Sigh, right offset for the wrong register. Get the PC (the address we

interrupted) rather than LR (the return address from the function we
interrupted).

Also, change u_short and u_int to unsigned short and unsigned int, since
gcc recently decided that those aren't part of the C99 standard.

Finally, add profilable versions of memcpy, memset, and friends, because
they get called a lot in the course of unit testing, and it would be nice
to know who's calling them.

1 files changed, 101 insertions, 0 deletions

diff --git a/memfunc.c b/memfunc.c
new file mode 100644
index 0000000..fd94b28
--- /dev/null
+++ b/memfunc.c
@@ -0,0 +1,101 @@
+#include <stdint.h>
+#include <string.h>
+
+/*
+ * Profilable substitutes for mem*(), lacking libc_p.a
+ *
+ * This code was written with reference to newlib, but does not copy every
+ * quirk and loop-unrolling optimization from newlib. Its only purpose is
+ * to let us figure out who is calling memcpy 2 million times.
+ */
+
+#define is_word_aligned(x) (((size_t)(x) & 3) == 0)
+
+void *memcpy(void *dst, const void *src, size_t n)
+{
+    uint8_t *d8 = (uint8_t *)dst;
+    uint8_t *s8 = (uint8_t *)src;
+
+    if (n >= 4 && is_word_aligned(src) && is_word_aligned(dst)) {
+        uint32_t *d32 = (uint32_t *)dst;
+        uint32_t *s32 = (uint32_t *)src;
+        while (n >= 4) {
+            *d32++ = *s32++;
+            n -= 4;
+        }
+        d8 = (uint8_t *)d32;
+        s8 = (uint8_t *)s32;
+    }
+    while (n-- > 0) {
+        *d8++ = *s8++;
+    }
+
+    return dst;
+}
+
+void *memset(void *dst, int c, size_t n)
+{
+    uint8_t *d8 = (uint8_t *)dst;
+    uint8_t c8 = (uint8_t)c;
+
+    if (n >= 4 && is_word_aligned(dst)) {
+        uint32_t *d32 = (uint32_t *)dst;
+        uint32_t c32 = (c8 << 24) | (c8 << 16) | (c8 << 8) | (c8);
+        while (n >= 4) {
+            *d32++ = c32;
+            n -= 4;
+        }
+        d8 = (uint8_t *)d32;
+    }
+    while (n-- > 0) {
+        *d8++ = c8;
+    }
+
+    return dst;
+}
+
+int memcmp(const void *dst, const void *src, size_t n)
+{
+    uint8_t *d8 = (uint8_t *)dst;
+    uint8_t *s8 = (uint8_t *)src;
+
+    if (n >= 4 && is_word_aligned(src) && is_word_aligned(dst)) {
+        uint32_t *d32 = (uint32_t *)dst;
+        uint32_t *s32 = (uint32_t *)src;
+        while (n >= 4) {
+            if (*d32 != *s32)
+                break;
+            d32++;
+            s32++;
+            n -= 4;
+        }
+        d8 = (uint8_t *)d32;
+        s8 = (uint8_t *)s32;
+    }
+    while (n-- > 0) {
+        if (*d8 != *s8)
+            return (*d8 - *s8);
+        d8++;
+        s8++;
+    }
+
+    return 0;
+}
+
+void *memmove(void *dst, const void *src, size_t n)
+{
+    uint8_t *d8 = (uint8_t *)dst;
+    uint8_t *s8 = (uint8_t *)src;
+
+    if ((s8 < d8) && (d8 < s8 + n)) {
+        /* Destructive overlap...have to copy backwards */
+        s8 += n;
+        d8 += n;
+        while (n-- > 0) {
+            *--d8 = *--s8;
+	}
+        return dst;
+    }
+
+    return memcpy(dst, src, n);
+}