Annotation of gforth/decstation.h, revision 1.1
1.1 ! anton 1: /*
! 2: $Id: decstation.h,v 1.8 1993/05/25 10:24:18 anton Exp $
! 3: Copyright 1992 by the ANSI figForth Development Group
! 4:
! 5: This is the machine-specific part for a Decstation running Ultrix
! 6: */
! 7:
! 8:
! 9: /* Cell and UCell must be the same size as a pointer */
! 10: typedef long Cell;
! 11: typedef unsigned long UCell;
! 12:
! 13: /* DCell and UDCell must be twice as large as Cell */
! 14: typedef long long DCell;
! 15: typedef unsigned long long UDCell;
! 16:
! 17: /* define this if IEEE singles and doubles are available as C data types */
! 18: #define IEEE_FP
! 19:
! 20: /* the IEEE types are used only for loading and storing */
! 21: /* the IEEE double precision type */
! 22: typedef double DFloat;
! 23: /* the IEEE single precision type */
! 24: typedef float SFloat;
! 25:
! 26: /* define this if the least-significant byte is at the largets address */
! 27: /* #define BIG_ENDIAN */
! 28:
! 29: /* some definitions for composing opcodes */
! 30: #define JUMP_MASK 0x03ffffff
! 31: #define J_PATTERN 0x08000000
! 32: #define JAL_PATTERN 0x0c000000
! 33: /* this provides the first 4 bits of a jump address, i.e. it must be <16 */
! 34: #define SEGMENT_NUM 1
! 35:
! 36: #ifdef DIRECT_THREADED
! 37: /* PFA gives the parameter field address corresponding to a cfa */
! 38: # define PFA(cfa) (((Cell *)cfa)+2)
! 39: /* PFA1 is a special version for use just after a NEXT1 */
! 40: # define PFA1(cfa) PFA(cfa)
! 41: /* CODE_ADDRESS is the address of the code jumped to through the code field */
! 42: # define CODE_ADDRESS(cfa) ((Label)(((*(unsigned *)(cfa))^J_PATTERN^(SEGMENT_NUM<<26))<<2))
! 43: /* MAKE_CF creates an appropriate code field at the cfa; ca is the code address */
! 44: # define MAKE_CF(cfa,ca) ({long * _cfa = (long *)(cfa); \
! 45: _cfa[0] = J_PATTERN|((((long)(ca))&JUMP_MASK)>>2); /* J ca */ \
! 46: _cfa[1] = 0; /* nop */})
! 47: # ifdef undefined
! 48: /* the following version uses JAL to make PFA1 faster */
! 49: # define PFA1(label) ({register Cell *pfa asm("$31"); \
! 50: pfa; })
! 51: /* CODE_ADDRESS is the address of the code jumped to through the code field */
! 52: # define CODE_ADDRESS(cfa) ((Label)(((*(unsigned *)(cfa))^JAL_PATTERN^(SEGMENT_NUM<<26))<<2))
! 53: # define MAKE_CF(cfa,ca) ({long *_cfa = (long *)(cfa); \
! 54: long _ca = (long)(ca);
! 55: _cfa[0] = JAL_PATTERN|(((((long)_ca)>>2)+4)&JUMP_MASK), /* JAL ca+4 */ \
! 56: _cfa[1] = *(long *)_ca; /* delay slot */})
! 57: # endif /* undefined */
! 58:
! 59: /* this is the point where the does code starts if label points to the
! 60: * jump dodoes */
! 61: # define DOES_CODE(cfa) ((Xt *)(((char *)CODE_ADDRESS(cfa))+8))
! 62:
! 63: /* this is a special version of DOES_CODE for use in dodoes */
! 64: # define DOES_CODE1(cfa) DOES_CODE(cfa)
! 65:
! 66: # define DOES_HANDLER_SIZE 8
! 67: # define MAKE_DOES_CF(cfa, does_code) ({char *does_handlerp=((char *)does_code)-DOES_HANDLER_SIZE; \
! 68: MAKE_CF(cfa,does_handlerp); \
! 69: MAKE_DOES_HANDLER(does_handlerp);})
! 70: /* this stores a jump dodoes at addr */
! 71: # define MAKE_DOES_HANDLER(addr) ({long * _addr = (long *)addr; \
! 72: _addr[0] = J_PATTERN|((((long)DODOES)>>2)&JUMP_MASK); /* J dodoes */ \
! 73: _addr[1] = 0; /* nop */})
! 74: #endif
! 75: #ifdef undefined
! 76: /* and here are some more efficient versions that can be tried later */
! 77:
! 78: /* the first version saves one cycle by doing something useful in the
! 79: delay slot. !! check that the instruction in the delay slot is legal
! 80: */
! 81:
! 82: #define MAKE_DOESJUMP(addr) ({long * _addr = (long *)addr; \
! 83: _addr[0] = J_PATTERN|(((((long)symbols[3])>>2)+4)&JUMP_MASK), /* J dodoes+4 */ \
! 84: _addr[1] = *(long *)symbols[3]; /* delay */})
! 85:
! 86: /* the following version uses JAL to make DOES_CODE1 faster */
! 87: /* !! does the declaration clear the register ? */
! 88: /* it's ok to use the same reg as in PFA1:
! 89: dodoes is the only potential problem and I have taken care of it */
! 90: #define DOES_CODE1(cfa) ({register Code *_does_code asm("$31"); \
! 91: _does_code; })
! 92: #define MAKE_DOESJUMP(addr) ({long * _addr = (long *)addr; \
! 93: _addr[0] = JAL_PATTERN|(((((long)symbols[3])>>2)+4)&JUMP_MASK), /* JAL dodoes+4 */ \
! 94: _addr[1] = *(long *)symbols[3]; /* delay */})
! 95:
! 96: #endif
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