py/modbuiltins: Implement abs() by dispatching to MP_UNARY_OP_ABS.

This allows user classes to implement __abs__ special method, and saves
code size (104 bytes for x86_64), even though during refactor, an issue
was fixed and few optimizations were made:

* abs() of minimum (negative) small int value is calculated properly.
* objint_longlong and objint_mpz avoid allocating new object is the
  argument is already non-negative.

9 files changed, 44 insertions, 76 deletions

diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 1c76b8073..0486251b6 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -91,26 +91,7 @@ STATIC mp_obj_t mp_builtin___build_class__(size_t n_args, const mp_obj_t *args)
 MP_DEFINE_CONST_FUN_OBJ_VAR(mp_builtin___build_class___obj, 2, mp_builtin___build_class__);
 
 STATIC mp_obj_t mp_builtin_abs(mp_obj_t o_in) {
-    #if MICROPY_PY_BUILTINS_FLOAT
-    if (mp_obj_is_float(o_in)) {
-        mp_float_t value = mp_obj_float_get(o_in);
-        // TODO check for NaN etc
-        if (value < 0) {
-            return mp_obj_new_float(-value);
-        } else {
-            return o_in;
-        }
-    #if MICROPY_PY_BUILTINS_COMPLEX
-    } else if (MP_OBJ_IS_TYPE(o_in, &mp_type_complex)) {
-        mp_float_t real, imag;
-        mp_obj_complex_get(o_in, &real, &imag);
-        return mp_obj_new_float(MICROPY_FLOAT_C_FUN(sqrt)(real*real + imag*imag));
-    #endif
-    }
-    #endif
-
-    // this will raise a TypeError if the argument is not integral
-    return mp_obj_int_abs(o_in);
+    return mp_unary_op(MP_UNARY_OP_ABS, o_in);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_abs_obj, mp_builtin_abs);
 
diff --git a/py/objcomplex.c b/py/objcomplex.c
index 07b9d5d41..e7a3c244a 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -124,6 +124,11 @@ STATIC mp_obj_t complex_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
         case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT(mp_float_hash(o->real) ^ mp_float_hash(o->imag));
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_complex(-o->real, -o->imag);
+        case MP_UNARY_OP_ABS: {
+            mp_float_t real, imag;
+            mp_obj_complex_get(o_in, &real, &imag);
+            return mp_obj_new_float(MICROPY_FLOAT_C_FUN(sqrt)(real*real + imag*imag));
+        }
         default: return MP_OBJ_NULL; // op not supported
     }
 }
diff --git a/py/objfloat.c b/py/objfloat.c
index fadbbcb79..fefd78314 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -162,6 +162,15 @@ STATIC mp_obj_t float_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
         case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT(mp_float_hash(val));
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_float(-val);
+        case MP_UNARY_OP_ABS: {
+            mp_float_t value = mp_obj_float_get(o_in);
+            // TODO check for NaN etc
+            if (value < 0) {
+                return mp_obj_new_float(-value);
+            } else {
+                return o_in;
+            }
+        }
         default: return MP_OBJ_NULL; // op not supported
     }
 }
diff --git a/py/objint.c b/py/objint.c
index 6a73b4382..000a0404c 100644
--- a/py/objint.c
+++ b/py/objint.c
@@ -314,16 +314,6 @@ int mp_obj_int_sign(mp_obj_t self_in) {
     }
 }
 
-// This must handle int and bool types, and must raise a
-// TypeError if the argument is not integral
-mp_obj_t mp_obj_int_abs(mp_obj_t self_in) {
-    mp_int_t val = mp_obj_get_int(self_in);
-    if (val < 0) {
-        val = -val;
-    }
-    return MP_OBJ_NEW_SMALL_INT(val);
-}
-
 // This is called for operations on SMALL_INT that are not handled by mp_unary_op
 mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
     return MP_OBJ_NULL; // op not supported
diff --git a/py/objint.h b/py/objint.h
index a4d4ff32d..4b95acde9 100644
--- a/py/objint.h
+++ b/py/objint.h
@@ -57,7 +57,6 @@ mp_int_t mp_obj_int_hash(mp_obj_t self_in);
 mp_obj_t mp_obj_int_from_bytes_impl(bool big_endian, size_t len, const byte *buf);
 void mp_obj_int_to_bytes_impl(mp_obj_t self_in, bool big_endian, size_t len, byte *buf);
 int mp_obj_int_sign(mp_obj_t self_in);
-mp_obj_t mp_obj_int_abs(mp_obj_t self_in);
 mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in);
 mp_obj_t mp_obj_int_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in);
 mp_obj_t mp_obj_int_binary_op_extra_cases(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in);
diff --git a/py/objint_longlong.c b/py/objint_longlong.c
index ddfdae744..8d8ca1b2c 100644
--- a/py/objint_longlong.c
+++ b/py/objint_longlong.c
@@ -94,30 +94,6 @@ int mp_obj_int_sign(mp_obj_t self_in) {
     }
 }
 
