diff options
| -rw-r--r-- | instance_table.c | 54 |
1 files changed, 26 insertions, 28 deletions
diff --git a/instance_table.c b/instance_table.c index 254b9c8..4237b63 100644 --- a/instance_table.c +++ b/instance_table.c @@ -3,13 +3,6 @@ This file is part of toc. toc is distributed under version 3 of the GNU General Public License, without any warranty whatsoever. You should have received a copy of the GNU General Public License along with toc. If not, see <https://www.gnu.org/licenses/>. */ -/* - @TODO: better hash functions, especially for integers - (right now, nearby integers are close together in hash - space, which is bad with the way these hash tables - are designed) -*/ - // NOTE: any time you see 0x then 16 hexadecimal digits, that's probably a random number for hashing /* @@ -75,15 +68,15 @@ static U64 f64_hash(F64 f) { static U64 type_hash(Type *t) { static const U64 starters[TYPE_COUNT] = { - 0x40d8675d0f148df7, - 0xee4db91f31fdf2e1, - 0x94963ca71f7f0df4, - 0x95b9d36f45f27cf2, - 0x68d393d7cade0570, - 0x8191b5178d728e8c, - 0x50da97f1211b2423, - 0xc3977306abd0ae6c, - 0x87ea684427e1c521 + 0x40d8675d0f148df7, + 0xee4db91f31fdf2e1, + 0x94963ca71f7f0df4, + 0x95b9d36f45f27cf2, + 0x68d393d7cade0570, + 0x8191b5178d728e8c, + 0x50da97f1211b2423, + 0xc3977306abd0ae6c, + 0x87ea684427e1c521 }; U64 hash = starters[t->kind]; assert(t->flags & TYPE_IS_RESOLVED); @@ -119,6 +112,11 @@ static U64 type_hash(Type *t) { assert(0); return 0; } +// make x more random. +static inline U64 hash_u64(U64 x) { + return x * 0x442a1f5f377a25e9 + 0x36e1049ba954eac4; // room for improvement here +} + // Note that for these value hashing functions, values of different types may collide static U64 val_ptr_hash(void *v, Type *t) { assert(t->flags & TYPE_IS_RESOLVED); @@ -126,18 +124,18 @@ static U64 val_ptr_hash(void *v, Type *t) { case TYPE_UNKNOWN: return 0; case TYPE_BUILTIN: switch (t->builtin) { - case BUILTIN_I8: return (U64)*(I8 *)v; - case BUILTIN_U8: return (U64)*(U8 *)v; - case BUILTIN_I16: return (U64)*(I16 *)v; - case BUILTIN_U16: return (U64)*(U16 *)v; - case BUILTIN_I32: return (U64)*(I32 *)v; - case BUILTIN_U32: return (U64)*(U32 *)v; - case BUILTIN_I64: return (U64)*(I64 *)v; - case BUILTIN_U64: return (U64)*(U64 *)v; - case BUILTIN_F32: return f32_hash(*(F32 *)v); - case BUILTIN_F64: return f64_hash(*(F64 *)v); - case BUILTIN_CHAR: return (U64)*(char *)v; - case BUILTIN_BOOL: return (U64)*(bool *)v; + case BUILTIN_I8: return hash_u64((U64)*(I8 *)v); + case BUILTIN_U8: return hash_u64((U64)*(U8 *)v); + case BUILTIN_I16: return hash_u64((U64)*(I16 *)v); + case BUILTIN_U16: return hash_u64((U64)*(U16 *)v); + case BUILTIN_I32: return hash_u64((U64)*(I32 *)v); + case BUILTIN_U32: return hash_u64((U64)*(U32 *)v); + case BUILTIN_I64: return hash_u64((U64)*(I64 *)v); + case BUILTIN_U64: return hash_u64((U64)*(U64 *)v); + case BUILTIN_F32: return f32_hash(*(F32 *)v); + case BUILTIN_F64: return f64_hash(*(F64 *)v); + case BUILTIN_CHAR: return hash_u64((U64)*(char *)v); + case BUILTIN_BOOL: return hash_u64((U64)*(bool *)v); case BUILTIN_VARARGS: { U64 hash = 1; VarArg *vals = *(VarArg **)v; |