diff options
Diffstat (limited to 'newlib/libc/machine/m32c/setjmp.S')
| -rw-r--r-- | newlib/libc/machine/m32c/setjmp.S | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/newlib/libc/machine/m32c/setjmp.S b/newlib/libc/machine/m32c/setjmp.S new file mode 100644 index 000000000..96cd0f20d --- /dev/null +++ b/newlib/libc/machine/m32c/setjmp.S @@ -0,0 +1,133 @@ +/* + +Copyright (c) 2005 Red Hat Incorporated. +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + The name of Red Hat Incorporated may not be used to endorse + or promote products derived from this software without specific + prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY +DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +*/ + +#if defined(__r8c_cpu__) || defined(__m16c_cpu__) +#define A16 1 +#endif + +/* We implement setjmp/longjmp much like the way gcc implements + exceptions - we create new stack frames, then switch to them and + return. Thus, the two setjmp's below each push all the relevent + registers, then copy the whole frame into the buffer (first $sp is + moved, then smovf copies the frame itself), and the two longjmps + restore $sp, copy the frame back into place, and issue the same + return as the setjmp would have used. + + Since the sizes of registers differs between the 16 and 24 bit + models, we provide separate implementations for each rather than + trying to parameterize them. + + Jump buffer sizes: 21 bytes for 16 bit, 34 bytes for 24 bit. +*/ + + .text + +#ifdef A16 /* 16 bit versions */ + + .global _setjmp +_setjmp: + enter #0 + pushm r1,r2,r3,a0,a1,sb,fb + +; At this point, the stack looks like this: +; ... [pc:3] [oldfb:2] <fb> [r1:2] [r2:2] [r3:2] [a0:2] [a1:2] [sb:2] [fb:2] <sp> */ + + mov.w r1,a1 ; a1 is the destination of smovf + mov.b #0,r1h + stc sp,a0 ; r1h:a0 is the source of smovf + mov.w a0,[a1] + add.w #2,a1 + mov.w #19,r3 ; plus two for sp later + smovf.b + + ; Return 0 to caller. + mov.w #0,r0 + popm r1,r2,r3,a0,a1,sb,fb + exitd + + .global _longjmp +_longjmp: + enter #0 + mov.w r1,a0 ; pointer to jump buf + mov.w r2,r0 ; setjmp's "new" return value + + mov.b #0,r1h ; r1h: a0 is the source, now jmpbuf + mov.w [a0],a1 ; dest is new stack + ldc a1,sp + add.w #2,a0 + mov.w #19,r3 + smovf.b + + ;; now return to our caller with this newly restored frame + popm r1,r2,r3,a0,a1,sb,fb + exitd + +#else /* 24 bit versions */ + + .global _setjmp +_setjmp: + enter #0 + pushm r1,r2,r3,a0,a1,sb,fb + +; At this point, the stack looks like this: +; ... [jbuf:4] [pc:4] [oldfb:4] <fb> [r1:2] [r2:2] [r3:2] [a0:4] [a1:4] [sb:4] [fb:4] <sp> */ + + mov.l 8[fb],a1 ; a1 is the destination of smovf + stc sp,a0 ; r1h:a0 is the source of smovf + mov.l a0,[a1] + add.l #4,a1 + mov.w #30,r3 ; plus two for sp later + smovf.b + + ; Return 0 to caller. + mov.w #0,r0 + popm r1,r2,r3,a0,a1,sb,fb + exitd + + .global _longjmp +_longjmp: + enter #0 +; ... [rv:2] [jbuf:4] [pc:4] [oldfb:4] <fb> + mov.l 8[fb],a0 ; pointer to jump buf + mov.w 12[fb],r0 ; setjmp's "new" return value + + mov.l [a0],a1 ; dest is new stack + ldc a1,sp + add.l #4,a0 + mov.w #30,r3 + smovf.b + + ;; now return to our caller with this newly restored frame + popm r1,r2,r3,a0,a1,sb,fb + exitd +#endif + |