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authorKenneth Graunke <kenneth@whitecape.org>2011-09-20 00:14:05 -0700
committerKenneth Graunke <kenneth@whitecape.org>2012-04-02 14:15:36 -0700
commitd0fa0cb52cebdcd0ca483b9cd7af6be2f228b8dc (patch)
tree668535c2189f6eed6f8074260fba7ca4e005411a
parent807e967c615dc80a264af5a89af7649f95481744 (diff)
glsl: Move constant expression handling from calls to signatures.
When translating a call from AST to HIR, we need to decide whether it can be evaluated to a constant before emitting any code (namely, the temporary declaration, assignment, and call.) Soon, ir_call will become a statement taking a dereference of where to store the return value, rather than an rvalue to be used on the RHS of an assignment. It will be more convenient to try evaluation before creating a call. ir_function_signature seems like a reasonable place. Signed-off-by: Kenneth Graunke <kenneth@whitecape.org> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
-rw-r--r--src/glsl/ir.h6
-rw-r--r--src/glsl/ir_constant_expression.cpp27
2 files changed, 25 insertions, 8 deletions
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 811eac08878..bb4f7759b30 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -478,6 +478,12 @@ public:
virtual ir_visitor_status accept(ir_hierarchical_visitor *);
/**
+ * Attempt to evaluate this function as a constant expression, given
+ * a list of the actual parameters. Returns NULL for non-built-ins.
+ */
+ ir_constant *constant_expression_value(exec_list *actual_parameters);
+
+ /**
* Get the name of the function for which this is a signature
*/
const char *function_name() const;
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 2910b2e162b..aa47c08d88a 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -1027,18 +1027,29 @@ ir_call::constant_expression_value()
if (this->type == glsl_type::error_type)
return NULL;
+ return this->callee->constant_expression_value(&this->actual_parameters);
+}
+
+
+ir_constant *
+ir_function_signature::constant_expression_value(exec_list *actual_parameters)
+{
+ const glsl_type *type = this->return_type;
+ if (type == glsl_type::void_type)
+ return NULL;
+
/* From the GLSL 1.20 spec, page 23:
* "Function calls to user-defined functions (non-built-in functions)
* cannot be used to form constant expressions."
*/
- if (!this->callee->is_builtin)
+ if (!this->is_builtin)
return NULL;
unsigned num_parameters = 0;
/* Check if all parameters are constant */
ir_constant *op[3];
- foreach_list(n, &this->actual_parameters) {
+ foreach_list(n, actual_parameters) {
ir_constant *constant = ((ir_rvalue *) n)->constant_expression_value();
if (constant == NULL)
return NULL;
@@ -1060,7 +1071,7 @@ ir_call::constant_expression_value()
ir_constant_data data;
memset(&data, 0, sizeof(data));
- const char *callee = this->callee_name();
+ const char *callee = this->function_name();
if (strcmp(callee, "abs") == 0) {
expr = new(mem_ctx) ir_expression(ir_unop_abs, type, op[0], NULL);
} else if (strcmp(callee, "all") == 0) {
@@ -1108,7 +1119,7 @@ ir_call::constant_expression_value()
for (unsigned c = 0; c < op[0]->type->components(); c++)
data.f[c] = atanhf(op[0]->value.f[c]);
} else if (strcmp(callee, "dFdx") == 0 || strcmp(callee, "dFdy") == 0) {
- return ir_constant::zero(mem_ctx, this->type);
+ return ir_constant::zero(mem_ctx, type);
} else if (strcmp(callee, "ceil") == 0) {
expr = new(mem_ctx) ir_expression(ir_unop_ceil, type, op[0], NULL);
} else if (strcmp(callee, "clamp") == 0) {
@@ -1199,7 +1210,7 @@ ir_call::constant_expression_value()
} else if (strcmp(callee, "fract") == 0) {
expr = new(mem_ctx) ir_expression(ir_unop_fract, type, op[0], NULL);
} else if (strcmp(callee, "fwidth") == 0) {
- return ir_constant::zero(mem_ctx, this->type);
+ return ir_constant::zero(mem_ctx, type);
} else if (strcmp(callee, "greaterThan") == 0) {
assert(op[0]->type->is_vector() && op[1] && op[1]->type->is_vector());
for (unsigned c = 0; c < op[0]->type->components(); c++) {
@@ -1305,7 +1316,7 @@ ir_call::constant_expression_value()
float length = sqrtf(dot(op[0], op[0]));
if (length == 0)
- return ir_constant::zero(mem_ctx, this->type);
+ return ir_constant::zero(mem_ctx, type);
for (unsigned c = 0; c < op[0]->type->components(); c++)
data.f[c] = op[0]->value.f[c] / length;
@@ -1356,7 +1367,7 @@ ir_call::constant_expression_value()
const float dot_NI = dot(op[1], op[0]);
const float k = 1.0F - eta * eta * (1.0F - dot_NI * dot_NI);
if (k < 0.0) {
- return ir_constant::zero(mem_ctx, this->type);
+ return ir_constant::zero(mem_ctx, type);
} else {
for (unsigned c = 0; c < type->components(); c++) {
data.f[c] = eta * op[0]->value.f[c] - (eta * dot_NI + sqrtf(k))
@@ -1425,5 +1436,5 @@ ir_call::constant_expression_value()
if (expr != NULL)
return expr->constant_expression_value();
- return new(mem_ctx) ir_constant(this->type, &data);
+ return new(mem_ctx) ir_constant(type, &data);
}