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/*
* 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.
*/
#ifndef QUICKTHREADS_AXP_H
#define QUICKTHREADS_AXP_H
#define QUICKTHREADS_GROW_DOWN
typedef unsigned long qt_word_t;
/* Stack layout on the Alpha:
Integer:
Caller-save: r0..r8, r22..r25, r27..r29
argument/caller-save: r16..r21
callee-save: r9..r15
return pc *callee-save*: r26
stack pointer: r30
zero: r31
Floating-point:
Caller-save: f0..f1, f10..f15
argument/caller-save: f16..f21, f22..f30
callee-save: f2..f9
zero: f31
Non-varargs:
+---
| padding
| f9
| f8
| f7
| f6
| f5
| f4
| f3
| f2
| r26
+---
| padding
| r29
| r15
| r14
| r13
| r12 on startup === `only'
| r11 on startup === `userf'
| r10 on startup === `qt'
| r9 on startup === `qu'
| r26 on startup === qt_start <--- qt.sp
+---
Conventions for varargs startup:
| :
| arg6
| iarg5
| :
| iarg0
| farg5
| :
| farg0
+---
| padding
| r29
| r15
| r14
| r13
| r12 on startup === `startup'
| r11 on startup === `vuserf'
| r10 on startup === `cleanup'
| r9 on startup === `qt'
| r26 on startup === qt_vstart <--- qt.sp
+---
Note: this is a pretty cheap/sleazy way to get things going,
but ``there must be a better way.'' For instance, some varargs
parameters could be loaded in to integer registers, or the return
address could be stored on top of the stack. */
/* Stack must be 16-byte aligned. */
#define QUICKTHREADS_STKALIGN (16)
/* How much space is allocated to hold all the crud for
initialization: 7 registers times 8 bytes/register. */
#define QUICKTHREADS_STKBASE (10 * 8)
#define QUICKTHREADS_VSTKBASE QUICKTHREADS_STKBASE
/* Offsets of various registers. */
#define QUICKTHREADS_R26 0
#define QUICKTHREADS_R9 1
#define QUICKTHREADS_R10 2
#define QUICKTHREADS_R11 3
#define QUICKTHREADS_R12 4
/* When a never-before-run thread is restored, the return pc points
to a fragment of code that starts the thread running. For
non-vargs functions, it just calls the client's `only' function.
For varargs functions, it calls the startup, user, and cleanup
functions.
The varargs startup routine always reads 12 8-byte arguments from
the stack. If fewer argumets were pushed, the startup routine
would read off the top of the stack. To prevent errors we always
allocate enough space. When there are fewer args, the preallocated
words are simply wasted. */
extern void qt_start(void);
#define QUICKTHREADS_ARGS_MD(sp) (QUICKTHREADS_SPUT (sp, QUICKTHREADS_R26, qt_start))
/* The AXP uses a struct for `va_list', so pass a pointer to the
struct. This may break some uses of `QUICKTHREADS_VARGS', but then we never
claimed it was totally portable. */
typedef void (qt_function_t)(void);
struct qt_t;
struct va_list;
extern struct qt_t *qt_vargs (struct qt_t *sp, int nbytes,
struct va_list *vargs, void *pt,
qt_function_t *startup,
qt_function_t *vuserf,
qt_function_t *cleanup);
#define QUICKTHREADS_VARGS(sp, nbytes, vargs, pt, startup, vuserf, cleanup) \
(qt_vargs (sp, nbytes, (struct va_list *)(&(vargs)), pt, \
(qt_function_t *) startup, (qt_function_t *)vuserf, \
(qt_function_t *)cleanup));
/* The *index* (positive offset) of where to put each value. */
#define QUICKTHREADS_ONLY_INDEX (QUICKTHREADS_R12)
#define QUICKTHREADS_USER_INDEX (QUICKTHREADS_R11)
#define QUICKTHREADS_ARGT_INDEX (QUICKTHREADS_R10)
#define QUICKTHREADS_ARGU_INDEX (QUICKTHREADS_R9)
#define QUICKTHREADS_VCLEANUP_INDEX (QUICKTHREADS_R10)
#define QUICKTHREADS_VUSERF_INDEX (QUICKTHREADS_R11)
#define QUICKTHREADS_VSTARTUP_INDEX (QUICKTHREADS_R12)
#define QUICKTHREADS_VARGT_INDEX (QUICKTHREADS_R9)
#endif /* ndef QUICKTHREADS_AXP_H */
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