KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

glsl: Optimize clamp(x, 0, 1) as saturate(x) 

v2: - Check that the base type is float (Ian Romanick)
v3: - Make sure comments reflect that we are doing a commutative operation
    - Add missing condition where the inner constant is 1.0 and outer constant is 0.0
    - Make indexing of operands easier to read (Matt Turner)

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
This commit is contained in:
Abdiel Janulgue 2014-06-19 22:15:14 -07:00
parent cbd0d643a3
commit 8f890b119e
1 changed files with 36 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/glsl/opt_algebraic.cpp
View File

@ -614,6 +614,42 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
break;
case ir_binop_min:
case ir_binop_max:
if (ir->type->base_type != GLSL_TYPE_FLOAT)
break;
/* Replace min(max) operations and its commutative combinations with
* a saturate operation
*/
for (int op = 0; op < 2; op++) {
ir_expression *minmax = op_expr[op];
ir_constant *outer_const = op_const[1 - op];
ir_expression_operation op_cond = (ir->operation == ir_binop_max) ?
ir_binop_min : ir_binop_max;
if (!minmax || !outer_const || (minmax->operation != op_cond))
continue;
/* Found a min(max) combination. Now try to see if its operands
* meet our conditions that we can do just a single saturate operation
*/
for (int minmax_op = 0; minmax_op < 2; minmax_op++) {
ir_rvalue *inner_val_a = minmax->operands[minmax_op];
ir_rvalue *inner_val_b = minmax->operands[1 - minmax_op];
if (!inner_val_a || !inner_val_b)
continue;
/* Found a {min|max} ({max|min} (x, 0.0), 1.0) operation and its variations */
if ((outer_const->is_one() && inner_val_a->is_zero()) ||
(inner_val_a->is_one() && outer_const->is_zero()))
return saturate(inner_val_b);
}
}
break;
case ir_unop_rcp:
if (op_expr[0] && op_expr[0]->operation == ir_unop_rcp)
return op_expr[0]->operands[0];