diff options
Diffstat (limited to 'newlib/libc/sys/mmixware/setjmp.S')
| -rw-r--r-- | newlib/libc/sys/mmixware/setjmp.S | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/newlib/libc/sys/mmixware/setjmp.S b/newlib/libc/sys/mmixware/setjmp.S new file mode 100644 index 000000000..e5f043155 --- /dev/null +++ b/newlib/libc/sys/mmixware/setjmp.S @@ -0,0 +1,85 @@ +/* Setjmp and longjmp for mmix. + + Copyright (C) 2001 Hans-Peter Nilsson. + + Permission to use, copy, modify, and distribute this software is freely + granted, provided that this notice is preserved with no changes. + THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE. + + jmp_buf[5]: + 0: fp + 1: rJ (return-address) + 2: sp + 3: rO *before* the setjmp call. + 4: temporary storage. Reserved between setjmp and longjmp. */ + +#ifdef __MMIX_ABI_GNU__ +#define arg1 $231 +#define arg2 $232 +#define outret $231 +#define popval 0 +#else +#define arg1 $0 +#define arg2 $1 +#define outret $0 +#define popval 1 +#endif + + .section .text.setjmp,"ax",@progbits + .global setjmp +setjmp: +% Store fp, sp and return address. Recycle the static-chain and +% structure-return registers as temporary register, since we need to keep +% the jmp_buf (parameter 1) and the return address across a "POP". + SET $251,arg1 + STOU $253,$251,0 + GET $252,rJ + STOU $252,$251,8 + STOU $254,$251,16 + SETL outret,0 + +% Jump through hoops to get the value of rO *before* the setjmp call. + GETA $255,0f + PUT rJ,$255 + POP popval,0 +0: + GET $255,rO + STOU $255,$251,24 + GO $255,$252,0 + .size setjmp,.-setjmp + + .section .text.longjmp,"ax",@progbits + .global longjmp +longjmp: +% Reset arg2 to 1 if it is 0 (see longjmp(2)) and store it in jmp_buf. +% Save arg1 in a global register, since it will be destroyed by the POPs +% (in the mmixware ABI). + CSZ arg2,arg2,1 + STOU arg2,arg1,32 + SET $251,arg1 + +% Loop and "POP 0,0" until rO is the expected value, like +% the expansion of nonlocal_goto_receiver, except that we put the return +% value in the right register and make sure that the POP causes it to +% enter the right return-value register as seen by the caller. For the +% GNU ABI, it is unnecessary to do this in the loop and perhaps the memory +% access can be hoisted outside the loop, but this is safe and simple and +% I see no need to optimize longjmps. + GETA $255,0f + PUT rJ,$255 + LDOU $255,$251,24 +0: + GET $252,rO + CMPU $252,$252,$255 + BNP $252,1f + LDOU outret,$251,32 + POP popval,0 +1: + LDOU $253,$251,0 + LDOU $255,$251,8 + LDOU $254,$251,16 + GO $255,$255,0 + .size longjmp,.-longjmp |