Mercurial > projects > ldc
view dmd2/stringtable.c @ 1047:6bb04dbee21f
Some calling convention work for x86-64:
- Implement x86-64 extern(C), hopefully correctly.
- Tried to be a bit smarter about extern(D) while I was there.
Interestingly, this code seems to be generating more efficient code than
gcc and llvm-gcc in some edge cases, like returning a `{ [7 x i8] }` loaded from
a stack slot from an extern(C) function. (gcc generates 7 1-byte loads, while
this code generates a 4-byte, a 2-byte and a 1-byte load)
I also added some changes to make sure structs being returned from functions or
passed in as parameters are stored in memory where the rest of the backend seems
to expect them to be. These should be removed when support for first-class
aggregates improves.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Fri, 06 Mar 2009 16:00:47 +0100 |
parents | f04dde6e882c |
children |
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// Copyright (c) 1999-2008 by Digital Mars // All Rights Reserved // written by Walter Bright // http://www.digitalmars.com // License for redistribution is by either the Artistic License // in artistic.txt, or the GNU General Public License in gnu.txt. // See the included readme.txt for details. #include <stdio.h> #include <string.h> #include <stdlib.h> #include "root.h" #include "mem.h" #include "dchar.h" #include "lstring.h" #include "stringtable.h" StringTable::StringTable(unsigned size) { table = (void **)mem.calloc(size, sizeof(void *)); tabledim = size; count = 0; } StringTable::~StringTable() { unsigned i; // Zero out dangling pointers to help garbage collector. // Should zero out StringEntry's too. for (i = 0; i < count; i++) table[i] = NULL; mem.free(table); table = NULL; } struct StringEntry { StringEntry *left; StringEntry *right; hash_t hash; StringValue value; static StringEntry *alloc(const dchar *s, unsigned len); }; StringEntry *StringEntry::alloc(const dchar *s, unsigned len) { StringEntry *se; se = (StringEntry *) mem.calloc(1,sizeof(StringEntry) - sizeof(Lstring) + Lstring::size(len)); se->value.lstring.length = len; se->hash = Dchar::calcHash(s,len); memcpy(se->value.lstring.string, s, len * sizeof(dchar)); return se; } void **StringTable::search(const dchar *s, unsigned len) { hash_t hash; unsigned u; int cmp; StringEntry **se; //printf("StringTable::search(%p,%d)\n",s,len); hash = Dchar::calcHash(s,len); u = hash % tabledim; se = (StringEntry **)&table[u]; //printf("\thash = %d, u = %d\n",hash,u); while (*se) { cmp = (*se)->hash - hash; if (cmp == 0) { cmp = (*se)->value.lstring.len() - len; if (cmp == 0) { cmp = Dchar::memcmp(s,(*se)->value.lstring.toDchars(),len); if (cmp == 0) break; } } if (cmp < 0) se = &(*se)->left; else se = &(*se)->right; } //printf("\treturn %p, %p\n",se, (*se)); return (void **)se; } StringValue *StringTable::lookup(const dchar *s, unsigned len) { StringEntry *se; se = *(StringEntry **)search(s,len); if (se) return &se->value; else return NULL; } StringValue *StringTable::update(const dchar *s, unsigned len) { StringEntry **pse; StringEntry *se; pse = (StringEntry **)search(s,len); se = *pse; if (!se) // not in table: so create new entry { se = StringEntry::alloc(s, len); *pse = se; } return &se->value; } StringValue *StringTable::insert(const dchar *s, unsigned len) { StringEntry **pse; StringEntry *se; pse = (StringEntry **)search(s,len); se = *pse; if (se) return NULL; // error: already in table else { se = StringEntry::alloc(s, len); *pse = se; } return &se->value; }