*
* ---------------------------------------------------------------------------*/
-#ifndef GCTHREAD_H
-#define GCTHREAD_H
+#ifndef SM_GCTHREAD_H
+#define SM_GCTHREAD_H
-#include "OSThreads.h"
#include "WSDeque.h"
+#pragma GCC visibility push(hidden)
+
/* -----------------------------------------------------------------------------
General scheme
typedef struct step_workspace_ {
step * step; // the step for this workspace
- struct gc_thread_ * gct; // the gc_thread that contains this workspace
+ struct gc_thread_ * my_gct; // the gc_thread that contains this workspace
// where objects to be scavenged go
bdescr * todo_bd;
extern nat n_gc_threads;
-extern gc_thread **gc_threads;
-
/* -----------------------------------------------------------------------------
The gct variable is thread-local and points to the current thread's
gc_thread structure. It is heavily accessed, so we try to put gct
__thread version.
-------------------------------------------------------------------------- */
+extern gc_thread **gc_threads;
+
+#if defined(THREADED_RTS)
+
#define GLOBAL_REG_DECL(type,name,reg) register type name REG(reg);
-#if defined(sparc_HOST_ARCH)
-// Don't use REG_base or R1 for gct on SPARC because they're getting clobbered
-// by something else. Not sure what yet. -- BL 2009/01/03
+#define SET_GCT(to) gct = (to)
+
+
+
+#if (defined(i386_HOST_ARCH) && defined(linux_HOST_OS))
+// Using __thread is better than stealing a register on x86/Linux, because
+// we have too few registers available. In my tests it was worth
+// about 5% in GC performance, but of course that might change as gcc
+// improves. -- SDM 2009/04/03
extern __thread gc_thread* gct;
#define DECLARE_GCT __thread gc_thread* gct;
+
+#elif defined(sparc_TARGET_ARCH)
+// On SPARC we can't pin gct to a register. Names like %l1 are just offsets
+// into the register window, which change on each function call.
+//
+// There are eight global (non-window) registers, but they're used for other purposes.
+// %g0 -- always zero
+// %g1 -- volatile over function calls, used by the linker
+// %g2-%g3 -- used as scratch regs by the C compiler (caller saves)
+// %g4 -- volatile over function calls, used by the linker
+// %g5-%g7 -- reserved by the OS
+
+extern __thread gc_thread* gct;
+#define DECLARE_GCT __thread gc_thread* gct;
+
+
#elif defined(REG_Base) && !defined(i386_HOST_ARCH)
// on i386, REG_Base is %ebx which is also used for PIC, so we don't
// want to steal it
GLOBAL_REG_DECL(gc_thread*, gct, REG_Base)
#define DECLARE_GCT /* nothing */
+
#elif defined(REG_R1)
GLOBAL_REG_DECL(gc_thread*, gct, REG_R1)
#define DECLARE_GCT /* nothing */
+
#elif defined(__GNUC__)
extern __thread gc_thread* gct;
#endif
-#endif // GCTHREAD_H
+#else // not the threaded RTS
+
+extern StgWord8 the_gc_thread[];
+
+#define gct ((gc_thread*)&the_gc_thread)
+#define SET_GCT(to) /*nothing*/
+#define DECLARE_GCT /*nothing*/
+
+#endif
+
+#pragma GCC visibility pop
+
+#endif // SM_GCTHREAD_H