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-rw-r--r--ext/systemc/src/sysc/qt/md/axp.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/ext/systemc/src/sysc/qt/md/axp.c b/ext/systemc/src/sysc/qt/md/axp.c
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+++ b/ext/systemc/src/sysc/qt/md/axp.c
@@ -0,0 +1,133 @@
+/*
+ * QuickThreads -- Threads-building toolkit.
+ * Copyright (c) 1993 by David Keppel
+ *
+ * Permission to use, copy, modify and distribute this software and
+ * its documentation for any purpose and without fee is hereby
+ * granted, provided that the above copyright notice and this notice
+ * appear in all copies. This software is provided as a
+ * proof-of-concept and for demonstration purposes; there is no
+ * representation about the suitability of this software for any
+ * purpose.
+ */
+
+#include <stdarg.h>
+#include "qt.h"
+
+
+/* Varargs is harder on the AXP. Parameters are saved on the stack as
+ something like (stack grows down to low memory; low at bottom of
+ picture):
+
+ | :
+ | arg6
+ +---
+ | iarg5
+ | :
+ | iarg3 <-- va_list._a0 + va_list._offset
+ | :
+ | iarg0 <-- va_list._a0
+ +---
+ | farg5
+ | :
+ | farg0
+ +---
+
+ When some of the arguments have known type, there is no need to
+ save all of them in the struct. So, for example, if the routine is
+ called
+
+ zork (int a0, float a1, int a2, ...)
+ {
+ va_list ap;
+ va_start (ap, a2);
+ qt_vargs (... &ap ...);
+ }
+
+ then offset is set to 3 * 8 (8 === sizeof machine word) = 24.
+
+ What this means for us is that the user's routine needs to be
+ called with an arg list where some of the words in the `any type'
+ parameter list have to be split and moved up in to the int/fp
+ region.
+
+ Ways in which this can fail:
+ - The user might not know the size of the pushed arguments anyway.
+ - Structures have funny promotion rules.
+ - Probably lots of other things.
+
+ All in all, we never promised varargs would work reliably. */
+
+
+
+#define QUICKTHREADS_VADJ(sp) (((char *)sp) - QUICKTHREADS_VSTKBASE)
+
+#define QUICKTHREADS_VARGS_MD0(sp, vabytes) \
+ ((qt_t *)(((char *)(sp)) - 6*2*8 - QUICKTHREADS_STKROUNDUP(vabytes)))
+
+extern void qt_vstart(void);
+#define QUICKTHREADS_VARGS_MD1(sp) (QUICKTHREADS_SPUT (sp, QUICKTHREADS_R26, qt_vstart))
+
+
+/* Different machines use different implementations for varargs.
+ Unfortunately, the code below ``looks in to'' the varargs
+ structure, `va_list', and thus depends on the conventions.
+ The following #defines try to deal with it but don't catch
+ everything. */
+
+#ifdef __GNUC__
+#define _a0 __base
+#define _offset __offset
+#else
+#ifdef __OSF1__
+#define _a0 a0
+#define _offset offset
+#endif
+#endif /* def __GNUC__ */
+
+
+ struct qt_t *
+qt_vargs (struct qt_t *qsp, int nbytes, struct va_list *vargs,
+ void *pt, qt_function_t *startup,
+ qt_function_t *vuserf, qt_function_t *cleanup)
+{
+ va_list ap;
+ int i;
+ int max; /* Maximum *words* of args to copy. */
+ int tmove; /* *Words* of args moved typed->typed. */
+ qt_word_t *sp;
+
+ ap = *(va_list *)vargs;
+ qsp = QUICKTHREADS_VARGS_MD0 (qsp, nbytes);
+ sp = (qt_word_t *)qsp;
+
+ tmove = 6 - ap._offset/sizeof(qt_word_t);
+
+ /* Copy from one typed area to the other. */
+ for (i=0; i<tmove; ++i) {
+ /* Integer args: */
+ sp[i+6] = ((qt_word_t *)(ap._a0 + ap._offset))[i];
+ /* Fp args: */
+ sp[i] = ((qt_word_t *)(ap._a0 + ap._offset))[i-6];
+ }
+
+ max = nbytes/sizeof(qt_word_t);
+
+ /* Copy from the untyped area to the typed area. Split each arg.
+ in to integer and floating-point save areas. */
+ for (; i<6 && i<max; ++i) {
+ sp[i] = sp[i+6] = ((qt_word_t *)(ap._a0 + ap._offset))[i];
+ }
+
+ /* Copy from the untyped area to the other untyped area. */
+ for (; i<max; ++i) {
+ sp[i+6] = ((qt_word_t *)(ap._a0 + ap._offset))[i];
+ }
+
+ QUICKTHREADS_VARGS_MD1 (QUICKTHREADS_VADJ(sp));
+ QUICKTHREADS_SPUT (QUICKTHREADS_VADJ(sp), QUICKTHREADS_VARGT_INDEX, pt);
+ QUICKTHREADS_SPUT (QUICKTHREADS_VADJ(sp), QUICKTHREADS_VSTARTUP_INDEX, startup);
+ QUICKTHREADS_SPUT (QUICKTHREADS_VADJ(sp), QUICKTHREADS_VUSERF_INDEX, vuserf);
+ QUICKTHREADS_SPUT (QUICKTHREADS_VADJ(sp), QUICKTHREADS_VCLEANUP_INDEX, cleanup);
+ return ((qt_t *)QUICKTHREADS_VADJ(sp));
+}