X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=blobdiff_plain;f=direct.c;h=b3f51f3c3b73356c638a0dc9b087cc20f67ab58d;hp=0c8dfb5b0fba563a5081a800c4cf64df83bb57f1;hb=4205233c8397c581b4d27ab36ab81ec896ef3dd0;hpb=412fe3614e2d9ea6bf35ebb5b335c1adb79b5c39

diff --git a/direct.c b/direct.c
index 0c8dfb5..b3f51f3 100644
--- a/direct.c
+++ b/direct.c
@@ -1,7 +1,7 @@
 //
 // 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
 //
@@ -51,6 +51,7 @@ int d_abs(void);
 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);
@@ -153,6 +154,7 @@ int (*dirtab[])() = {
 	d_nofpu,			// 65 nofpu
 	d_opt,				// 66 .opt
 	d_objproc,			// 67 .objproc
+	d_dsm,				// 68 .dsm
 };
 
 
@@ -1075,9 +1077,9 @@ int d_ds(WORD siz)
 
 	// 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
@@ -1094,7 +1096,7 @@ int d_ds(WORD siz)
 
 		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
@@ -1123,7 +1125,52 @@ int d_ds(WORD siz)
 	}
 
 	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
 }