Merge pull request #3157 from cremno/add-mrb_int_mul_overflow

add function for checked mrb_int multiplication

1 files changed, 6 insertions, 16 deletions

diff --git a/src/vm.c b/src/vm.c
index fd2a9384c..6f8c5109f 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1862,25 +1862,15 @@ RETRY_TRY_BLOCK:
       switch (TYPES2(mrb_type(regs[a]),mrb_type(regs[a+1]))) {
       case TYPES2(MRB_TT_FIXNUM,MRB_TT_FIXNUM):
         {
-          mrb_value z;
-
-          z = mrb_fixnum_mul(mrb, regs[a], regs[a+1]);
+          mrb_int x, y, z;
 
-          switch (mrb_type(z)) {
-          case MRB_TT_FIXNUM:
-            {
-              SET_INT_VALUE(regs[a], mrb_fixnum(z));
-            }
-            break;
-          case MRB_TT_FLOAT:
-            {
-              SET_FLOAT_VALUE(mrb, regs[a], mrb_float(z));
-            }
-            break;
-          default:
-            /* cannot happen */
+          x = mrb_fixnum(regs[a]);
+          y = mrb_fixnum(regs[a+1]);
+          if (mrb_int_mul_overflow(x, y, &z)) {
+            SET_FLOAT_VALUE(mrb, regs[a], (mrb_float)x * (mrb_float)y);
             break;
           }
+          SET_INT_VALUE(regs[a], z);
         }
         break;
       case TYPES2(MRB_TT_FIXNUM,MRB_TT_FLOAT):