Merge pull request #1918 from bettio/intn-consistent-api

intn: make API more consistent

Make sure that every arith. operation has a signed version, and `intn_digit_t`
type is always used.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later

Author: bettio

src/libAtomVM/bif.c

@@ -899,8 +899,8 @@ static term mul_maybe_bigint(Context *ctx, uint32_t fail_label, uint32_t live, t
     }
 
     intn_digit_t bigres[INTN_MAX_RES_LEN];
-    intn_mulmnu(bn1, bn1_len, bn2, bn2_len, bigres);
-    intn_integer_sign_t res_sign = intn_muldiv_sign(bn1_sign, bn2_sign);
+    intn_integer_sign_t res_sign;
+    intn_mulmn(bn1, bn1_len, bn1_sign, bn2, bn2_len, bn2_sign, bigres, &res_sign);
 
     return make_bigint(ctx, fail_label, live, bigres, bigres_len, res_sign);
 }
@@ -1066,8 +1066,8 @@ static term div_maybe_bigint(Context *ctx, uint32_t fail_label, uint32_t live, t
     }
 
     intn_digit_t bigres[INTN_MAX_RES_LEN];
-    size_t bigres_len = intn_divmnu(bn1, bn1_len, bn2, bn2_len, bigres, NULL, NULL);
-    intn_integer_sign_t res_sign = intn_muldiv_sign(bn1_sign, bn2_sign);
+    intn_integer_sign_t res_sign;
+    size_t bigres_len = intn_divmn(bn1, bn1_len, bn1_sign, bn2, bn2_len, bn2_sign, bigres, &res_sign, NULL, NULL);
 
     return make_bigint(ctx, fail_label, live, bigres, bigres_len, res_sign);
 }

src/libAtomVM/intn.c

@@ -38,6 +38,16 @@
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 
+/* Uncomment this for debug:
+void print_num(const intn_digit_t num[], int len)
+{
+    for (int i = 0; i < len; i++) {
+        fprintf(stderr, "0x%x ", (unsigned int) num[i]);
+    }
+    fprintf(stderr, "\n");
+}
+*/
+
 static size_t neg_and_count_in_place(intn_digit_t out[], size_t len);
 
 static inline size_t pad_uint16_to_digits(uint16_t n16[], size_t n16_len)
@@ -117,9 +127,9 @@ static void mulmnu32(const uint32_t u[], size_t m, const uint32_t v[], size_t n,
     */
 }
 
-void intn_mulmnu(const uint32_t u[], size_t m, const uint32_t v[], size_t n, uint32_t w[])
+void intn_mulmnu(const uint32_t m[], size_t m_len, const uint32_t n[], size_t n_len, uint32_t out[])
 {
-    mulmnu32(u, m, v, n, w);
+    mulmnu32(m, m_len, n, n_len, out);
 }
 
 #else
@@ -170,10 +180,10 @@ static void mulmnu16(const uint16_t u[], size_t m, const uint16_t v[], size_t n,
     */
 }
 
-void intn_mulmnu(const uint32_t u[], size_t m, const uint32_t v[], size_t n, uint32_t w[])
+void intn_mulmnu(const uint32_t m[], size_t m_len, const uint32_t n[], size_t n_len, uint32_t out[])
 {
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-    mulmnu16((const uint16_t *) u, m * 2, (const uint16_t *) v, n * 2, (uint16_t *) w);
+    mulmnu16((const uint16_t *) m, m_len * 2, (const uint16_t *) n, n_len * 2, (uint16_t *) out);
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 #error "Big endian not yet supported"
 #else
@@ -429,14 +439,6 @@ size_t intn_divmnu(const intn_digit_t m[], size_t m_len, const intn_digit_t n[],
     return padded_q_len / UINT16_IN_A_DIGIT;
 }
 
-void print_num(const uint32_t num[], int len)
-{
-    for (int i = 0; i < len; i++) {
-        fprintf(stderr, "0x%x ", (unsigned int) num[i]);
-    }
-    fprintf(stderr, "\n");
-}
-
 // This function assumes no leading zeros (lenght is used in comparison)
 // Caller must ensure this precondition
 int intn_cmp(const intn_digit_t a[], size_t a_len, const intn_digit_t b[], size_t b_len)
@@ -787,7 +789,7 @@ size_t intn_bnot(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_sig
     return res_count;
 }
 
-size_t intn_bsl(const intn_digit_t num[], size_t len, size_t n, uint32_t *out)
+size_t intn_bsl(const intn_digit_t num[], size_t len, size_t n, intn_digit_t *out)
 {
     size_t digit_bit_size = sizeof(uint32_t) * 8;
 
@@ -864,7 +866,7 @@ void bsru(
 }
 
 size_t intn_bsr(
-    const intn_digit_t num[], size_t len, intn_integer_sign_t num_sign, size_t n, uint32_t *out)
+    const intn_digit_t num[], size_t len, intn_integer_sign_t num_sign, size_t n, intn_digit_t *out)
 {
     size_t digit_bit_size = sizeof(uint32_t) * 8;
     size_t counted_digits = intn_count_digits(num, len);

src/libAtomVM/intn.h

@@ -70,6 +70,9 @@ typedef enum
 
 typedef uint32_t intn_digit_t;
 
