+/***********************************************************************
+ *IR Code-Generation
+ *
+ * Since the IR has the convention of putting 'write' operands
+ * at the beginning, we have to rotate the operands of instructions
+ * properly in order to generate valid QCVM code.
+ *
+ * Having destinations at a fixed position is more convenient. In QC
+ * this is *mostly* OPC, but FTE adds at least 2 instructions which
+ * read from from OPA, and store to OPB rather than OPC. Which is
+ * partially the reason why the implementation of these instructions
+ * in darkplaces has been delayed for so long.
+ *
+ * Breaking conventions is annoying...
+ */
+static bool ir_builder_gen_global(ir_builder *self, ir_value *global);
+
+static bool gen_global_field(ir_value *global)
+{
+ if (global->isconst)
+ {
+ ir_value *fld = global->constval.vpointer;
+ if (!fld) {
+ printf("Invalid field constant with no field: %s\n", global->name);
+ return false;
+ }
+
+ /* Now, in this case, a relocation would be impossible to code
+ * since it looks like this:
+ * .vector v = origin; <- parse error, wtf is 'origin'?
+ * .vector origin;
+ *
+ * But we will need a general relocation support later anyway
+ * for functions... might as well support that here.
+ */
+ if (!fld->code.globaladdr) {
+ printf("FIXME: Relocation support\n");
+ return false;
+ }
+
+ /* copy the field's value */
+ global->code.globaladdr = code_globals_add(code_globals_data[fld->code.globaladdr]);
+ }
+ else
+ {
+ prog_section_field fld;
+
+ fld.name = global->code.name;
+ fld.offset = code_fields_elements;
+ fld.type = global->fieldtype;
+
+ if (fld.type == TYPE_VOID) {
+ printf("Field is missing a type: %s\n", global->name);
+ return false;
+ }
+
+ if (code_fields_add(fld) < 0)
+ return false;
+
+ global->code.globaladdr = code_globals_add(fld.offset);
+ }
+ if (global->code.globaladdr < 0)
+ return false;
+ return true;
+}
+
+static bool gen_global_pointer(ir_value *global)
+{
+ if (global->isconst)
+ {
+ ir_value *target = global->constval.vpointer;
+ if (!target) {
+ printf("Invalid pointer constant: %s\n", global->name);
+ /* NULL pointers are pointing to the NULL constant, which also
+ * sits at address 0, but still has an ir_value for itself.
+ */
+ return false;
+ }
+
+ /* Here, relocations ARE possible - in fteqcc-enhanced-qc:
+ * void() foo; <- proto
+ * void() *fooptr = &foo;
+ * void() foo = { code }
+ */
+ if (!target->code.globaladdr) {
+ /* FIXME: Check for the constant nullptr ir_value!
+ * because then code.globaladdr being 0 is valid.
+ */
+ printf("FIXME: Relocation support\n");
+ return false;
+ }
+
+ global->code.globaladdr = code_globals_add(target->code.globaladdr);
+ }
+ else
+ {
+ global->code.globaladdr = code_globals_add(0);
+ }
+ if (global->code.globaladdr < 0)
+ return false;
+ return true;
+}
+
+static bool gen_blocks_recursive(ir_function *func, ir_block *block)
+{
+ prog_section_statement stmt;
+ ir_instr *instr;
+ ir_block *target;
+ ir_block *ontrue;
+ ir_block *onfalse;
+ size_t stidx;
+ size_t i;
+
+tailcall:
+ block->generated = true;
+ block->code_start = code_statements_elements;
+ for (i = 0; i < block->instr_count; ++i)
+ {
+ instr = block->instr[i];
+
+ if (instr->opcode == VINSTR_PHI) {
+ printf("cannot generate virtual instruction (phi)\n");
+ return false;
+ }
+
+ if (instr->opcode == VINSTR_JUMP) {
+ target = instr->bops[0];
+ /* for uncoditional jumps, if the target hasn't been generated
+ * yet, we generate them right here.
