mie: implement instruction selection graph generation for binary ops and load/store

mie/select/instr.c

@@ -0,0 +1,32 @@
+#include "builder.h"
+
+#include <mie/select/opcode.h>
+#include <stddef.h>
+
+#define DECLARE_INSTR_TYPE(name)   extern struct select_instr_type select_##name
+#define INSTR_TYPE_ENTRY(op, name) [MIE_INSTR_##op] = &select_##name
+
+DECLARE_INSTR_TYPE(alloca);
+DECLARE_INSTR_TYPE(add);
+DECLARE_INSTR_TYPE(sub);
+DECLARE_INSTR_TYPE(mul);
+DECLARE_INSTR_TYPE(div);
+DECLARE_INSTR_TYPE(load);
+DECLARE_INSTR_TYPE(store);
+
+static const struct select_instr_type *instr_types[] = {
+	INSTR_TYPE_ENTRY(ALLOCA, alloca), INSTR_TYPE_ENTRY(ADD, add),
+	INSTR_TYPE_ENTRY(SUB, sub),       INSTR_TYPE_ENTRY(MUL, mul),
+	INSTR_TYPE_ENTRY(DIV, div),       INSTR_TYPE_ENTRY(LOAD, load),
+	INSTR_TYPE_ENTRY(STORE, store),
+};
+static const size_t nr_instr_types = sizeof instr_types / sizeof instr_types[0];
+
+const struct select_instr_type *select_type_for_instr(enum mie_instr_type instr)
+{
+	if (instr < 0 || instr >= nr_instr_types) {
+		return NULL;
+	}
+
+	return instr_types[instr];
+}