+// Uncomment this for debug
+// void print_num(const intn_digit_t num[], int len);
+
 int intn_cmp(const intn_digit_t a[], size_t a_len, const intn_digit_t b[], size_t b_len);
 
 size_t intn_addmnu(
@@ -90,14 +93,34 @@ size_t intn_submn(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_si
 
 size_t intn_sub_int64(int64_t num1, int64_t num2, intn_digit_t *out, intn_integer_sign_t *out_sign);
 
+static inline intn_integer_sign_t intn_muldiv_sign(intn_integer_sign_t s1, intn_integer_sign_t s2)
+{
+    return (intn_integer_sign_t) ((unsigned int) s1 ^ (unsigned int) s2) & IntNNegativeInteger;
+}
+
 void intn_mulmnu(
-    const intn_digit_t u[], size_t m, const intn_digit_t v[], size_t n, intn_digit_t w[]);
+    const intn_digit_t m[], size_t m_len, const intn_digit_t n[], size_t n_len, intn_digit_t out[]);
+
+static inline void intn_mulmn(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_sign,
+    const intn_digit_t n[], size_t n_len, intn_integer_sign_t n_sign, intn_digit_t out[],
+    intn_integer_sign_t *out_sign)
+{
+    *out_sign = intn_muldiv_sign(m_sign, n_sign);
+    intn_mulmnu(m, m_len, n, n_len, out);
+}
+
 void intn_mul_int64(int64_t num1, int64_t num2, intn_digit_t *out, intn_integer_sign_t *out_sign);
 
 size_t intn_divmnu(const intn_digit_t m[], size_t m_len, const intn_digit_t n[], size_t n_len,
     intn_digit_t q_out[], intn_digit_t r_out[], size_t *r_out_len);
 
-void print_num(const uint32_t num[], int len);
+static inline size_t intn_divmn(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_sign,
+    const intn_digit_t n[], size_t n_len, intn_integer_sign_t n_sign, intn_digit_t q_out[],
+    intn_integer_sign_t *qout_sign, intn_digit_t r_out[], size_t *r_out_len)
+{
+    *qout_sign = intn_muldiv_sign(m_sign, n_sign);
+    return intn_divmnu(m, m_len, n, n_len, q_out, r_out, r_out_len);
+}
 
 size_t intn_bormn(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_sign,
     const intn_digit_t n[], size_t n_len, intn_integer_sign_t n_sign, intn_digit_t out[],
@@ -114,10 +137,10 @@ size_t intn_bxormn(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_s
 size_t intn_bnot(const intn_digit_t m[], size_t m_len, intn_integer_sign_t m_sign,
     intn_digit_t out[], intn_integer_sign_t *out_sign);
 
-size_t intn_bsl(const intn_digit_t num[], size_t len, size_t n, uint32_t *out);
+size_t intn_bsl(const intn_digit_t num[], size_t len, size_t n, intn_digit_t *out);
 
 size_t intn_bsr(
-    const intn_digit_t num[], size_t len, intn_integer_sign_t num_sign, size_t n, uint32_t *out);
+    const intn_digit_t num[], size_t len, intn_integer_sign_t num_sign, size_t n, intn_digit_t *out);
 
 size_t intn_count_digits(const intn_digit_t *num, size_t num_len);
 
@@ -149,7 +172,7 @@ static inline void intn_copy(
     memset(out + num_len, 0, (extend_to - num_len) * sizeof(intn_digit_t));
 }
 
-static inline void intn_u64_to_digits(uint64_t absu64, uint32_t out[])
+static inline void intn_u64_to_digits(uint64_t absu64, intn_digit_t out[])
 {
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
     memcpy(out, &absu64, sizeof(absu64));
@@ -162,7 +185,7 @@ static inline void intn_u64_to_digits(uint64_t absu64, uint32_t out[])
 #endif
 }
 
-static inline void int64_to_intn_2(int64_t i64, uint32_t out[], intn_integer_sign_t *out_sign)
+static inline void int64_to_intn_2(int64_t i64, intn_digit_t out[], intn_integer_sign_t *out_sign)
 {
     bool is_negative;
     uint64_t absu64 = int64_safe_unsigned_abs_set_flag(i64, &is_negative);
@@ -212,9 +235,4 @@ static inline bool intn_fits_int64(const intn_digit_t num[], size_t len, intn_in
     return false;
 }
 
-static inline intn_integer_sign_t intn_muldiv_sign(intn_integer_sign_t s1, intn_integer_sign_t s2)
-{
-    return (intn_integer_sign_t) ((unsigned int) s1 ^ (unsigned int) s2) & IntNNegativeInteger;
-}
-
 #endif