+ */
+ if (!target->generated) {
+ block = target;
+ goto tailcall;
+ }
+
+ /* otherwise we generate a jump instruction */
+ stmt.opcode = INSTR_GOTO;
+ stmt.o1.s1 = (target->code_start) - code_statements_elements;
+ stmt.o2.s1 = 0;
+ stmt.o3.s1 = 0;
+ if (code_statements_add(stmt) < 0)
+ return false;
+
+ /* no further instructions can be in this block */
+ return true;
+ }
+
+ if (instr->opcode == VINSTR_COND) {
+ ontrue = instr->bops[0];
+ onfalse = instr->bops[1];
+ /* TODO: have the AST signal which block should
+ * come first: eg. optimize IFs without ELSE...
+ */
+
+ stmt.o1.u1 = instr->_ops[0]->code.globaladdr;
+ stmt.o2.u1 = 0;
+ stmt.o3.s1 = 0;
+
+ if (ontrue->generated) {
+ stmt.opcode = INSTR_IF;
+ stmt.o2.s1 = (ontrue->code_start-1) - code_statements_elements;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ }
+ if (onfalse->generated) {
+ stmt.opcode = INSTR_IFNOT;
+ stmt.o2.s1 = (onfalse->code_start-1) - code_statements_elements;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ }
+ if (!ontrue->generated) {
+ if (onfalse->generated) {
+ block = ontrue;
+ goto tailcall;
+ }
+ }
+ if (!onfalse->generated) {
+ if (ontrue->generated) {
+ block = onfalse;
+ goto tailcall;
+ }
+ }
+ /* neither ontrue nor onfalse exist */
+ stmt.opcode = INSTR_IFNOT;
+ stidx = code_statements_elements;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ /* on false we jump, so add ontrue-path */
+ if (!gen_blocks_recursive(func, ontrue))
+ return false;
+ /* fixup the jump address */
+ code_statements_data[stidx].o2.s1 = code_statements_elements - stidx;
+ /* generate onfalse path */
+ if (onfalse->generated) {
+ /* fixup the jump address */
+ code_statements_data[stidx].o2.s1 = (onfalse->code_start) - (stidx);
+ /* may have been generated in the previous recursive call */
+ stmt.opcode = INSTR_GOTO;
+ stmt.o1.s1 = (onfalse->code_start) - code_statements_elements;
+ stmt.o2.s1 = 0;
+ stmt.o3.s1 = 0;
+ return (code_statements_add(stmt) >= 0);
+ }
+ /* if not, generate now */
+ block = onfalse;
+ goto tailcall;
+ }
+
+ if (instr->opcode >= INSTR_CALL0 && instr->opcode <= INSTR_CALL8) {
+ /* Trivial call translation:
+ * copy all params to OFS_PARM*
+ * if the output's storetype is not store_return,
+ * add append a STORE instruction!
+ *
+ * NOTES on how to do it better without much trouble:
+ * -) The liferanges!
+ * Simply check the liferange of all parameters for
+ * other CALLs. For each param with no CALL in its
+ * liferange, we can store it in an OFS_PARM at
+ * generation already. This would even include later
+ * reuse.... probably... :)
+ */
+ size_t p;
+ ir_value *retvalue;
+
+ for (p = 0; p < instr->params_count; ++p)
+ {
+ ir_value *param = instr->params[p];
+
+ stmt.opcode = INSTR_STORE_F;
+ stmt.o3.u1 = 0;
+
+ stmt.opcode = type_store_instr[param->vtype];
+ stmt.o1.u1 = param->code.globaladdr;
+ stmt.o2.u1 = OFS_PARM0 + 3 * p;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ }
+ stmt.opcode = INSTR_CALL0 + instr->params_count;
+ if (stmt.opcode > INSTR_CALL8)
+ stmt.opcode = INSTR_CALL8;
+ stmt.o1.u1 = instr->_ops[1]->code.globaladdr;
+ stmt.o2.u1 = 0;
+ stmt.o3.u1 = 0;
+ if (code_statements_add(stmt) < 0)
+ return false;
+
+ retvalue = instr->_ops[0];
+ if (retvalue && retvalue->store != store_return && retvalue->life_count)
+ {
+ /* not to be kept in OFS_RETURN */
+ stmt.opcode = type_store_instr[retvalue->vtype];
+ stmt.o1.u1 = OFS_RETURN;
+ stmt.o2.u1 = retvalue->code.globaladdr;
+ stmt.o3.u1 = 0;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ }
+ continue;
+ }
+
+ if (instr->opcode == INSTR_STATE) {
+ printf("TODO: state instruction\n");
+ return false;
+ }
+
+ stmt.opcode = instr->opcode;
+ stmt.o1.u1 = 0;
+ stmt.o2.u1 = 0;
+ stmt.o3.u1 = 0;
+
+ /* This is the general order of operands */
+ if (instr->_ops[0])
+ stmt.o3.u1 = instr->_ops[0]->code.globaladdr;
+
+ if (instr->_ops[1])
+ stmt.o1.u1 = instr->_ops[1]->code.globaladdr;
+
+ if (instr->_ops[2])
+ stmt.o2.u1 = instr->_ops[2]->code.globaladdr;
+
+ if (stmt.opcode == INSTR_RETURN || stmt.opcode == INSTR_DONE)
+ {
+ stmt.o1.u1 = stmt.o3.u1;
+ stmt.o3.u1 = 0;
+ }
+ else if (stmt.opcode >= INSTR_STORE_F &&
+ stmt.opcode <= INSTR_STORE_FNC)
+ {
+ /* 2-operand instructions with A -> B */
+ stmt.o2.u1 = stmt.o3.u1;
+ stmt.o3.u1 = 0;
+ }
+
+ if (code_statements_add(stmt) < 0)
+ return false;
+ }
+ return true;
+}
+
+static bool gen_function_code(ir_function *self)
+{
+ ir_block *block;
+ prog_section_statement stmt;
+
+ /* Starting from entry point, we generate blocks "as they come"
+ * for now. Dead blocks will not be translated obviously.
+ */
+ if (!self->blocks_count) {
+ printf("Function '%s' declared without body.\n", self->name);
+ return false;
+ }
+
+ block = self->blocks[0];
+ if (block->generated)
+ return true;
+
+ if (!gen_blocks_recursive(self, block)) {
+ printf("failed to generate blocks for '%s'\n", self->name);
+ return false;
+ }
+
+ /* otherwise code_write crashes since it debug-prints functions until AINSTR_END */
+ stmt.opcode = AINSTR_END;
+ stmt.o1.u1 = 0;
+ stmt.o2.u1 = 0;
+ stmt.o3.u1 = 0;
+ if (code_statements_add(stmt) < 0)
+ return false;
+ return true;
+}
+
+static bool gen_global_function(ir_builder *ir, ir_value *global)
+{
+ prog_section_function fun;
+ ir_function *irfun;
+
+ size_t i;
+ size_t local_var_end;
+
+ if (!global->isconst || (!global->constval.vfunc))
+ {
+ printf("Invalid state of function-global: not constant: %s\n", global->name);
+ return false;
+ }
+
+ irfun = global->constval.vfunc;
+
+ fun.name = global->code.name;
+ fun.file = code_cachedstring(global->context.file);
+ fun.profile = 0; /* always 0 */
+ fun.nargs = irfun->params_count;
+
+ for (i = 0;i < 8; ++i) {
+ if (i >= fun.nargs)
+ fun.argsize[i] = 0;
+ else
+ fun.argsize[i] = type_sizeof[irfun->params[i]];
+ }
+
+ fun.firstlocal = code_globals_elements;
+ fun.locals = irfun->allocated_locals + irfun->locals_count;
+
+ local_var_end = 0;
+ for (i = 0; i < irfun->locals_count; ++i) {
+ if (!ir_builder_gen_global(ir, irfun->locals[i])) {
+ printf("Failed to generate global %s\n", irfun->locals[i]->name);
+ return false;
+ }
+ }
+ if (irfun->locals_count) {
+ ir_value *last = irfun->locals[irfun->locals_count-1];
+ local_var_end = last->code.globaladdr;
+ local_var_end += type_sizeof[last->vtype];
+ }
+ for (i = 0; i < irfun->values_count; ++i)
+ {
+ /* generate code.globaladdr for ssa values */
+ ir_value *v = irfun->values[i];
+ v->code.globaladdr = local_var_end + v->code.local;
+ }
+ for (i = 0; i < irfun->locals_count; ++i) {
+ /* fill the locals with zeros */
+ code_globals_add(0);
+ }
+
+ if (irfun->builtin)
+ fun.entry = irfun->builtin;
+ else {
+ fun.entry = code_statements_elements;
+ if (!gen_function_code(irfun)) {
+ printf("Failed to generate code for function %s\n", irfun->name);
+ return false;
+ }
+ }
+
+ return (code_functions_add(fun) >= 0);
+}
+
+static bool ir_builder_gen_global(ir_builder *self, ir_value *global)
+{
+ size_t i;
+ int32_t *iptr;
+ prog_section_def def;
+
+ def.type = global->vtype;
+ def.offset = code_globals_elements;
+ def.name = global->code.name = code_genstring(global->name);
+
+ switch (global->vtype)
+ {
+ case TYPE_POINTER:
+ if (code_defs_add(def) < 0)
+ return false;
+ return gen_global_pointer(global);
+ case TYPE_FIELD:
+ if (code_defs_add(def) < 0)
+ return false;
+ return gen_global_field(global);
+ case TYPE_ENTITY:
+ /* fall through */
+ case TYPE_FLOAT:
+ {
+ if (code_defs_add(def) < 0)
+ return false;
+
+ if (global->isconst) {
+ iptr = (int32_t*)&global->constval.vfloat;
+ global->code.globaladdr = code_globals_add(*iptr);
+ } else
+ global->code.globaladdr = code_globals_add(0);
+
+ return global->code.globaladdr >= 0;
+ }
+ case TYPE_STRING:
+ {
+ if (code_defs_add(def) < 0)
+ return false;
+ if (global->isconst)
+ global->code.globaladdr = code_globals_add(code_cachedstring(global->constval.vstring));
+ else
+ global->code.globaladdr = code_globals_add(0);
+ return global->code.globaladdr >= 0;
+ }
+ case TYPE_VECTOR:
+ {
+ size_t d;
+ if (code_defs_add(def) < 0)
+ return false;
+
+ if (global->isconst) {
+ iptr = (int32_t*)&global->constval.vvec;
+ global->code.globaladdr = code_globals_add(iptr[0]);
+ if (global->code.globaladdr < 0)
+ return false;
+ for (d = 1; d < type_sizeof[global->vtype]; ++d)
+ {
+ if (code_globals_add(iptr[d]) < 0)
+ return false;
+ }
+ } else {
+ global->code.globaladdr = code_globals_add(0);
+ if (global->code.globaladdr < 0)
+ return false;
+ for (d = 1; d < type_sizeof[global->vtype]; ++d)
+ {
+ if (code_globals_add(0) < 0)
+ return false;
+ }
+ }
+ return global->code.globaladdr >= 0;
+ }
+ case TYPE_FUNCTION:
+ if (code_defs_add(def) < 0)
+ return false;
+ global->code.globaladdr = code_globals_elements;
+ code_globals_add(code_functions_elements);
+ return gen_global_function(self, global);
+ case TYPE_VARIANT:
+ /* assume biggest type */
+ global->code.globaladdr = code_globals_add(0);
+ for (i = 1; i < type_sizeof[TYPE_VARIANT]; ++i)
+ code_globals_add(0);
+ return true;
+ default:
+ /* refuse to create 'void' type or any other fancy business. */
+ printf("Invalid type for global variable %s\n", global->name);
+ return false;
+ }
+}
+
+bool ir_builder_generate(ir_builder *self, const char *filename)
+{
+ size_t i;
+
+ code_init();
+
+ for (i = 0; i < self->globals_count; ++i)
+ {
+ if (!ir_builder_gen_global(self, self->globals[i])) {
+ return false;
+ }
+ }
+
+ printf("writing '%s'...\n", filename);
+ return code_write(filename);
+}
+