Module Name: src
Committed By: thorpej
Date: Wed Jul 7 03:30:35 UTC 2021
Modified Files:
src/sys/arch/alpha/alpha: locore.s patch.c
Log Message:
Provide a BWX version of alpha_copystr() and patch it into place if
the system supports the BWX extension. The inner loop of the BWX
version is 42% shorter than the non-BWX version (7 vs 12 insns).
To generate a diff of this commit:
cvs rdiff -u -r1.138 -r1.139 src/sys/arch/alpha/alpha/locore.s
cvs rdiff -u -r1.5 -r1.6 src/sys/arch/alpha/alpha/patch.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/alpha/alpha/locore.s
diff -u src/sys/arch/alpha/alpha/locore.s:1.138 src/sys/arch/alpha/alpha/locore.s:1.139
--- src/sys/arch/alpha/alpha/locore.s:1.138 Wed Jul 7 02:44:04 2021
+++ src/sys/arch/alpha/alpha/locore.s Wed Jul 7 03:30:35 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.s,v 1.138 2021/07/07 02:44:04 thorpej Exp $ */
+/* $NetBSD: locore.s,v 1.139 2021/07/07 03:30:35 thorpej Exp $ */
/*-
* Copyright (c) 1999, 2000, 2019 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
#include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: locore.s,v 1.138 2021/07/07 02:44:04 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: locore.s,v 1.139 2021/07/07 03:30:35 thorpej Exp $");
#include "assym.h"
@@ -902,6 +902,44 @@ LEAF_NOPROFILE(lwp_trampoline, 0)
/*
* alpha_copystr(const void *from, void *to, size_t len, size_t *donep)
*/
+ .arch ev56
+LEAF(alpha_copystr_bwx, 4)
+ LDGP(pv)
+
+ mov a2, t0 /* t0 = i = len */
+ beq a2, 5f /* if (len == 0), bail */
+
+1: ldbu t1, 0(a0) /* t1 = *from */
+ subl a2, 1, a2 /* len-- */
+ addq a0, 1, a0 /* from++ */
+ stb t1, 0(a1) /* *to = t1 */
+ beq t1, 2f /* if (t1 == '\0'), bail out */
+ addq a1, 1, a1 /* to++ */
+ bne a2, 1b /* if (len != 0), copy more */
+
+2: beq a3, 3f /* if (lenp != NULL) */
+ subl t0, a2, t0 /* *lenp = (i - len) */
+ stq t0, 0(a3)
+3: bne t1, 4f /* *from != '\0'; leave in a huff */
+
+ mov zero, v0 /* return 0. */
+ RET
+
+4: ldiq v0, ENAMETOOLONG
+ RET
+
+5: ldiq t1, 1 /* fool the test above... */
+ br zero, 2b
+
+ nop /* pad to same length as... */
+ nop /* non-BWX version. */
+ nop
+ nop
+ nop
+ EXPORT(alpha_copystr_bwx_end)
+ END(alpha_copystr_bwx)
+ .arch ev4
+
LEAF(alpha_copystr, 4)
LDGP(pv)
@@ -935,6 +973,7 @@ LEAF(alpha_copystr, 4)
5: ldiq t1, 1 /* fool the test above... */
br zero, 2b
+ EXPORT(alpha_copystr_end)
END(alpha_copystr)
NESTED(copyinstr, 4, 16, ra, IM_RA|IM_S0, 0)
Index: src/sys/arch/alpha/alpha/patch.c
diff -u src/sys/arch/alpha/alpha/patch.c:1.5 src/sys/arch/alpha/alpha/patch.c:1.6
--- src/sys/arch/alpha/alpha/patch.c:1.5 Fri Sep 4 03:41:49 2020
+++ src/sys/arch/alpha/alpha/patch.c Wed Jul 7 03:30:35 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: patch.c,v 1.5 2020/09/04 03:41:49 thorpej Exp $ */
+/* $NetBSD: patch.c,v 1.6 2021/07/07 03:30:35 thorpej Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: patch.c,v 1.5 2020/09/04 03:41:49 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: patch.c,v 1.6 2021/07/07 03:30:35 thorpej Exp $");
#include "opt_multiprocessor.h"
@@ -57,6 +57,9 @@ void _membar_sync_end(void);
void _membar_sync_mp(void);
void _membar_sync_mp_end(void);
+extern char alpha_copystr_bwx[], alpha_copystr_bwx_end[];
+extern char alpha_copystr[], alpha_copystr_end[];
+
static void __attribute__((__unused__))
patchfunc(void *from_s, void *from_e, void *to_s, void *to_e)
{
@@ -85,6 +88,11 @@ alpha_patch(bool is_mp)
* kernel code.
*/
+ if (cpu_amask & ALPHA_AMASK_BWX) {
+ patchfunc(alpha_copystr_bwx, alpha_copystr_bwx_end,
+ alpha_copystr, alpha_copystr_end);
+ }
+
#if defined(MULTIPROCESSOR)
if (is_mp) {
KASSERT(curcpu()->ci_flags & CPUF_PRIMARY);
