glsl: move to compiler/

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Matt Turner <mattst88@gmail.com>
Acked-by: Jose Fonseca <jfonseca@vmware.com>

1 files changed, 404 insertions, 0 deletions

diff --git a/src/compiler/glsl/ir_function.cpp b/src/compiler/glsl/ir_function.cpp
new file mode 100644
index 0000000..0b4cb4b
--- /dev/null
+++ b/src/compiler/glsl/ir_function.cpp
@@ -0,0 +1,404 @@
+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "compiler/glsl_types.h"
+#include "ir.h"
+#include "glsl_parser_extras.h"
+#include "main/errors.h"
+
+typedef enum {
+   PARAMETER_LIST_NO_MATCH,
+   PARAMETER_LIST_EXACT_MATCH,
+   PARAMETER_LIST_INEXACT_MATCH /*< Match requires implicit conversion. */
+} parameter_list_match_t;
+
+/**
+ * \brief Check if two parameter lists match.
+ *
+ * \param list_a Parameters of the function definition.
+ * \param list_b Actual parameters passed to the function.
+ * \see matching_signature()
+ */
+static parameter_list_match_t
+parameter_lists_match(_mesa_glsl_parse_state *state,
+                      const exec_list *list_a, const exec_list *list_b)
+{
+   const exec_node *node_a = list_a->head;
+   const exec_node *node_b = list_b->head;
+
+   /* This is set to true if there is an inexact match requiring an implicit
+    * conversion. */
+   bool inexact_match = false;
+
+   for (/* empty */
+	; !node_a->is_tail_sentinel()
+	; node_a = node_a->next, node_b = node_b->next) {
+      /* If all of the parameters from the other parameter list have been
+       * exhausted, the lists have different length and, by definition,
+       * do not match.
+       */
+      if (node_b->is_tail_sentinel())
+	 return PARAMETER_LIST_NO_MATCH;
+
+
+      const ir_variable *const param = (ir_variable *) node_a;
+      const ir_rvalue *const actual = (ir_rvalue *) node_b;
+
+      if (param->type == actual->type)
+	 continue;
+
+      /* Try to find an implicit conversion from actual to param. */
+      inexact_match = true;
+      switch ((enum ir_variable_mode)(param->data.mode)) {
+      case ir_var_auto:
+      case ir_var_uniform:
+      case ir_var_shader_storage:
+      case ir_var_temporary:
+	 /* These are all error conditions.  It is invalid for a parameter to
+	  * a function to be declared as auto (not in, out, or inout) or
+	  * as uniform.
+	  */
+	 assert(0);
+	 return PARAMETER_LIST_NO_MATCH;
+
+      case ir_var_const_in:
+      case ir_var_function_in:
+	 if (!actual->type->can_implicitly_convert_to(param->type, state))
+	    return PARAMETER_LIST_NO_MATCH;
+	 break;
+
+      case ir_var_function_out:
+	 if (!param->type->can_implicitly_convert_to(actual->type, state))
+	    return PARAMETER_LIST_NO_MATCH;
+	 break;
+
+      case ir_var_function_inout:
+	 /* Since there are no bi-directional automatic conversions (e.g.,
+	  * there is int -> float but no float -> int), inout parameters must
+	  * be exact matches.
+	  */
+	 return PARAMETER_LIST_NO_MATCH;
+
+      default:
+	 assert(false);
+	 return PARAMETER_LIST_NO_MATCH;
+      }
+   }
+
+   /* If all of the parameters from the other parameter list have been
+    * exhausted, the lists have different length and, by definition, do not
+    * match.
+    */
+   if (!node_b->is_tail_sentinel())
+      return PARAMETER_LIST_NO_MATCH;
+
+   if (inexact_match)
+      return PARAMETER_LIST_INEXACT_MATCH;
+   else
+      return PARAMETER_LIST_EXACT_MATCH;
+}
+
+
+/* Classes of parameter match, sorted (mostly) best matches first.
+ * See is_better_parameter_match() below for the exceptions.
