From: dlg <dlg@openbsd.org>
Date: Wed, 17 Aug 2016 11:09:01 +0000 (+0000)
Subject: use a register variable to get at the curcpu pointer in %g7
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=b69b316e016cc1c4a9d17118a7857c9c196be354;p=openbsd

use a register variable to get at the curcpu pointer in %g7

this lets us define curcpu(), cpu_number(), etc as derefs of this
variable rather than having to write asm to copy it into another
register for the same derefs.

this provides shorter inlined code that wastes less registers.

ok kettenis@ who notes we use this these on other archs already
---

diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index d349496f189..570d5dc5152 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.88 2015/08/28 23:28:39 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.89 2016/08/17 11:09:01 dlg Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 2001/06/14 22:56:58 thorpej Exp $ */
 
 /*
@@ -169,22 +169,12 @@ struct cpu_info {
 
 extern struct cpu_info *cpus;
 
-#define curpcb		curcpu()->ci_cpcb
-#define fpproc		curcpu()->ci_fpproc
-
 #ifdef MULTIPROCESSOR
 
-#define	cpu_number()	(curcpu()->ci_number)
-
-extern __inline struct cpu_info *curcpu(void);
-extern __inline struct cpu_info *
-curcpu(void)
-{
-	struct cpu_info *ci;
+register struct cpu_info *__curcpu asm ("%g7");
 
-	__asm volatile("mov %%g7, %0" : "=r"(ci));
-	return (ci->ci_self);
-}
+#define curcpu()	(__curcpu->ci_self)
+#define cpu_number()	(__curcpu->ci_number)
 
 #define CPU_IS_PRIMARY(ci)	((ci)->ci_number == 0)
 #define CPU_INFO_ITERATOR	int
@@ -200,10 +190,11 @@ void	sparc64_broadcast_ipi(void (*)(void), u_int64_t, u_int64_t);
 
 void	cpu_unidle(struct cpu_info *);
 
-#else
+#else /* MULTIPROCESSOR */
 
+#define	__curcpu	((struct cpu_info *)CPUINFO_VA)
+#define curcpu()	__curcpu
 #define cpu_number()	0
-#define	curcpu()	((struct cpu_info *)CPUINFO_VA)
 
 #define CPU_IS_PRIMARY(ci)	1
 #define CPU_INFO_ITERATOR	int
@@ -214,7 +205,10 @@ void	cpu_unidle(struct cpu_info *);
 
 #define cpu_unidle(ci)
 
-#endif
+#endif /* MULTIPROCESSOR */
+
+#define curpcb		__curcpu->ci_cpcb
+#define fpproc		__curcpu->ci_fpproc
 
 #define CPU_BUSY_CYCLE()	do {} while (0)