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Length: 1959 (0x7a7)
Types: TextFile
Notes: UNIX file
Names: »ptrmath.s«
└─⟦f27320a65⟧ Bits:30001972 Commodore 900 hard disk image with partial source code
└─⟦2d53db1df⟧ UNIX V7 Filesystem
└─ ⟦this⟧ »hr/src/smgr/ptrmath.s«
.shri .globl subptr_ .globl addptr_ .globl incptr_ .globl decptr_ /* mar-26-85 : offset to be added extended to double precision */ addptr_: ldl rr0, SS|4(r15) ldl rr2, SS|8(r15) add r1, r3 /* add offset amount */ adcb rh0, rl2 /* add any segment overflow */ ret un /* mar-26-85 : updated as addptr */ subptr_: ldl rr0, SS|4(r15) ldl rr2, SS|8(r15) sub r1, r3 /* subtract offset amount */ sbcb rh0, rl2 /* get the overflow */ ret un incptr_: ldl rr4, SS|4(r15) / fetch pointer to srcw pointer ldl rr2, (rr4) / fetch the srcw pointer exb rh2, rl2 / move seg number down slll rr2, $3 / shift whole thing over three ldl rr4, SS|8(r15) / get address of bit position add r3, (rr4) / add current bit position ldl rr0, SS|12(r15) / get increment value addl rr2, rr0 / add the increment to current ld r0, r3 / get copy of low word and r0, $0xf ld rr4, SS|8(r15) / get address of bit pointer ld (rr4), r0 / save off new bit position srll rr2, $3 / shift back to remove bitpos andb rl3, $0xFE / eliminate lowest bit position exb rh2,rl2 / put segno back in place ldl rr4, SS|4(r15) / get address of word pointer ldl (rr4), rr2 / and save it back ret un decptr_: ldl rr4, SS|4(r15) / fetch pointer to srcw pointer ldl rr2, (rr4) / fetch the srcw pointer exb rh2, rl2 / move seg number down slll rr2, $3 / shift whole thing over three ldl rr4, SS|8(r15) / get address of bit position add r3, (rr4) / add current bit position ldl rr0, SS|12(r15) / get increment value subl rr2, rr0 / add the increment to current ld r0, r3 / get copy of low word and r0, $0xf ld rr4, SS|8(r15) / get address of bit pointer ld (rr4), r0 / save off new bit position srll rr2, $3 / shift back to remove bitpos andb rl3, $0xFE / eliminate lowest bit position exb rh2,rl2 / put segno back in place ldl rr4, SS|4(r15) / get address of word pointer ldl (rr4), rr2 / and save it back ret un