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- I already checked in something better than this

This commit is contained in:
Bryce Denney 2002-09-05 16:02:43 +00:00
parent 7cef3cc3a4
commit 53d71821c1
1 changed files with 0 additions and 78 deletions
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78
bochs/patches/patch.mem-realign
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@ -1,78 +0,0 @@
----------------------------------------------------------------------
Patch name: patch.mem-realign
Author: Bryce Denney
Date: Tue Sep 3 12:59:35 2002
Detailed description:
Some of Kevin's optimizations depend on the memory vector being
aligned on an 8-byte boundary, so he added a BX_PANIC if the
alignment was wrong. On win32, I ran into this panic so here's an
attempt to guarantee that the vector starts on an 8-bit boundary.
Maybe there's a better way, but this appears to work.
Patch was created with:
cvs diff -u
Apply patch to what version:
cvs checked out on DATE, release version VER
Instructions:
To patch, go to main bochs directory.
Type "patch -p0 < THIS_PATCH_FILE".
----------------------------------------------------------------------
Index: memory/misc_mem.cc
===================================================================
RCS file: /cvsroot/bochs/bochs/memory/misc_mem.cc,v
retrieving revision 1.27
diff -u -b -r1.27 misc_mem.cc
--- memory/misc_mem.cc 3 Sep 2002 16:44:33 -0000 1.27
+++ memory/misc_mem.cc 3 Sep 2002 16:52:26 -0000
@@ -65,16 +65,17 @@
// BX_MEM_C constructor
BX_MEM_C::BX_MEM_C(size_t memsize)
{
- vector = new Bit8u[memsize];
+ // Alloc 8 extra bytes so that the realignment operation is safe.
+ vector = new Bit8u[memsize+8];
len = memsize;
megabytes = len / (1024*1024);
- if ( ((unsigned) vector) & 0x7 ) {
+ while (7 & ((unsigned) vector)) {
// Memory needs to be at least aligned to 8-byte boundaries for
// the TLB method of storing the host page address in the same
// field as 'combined_access' because the bottom 3 bits are used
// to cache access values.
- delete [] vector;
- BX_PANIC( ("BX_MEM_C constructor: memory not suitably aligned.") );
+ BX_DEBUG (("memory vector %p not aligned right; bumping up vector by 1", vector));
+ vector++;
}
}
#endif // #if BX_PROVIDE_CPU_MEMORY
@@ -104,15 +105,19 @@
if (BX_MEM_THIS vector == NULL) {
// memory not already allocated, do now...
- BX_MEM_THIS vector = new Bit8u[memsize];
+ // Alloc 8 extra bytes so that the realignment operation is safe.
+ BX_MEM_THIS vector = new Bit8u[memsize+8];
+ while (7 & ((unsigned) vector)) {
+ // Memory needs to be at least aligned to 8-byte boundaries for
+ // the TLB method of storing the host page address in the same
+ // field as 'combined_access' because the bottom 3 bits are used
+ // to cache access values.
+ BX_DEBUG (("memory vector %p not aligned right; bumping up vector by 1", vector));
+ vector++;
+ }
BX_MEM_THIS len = memsize;
BX_MEM_THIS megabytes = memsize / (1024*1024);
BX_INFO(("%.2fMB", (float)(BX_MEM_THIS megabytes) ));
- if ( ((unsigned) vector) & 0x7 ) {
- // See note above, similar check.
- delete [] vector;
- BX_PANIC( ("BX_MEM_C constructor: memory not suitably aligned.") );
- }
}
// initialize all memory to 0x00
memset(BX_MEM_THIS vector, 0x00, BX_MEM_THIS len);