise_assign_pack(ir_rvalue *lhs, ir_rvalue *rhs);
+ void bitwise_assign_unpack(ir_rvalue *lhs, ir_rvalue *rhs);
unsigned lower_rvalue(ir_rvalue *rvalue, unsigned fine_location,
ir_variable *unpacked_var, const char *name,
bool gs_input_toplevel, unsigned vertex_index);
@@ -221,13 +226,19 @@ private:
* appropriate place in the shader once the visitor has finished running.
*/
exec_list *out_instructions;
+
+ /**
+ * Exec list into which the visitor should insert any new variables.
+ */
+ exec_list *out_variables;
};
} /* anonymous namespace */
lower_packed_varyings_visitor::lower_packed_varyings_visitor(
void *mem_ctx, unsigned locations_used, ir_variable_mode mode,
- unsigned gs_input_vertices, exec_list *out_instructions)
+ unsigned gs_input_vertices, exec_list *out_instructions,
+ exec_list *out_variables)
: mem_ctx(mem_ctx),
locations_used(locations_used),
packed_varyings((ir_variable **)
@@ -235,7 +246,8 @@ lower_packed_varyings_visitor::lower_packed_varyings_visitor(
locations_used)),
mode(mode),
gs_input_vertices(gs_input_vertices),
- out_instructions(out_instructions)
+ out_instructions(out_instructions),
+ out_variables(out_variables)
{
}
@@ -274,6 +286,7 @@ lower_packed_varyings_visitor::run(exec_list *instructions)
}
}
+#define SWIZZLE_ZWZW MAKE_SWIZZLE4(SWIZZLE_Z, SWIZZLE_W, SWIZZLE_Z, SWIZZLE_W)
/**
* Make an ir_assignment from \c rhs to \c lhs, performing appropriate
@@ -281,7 +294,7 @@ lower_packed_varyings_visitor::run(exec_list *instructions)
*
* This function is called when packing varyings.
*/
-ir_assignment *
+void
lower_packed_varyings_visitor::bitwise_assign_pack(ir_rvalue *lhs,
ir_rvalue *rhs)
{
@@ -300,12 +313,28 @@ lower_packed_varyings_visitor::bitwise_assign_pack(ir_rvalue *lhs,
rhs = new(this->mem_ctx)
ir_expression(ir_unop_bitcast_f2i, lhs->type, rhs);
break;
+ case GLSL_TYPE_DOUBLE:
+ assert(rhs->type->vector_elements <= 2);
+ if (rhs->type->vector_elements == 2) {
+ ir_variable *t = new(mem_ctx) ir_variable(lhs->type, "pack", ir_var_temporary);
+
+ assert(lhs->type->vector_elements == 4);
+ this->out_variables->push_tail(t);
+ this->out_instructions->push_tail(
+ assign(t, u2i(expr(ir_unop_unpack_double_2x32, swizzle_x(rhs->clone(mem_ctx, NULL)))), 0x3));
+ this->out_instructions->push_tail(
+ assign(t, u2i(expr(ir_unop_unpack_double_2x32, swizzle_y(rhs))), 0xc));
+ rhs = deref(t).val;
+ } else {
+ rhs = u2i(expr(ir_unop_unpack_double_2x32, rhs));
+ }
+ break;
default:
assert(!"Unexpected type conversion while lowering varyings");
break;
}
}
- return new(this->mem_ctx) ir_assignment(lhs, rhs);
+ this->out_instructions->push_tail(new (this->mem_ctx) ir_assignment(lhs, rhs));
}
@@ -315,7 +344,7 @@ lower_packed_varyings_visitor::bitwise_assign_pack(ir_rvalue *lhs,
*
* This function is called when unpacking varyings.
*/
-ir_assignment *
+void
lower_packed_varyings_visitor::bitwise_assign_unpack(ir_rvalue *lhs,
ir_rvalue *rhs)
{
@@ -334,12 +363,27 @@ lower_packed_varyings_visitor::bitwise_assign_unpack(ir_rvalue *lhs,
rhs = new(this->mem_ctx)
ir_expression(ir_unop_bitcast_i2f, lhs->type, rhs);
break;
+ case GLSL_TYPE_DOUBLE:
+ assert(lhs->type->vector_elements <= 2);
+ if (lhs->type->vector_elements == 2) {
+ ir_variable *t = new(mem_ctx) ir_variable(lhs->type, "unpack", ir_var_temporary);
+ assert(rhs->type->vector_elements == 4);
+ this->out_variables->push_tail(t);
+ this->out_instructions->push_tail(
+ assign(t, expr(ir_unop_pack_double_2x32, i2u(swizzle_xy(rhs->clone(mem_ctx, NULL)))), 0x1));
+ this->out_instructions->push_tail(
+ assign(t, expr(ir_unop_pack_double_2x32, i2u(swizzle(rhs->clone(mem_ctx, NULL), SWIZZLE_ZWZW, 2))), 0x2));
+ rhs = deref(t).val;
+ } else {
+ rhs = expr(ir_unop_pack_double_2x32, i2u(rhs));
+ }
+ break;
default:
assert(!"Unexpected type conversion while lowering varyings");
break;
}
}
- return new(this->mem_ctx) ir_assignment(lhs, rhs);
+ this->out_instructions->push_tail(new(this->mem_ctx) ir_assignment(lhs, rhs));
}
@@ -372,6 +416,7 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
bool gs_input_toplevel,
unsigned vertex_index)
{
+ unsigned dmul = rvalue->type->is_double() ? 2 : 1;
/* When gs_input_toplevel is set, we should be looking at a geometry shader
* input array.
