MMIX 2009 — Release 2011-08-31.

README

@@ -73,7 +73,7 @@ pages to the front (those pages appear at the end). Read the introductory
 parts of those documents, and please report any errors you find to
 knuth-bug@cs.stanford.edu. If your system is unable to create those documents
 for some reason, go to
-   http://www-cs-faculty.stanford.edu/~knuth/mmix.html
+   http://www-cs-faculty.stanford.edu/~knuth/mmix-news.html
 and download the compressed PostScript files from there.
 Say "make clean" when you've got hardcopy.
 

cp.mms

@@ -12,4 +12,4 @@ Main LDA  $255,ArgR
      LDA  $255,ArgW
      TRAP 0,Fwrite,StdOut
      JMP  Main
-Done TRAP 0,0,Halt
+Done TRAP 0,Halt,0

mmix-arith.w

@@ -69,8 +69,6 @@ octa zero_octa; /* |zero_octa.h=zero_octa.l=0| */
 octa neg_one={-1,-1}; /* |neg_one.h=neg_one.l=-1| */
 octa inf_octa={0x7ff00000,0}; /* floating point $+\infty$ */
 octa standard_NaN={0x7ff80000,0}; /* floating point NaN(.5) */
-octa aux; /* auxiliary output of a subroutine */
-bool overflow; /* set by certain subroutines for signed arithmetic */
 
 @ It's easy to add and subtract octabytes, if we aren't terribly
 worried about speed.
@@ -172,8 +170,8 @@ octa omult(y,z)
 }
 
 @ @<Glob...@>=
-extern octa aux; /* secondary output of subroutines with multiple outputs */
-extern bool overflow;
+octa aux; /* secondary output of subroutines with multiple outputs */
+bool overflow; /* set by certain subroutines for signed arithmetic */
 
 @ @<Unpack the mult...@>=
 u[3]=y.h>>16, u[2]=y.h&0xffff, u[1]= y.l>>16, u[0]=y.l&0xffff;

mmix-doc.w

@@ -2990,7 +2990,7 @@ for instructions, or to 2 if the key was present in the TC for data,
 or to~3 if the key was present in both. This instruction is for the
 operating system only. (Changes to the TC are not immediate; so \.{SYNC}
 and/or \.{SYNCD} ought to be done when appropriate, as discussed in
-{\sc MMIX-PIPE}.)
+{\mc MMIX-PIPE}.)
 
 @ We mentioned earlier that
 cheap versions of\/ \MMIX\ might calculate the physical addresses with

mmix-mem.w

@@ -29,8 +29,8 @@ static char buf[20];
 static char *kind[]={"byte","wyde","tetra","octa"};
 extern octa shift_left @,@,@[ARGS((octa y,int s))@];
   /* $y\LL s$, $0\le s\le64$ */
-extern octa shift_right @,@,@[ARGS((octa y,int s,int uns))@];
-  /* $y\GG s$, signed if |!uns| */
+extern octa shift_right @,@,@[ARGS((octa y,int s,int u))@];
+  /* $y\GG s$, signed if |!u| */
 
 @ If the |interactive_read_bit| of the |verbose| control is set,
 the user is supposed to supply values dynamically. Otherwise

mmix-pipe.w

@@ -355,8 +355,8 @@ extern octa oandn @,@,@[ARGS((octa y,octa z))@];
   /* $y\land \bar z$ */
 extern octa shift_left @,@,@[ARGS((octa y,int s))@];
   /* $y\LL s$, $0\le s\le64$ */
-extern octa shift_right @,@,@[ARGS((octa y,int s,int uns))@];
-  /* $y\GG s$, signed if |!uns| */
+extern octa shift_right @,@,@[ARGS((octa y,int s,int u))@];
+  /* $y\GG s$, signed if |!u| */
 extern octa omult @,@,@[ARGS((octa y,octa z))@];
   /* unsigned $(|aux|,x)=y\times z$ */
 extern octa signed_omult @,@,@[ARGS((octa y,octa z))@];
@@ -5827,7 +5827,8 @@ already present.)
 
