This libgo patch improves the big-endian hash function for key sizes
less than 8 bytes. The previous hash function would always make all
hash values a large multiple of some constants, which interacted badly
with the map code. This patch fixes that problem and fixes PR 52342.
Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
Committed to mainline.
Ian
diff -r 071257161dab libgo/runtime/go-type-identity.c
--- a/libgo/runtime/go-type-identity.c Sun Mar 04 22:03:57 2012 -0800
+++ b/libgo/runtime/go-type-identity.c Sun Mar 04 22:36:37 2012 -0800
@@ -6,6 +6,7 @@
#include <stddef.h>
+#include "config.h"
#include "go-type.h"
/* The 64-bit type. */
@@ -31,7 +32,11 @@
unsigned char a[8];
} u;
u.v = 0;
- __builtin_memcpy (&u.a, key, key_size);
+#ifdef WORDS_BIGENDIAN
+ __builtin_memcpy (&u.a[8 - key_size], key, key_size);
+#else
+ __builtin_memcpy (&u.a[0], key, key_size);
+#endif
if (sizeof (uintptr_t) >= 8)
return (uintptr_t) u.v;
else
