Mercurial > projects > ldc
view dmd/root/lstring.c @ 1491:360a8e8eea51
Teach stack promotion to walk the CFG when a potential reuse of an allocation
is found to see if it can actually happen instead of just assuming it will.
This allows it to catch cases like
{{{
int i;
Foo f;
while (cond(i))
f = new Foo(i++);
return f.value;
}}}
where it previously wouldn't because a phi using the allocation would appear in
the condition block to propagate it to the use after the loop.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Thu, 11 Jun 2009 02:04:44 +0200 |
parents | 1853dcd9b944 |
children |
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// lstring.c // Copyright (c) 1999-2002 by Digital Mars // All Rights Reserved // written by Walter Bright // 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 <stdlib.h> #include "dchar.h" #include "rmem.h" #include "lstring.h" #ifdef _MSC_VER // prevent compiler internal crash Lstring Lstring::zero; #else Lstring Lstring::zero = LSTRING_EMPTY(); #endif Lstring *Lstring::ctor(const dchar *p, unsigned length) { Lstring *s; s = alloc(length); memcpy(s->string, p, length * sizeof(dchar)); return s; } Lstring *Lstring::alloc(unsigned length) { Lstring *s; s = (Lstring *)mem.malloc(size(length)); s->length = length; s->string[length] = 0; return s; } Lstring *Lstring::append(const Lstring *s) { Lstring *t; if (!s->length) return this; t = alloc(length + s->length); memcpy(t->string, string, length * sizeof(dchar)); memcpy(t->string + length, s->string, s->length * sizeof(dchar)); return t; } Lstring *Lstring::substring(int start, int end) { Lstring *t; if (start == end) return &zero; t = alloc(end - start); memcpy(t->string, string + start, (end - start) * sizeof(dchar)); return t; }