//
// RMAC - Reboot's Macro Assembler for all Atari computers
// DIRECT.C - Directive Handling
-// Copyright (C) 199x Landon Dyer, 2011-2019 Reboot and Friends
+// Copyright (C) 199x Landon Dyer, 2011-2020 Reboot and Friends
// RMAC derived from MADMAC v1.07 Written by Landon Dyer, 1986
// Source utilised with the kind permission of Landon Dyer
//
int d_comm(void);
int d_dc(WORD);
int d_ds(WORD);
+int d_dsm(WORD);
int d_dcb(WORD);
int d_globl(void);
int d_gpu(void);
d_nofpu, // 65 nofpu
d_opt, // 66 .opt
d_objproc, // 67 .objproc
+ d_dsm, // 68 .dsm
};
// Check to see if the value being passed in is negative (who the hell does
// that?--nobody does; it's the code gremlins, or rum, what does it)
- // N.B.: Since 'eval' is of type uint32_t, if it goes negative, it will
+ // N.B.: Since 'eval' is of type uint64_t, if it goes negative, it will
// have its high bit set.
- if (eval & 0x80000000)
+ if (eval & 0x8000000000000000)
return error("negative sizes not allowed in DS");
// In non-TDB section (BSS, ABS and M6502) just advance the location
just_bss = 1; // No data deposited (8-bit CPU mode)
}
- else if (cursect == M56001P || cursect == M56001X || cursect == M56001Y || cursect == M56001L)
+ else if (cursect & M56KPXYL)
{
// Change segment instead of marking blanks.
// Only mark segments we actually wrote something
}
ErrorIfNotAtEOL();
- return 0;
+ return OK;
+}
+
+
+//
+// dsm[.siz] expression
+// Define modulo storage
+// Quoting the Motorola assembler manual:
+// "The DSM directive reserves a block of memory the length of which in words is equal to
+// the value of <expression>.If the runtime location counter is not zero, this directive first
+// advances the runtime location counter to a base address that is a multiple of 2k, where
+// 2k >= <expression>."
+// The kicker of course is written a few sentences after:
+// "<label>, if present, will be assigned the value of the runtime location counter after a valid
+// base address has been established."
+//
+int d_dsm(WORD siz)
+{
+ TOKEN * tok_current = tok; // Keep track of where tok was when we entered this procedure
+ uint64_t eval;
+
+ if (abs_expr(&eval) != OK)
+ return 0;
+
+ // Round up to the next highest power of 2
+ // Nicked from https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
+ eval--;
+ eval |= eval >> 1;
+ eval |= eval >> 2;
+ eval |= eval >> 4;
+ eval |= eval >> 8;
+ eval |= eval >> 16;
+
+ int units_to_skip;
+ units_to_skip = eval + 1 - sloc;
+ sloc += units_to_skip; // Bump up sloc - TODO: check if this goes over the RAM limits?
+
+ // If a label has been defined in the same line as dsm, its value also needs to be adjusted
+ if (label_defined)
+ {
+ SYM * label = lookup(label_defined, LABEL, 0);
+ label->svalue += units_to_skip;
+ }
+
+ tok = tok_current; // Rewind tok back to where it was
+ return d_ds(siz); // And let d_ds take over from here
}