; pa-risc.s -- assembly support.
; 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.
; This file (pa-risc.s) is part of the port of QuickThreads for
; PA-RISC 1.1 architecture. This file implements context switches
; and thread startup. It was written in 1994 by Uwe Reder
; (`uereder@cip.informatik.uni-erlangen.de') for the Operating
; Systems Department (IMMD4) at the University of Erlangen/Nuernberg
; Germany.
; Callee saves general registers gr3..gr18,
; floating-point registers fr12..fr21.
.CODE
.IMPORT $$dyncall, MILLICODE
.IMPORT qt_error, CODE
.EXPORT qt_blocki, ENTRY
.EXPORT qt_block, ENTRY
.EXPORT qt_abort, ENTRY
.EXPORT qt_start, ENTRY
.EXPORT qt_vstart, ENTRY
; arg0: ptr to function (helper) to call once curr is suspended
; and control is on arg3's stack.
; arg1: 1'th arg to *arg0.
; arg2: 2'th arg to *arg0.
; arg3: sp of new thread.
qt_blocki
.PROC
.CALLINFO CALLER, FRAME=0, SAVE_RP, ENTRY_GR=18
.ENTRY
stw %rp,-20(%sp) ; save rp to old frame-marker
stwm %r3,128(%sp) ; save callee-saves general registers
stw %r4,-124(%sp)
stw %r5,-120(%sp)
stw %r6,-116(%sp)
stw %r7,-112(%sp)
stw %r8,-108(%sp)
stw %r9,-104(%sp)
stw %r10,-100(%sp)
stw %r11,-96(%sp)
stw %r12,-92(%sp)
stw %r13,-88(%sp)
stw %r14,-84(%sp)
stw %r15,-80(%sp)
stw %r16,-76(%sp)
stw %r17,-72(%sp)
stw %r18,-68(%sp)
qt_abort
copy %arg0,%r22 ; helper to be called by $$dyncall
copy %sp,%arg0 ; pass current sp as arg0 to helper
copy %arg3,%sp ; set new sp
.CALL
bl $$dyncall,%mrp ; call helper
copy %mrp,%rp
ldw -68(%sp),%r18 ; restore general registers
ldw -72(%sp),%r17
ldw -76(%sp),%r16
ldw -80(%sp),%r15
ldw -84(%sp),%r14
ldw -88(%sp),%r13
ldw -92(%sp),%r12
ldw -96(%sp),%r11
ldw -100(%sp),%r10
ldw -104(%sp),%r9
ldw -108(%sp),%r8
ldw -112(%sp),%r7
ldw -116(%sp),%r6
ldw -120(%sp),%r5
ldw -124(%sp),%r4
ldw -148(%sp),%rp ; restore return-pointer
bv %r0(%rp) ; return to caller
ldwm -128(%sp),%r3
.EXIT
.PROCEND
qt_block
.PROC
.CALLINFO CALLER, FRAME=0, SAVE_RP, ENTRY_FR=21
.ENTRY
stw %rp,-20(%sp) ; save rp to old frame-marker
fstds,ma %fr12,8(%sp) ; save callee-saves float registers
fstds,ma %fr13,8(%sp)
fstds,ma %fr14,8(%sp)
fstds,ma %fr15,8(%sp)
fstds,ma %fr16,8(%sp)
fstds,ma %fr17,8(%sp)
fstds,ma %fr18,8(%sp)
fstds,ma %fr19,8(%sp)
fstds,ma %fr20,8(%sp)
fstds,ma %fr21,8(%sp)
.CALL
bl qt_blocki,%rp
ldo 48(%sp),%sp
ldo -48(%sp),%sp
fldds,mb -8(%sp),%fr21 ; restore callee-saves float registers
fldds,mb -8(%sp),%fr20
fldds,mb -8(%sp),%fr19
fldds,mb -8(%sp),%fr18
fldds,mb -8(%sp),%fr17
fldds,mb -8(%sp),%fr16
fldds,mb -8(%sp),%fr15
fldds,mb -8(%sp),%fr14
fldds,mb -8(%sp),%fr13
ldw -28(%sp),%rp ; restore return-pointer
bv %r0(%rp) ; return to caller.
fldds,mb -8(%sp),%fr12
.EXIT
.PROCEND
qt_start
.PROC
.CALLINFO CALLER, FRAME=0
.ENTRY
copy %r18,%arg0 ; set user arg `pu'.
copy %r17,%arg1 ; ... user function pt.
copy %r16,%arg2 ; ... user function userf.
; %r22 is a caller-saves register
copy %r15,%r22 ; function to be called by $$dyncall
.CALL ; in=%r22
bl $$dyncall,%mrp ; call `only'.
copy %mrp,%rp
bl,n qt_error,%r0 ; `only' erroniously returned.
.EXIT
.PROCEND
; Varargs
;
; First, call `startup' with the `pt' argument.
;
; Next, call the user's function with all arguments.
; We don't know whether arguments are integers, 32-bit floating-points or
; even 64-bit floating-points, so we reload all the registers, possibly
; with garbage arguments. The thread creator provided non-garbage for
; the arguments that the callee actually uses, so the callee never gets
; garbage.
;
; -48 -44 -40 -36 -32
; | arg3 | arg2 | arg1 | arg0 |
; -----------------------------
; integers: arg3 arg2 arg1 arg0
; 32-bit fps: farg3 farg2 farg1 farg0
; 64-bit fps: <---farg3--> <---farg1-->
;
; Finally, call `cleanup' with the `pt' argument and with the return value
; from the user's function. It is an error for `cleanup' to return.
qt_vstart
.PROC
.CALLINFO CALLER, FRAME=0
.ENTRY
; Because the startup function may damage the fixed arguments
; on the stack (PA-RISC Procedure Calling Conventions Reference
; Manual, 2.4 Fixed Arguments Area), we allocate a seperate
; stack frame for it.
ldo 64(%sp),%sp
; call: void startup(void *pt)
copy %r15,%arg0 ; `pt' is arg0 to `startup'.
copy %r16,%r22
.CALL
bl $$dyncall,%mrp ; Call `startup'.
copy %mrp,%rp
ldo -64(%sp),%sp
; call: void *qt_vuserf_t(...)
ldw -36(%sp),%arg0 ; Load args to integer registers.
ldw -40(%sp),%arg1
ldw -44(%sp),%arg2
ldw -48(%sp),%arg3
; Index of fld[w|d]s only ranges from -16 to 15, so we
; take r22 to be our new base register.
ldo -32(%sp),%r22
fldws -4(%r22),%farg0 ; Load args to floating-point registers.
fldds -8(%r22),%farg1
fldws -12(%r22),%farg2
fldds -16(%r22),%farg3
copy %r17,%r22
.CALL
bl $$dyncall,%mrp ; Call `userf'.
copy %mrp,%rp
; call: void cleanup(void *pt, void *vuserf_return)
copy %r15,%arg0 ; `pt' is arg0 to `cleanup'.
copy %ret0,%arg1 ; Return-value is arg1 to `cleanup'.
copy %r18,%r22
.CALL
bl $$dyncall,%mrp ; Call `cleanup'.
copy %mrp,%rp
bl,n qt_error,%r0
.EXIT
.PROCEND