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| author | Sverker Eriksson <[email protected]> | 2010-06-16 17:58:35 +0200 |
|---|---|---|
| committer | Sverker Eriksson <[email protected]> | 2010-07-05 15:29:17 +0200 |
| commit | e5d41874ec0d2aaf2037d10dd92091edd2405924 (patch) | |
| tree | 29bd6fc639f50c35555cfbadeacaf711bef12bde /erts/emulator/beam | |
| parent | fdf51bf4a7127883705d71dab1bbd4556b28e05a (diff) | |
| download | otp-e5d41874ec0d2aaf2037d10dd92091edd2405924.tar.gz otp-e5d41874ec0d2aaf2037d10dd92091edd2405924.tar.bz2 otp-e5d41874ec0d2aaf2037d10dd92091edd2405924.zip | |
term_to_binary use all 32 bits of INTEGER_EXT
Earlier, external format INTEGER_EXT was only produced for 28-bit
signed integers. Now full 32-bit signed integers are produced as
INTEGER_EXT to avoid the more costly SMALL_BIG_EXT format. Both old
and new code can read 32-bit INTEGER_EXT.
Also fixed integer encoding bugs in erl_interface erl_encode/erl_decode.
(Thanks to Alexander Demidenko for reporting)
Diffstat (limited to 'erts/emulator/beam')
| -rw-r--r-- | erts/emulator/beam/external.c | 53 |
1 files changed, 35 insertions, 18 deletions
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c index f41b61d73d..466165f26f 100644 --- a/erts/emulator/beam/external.c +++ b/erts/emulator/beam/external.c @@ -65,11 +65,9 @@ # endif #endif -/* - * For backward compatibility reasons, only encode integers that - * fit in 28 bits (signed) using INTEGER_EXT. +/* Does Sint fit in Sint32? */ -#define IS_SSMALL28(x) (((Uint) (((x) >> (28-1)) + 1)) < 2) +#define IS_SSMALL32(x) (((Uint) (((x) >> (32-1)) + 1)) < 2) /* * Valid creations for nodes are 1, 2, or 3. 0 can also be sent @@ -1571,13 +1569,15 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags) case SMALL_DEF: { + /* From R14B we no longer restrict INTEGER_EXT to 28 bits, + * as done earlier for backward compatibility reasons. */ Sint val = signed_val(obj); if ((Uint)val < 256) { *ep++ = SMALL_INTEGER_EXT; put_int8(val, ep); ep++; - } else if (sizeof(Sint) == 4 || IS_SSMALL28(val)) { + } else if (sizeof(Sint) == 4 || IS_SSMALL32(val)) { *ep++ = INTEGER_EXT; put_int32(val, ep); ep += 4; @@ -1599,18 +1599,32 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags) break; case BIG_DEF: - if ((n = big_bytes(obj)) < 256) { - *ep++ = SMALL_BIG_EXT; - put_int8(n, ep); - ep += 1; - } - else { - *ep++ = LARGE_BIG_EXT; - put_int32(n, ep); - ep += 4; + { + int sign = big_sign(obj); + n = big_bytes(obj); + if (sizeof(Sint)==4 && n<=4) { + Uint dig = big_digit(obj,0); + Sint val = sign ? -dig : dig; + if ((val<0) == sign) { + *ep++ = INTEGER_EXT; + put_int32(val, ep); + ep += 4; + break; + } + } + if (n < 256) { + *ep++ = SMALL_BIG_EXT; + put_int8(n, ep); + ep += 1; + } + else { + *ep++ = LARGE_BIG_EXT; + put_int32(n, ep); + ep += 4; + } + *ep++ = sign; + ep = big_to_bytes(obj, ep); } - *ep++ = big_sign(obj); - ep = big_to_bytes(obj, ep); break; case PID_DEF: @@ -2687,7 +2701,7 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags) if ((Uint)val < 256) result += 1 + 1; /* SMALL_INTEGER_EXT */ - else if (sizeof(Sint) == 4 || IS_SSMALL28(val)) + else if (sizeof(Sint) == 4 || IS_SSMALL32(val)) result += 1 + 4; /* INTEGER_EXT */ else { DeclareTmpHeapNoproc(tmp_big,2); @@ -2699,7 +2713,10 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags) } break; case BIG_DEF: - if ((i = big_bytes(obj)) < 256) + i = big_bytes(obj); + if (sizeof(Sint)==4 && i <= 4 && (big_digit(obj,0)-big_sign(obj)) < (1<<31)) + result += 1 + 4; /* INTEGER_EXT */ + else if (i < 256) result += 1 + 1 + 1 + i; /* tag,size,sign,digits */ else result += 1 + 4 + 1 + i; /* tag,size,sign,digits */ |