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Re: [PATCH][AArch64] Inline mempcpy again
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>, Szabolcs Nagy <Szabolcs dot Nagy at arm dot com>
- Cc: nd <nd at arm dot com>
- Date: Fri, 29 Jun 2018 14:48:30 +0000
- Subject: Re: [PATCH][AArch64] Inline mempcpy again
- References: <AM5PR0802MB2610223EAFFF5D9F3CC5378E83D20@AM5PR0802MB2610.eurprd08.prod.outlook.com>
ping
From: Wilco Dijkstra
Sent: 29 June 2017 17:20
To: libc-alpha@sourceware.org
Cc: nd
Subject: [PATCH][AArch64] Inline mempcpy again
Recent changes removed the generic mempcpy inline. Given GCC still
doesn't optimize mempcpy (PR70140), I am adding it again. Since
string/string.h no longer includes an architecture specific header, do this
inside include/string.h and for now only on AArch64.
OK for commit?
ChangeLog:
2017-06-29 Wilco Dijkstra <wdijkstr@arm.com>
* include/string.h: (mempcpy): Redirect to __mempcpy_inline.
(__mempcpy): Likewise.
(__mempcpy_inline): New inline function.
* sysdeps/aarch64/string_private.h: Define _INLINE_mempcpy.
--
diff --git a/include/string.h b/include/string.h
index 069efd0b87010e5fdb64c87ced7af1dc4f54f232..46b90b8f346149f075fad026e562dfb27b658969 100644
--- a/include/string.h
+++ b/include/string.h
@@ -197,4 +197,23 @@ extern char *__strncat_chk (char *__restrict __dest,
size_t __len, size_t __destlen) __THROW;
#endif
+#if defined __USE_GNU && defined __OPTIMIZE__ \
+ && defined __extern_always_inline && __GNUC_PREREQ (3,2) \
+ && defined _INLINE_mempcpy
+
+#undef mempcpy
+#undef __mempcpy
+
+#define mempcpy(dest, src, n) __mempcpy_inline (dest, src, n)
+#define __mempcpy(dest, src, n) __mempcpy_inline (dest, src, n)
+
+__extern_always_inline void *
+__mempcpy_inline (void *__restrict __dest,
+ const void *__restrict __src, size_t __n)
+{
+ return (char *) memcpy (__dest, __src, __n) + __n;
+}
+
+#endif
+
#endif
diff --git a/sysdeps/aarch64/string_private.h b/sysdeps/aarch64/string_private.h
index 09dedbf3db40cf06077a44af992b399a6b37b48d..8b8fdddcc17a3f69455e72efe9c3616d2d33abe2 100644
--- a/sysdeps/aarch64/string_private.h
+++ b/sysdeps/aarch64/string_private.h
@@ -18,3 +18,6 @@
/* AArch64 implementations support efficient unaligned access. */
#define _STRING_ARCH_unaligned 1
+
+/* Inline mempcpy since GCC doesn't optimize it (PR70140). */
+#define _INLINE_mempcpy 1