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authorJordan Justen <[email protected]>2013-11-04 10:23:24 -0800
committerMatt Turner <[email protected]>2014-01-21 14:20:44 -0800
commit8d37e9915a3b21b496269a39f677a80a6e02cb2c (patch)
treeb564cca17c8695a669815f2956e75f2563abea03 /src/glsl
parent13100ac142e935c422018d5152b27ce3564def08 (diff)
glsl: Optimize open-coded lrp into lrp.
total instructions in shared programs: 1498191 -> 1487051 (-0.74%) instructions in affected programs: 669388 -> 658248 (-1.66%) GAINED: 1 LOST: 0 Reviewed-by: Matt Turner <[email protected]> Signed-off-by: Jordan Justen <[email protected]>
Diffstat (limited to 'src/glsl')
-rw-r--r--src/glsl/opt_algebraic.cpp52
1 files changed, 52 insertions, 0 deletions
diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp
index 332f0b77b87..d1f6435f44f 100644
--- a/src/glsl/opt_algebraic.cpp
+++ b/src/glsl/opt_algebraic.cpp
@@ -285,6 +285,58 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir)
reassociate_constant(ir, 0, op_const[0], op_expr[1]);
if (op_const[1] && !op_const[0])
reassociate_constant(ir, 1, op_const[1], op_expr[0]);
+
+ /* Replace (-x + y) * a + x and commutative variations with lrp(x, y, a).
+ *
+ * (-x + y) * a + x
+ * (x * -a) + (y * a) + x
+ * x + (x * -a) + (y * a)
+ * x * (1 - a) + y * a
+ * lrp(x, y, a)
+ */
+ for (int mul_pos = 0; mul_pos < 2; mul_pos++) {
+ ir_expression *mul = op_expr[mul_pos];
+
+ if (!mul || mul->operation != ir_binop_mul)
+ continue;
+
+ /* Multiply found on one of the operands. Now check for an
+ * inner addition operation.
+ */
+ for (int inner_add_pos = 0; inner_add_pos < 2; inner_add_pos++) {
+ ir_expression *inner_add =
+ mul->operands[inner_add_pos]->as_expression();
+
+ if (!inner_add || inner_add->operation != ir_binop_add)
+ continue;
+
+ /* Inner addition found on one of the operands. Now check for
+ * one of the operands of the inner addition to be the negative
+ * of x_operand.
+ */
+ for (int neg_pos = 0; neg_pos < 2; neg_pos++) {
+ ir_expression *neg =
+ inner_add->operands[neg_pos]->as_expression();
+
+ if (!neg || neg->operation != ir_unop_neg)
+ continue;
+
+ ir_rvalue *x_operand = ir->operands[1 - mul_pos];
+
+ if (!neg->operands[0]->equals(x_operand))
+ continue;
+
+ ir_rvalue *y_operand = inner_add->operands[1 - neg_pos];
+ ir_rvalue *a_operand = mul->operands[1 - inner_add_pos];
+
+ if (x_operand->type != y_operand->type ||
+ x_operand->type != a_operand->type)
+ continue;
+
+ return lrp(x_operand, y_operand, a_operand);
+ }
+ }
+ }
break;
case ir_binop_sub: