Prepare dump_ir to apply optimization or not

Split `gen_defun` to generating code
and applying optimization/register allocation.

src/_debug/dump_ir.c

@@ -8,6 +8,7 @@
 #include "fe_misc.h"
 #include "ir.h"
 #include "lexer.h"
+#include "optimize.h"
 #include "parser.h"
 #include "regalloc.h"
 #include "table.h"
@@ -24,11 +25,13 @@ static void dump_vreg(FILE *fp, VReg *vreg) {
   static const char *kSize[] = {"b", "w", "d", ""};
   if (vreg->flag & VRF_CONST) {
     fprintf(fp, "(%" PRId64 ")", vreg->fixnum);
-  } else {
+  } else if (vreg->phys >= 0) {
     char regtype = 'R';
     if (vreg->flag & VRF_FLONUM)
       regtype = 'F';
     fprintf(fp, "%c%d%s<v%d>", regtype, vreg->phys, kSize[vreg->vsize], vreg->virt);
+  } else {
+    fprintf(fp, "v%d", vreg->virt);
   }
 }
 
@@ -215,18 +218,35 @@ static void dump_func_ir(Function *func) {
 }
 
 void do_dump_ir(Vector *decls) {
+  if (decls == NULL)
+    return;
+
   for (int i = 0, len = decls->len; i < len; ++i) {
     Declaration *decl = decls->data[i];
-    if (decl == NULL)
+    if (decl == NULL || decl->kind != DCL_DEFUN)
+      continue;
+    Function *func = decl->defun.func;
+    if (!gen_defun(func))
       continue;
 
-    switch (decl->kind) {
-    case DCL_DEFUN:
-      dump_func_ir(decl->defun.func);
-      break;
-    case DCL_VARDECL:
-      break;
-    }
+    curfunc = func;
+    FuncBackend *fnbe = func->extra;
+
+    optimize(fnbe->ra, fnbe->bbcon);
+
+    prepare_register_allocation(func);
+    // tweak_irs(fnbe);
+    analyze_reg_flow(fnbe->bbcon);
+
+    alloc_physical_registers(fnbe->ra, fnbe->bbcon);
+    map_virtual_to_physical_registers(fnbe->ra);
+    detect_living_registers(fnbe->ra, fnbe->bbcon);
+
+    alloc_stack_variables_onto_stack_frame(func);
+
+    curfunc = NULL;
+
+    dump_func_ir(func);
   }
 }
 
@@ -271,8 +291,6 @@ int main(int argc, char *argv[]) {
   if (compile_error_count != 0)
     exit(1);
 
-  gen(toplevel);
-
   do_dump_ir(toplevel);
 
   return 0;

src/cc/backend/codegen.c

@@ -654,7 +654,7 @@ void gen_stmt(Stmt *stmt) {
 
 ////////////////////////////////////////////////
 
-static void prepare_register_allocation(Function *func) {
+void prepare_register_allocation(Function *func) {
   bool require_stack_frame = (func->flag & FUNCF_STACK_MODIFIED) != 0;
   // Handle function parameters first.
   const Vector *params = func->type->func.params;
@@ -732,7 +732,7 @@ static void prepare_register_allocation(Function *func) {
   }
 }
 
-static void map_virtual_to_physical_registers(RegAlloc *ra) {
+void map_virtual_to_physical_registers(RegAlloc *ra) {
   for (int i = 0, vreg_count = ra->vregs->len; i < vreg_count; ++i) {
     VReg *vreg = ra->vregs->data[i];
     if (vreg == NULL)
@@ -743,7 +743,7 @@ static void map_virtual_to_physical_registers(RegAlloc *ra) {
 }
 
 // Detect living registers for each instruction.
-static void detect_living_registers(RegAlloc *ra, BBContainer *bbcon) {
+void detect_living_registers(RegAlloc *ra, BBContainer *bbcon) {
   int maxbit = ra->settings->phys_max + ra->settings->fphys_max;
   unsigned long living_pregs = 0;
   assert((int)sizeof(living_pregs) * CHAR_BIT >= maxbit);
@@ -809,7 +809,7 @@ static void detect_living_registers(RegAlloc *ra, BBContainer *bbcon) {
 #undef VREGFOR
 }
 
-static void alloc_stack_variables_onto_stack_frame(Function *func) {
+void alloc_stack_variables_onto_stack_frame(Function *func) {
   FuncBackend *fnbe = func->extra;
   size_t frame_size = fnbe->frame_size;
 
@@ -880,14 +880,14 @@ static void alloc_stack_variables_onto_stack_frame(Function *func) {
   fnbe->frame_size = frame_size;
 }
 
-static void gen_defun(Function *func) {
+bool gen_defun(Function *func) {
   if (func->scopes == NULL)  // Prototype definition
-    return;
+    return false;
 
   VarInfo *funcvi = scope_find(global_scope, func->name, NULL);
   if (funcvi != NULL && satisfy_inline_criteria(funcvi) && !(funcvi->storage & VS_STATIC)) {
     // Omit inline function: func->extra preserves the value (NULL).
-    return;
+    return false;
   }
 
   curfunc = func;
@@ -924,6 +924,15 @@ static void gen_defun(Function *func) {
   set_curbb(fnbe->ret_bb);
   curbb = NULL;
 
+  curfunc = NULL;
+  curra = NULL;
+  return true;
+}
+
+static void gen_defun_after(Function *func) {
+  FuncBackend *fnbe = func->extra;
+  curfunc = func;
+
   optimize(fnbe->ra, fnbe->bbcon);
 
   prepare_register_allocation(func);
@@ -937,16 +946,19 @@ static void gen_defun(Function *func) {
   alloc_stack_variables_onto_stack_frame(func);
 
   curfunc = NULL;
-  curra = NULL;
 }
 
-void gen_decl(Declaration *decl) {
+static void gen_decl(Declaration *decl) {
   if (decl == NULL)
     return;
 
   switch (decl->kind) {
   case DCL_DEFUN:
-    gen_defun(decl->defun.func);
+    {
+      Function *func = decl->defun.func;
+      if (gen_defun(func))
+        gen_defun_after(func);
+    }
     break;
   case DCL_VARDECL:
     break;

src/cc/backend/codegen.h

@@ -10,6 +10,7 @@
 typedef struct BB BB;
 typedef struct Expr Expr;
 typedef struct Function Function;
+typedef struct RegAlloc RegAlloc;
 typedef struct Stmt Stmt;
 typedef struct StructInfo StructInfo;
 typedef struct Type Type;
@@ -54,3 +55,9 @@ typedef struct {
 void enumerate_register_params(
     Function *func, RegParamInfo iargs[], int max_ireg, RegParamInfo fargs[], int max_freg,
     int *piarg_count, int *pfarg_count);
+
+bool gen_defun(Function *func);
+void prepare_register_allocation(Function *func);
+void map_virtual_to_physical_registers(RegAlloc *ra);
+void detect_living_registers(RegAlloc *ra, BBContainer *bbcon);
+void alloc_stack_variables_onto_stack_frame(Function *func);