label routines for implementing branches, jumps

1 files changed, 77 insertions, 0 deletions

diff --git a/src/mesa/shader/slang/slang_label.c b/src/mesa/shader/slang/slang_label.c
new file mode 100644
index 00000000000..4d35d2e72a1
--- /dev/null
+++ b/src/mesa/shader/slang/slang_label.c
@@ -0,0 +1,77 @@
+
+
+/**
+ * Functions for managing instruction labels.
+ * Basically, this is used to manage the problem of forward branches where
+ * we have a branch instruciton but don't know the target address yet.
+ */
+
+
+#include "slang_label.h"
+
+
+slang_label *
+_slang_label_new(const char *name)
+{
+   slang_label *l = (slang_label *) _mesa_calloc(sizeof(slang_label));
+   if (l) {
+      l->Name = _mesa_strdup(name);
+      l->Location = -1;
+   }
+   return l;
+}
+
+void
+_slang_label_delete(slang_label *l)
+{
+   if (l->Name)
+      _mesa_free(l->Name);
+   if (l->References)
+      _mesa_free(l->References);
+   _mesa_free(l);
+}
+
+
+void
+_slang_label_add_reference(slang_label *l, GLuint inst)
+{
+   const GLuint oldSize = l->NumReferences * sizeof(GLuint);
+   assert(l->Location < 0);
+   l->References = _mesa_realloc(l->References,
+                                 oldSize, oldSize + sizeof(GLuint));
+   if (l->References) {
+      l->References[l->NumReferences] = inst;
+      l->NumReferences++;
+   }
+}
+
+
+GLint
+_slang_label_get_location(const slang_label *l)
+{
+   return l->Location;
+}
+
+
+void
+_slang_label_set_location(slang_label *l, GLint location,
+                          struct gl_program *prog)
+{
+   GLuint i;
+
+   assert(l->Location < 0);
+   assert(location >= 0);
+
+   l->Location = location;
+
+   /* for the instructions that were waiting to learn the label's location: */
+   for (i = 0; i < l->NumReferences; i++) {
+      const GLuint j = l->References[i];
+      prog->Instructions[j].BranchTarget = location;
+   }
+
+   if (l->References) {
+      _mesa_free(l->References);
+      l->References = NULL;
+   }
+}