--- /dev/null
+/*
+ * 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 QT_MIPS_H
+#define QT_MIPS_H
+
+typedef unsigned long qt_word_t;
+
+#define QT_GROW_DOWN
+
+/* Stack layout on the mips:
+
+ Callee-save registers are: $16-$23, $30; $f20-$f30.
+ Also save $31, return pc.
+
+ Non-varargs:
+
+ +---
+ | $f30 The first clump is only saved if `qt_block'
+ | $f28 is called, in which case it saves the fp regs
+ | $f26 then calls `qt_blocki' to save the int regs.
+ | $f24
+ | $f22
+ | $f20
+ | $31 === return pc in `qt_block'
+ +---
+ | $31 === return pc; on startup == qt_start
+ | $30
+ | $23
+ | $22
+ | $21
+ | $20
+ | $19 on startup === only
+ | $18 on startup === $a2 === userf
+ | $17 on startup === $a1 === pt
+ | $16 on startup === $a0 === pu
+ | <a3> save area req'd by MIPS calling convention
+ | <a2> save area req'd by MIPS calling convention
+ | <a1> save area req'd by MIPS calling convention
+ | <a0> save area req'd by MIPS calling convention <--- sp
+ +---
+
+ Conventions for varargs:
+
+ | args ...
+ +---
+ | :
+ | :
+ | $21
+ | $20
+ | $19 on startup === `userf'
+ | $18 on startup === `startup'
+ | $17 on startup === `pt'
+ | $16 on startup === `cleanup'
+ | <a3>
+ | <a2>
+ | <a1>
+ | <a0> <--- sp
+ +---
+
+ Note: if we wanted to, we could muck about and try to get the 4
+ argument registers loaded in to, e.g., $22, $23, $30, and $31,
+ and the return pc in, say, $20. Then, the first 4 args would
+ not need to be loaded from memory, they could just use
+ register-to-register copies. */
+
+
+/* Stack must be doubleword aligned. */
+#define QT_STKALIGN (8) /* Doubleword aligned. */
+
+/* How much space is allocated to hold all the crud for
+ initialization: $16-$23, $30, $31. Just do an integer restore,
+ no need to restore floating-point. Four words are needed for the
+ argument save area for the helper function that will be called for
+ the old thread, just before the new thread starts to run. */
+
+#define QT_STKBASE (14 * 4)
+#define QT_VSTKBASE QT_STKBASE
+
+
+/* Offsets of various registers. */
+#define QT_31 (9+4)
+#define QT_19 (3+4)
+#define QT_18 (2+4)
+#define QT_17 (1+4)
+#define QT_16 (0+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 4 words of arguments from
+ the stack. If there are less than 4 words of arguments, then the
+ startup routine can read off the top of the stack. To prevent
+ errors we always allocate 4 words. If there are more than 3 words
+ of arguments, the 4 preallocated words are simply wasted. */
+
+extern void qt_start(void);
+#define QT_ARGS_MD(sp) (QT_SPUT (sp, QT_31, qt_start))
+
+#define QT_VARGS_MD0(sp, vabytes) \
+ ((qt_t *)(((char *)(sp)) - 4*4 - QT_STKROUNDUP(vabytes)))
+
+extern void qt_vstart(void);
+#define QT_VARGS_MD1(sp) (QT_SPUT (sp, QT_31, qt_vstart))
+
+#define QT_VARGS_DEFAULT
+
+
+/* The *index* (positive offset) of where to put each value. */
+#define QT_ONLY_INDEX (QT_19)
+#define QT_USER_INDEX (QT_18)
+#define QT_ARGT_INDEX (QT_17)
+#define QT_ARGU_INDEX (QT_16)
+
+#define QT_VCLEANUP_INDEX (QT_16)
+#define QT_VUSERF_INDEX (QT_19)
+#define QT_VSTARTUP_INDEX (QT_18)
+#define QT_VARGT_INDEX (QT_17)
+
+#endif /* ndef QT_MIPS_H */
projects / lilypond.git / blobdiff