Let memory allocation be aligned on 8-byte boundaries.

diff --git a/lib/libc/ansi/calloc.c b/lib/libc/ansi/calloc.c
index cccd79ab7a3b83e6933f81388339887f941ebd64..0c4323902b81d9e7a538178c837c54057532cc3f 100644 (file)
--- a/lib/libc/ansi/calloc.c
+++ b/lib/libc/ansi/calloc.c
@@ -1,7 +1,16 @@
 /* $Header$ */
 #include       <stdlib.h>
 
-#define ALIGN(x)       (((x) + (sizeof(size_t) - 1)) & ~(sizeof(size_t) - 1))
+/* replace undef by define */
+#define  ALIGN_EIGHT_BYTES /* Use 8-byte alignment. */
+
+#ifdef  ALIGN_EIGHT_BYTES
+#define ALIGN_SIZE 8
+#else
+#define ALIGN_SIZE sizeof(size_t)
+#endif
+
+#define ALIGN(x)       (((x) + (ALIGN_SIZE - 1)) & ~(ALIGN_SIZE - 1))
 
 void *
 calloc(size_t nelem, size_t elsize)

diff --git a/lib/libc/ansi/malloc.c b/lib/libc/ansi/malloc.c
index d6990fef830009b186967c96081cd92d25b6939c..f4644f1c269020ade924965ad3134c2d3e9a4e28 100644 (file)
--- a/lib/libc/ansi/malloc.c
+++ b/lib/libc/ansi/malloc.c
@@ -1,8 +1,9 @@
 /* $Header$ */
 
 /* replace undef by define */
-#define         DEBUG          /* check assertions */
-#undef  SLOWDEBUG      /* some extra test loops (requires DEBUG) */
+#define  ALIGN_EIGHT_BYTES /* Use 8-byte alignment. */
+#define         DEBUG             /* check assertions */
+#undef  SLOWDEBUG         /* some extra test loops (requires DEBUG) */
 
 #ifndef DEBUG
 #define NDEBUG
@@ -24,7 +25,11 @@
 #else
 #define BRKSIZE                4096
 #endif
+#ifdef ALIGN_EIGHT_BYTES
+#define PTRSIZE                8
+#else
 #define        PTRSIZE         ((int) sizeof(void *))
+#endif
 #define Align(x,a)     (((x) + (a - 1)) & ~(a - 1))
 #define NextSlot(p)    (* (void **) ((p) - PTRSIZE))
 #define NextFree(p)    (* (void **) (p))
@@ -41,6 +46,9 @@
  * linked together by a pointer at the start of the
  * user visable part, so just after the next-slot pointer.
  * Free slots are merged together by free().
+ *
+ * Since modern processors prefer 8-byte alignment, we now pretend
+ * our pointers are 8 bytes wide.
  */
 
 extern void *_sbrk(int);
@@ -67,16 +75,17 @@ static int grow(size_t len)
 }
 
 void *
-malloc(size_t size)
+malloc(const size_t size)
 {
   register char *prev, *p, *next, *new;
-  register unsigned len, ntries;
+  unsigned ntries;
 
   if (size == 0)
        return NULL;
 
   for (ntries = 0; ntries < 2; ntries++) {
-       if ((len = Align(size, PTRSIZE) + PTRSIZE) < 2 * PTRSIZE) {
+       unsigned len = Align(size, PTRSIZE) + PTRSIZE;
+       if (len < 2 * PTRSIZE) {
                errno = ENOMEM;
                return NULL;
        }

diff --git a/lib/libc/arch/i386/misc/alloca.S b/lib/libc/arch/i386/misc/alloca.S
index 24de081fba8ba8abc8597d61023e0d4eef420056..0c9b598fefabc413f6e6beafb15d840575d56b5f 100644 (file)
--- a/lib/libc/arch/i386/misc/alloca.S
+++ b/lib/libc/arch/i386/misc/alloca.S
@@ -10,7 +10,7 @@ _alloca:
        pop     %ecx    /* Return address */
        pop     %eax    /* Bytes to allocate */
        addl    $2*4+3, %eax    /* Add space for two saved register variables */
-       andb    $0xFC, %al      /* Align */
+       andb    $0xF8, %al      /* Align */
        movl    %esp, %ebx      /* Keep current esp */
        subl    %eax, %esp      /* Lower stack */
        movl    %esp, %eax      /* Return value */
@@ -24,7 +24,7 @@ _alloca:
        pop     %ecx    /* Return address */
        pop     %eax    /* Bytes to allocate */
        addl    $3, %eax
-       andb    $0xFC, %al      /* Align */
+       andb    $0xF8, %al      /* Align */
        subl    %eax, %esp      /* Lower stack */
        movl    %esp, %eax      /* Return value */
        push    %eax    /* Dummy argument */