Reduced working `Rational` object allocations

When rationalizing negative values.

rational.c

@@ -1712,21 +1712,30 @@ static VALUE
 nurat_rationalize(int argc, VALUE *argv, VALUE self)
 {
     VALUE e, a, b, p, q;
+    VALUE rat = self;
+    get_dat1(self);
 
     if (rb_check_arity(argc, 0, 1) == 0)
 	return self;
 
-    if (nurat_negative_p(self))
-	return rb_rational_uminus(nurat_rationalize(argc, argv, rb_rational_uminus(self)));
-
     e = f_abs(argv[0]);
-    a = f_sub(self, e);
-    b = f_add(self, e);
+
+    if (INT_NEGATIVE_P(dat->num)) {
+        rat = f_rational_new2(RBASIC_CLASS(self), rb_int_uminus(dat->num), dat->den);
+    }
+
+    a = FIXNUM_ZERO_P(e) ? rat : rb_rational_minus(rat, e);
+    b = FIXNUM_ZERO_P(e) ? rat : rb_rational_plus(rat, e);
 
     if (f_eqeq_p(a, b))
 	return self;
 
     nurat_rationalize_internal(a, b, &p, &q);
+    if (rat != self) {
+        RATIONAL_SET_NUM(rat, rb_int_uminus(p));
+        RATIONAL_SET_DEN(rat, q);
+        return rat;
+    }
     return f_rational_new2(CLASS_OF(self), p, q);
 }
 
@@ -2238,7 +2247,7 @@ rb_flt_rationalize_with_prec(VALUE flt, VALUE prec)
 VALUE
 rb_flt_rationalize(VALUE flt)
 {
-    VALUE a, b, f, p, q;
+    VALUE a, b, f, p, q, den;
     int n;
 
     float_decode_internal(flt, &f, &n);
@@ -2246,7 +2255,7 @@ rb_flt_rationalize(VALUE flt)
         return rb_rational_new1(rb_int_lshift(f, INT2FIX(n)));
 
     {
-        VALUE radix_times_f, den;
+        VALUE radix_times_f;
 
         radix_times_f = rb_int_mul(INT2FIX(FLT_RADIX), f);
 #if FLT_RADIX == 2 && 0
@@ -2255,13 +2264,15 @@ rb_flt_rationalize(VALUE flt)
         den = rb_int_positive_pow(FLT_RADIX, 1-n);
 #endif
 
-        a = rb_rational_new2(rb_int_minus(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
-        b = rb_rational_new2(rb_int_plus(radix_times_f, INT2FIX(FLT_RADIX - 1)), den);
+        a = rb_int_minus(radix_times_f, INT2FIX(FLT_RADIX - 1));
+        b = rb_int_plus(radix_times_f, INT2FIX(FLT_RADIX - 1));
     }
 
-    if (nurat_eqeq_p(a, b))
+    if (f_eqeq_p(a, b))
         return float_to_r(flt);
 
+    a = rb_rational_new2(a, den);
+    b = rb_rational_new2(b, den);
     nurat_rationalize_internal(a, b, &p, &q);
     return rb_rational_new2(p, q);
 }
@@ -2284,16 +2295,18 @@ static VALUE
 float_rationalize(int argc, VALUE *argv, VALUE self)
 {
     double d = RFLOAT_VALUE(self);
-
-    if (d < 0.0)
-        return rb_rational_uminus(float_rationalize(argc, argv, DBL2NUM(-d)));
+    VALUE rat;
+    int neg = d < 0.0;
+    if (neg) self = DBL2NUM(-d);
 
     if (rb_check_arity(argc, 0, 1)) {
-        return rb_flt_rationalize_with_prec(self, argv[0]);
+        rat = rb_flt_rationalize_with_prec(self, argv[0]);
     }
     else {
-        return rb_flt_rationalize(self);
+        rat = rb_flt_rationalize(self);
     }
+    if (neg) RATIONAL_SET_NUM(rat, rb_int_uminus(RRATIONAL(rat)->num));
+    return rat;
 }
 
 inline static int