VM: fixes a bug with the handling of 0 bignums, and declares bignum/mod

to maybe output fixnums
slavapestov · Jun 27, 2015 · 35b04f8 · 35b04f8
1 parent 0d02ff8
commit 35b04f8
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/basis/stack-checker/known-words/known-words.factor b/basis/stack-checker/known-words/known-words.factor
@@ -336,7 +336,7 @@ M: object infer-call* \ call bad-macro-input ;
 \ bignum-gcd { bignum bignum } { bignum } define-primitive \ bignum-gcd make-foldable
 \ bignum-shift { bignum fixnum } { bignum } define-primitive \ bignum-shift make-foldable
 \ bignum/i { bignum bignum } { bignum } define-primitive \ bignum/i make-foldable
-\ bignum/mod { bignum bignum } { bignum bignum } define-primitive \ bignum/mod make-foldable
+\ bignum/mod { bignum bignum } { bignum integer } define-primitive \ bignum/mod make-foldable
 \ bignum< { bignum bignum } { object } define-primitive \ bignum< make-foldable
 \ bignum<= { bignum bignum } { object } define-primitive \ bignum<= make-foldable
 \ bignum= { bignum bignum } { object } define-primitive \ bignum= make-foldable

diff --git a/vm/math.cpp b/vm/math.cpp
@@ -3,6 +3,8 @@
 namespace factor {
 
 cell bignum_maybe_to_fixnum(bignum* bn) {
+  if (BIGNUM_ZERO_P(bn))
+    return tag_fixnum(0);
   fixnum len = BIGNUM_LENGTH(bn);
   bignum_digit_type *digits = BIGNUM_START_PTR(bn);
   if (len == 1 && digits[0] >= fixnum_min && digits[0] <= fixnum_max) {
@@ -143,7 +145,7 @@ void factor_vm::primitive_bignum_divmod() {
   bignum* q, *r;
   bignum_divide(x, y, &q, &r);
   *s1 = tag<bignum>(q);
-  *s0 = tag<bignum>(r);
+  *s0 = bignum_maybe_to_fixnum(r);
 }
 
 void factor_vm::primitive_bignum_mod() {