*/
@@ -405,17 +450,26 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
return this->lower_arraylike(rvalue, rvalue->type->matrix_columns,
fine_location, unpacked_var, name,
false, vertex_index);
- } else if (rvalue->type->vector_elements + fine_location % 4 > 4) {
+ } else if (rvalue->type->vector_elements * dmul +
+ fine_location % 4 > 4) {
/* This vector is going to be "double parked" across two varying slots,
- * so handle it as two separate assignments.
+ * so handle it as two separate assignments. For doubles, a dvec3/dvec4
+ * can end up being spread over 3 slots. However the second splitting
+ * will happen later, here we just always want to split into 2.
*/
- unsigned left_components = 4 - fine_location % 4;
- unsigned right_components
- = rvalue->type->vector_elements - left_components;
+ unsigned left_components, right_components;
unsigned left_swizzle_values[4] = { 0, 0, 0, 0 };
unsigned right_swizzle_values[4] = { 0, 0, 0, 0 };
char left_swizzle_name[4] = { 0, 0, 0, 0 };
char right_swizzle_name[4] = { 0, 0, 0, 0 };
+
+ left_components = 4 - fine_location % 4;
+ if (rvalue->type->is_double()) {
+ /* We might actually end up with 0 left components! */
+ left_components /= 2;
+ }
+ right_components = rvalue->type->vector_elements - left_components;
+
for (unsigned i = 0; i < left_components; i++) {
left_swizzle_values[i] = i;
left_swizzle_name[i] = "xyzw"[i];
@@ -433,9 +487,13 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
= ralloc_asprintf(this->mem_ctx, "%s.%s", name, left_swizzle_name);
char *right_name
= ralloc_asprintf(this->mem_ctx, "%s.%s", name, right_swizzle_name);
- fine_location = this->lower_rvalue(left_swizzle, fine_location,
- unpacked_var, left_name, false,
- vertex_index);
+ if (left_components)
+ fine_location = this->lower_rvalue(left_swizzle, fine_location,
+ unpacked_var, left_name, false,
+ vertex_index);
+ else
+ /* Top up the fine location to the next slot */
+ fine_location++;
return this->lower_rvalue(right_swizzle, fine_location, unpacked_var,
right_name, false, vertex_index);
} else {
@@ -443,7 +501,7 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
* varying.
*/
unsigned swizzle_values[4] = { 0, 0, 0, 0 };
- unsigned components = rvalue->type->vector_elements;
+ unsigned components = rvalue->type->vector_elements * dmul;
unsigned location = fine_location / 4;
unsigned location_frac = fine_location % 4;
for (unsigned i = 0; i < components; ++i)
@@ -454,13 +512,9 @@ lower_packed_varyings_visitor::lower_rvalue(ir_rvalue *rvalue,
ir_swizzle *swizzle = new(this->mem_ctx)
ir_swizzle(packed_deref, swizzle_values, components);
if (this->mode == ir_var_shader_out) {
- ir_assignment *assignment
- = this->bitwise_assign_pack(swizzle, rvalue);
- this->out_instructions->push_tail(assignment);
+ this->bitwise_assign_pack(swizzle, rvalue);
} else {
- ir_assignment *assignment
- = this->bitwise_assign_unpack(rvalue, swizzle);
- this->out_instructions->push_tail(assignment);
+ this->bitwise_assign_unpack(rvalue, swizzle);
}
return fine_location + components;
}
@@ -598,7 +652,7 @@ lower_packed_varyings_visitor::needs_lowering(ir_variable *var)
}
if (type->is_array())
type = type->fields.array;
- if (type->vector_elements == 4)
+ if (type->vector_elements == 4 && !type->is_double())
return false;
return true;
}
@@ -657,9 +711,11 @@ lower_packed_varyings(void *mem_ctx, unsigned locations_used,
exec_list void_parameters;
ir_function_signature *main_func_sig
= main_func->matching_signature(NULL, &void_parameters, false);
- exec_list new_instructions;
+ exec_list new_instructions, new_variables;
lower_packed_varyings_visitor visitor(mem_ctx, locations_used, mode,
- gs_input_vertices, &new_instructions);
+ gs_input_vertices,
+ &new_instructions,
+ &new_variables);
visitor.run(instructions);
if (mode == ir_var_shader_out) {
if (shader->Stage == MESA_SHADER_GEOMETRY) {
@@ -667,15 +723,22 @@ lower_packed_varyings(void *mem_ctx, unsigned locations_used,
* to EmitVertex()
*/
lower_packed_varyings_gs_splicer splicer(mem_ctx, &new_instructions);
+
+ /* Add all the variables in first. */
+ main_func_sig->body.head->insert_before(&new_variables);
+
+ /* Now update all the EmitVertex instances */
splicer.run(instructions);
} else {
/* For other shader types, outputs need to be lowered at the end of
* main()
*/
+ main_func_sig->body.append_list(&new_variables);
main_func_sig->body.append_list(&new_instructions);
}
} else {
/* Shader inputs need to be lowered at the beginning of main() */
main_func_sig->body.head->insert_before(&new_instructions);
+ main_func_sig->body.head->insert_before(&new_variables);
}
}
--
2.0.5
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