From: cuz Date: Wed, 5 Jan 2005 21:07:23 +0000 (+0000) Subject: New function: _aligned_malloc X-Git-Tag: V2.12.0~487 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=7caee98fc00ac37369ba41c73cdb4c3faca0d384;p=cc65 New function: _aligned_malloc git-svn-id: svn://svn.cc65.org/cc65/trunk@3349 b7a2c559-68d2-44c3-8de9-860c34a00d81 --- diff --git a/include/stdlib.h b/include/stdlib.h index f18421a41..692448167 100644 --- a/include/stdlib.h +++ b/include/stdlib.h @@ -6,7 +6,7 @@ /* */ /* */ /* */ -/* (C) 1998-2004 Ullrich von Bassewitz */ +/* (C) 1998-2005 Ullrich von Bassewitz */ /* Römerstrasse 52 */ /* D-70794 Filderstadt */ /* EMail: uz@cc65.org */ @@ -62,6 +62,15 @@ void __fastcall__ free (void* block); /* Non standard memory management functions */ +void* __fastcall__ _aligned_malloc (size_t size, size_t alignment) +/* Allocate a block of memory with the given size, which is aligned to a + * memory address that is a multiple of alignment. alignment MUST NOT be + * zero and MUST be a power of two, otherwise a call to this function will + * cause undefined behaviour. The function returns NULL if not enough memory + * is available to satisfy the request. To free the allocated block, use the + * free() function. + */ + void __fastcall__ _heapadd (void* mem, size_t size); /* Add a block to the heap */ diff --git a/libsrc/common/.cvsignore b/libsrc/common/.cvsignore index b91764795..89274f351 100644 --- a/libsrc/common/.cvsignore +++ b/libsrc/common/.cvsignore @@ -1,5 +1,6 @@ *.lst _afailed.s +_aligned_malloc.s _hextab.s _poserror.s _scanf.s diff --git a/libsrc/common/Makefile b/libsrc/common/Makefile index 7a6eeb1b5..9f44723f4 100644 --- a/libsrc/common/Makefile +++ b/libsrc/common/Makefile @@ -29,41 +29,42 @@ CFLAGS = -Osir -g -T -t $(SYS) --forget-inc-paths -I . -I ../../include #-------------------------------------------------------------------------- # Object files -C_OBJS = _afailed.o \ - _hextab.o \ - _poserror.o \ - _scanf.o \ - abort.o \ - asctime.o \ - bsearch.o \ - errormsg.o \ - fdopen.o \ - fgetc.o \ - fgetpos.o \ - fgets.o \ - fputc.o \ - fputs.o \ - freopen.o \ - fseek.o \ - fsetpos.o \ - ftell.o \ - getchar.o \ - gets.o \ - gmtime.o \ - locale.o \ - localtime.o \ - mktime.o \ - perror.o \ - puts.o \ - qsort.o \ - realloc.o \ - rewind.o \ - scanf.o \ - sleep.o \ - strftime.o \ - strxfrm.o \ - strtok.o \ - system.o \ +C_OBJS = _afailed.o \ + _aligned_malloc.o \ + _hextab.o \ + _poserror.o \ + _scanf.o \ + abort.o \ + asctime.o \ + bsearch.o \ + errormsg.o \ + fdopen.o \ + fgetc.o \ + fgetpos.o \ + fgets.o \ + fputc.o \ + fputs.o \ + freopen.o \ + fseek.o \ + fsetpos.o \ + ftell.o \ + getchar.o \ + gets.o \ + gmtime.o \ + locale.o \ + localtime.o \ + mktime.o \ + perror.o \ + puts.o \ + qsort.o \ + realloc.o \ + rewind.o \ + scanf.o \ + sleep.o \ + strftime.o \ + strxfrm.o \ + strtok.o \ + system.o \ timezone.o diff --git a/libsrc/common/_aligned_malloc.c b/libsrc/common/_aligned_malloc.c new file mode 100644 index 000000000..a74608b35 --- /dev/null +++ b/libsrc/common/_aligned_malloc.c @@ -0,0 +1,163 @@ +/*****************************************************************************/ +/* */ +/* _aligned_malloc */ +/* */ +/* Allocate an aligned memory block */ +/* */ +/* */ +/* */ +/* (C) 2004-2005 Ullrich von Bassewitz */ +/* Römerstrasse 52 */ +/* D-70794 Filderstadt */ +/* EMail: uz@cc65.org */ +/* */ +/* */ +/* This software is provided 'as-is', without any expressed or implied */ +/* warranty. In no event will the authors be held liable for any damages */ +/* arising from the use of this software. */ +/* */ +/* Permission is granted to anyone to use this software for any purpose, */ +/* including commercial applications, and to alter it and redistribute it */ +/* freely, subject to the following restrictions: */ +/* */ +/* 1. The origin of this software must not be misrepresented; you must not */ +/* claim that you wrote the original software. If you use this software */ +/* in a product, an acknowledgment in the product documentation would be */ +/* appreciated but is not required. */ +/* 2. Altered source versions must be plainly marked as such, and must not */ +/* be misrepresented as being the original software. */ +/* 3. This notice may not be removed or altered from any source */ +/* distribution. */ +/* */ +/*****************************************************************************/ + + + +#include +#include <_heap.h> + + + +/* This is a very simple version of an aligned memory allocator. We will + * allocate a greater block, so we can place the aligned block within it + * that is returned. We use our knowledge about the internal heap + * structures to free the unused parts of the bigger block (the two chunks + * below and above the aligned block). + */ + + + +void* __fastcall__ _aligned_malloc (size_t size, size_t alignment) +/* Allocate a block of memory with the given size, which is aligned to a + * memory address that is a multiple of alignment. alignment MUST NOT be + * zero and MUST be a power of two, otherwise a call to this function will + * cause undefined behaviour. The function returns NULL if not enough memory + * is available to satisfy the request. To free the allocated block, use the + * free() function. + */ +{ + size_t rawsize; + size_t uppersize; + size_t lowersize; + register struct usedblock* b; + register struct usedblock* u; + register struct usedblock* p; + + /* Handle requests for zero sized blocks */ + if (size == 0) { + return 0; + } + + /* We don't really need alignment, but alignment-1 */ + --alignment; + + /* Round up the block size and allocate memory. We don't need to account + * for the additional admin data needed to manage the used block, since + * the block returned by malloc has this overhead added one time, and + * the worst thing that may happen is that we cannot free the upper and + * lower blocks. + */ + b = malloc (size + alignment); + + /* Handle out of memory */ + if (b == 0) { + return 0; + } + + /* Create a new pointer that points to the user visible aligned block. */ + u = (struct usedblock*) (((unsigned)b + alignment) & ~alignment); + + /* Get the raw block pointer, which is located just below the user visible + * block. The first word of this raw block is the total size of the block + * including the admin space. + */ + b = (b-1)->start; + rawsize = b->size; + + /* Get a pointer to the (raw) upper block */ + p = (struct usedblock*) (size + (unsigned)u); + + /* Check if we can free the space above the allocated block. This is the + * case if the size of the block is at least sizeof (struct freeblock) + * bytes and the size of the remaining block is at least of this size, + * too. If the upper block is smaller, we will just pass it to the caller + * together with the requested aligned block. + */ + uppersize = rawsize + (unsigned)b - (unsigned)p; + if (uppersize >= sizeof (struct freeblock) && + (rawsize - uppersize) >= sizeof (struct freeblock)) { + + /* Setup the usedblock structure */ + p->size = uppersize; + p->start = p; + + /* Generate a pointer to the user space and free the block */ + free (p + 1); + + /* Decrement the raw block size by the amount of space just free'd */ + rawsize -= uppersize; + } + + /* Check if we can free the space below the allocated block. This is the + * case, if the size of the block is at least sizeof (struct freeblock) + * bytes and the size of the remaining block is at least of this size, + * too. If the lower block is smaller, we will just pass it to the caller + * together with the requested aligned block. + * Beware: We need an additional struct usedblock in the lower block which + * is part of the block that is passed back to the caller. + */ + lowersize = ((unsigned)u - (unsigned)b) - sizeof (struct usedblock); + if (lowersize >= sizeof (struct freeblock) && + (rawsize - lowersize) >= sizeof (struct freeblock)) { + + /* b does already point to the raw lower block. Setup the usedblock + * structure. + */ + b->size = lowersize; + b->start = b; + + /* Generate a pointer to the user space and free the block */ + free (b + 1); + + /* Decrement the raw block size by the amount of space just free'd */ + rawsize -= lowersize; + + /* Set b to the raw user block */ + b = u - 1; + } + + /* u does now point to the user visible block, while b points to the raw + * block, and rawsize contains the size of the raw block. Setup the + * usedblock structure but beware: If we didn't free the lower block, it + * is splitted, which means that we must use u to write the start field, + * and b to write the size. + */ + (u-1)->start = b; + b->size = rawsize; + + /* Return the user portion of the aligned block */ + return u; +} + + +