+ * */
+typedef enum {
+   PARAMETER_EXACT_MATCH,
+   PARAMETER_FLOAT_TO_DOUBLE,
+   PARAMETER_INT_TO_FLOAT,
+   PARAMETER_INT_TO_DOUBLE,
+   PARAMETER_OTHER_CONVERSION,
+} parameter_match_t;
+
+
+static parameter_match_t
+get_parameter_match_type(const ir_variable *param,
+                         const ir_rvalue *actual)
+{
+   const glsl_type *from_type;
+   const glsl_type *to_type;
+
+   if (param->data.mode == ir_var_function_out) {
+      from_type = param->type;
+      to_type = actual->type;
+   } else {
+      from_type = actual->type;
+      to_type = param->type;
+   }
+
+   if (from_type == to_type)
+      return PARAMETER_EXACT_MATCH;
+
+   if (to_type->base_type == GLSL_TYPE_DOUBLE) {
+      if (from_type->base_type == GLSL_TYPE_FLOAT)
+         return PARAMETER_FLOAT_TO_DOUBLE;
+      return PARAMETER_INT_TO_DOUBLE;
+   }
+
+   if (to_type->base_type == GLSL_TYPE_FLOAT)
+      return PARAMETER_INT_TO_FLOAT;
+
+   /* int -> uint and any other oddball conversions */
+   return PARAMETER_OTHER_CONVERSION;
+}
+
+
+static bool
+is_better_parameter_match(parameter_match_t a_match,
+                          parameter_match_t b_match)
+{
+   /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec):
+    *
+    * 1. An exact match is better than a match involving any implicit
+    * conversion.
+    *
+    * 2. A match involving an implicit conversion from float to double
+    * is better than match involving any other implicit conversion.
+    *
+    * [XXX: Not in GLSL 4.0: Only in ARB_gpu_shader5:
+    * 3. A match involving an implicit conversion from either int or uint
+    * to float is better than a match involving an implicit conversion
+    * from either int or uint to double.]
+    *
+    * If none of the rules above apply to a particular pair of conversions,
+    * neither conversion is considered better than the other.
+    *
+    * --
+    *
+    * Notably, the int->uint conversion is *not* considered to be better
+    * or worse than int/uint->float or int/uint->double.
+    */
+
+   if (a_match >= PARAMETER_INT_TO_FLOAT && b_match == PARAMETER_OTHER_CONVERSION)
+      return false;
+
+   return a_match < b_match;
+}
+
+
+static bool
+is_best_inexact_overload(const exec_list *actual_parameters,
+                         ir_function_signature **matches,
+                         int num_matches,
+                         ir_function_signature *sig)
+{
+   /* From section 6.1 of the GLSL 4.00 spec (and the ARB_gpu_shader5 spec):
+    *
+    * "A function definition A is considered a better
+    * match than function definition B if:
+    *
+    *   * for at least one function argument, the conversion for that argument
+    *     in A is better than the corresponding conversion in B; and
+    *
+    *   * there is no function argument for which the conversion in B is better
+    *     than the corresponding conversion in A.
+    *
+    * If a single function definition is considered a better match than every
+    * other matching function definition, it will be used.  Otherwise, a
+    * semantic error occurs and the shader will fail to compile."
+    */
+   for (ir_function_signature **other = matches;
+        other < matches + num_matches; other++) {
+      if (*other == sig)
+         continue;
+
+      const exec_node *node_a = sig->parameters.head;
+      const exec_node *node_b = (*other)->parameters.head;
+      const exec_node *node_p = actual_parameters->head;
+
+      bool better_for_some_parameter = false;
+
+      for (/* empty */
+           ; !node_a->is_tail_sentinel()
+           ; node_a = node_a->next,
+             node_b = node_b->next,
+             node_p = node_p->next) {
+         parameter_match_t a_match = get_parameter_match_type(
+               (const ir_variable *)node_a,
+               (const ir_rvalue *)node_p);
+         parameter_match_t b_match = get_parameter_match_type(
+               (const ir_variable *)node_b,
+               (const ir_rvalue *)node_p);
+
+         if (is_better_parameter_match(a_match, b_match))
+               better_for_some_parameter = true;
+
+         if (is_better_parameter_match(b_match, a_match))
+               return false;     /* B is better for this parameter */
+      }
+
+      if (!better_for_some_parameter)
+         return false;     /* A must be better than B for some parameter */
+
+   }
+
+   return true;
+}
+
+
+static ir_function_signature *
+choose_best_inexact_overload(_mesa_glsl_parse_state *state,
+                             const exec_list *actual_parameters,
+                             ir_function_signature **matches,
+                             int num_matches)
+{
+   if (num_matches == 0)
+      return NULL;
+
+   if (num_matches == 1)
+      return *matches;
+
+   /* Without GLSL 4.0 / ARB_gpu_shader5, there is no overload resolution
+    * among multiple inexact matches. Note that state may be NULL here if
