optimized bound checking

1 files changed, 14 insertions, 9 deletions

diff --git a/tcc.c b/tcc.c
index 8494e5a..0554cd4 100644
--- a/tcc.c
+++ b/tcc.c
@@ -286,6 +286,8 @@ struct TCCState {
                                 char/short stored in integer registers) */
 #define VT_MUSTBOUND 0x0800  /* bound checking must be done before
                                 dereferencing value */
+#define VT_BOUNDED   0x8000  /* value is bounded. The address of the
+                                bounding function call point is in vc */
 #define VT_LVAL_BYTE     0x1000  /* lvalue is a byte */
 #define VT_LVAL_SHORT    0x2000  /* lvalue is a short */
 #define VT_LVAL_UNSIGNED 0x4000  /* lvalue is unsigned */
@@ -2660,12 +2662,16 @@ void gbound(void)
     vtop->r &= ~VT_MUSTBOUND;
     /* if lvalue, then use checking code before dereferencing */
     if (vtop->r & VT_LVAL) {
-        lval_type = vtop->r & (VT_LVAL_TYPE | VT_LVAL);
-        gaddrof();
-        vpushi(0);
-        gen_bounded_ptr_add1();
-        gen_bounded_ptr_add2(1);
-        vtop->r |= lval_type;
+        /* if not VT_BOUNDED value, then make one */
+        if (!(vtop->r & VT_BOUNDED)) {
+            lval_type = vtop->r & (VT_LVAL_TYPE | VT_LVAL);
+            gaddrof();
+            vpushi(0);
+            gen_bounded_ptr_add();
+            vtop->r |= lval_type;
+        }
+        /* then check for dereferencing */
+        gen_bounded_ptr_deref();
     }
 }
 #endif
@@ -3365,9 +3371,8 @@ void gen_op(int op)
                     vswap();
                     gen_op('-');
                 }
-                gen_bounded_ptr_add1();
-                gen_bounded_ptr_add2(0);
-            } else 
+                gen_bounded_ptr_add();
+            } else
 #endif
             {
                 gen_opic(op);