Module Name: src
Committed By: rin
Date: Thu Jun 2 00:32:14 UTC 2022
Modified Files:
src/sys/arch/powerpc/powerpc: fix_unaligned.c
Log Message:
As a tiny optimization, rearrange cases as follows:
(1) load/store of format D (base + disp)
(2) load/store of format X (base + index)
(3) lmw and stmw
For clang-compiled userland (*), their frequencies are roughly,
(1) > (2) >> (3) ~ 0.
Improvement should be minor; we are already trapped in the alignment
fault handler.
(*) clang unconditionally emits unaligned memory access for powerpc.
Undocumented -disable-ppc-unaligned option does not work...
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/sys/arch/powerpc/powerpc/fix_unaligned.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/powerpc/powerpc/fix_unaligned.c
diff -u src/sys/arch/powerpc/powerpc/fix_unaligned.c:1.1 src/sys/arch/powerpc/powerpc/fix_unaligned.c:1.2
--- src/sys/arch/powerpc/powerpc/fix_unaligned.c:1.1 Mon May 30 13:58:51 2022
+++ src/sys/arch/powerpc/powerpc/fix_unaligned.c Thu Jun 2 00:32:14 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: fix_unaligned.c,v 1.1 2022/05/30 13:58:51 rin Exp $ */
+/* $NetBSD: fix_unaligned.c,v 1.2 2022/06/02 00:32:14 rin Exp $ */
/*
* Copyright (c) 2022 The NetBSD Foundation, Inc.
@@ -51,7 +51,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fix_unaligned.c,v 1.1 2022/05/30 13:58:51 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fix_unaligned.c,v 1.2 2022/06/02 00:32:14 rin Exp $");
#include "opt_ddb.h"
#include "opt_ppcarch.h"
@@ -187,27 +187,55 @@ emul_unaligned(struct trapframe *tf, ksi
int flags;
switch (insn->i_any.i_opcd) {
- case OPC_LMW:
- UA_EVCNT_INCR(lmw);
-#ifdef FIX_UNALIGNED_LSTMW
+ case OPC_LWZ:
+ UA_EVCNT_INCR(lwz);
flags = UAF_LOAD;
- if (do_lstmw(tf, insn, flags))
- goto fault;
- return false;
-#else
- goto unknown;
-#endif
+ break;
- case OPC_STMW:
- UA_EVCNT_INCR(stmw);
-#ifdef FIX_UNALIGNED_LSTMW
+ case OPC_LWZU:
+ UA_EVCNT_INCR(lwzu);
+ flags = UAF_LOAD | UAF_UPDATE;
+ break;
+
+ case OPC_STW:
+ UA_EVCNT_INCR(stw);
flags = UAF_STORE;
- if (do_lstmw(tf, insn, flags))
- goto fault;
- return false;
-#else
- goto unknown;
-#endif
+ break;
+
+ case OPC_STWU:
+ UA_EVCNT_INCR(stwu);
+ flags = UAF_STORE | UAF_UPDATE;
+ break;
+
+ case OPC_LHZ:
+ UA_EVCNT_INCR(lhz);
+ flags = UAF_LOAD | UAF_HALF;
+ break;
+
+ case OPC_LHZU:
+ UA_EVCNT_INCR(lhzu);
+ flags = UAF_LOAD | UAF_HALF | UAF_UPDATE;
+ break;
+
+ case OPC_LHA:
+ UA_EVCNT_INCR(lha);
+ flags = UAF_LOAD | UAF_HALF | UAF_ALGEBRA;
+ break;
+
+ case OPC_LHAU:
+ UA_EVCNT_INCR(lhau);
+ flags = UAF_LOAD | UAF_HALF | UAF_ALGEBRA | UAF_UPDATE;
+ break;
+
+ case OPC_STH:
+ UA_EVCNT_INCR(sth);
+ flags = UAF_STORE | UAF_HALF;
+ break;
+
+ case OPC_STHU:
+ UA_EVCNT_INCR(sthu);
+ flags = UAF_STORE | UAF_HALF | UAF_UPDATE;
+ break;
case OPC_integer_31:
switch (insn->i_x.i_xo) {
@@ -287,55 +315,27 @@ emul_unaligned(struct trapframe *tf, ksi
}
break;
- case OPC_LWZ:
- UA_EVCNT_INCR(lwz);
+ case OPC_LMW:
+ UA_EVCNT_INCR(lmw);
+#ifdef FIX_UNALIGNED_LSTMW
flags = UAF_LOAD;
- break;
-
- case OPC_LWZU:
- UA_EVCNT_INCR(lwzu);
- flags = UAF_LOAD | UAF_UPDATE;
- break;
+ if (do_lstmw(tf, insn, flags))
+ goto fault;
+ return false;
+#else
+ goto unknown;
+#endif
- case OPC_STW:
- UA_EVCNT_INCR(stw);
+ case OPC_STMW:
+ UA_EVCNT_INCR(stmw);
+#ifdef FIX_UNALIGNED_LSTMW
flags = UAF_STORE;
- break;
-
- case OPC_STWU:
- UA_EVCNT_INCR(stwu);
- flags = UAF_STORE | UAF_UPDATE;
- break;
-
- case OPC_LHZ:
- UA_EVCNT_INCR(lhz);
- flags = UAF_LOAD | UAF_HALF;
- break;
-
- case OPC_LHZU:
- UA_EVCNT_INCR(lhzu);
- flags = UAF_LOAD | UAF_HALF | UAF_UPDATE;
- break;
-
- case OPC_LHA:
- UA_EVCNT_INCR(lha);
- flags = UAF_LOAD | UAF_HALF | UAF_ALGEBRA;
- break;
-
- case OPC_LHAU:
- UA_EVCNT_INCR(lhau);
- flags = UAF_LOAD | UAF_HALF | UAF_ALGEBRA | UAF_UPDATE;
- break;
-
- case OPC_STH:
- UA_EVCNT_INCR(sth);
- flags = UAF_STORE | UAF_HALF;
- break;
-
- case OPC_STHU:
- UA_EVCNT_INCR(sthu);
- flags = UAF_STORE | UAF_HALF | UAF_UPDATE;
- break;
+ if (do_lstmw(tf, insn, flags))
+ goto fault;
+ return false;
+#else
+ goto unknown;
+#endif
default:
UA_EVCNT_INCR(unknown);