+    * called from the linker; in that case we assume everything supported in
+    * any GLSL version is available. */
+   if (!state || state->is_version(400, 0) || state->ARB_gpu_shader5_enable) {
+      for (ir_function_signature **sig = matches; sig < matches + num_matches; sig++) {
+         if (is_best_inexact_overload(actual_parameters, matches, num_matches, *sig))
+            return *sig;
+      }
+   }
+
+   return NULL;   /* no best candidate */
+}
+
+
+ir_function_signature *
+ir_function::matching_signature(_mesa_glsl_parse_state *state,
+                                const exec_list *actual_parameters,
+                                bool allow_builtins)
+{
+   bool is_exact;
+   return matching_signature(state, actual_parameters, allow_builtins,
+                             &is_exact);
+}
+
+ir_function_signature *
+ir_function::matching_signature(_mesa_glsl_parse_state *state,
+                                const exec_list *actual_parameters,
+                                bool allow_builtins,
+                                bool *is_exact)
+{
+   ir_function_signature **inexact_matches = NULL;
+   ir_function_signature **inexact_matches_temp;
+   ir_function_signature *match = NULL;
+   int num_inexact_matches = 0;
+
+   /* From page 42 (page 49 of the PDF) of the GLSL 1.20 spec:
+    *
+    * "If an exact match is found, the other signatures are ignored, and
+    *  the exact match is used.  Otherwise, if no exact match is found, then
+    *  the implicit conversions in Section 4.1.10 "Implicit Conversions" will
+    *  be applied to the calling arguments if this can make their types match
+    *  a signature.  In this case, it is a semantic error if there are
+    *  multiple ways to apply these conversions to the actual arguments of a
+    *  call such that the call can be made to match multiple signatures."
+    */
+   foreach_in_list(ir_function_signature, sig, &this->signatures) {
+      /* Skip over any built-ins that aren't available in this shader. */
+      if (sig->is_builtin() && (!allow_builtins ||
+                                !sig->is_builtin_available(state)))
+         continue;
+
+      switch (parameter_lists_match(state, & sig->parameters, actual_parameters)) {
+      case PARAMETER_LIST_EXACT_MATCH:
+         *is_exact = true;
+         free(inexact_matches);
+         return sig;
+      case PARAMETER_LIST_INEXACT_MATCH:
+         inexact_matches_temp = (ir_function_signature **)
+               realloc(inexact_matches,
+                       sizeof(*inexact_matches) *
+                       (num_inexact_matches + 1));
+         if (inexact_matches_temp == NULL) {
+            _mesa_error_no_memory(__func__);
+            free(inexact_matches);
+            return NULL;
+         }
+         inexact_matches = inexact_matches_temp;
+         inexact_matches[num_inexact_matches++] = sig;
+         continue;
+      case PARAMETER_LIST_NO_MATCH:
+	 continue;
+      default:
+	 assert(false);
+	 return NULL;
+      }
+   }
+
+   /* There is no exact match (we would have returned it by now).  If there
+    * are multiple inexact matches, the call is ambiguous, which is an error.
+    *
+    * FINISHME: Report a decent error.  Returning NULL will likely result in
+    * FINISHME: a "no matching signature" error; it should report that the
+    * FINISHME: call is ambiguous.  But reporting errors from here is hard.
+    */
+   *is_exact = false;
+
+   match = choose_best_inexact_overload(state, actual_parameters,
+                                        inexact_matches, num_inexact_matches);
+
+   free(inexact_matches);
+   return match;
+}
+
+
+static bool
+parameter_lists_match_exact(const exec_list *list_a, const exec_list *list_b)
+{
+   const exec_node *node_a = list_a->head;
+   const exec_node *node_b = list_b->head;
+
+   for (/* empty */
+	; !node_a->is_tail_sentinel() && !node_b->is_tail_sentinel()
+	; node_a = node_a->next, node_b = node_b->next) {
+      ir_variable *a = (ir_variable *) node_a;
+      ir_variable *b = (ir_variable *) node_b;
+
+      /* If the types of the parameters do not match, the parameters lists
+       * are different.
+       */
+      if (a->type != b->type)
+         return false;
+   }
+
+   /* Unless both lists are exhausted, they differ in length and, by
+    * definition, do not match.
+    */
+   return (node_a->is_tail_sentinel() == node_b->is_tail_sentinel());
+}
+
+ir_function_signature *
+ir_function::exact_matching_signature(_mesa_glsl_parse_state *state,
+                                      const exec_list *actual_parameters)
+{
+   foreach_in_list(ir_function_signature, sig, &this->signatures) {
+      /* Skip over any built-ins that aren't available in this shader. */
+      if (sig->is_builtin() && !sig->is_builtin_available(state))
+         continue;
+
+      if (parameter_lists_match_exact(&sig->parameters, actual_parameters))
+	 return sig;
+   }
+   return NULL;
+}