svn commit: r210623 - in head/sys: amd64/include i386/include ia64/include

John Baldwin jhb at FreeBSD.org
Thu Jul 29 18:44:11 UTC 2010


Author: jhb
Date: Thu Jul 29 18:44:10 2010
New Revision: 210623
URL: http://svn.freebsd.org/changeset/base/210623

Log:
  Mark the __curthread() functions as __pure2 and remove the volatile keyword
  from the inline assembly.  This allows the compiler to cache invocations of
  curthread since it's value does not change within a thread context.
  
  Submitted by:	zec (i386)
  MFC after:	1 week

Modified:
  head/sys/amd64/include/pcpu.h
  head/sys/i386/include/pcpu.h
  head/sys/ia64/include/pcpu.h

Modified: head/sys/amd64/include/pcpu.h
==============================================================================
--- head/sys/amd64/include/pcpu.h	Thu Jul 29 18:02:57 2010	(r210622)
+++ head/sys/amd64/include/pcpu.h	Thu Jul 29 18:44:10 2010	(r210623)
@@ -216,12 +216,12 @@ extern struct pcpu *pcpup;
 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
 
-static __inline struct thread *
+static __inline __pure2 struct thread *
 __curthread(void)
 {
 	struct thread *td;
 
-	__asm __volatile("movq %%gs:0,%0" : "=r" (td));
+	__asm("movq %%gs:0,%0" : "=r" (td));
 	return (td);
 }
 #define	curthread		(__curthread())

Modified: head/sys/i386/include/pcpu.h
==============================================================================
--- head/sys/i386/include/pcpu.h	Thu Jul 29 18:02:57 2010	(r210622)
+++ head/sys/i386/include/pcpu.h	Thu Jul 29 18:44:10 2010	(r210623)
@@ -223,12 +223,12 @@ extern struct pcpu *pcpup;
 #define	PCPU_PTR(member)	__PCPU_PTR(pc_ ## member)
 #define	PCPU_SET(member, val)	__PCPU_SET(pc_ ## member, val)
 
-static __inline struct thread *
+static __inline __pure2 struct thread *
 __curthread(void)
 {
 	struct thread *td;
 
-	__asm __volatile("movl %%fs:0,%0" : "=r" (td));
+	__asm("movl %%fs:0,%0" : "=r" (td));
 	return (td);
 }
 #define	curthread		(__curthread())

Modified: head/sys/ia64/include/pcpu.h
==============================================================================
--- head/sys/ia64/include/pcpu.h	Thu Jul 29 18:02:57 2010	(r210622)
+++ head/sys/ia64/include/pcpu.h	Thu Jul 29 18:44:10 2010	(r210623)
@@ -70,12 +70,12 @@ struct pcpu;
 
 register struct pcpu *pcpup __asm__("r13");
 
-static __inline struct thread *
+static __inline __pure2 struct thread *
 __curthread(void)
 {
 	struct thread *td;
 
-	__asm __volatile("ld8.acq %0=[r13]" : "=r"(td));
+	__asm("ld8.acq %0=[r13]" : "=r"(td));
 	return (td);
 }
 #define	curthread	(__curthread())


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