-// This must handle int and bool types, and must raise a
-// TypeError if the argument is not integral
-mp_obj_t mp_obj_int_abs(mp_obj_t self_in) {
-    if (MP_OBJ_IS_TYPE(self_in, &mp_type_int)) {
-        mp_obj_int_t *self = self_in;
-        self = mp_obj_new_int_from_ll(self->val);
-        if (self->val < 0) {
-            // TODO could overflow long long
-            self->val = -self->val;
-        }
-        return self;
-    } else {
-        mp_int_t val = mp_obj_get_int(self_in);
-        if (val == MP_SMALL_INT_MIN) {
-            return mp_obj_new_int_from_ll(-val);
-        } else {
-            if (val < 0) {
-                val = -val;
-            }
-            return MP_OBJ_NEW_SMALL_INT(val);
-        }
-    }
-}
-
 mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
     mp_obj_int_t *o = o_in;
     switch (op) {
@@ -130,6 +106,16 @@ mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_int_from_ll(-o->val);
         case MP_UNARY_OP_INVERT: return mp_obj_new_int_from_ll(~o->val);
+        case MP_UNARY_OP_ABS: {
+            mp_obj_int_t *self = MP_OBJ_TO_PTR(o_in);
+            if (self->val >= 0) {
+                return o_in;
+            }
+            self = mp_obj_new_int_from_ll(self->val);
+            // TODO could overflow long long
+            self->val = -self->val;
+            return MP_OBJ_FROM_PTR(self);
+        }
         default: return MP_OBJ_NULL; // op not supported
     }
 }
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
index 0e318b492..15aad1d4d 100644
--- a/py/objint_mpz.c
+++ b/py/objint_mpz.c
@@ -141,27 +141,6 @@ int mp_obj_int_sign(mp_obj_t self_in) {
     }
 }
 
-// This must handle int and bool types, and must raise a
-// TypeError if the argument is not integral
-mp_obj_t mp_obj_int_abs(mp_obj_t self_in) {
-    if (MP_OBJ_IS_TYPE(self_in, &mp_type_int)) {
-        mp_obj_int_t *self = MP_OBJ_TO_PTR(self_in);
-        mp_obj_int_t *self2 = mp_obj_int_new_mpz();
-        mpz_abs_inpl(&self2->mpz, &self->mpz);
-        return MP_OBJ_FROM_PTR(self2);
-    } else {
-        mp_int_t val = mp_obj_get_int(self_in);
-        if (val == MP_SMALL_INT_MIN) {
-            return mp_obj_new_int_from_ll(-val);
-        } else {
-            if (val < 0) {
-                val = -val;
-            }
-            return MP_OBJ_NEW_SMALL_INT(val);
-        }
-    }
-}
-
 mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
     mp_obj_int_t *o = MP_OBJ_TO_PTR(o_in);
     switch (op) {
@@ -170,6 +149,15 @@ mp_obj_t mp_obj_int_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: { mp_obj_int_t *o2 = mp_obj_int_new_mpz(); mpz_neg_inpl(&o2->mpz, &o->mpz); return MP_OBJ_FROM_PTR(o2); }
         case MP_UNARY_OP_INVERT: { mp_obj_int_t *o2 = mp_obj_int_new_mpz(); mpz_not_inpl(&o2->mpz, &o->mpz); return MP_OBJ_FROM_PTR(o2); }
+        case MP_UNARY_OP_ABS: {
+            mp_obj_int_t *self = MP_OBJ_TO_PTR(o_in);
+            if (self->mpz.neg == 0) {
+                return o_in;
+            }
+            mp_obj_int_t *self2 = mp_obj_int_new_mpz();
+            mpz_abs_inpl(&self2->mpz, &self->mpz);
+            return MP_OBJ_FROM_PTR(self2);
+        }
         default: return MP_OBJ_NULL; // op not supported
     }
 }
diff --git a/py/runtime.c b/py/runtime.c
index c533558da..f21eed204 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -231,6 +231,15 @@ mp_obj_t mp_unary_op(mp_unary_op_t op, mp_obj_t arg) {
                 } else {
                     return MP_OBJ_NEW_SMALL_INT(-val);
                 }
+            case MP_UNARY_OP_ABS:
+                if (val >= 0) {
+                    return arg;
+                } else if (val == MP_SMALL_INT_MIN) {
+                    // check for overflow
+                    return mp_obj_new_int(-val);
+                } else {
+                    return MP_OBJ_NEW_SMALL_INT(-val);
+                }
             default:
                 assert(op == MP_UNARY_OP_INVERT);
                 return MP_OBJ_NEW_SMALL_INT(~val);
diff --git a/py/runtime0.h b/py/runtime0.h
index a3e9d46b9..54bf192d3 100644
--- a/py/runtime0.h
+++ b/py/runtime0.h
@@ -50,6 +50,7 @@ typedef enum {
     MP_UNARY_OP_NEGATIVE,
     MP_UNARY_OP_INVERT,
     MP_UNARY_OP_NOT,
+    MP_UNARY_OP_ABS, // __abs__
     MP_UNARY_OP_SIZEOF, // for sys.getsizeof()
 } mp_unary_op_t;