 @<Cases for stage 1 execution@>=
 case noop:@+if (data->interrupt&F_BIT) goto emulate_virt;
-case jmp: case pushj: case incrl: case unsave: goto fin_ex;
+case incrl: case unsave: goto fin_ex;
+case jmp: case pushj: data->go.o=data->z.o; goto fin_ex;
 case sav:@+if (!(data->mem_x)) goto fin_ex;
 case incgamma: case save: data->i=st; goto switch1;
 case decgamma: case unsav: data->i=ld; goto switch1;

mmix-sim.w

@@ -606,8 +606,8 @@ extern octa oand @,@,@[ARGS((octa y,octa z))@];
   /* $y\land z$ */
 extern octa shift_left @,@,@[ARGS((octa y,int s))@];
   /* $y\LL s$, $0\le s\le64$ */
-extern octa shift_right @,@,@[ARGS((octa y,int s,int uns))@];
-  /* $y\GG s$, signed if |!uns| */
+extern octa shift_right @,@,@[ARGS((octa y,int s,int u))@];
+  /* $y\GG s$, signed if |!u| */
 extern octa omult @,@,@[ARGS((octa y,octa z))@];
   /* unsigned $(|aux|,x)=y\times z$ */
 extern octa signed_omult @,@,@[ARGS((octa y,octa z))@];
@@ -2197,7 +2197,7 @@ case GET:@+if (yy!=0 || zz>=32) goto illegal_inst;
 case PUT: case PUTI:@+ if (yy!=0 || xx>=32) goto illegal_inst;
   strcpy(rhs,"%z = %#z");
   if (xx>=8) {
-    if (xx<=11) goto illegal_inst; /* can't change rC, rN, rO, rS */
+    if (xx<=11 && xx!=8) goto illegal_inst; /* can't change rN, rO, rS */
     if (xx<=18) goto privileged_inst;
     if (xx==rA) @<Get ready to update rA@>@;
     else if (xx==rL) @<Set $L=z=\min(z,L)$@>@;

mmixal.w

@@ -276,15 +276,15 @@ stand respectively for
 $(x\times y)\bmod2^{64}$ (multiplication), $\lfloor x/y\rfloor$ (division),
 $\lfloor2^{64}x/y\rfloor$ (fractional division), $x\bmod y$ (remainder),
 $(x\times2^y)\bmod2^{64}$ (left~shift), $\lfloor x/2^y\rfloor$
-(right shift), and $x\land y$ (bitwise and) on unsigned octabytes.
+(right shift), and $x\mathbin{\char`\&}y$ (bitwise and) on unsigned octabytes.
 Division is legal only if $y>0$; fractional division is
 legal only if $x<y$. None of the strong binary operations can be
 applied to register numbers.
 
 The weak binary operations \.{x+y}, \.{x-y}, \.{x\char'174 y}, and
 \.{x\^y} stand respectively for $(x+y)\bmod2^{64}$ (addition),
-$(x-y)\bmod2^{64}$ (subtraction),
-$x\lor y$ (bitwise or), and $x\oplus y$ (bitwise exclusive-or) on
+$(x-y)\bmod2^{64}$ (subtraction), $x\mathbin{\mkern1mu\vert\mkern1mu}y$
+(bitwise or), and $x\oplus y$ (bitwise exclusive-or) on
 unsigned octabytes. These operations can be applied to register
 numbers only in four contexts: $\<register>+\<pure>$, $\<pure>+\<register>$,
 $\<register>-\<pure>$
@@ -969,8 +969,8 @@ extern octa oand @,@,@[ARGS((octa y,octa z))@];
   /* $y\land z$ */
 extern octa shift_left @,@,@[ARGS((octa y,int s))@];
   /* $y\LL s$, $0\le s\le64$ */
-extern octa shift_right @,@,@[ARGS((octa y,int s,int uns))@];
-  /* $y\GG s$, signed if |!uns| */
+extern octa shift_right @,@,@[ARGS((octa y,int s,int u))@];
+  /* $y\GG s$, signed if |!u| */
 extern octa omult @,@,@[ARGS((octa y,octa z))@];
   /* unsigned $(|aux|,x)=y\times z$ */
 extern octa odiv @,@,@[ARGS((octa x,octa y,octa z))@];
@@ -1080,7 +1080,7 @@ as a comment by the assembler.
 @<Check for a line directive@>=
 {
   for (p=buffer+1;isspace(*p);p++);
-  for (j=*p++-'0';isdigit(*p);p++) j=10*j+*p-'0';
+  for (j=0;isdigit(*p);p++) j=10*j+*p-'0';
   for (;isspace(*p);p++);
   if (*p=='\"') {
     if (!filename[filename_count]) {
@@ -1089,11 +1089,17 @@ as a comment by the assembler.
         panic("Capacity exceeded: Out of filename memory");
 @.Capacity exceeded...@>
     }
-    for (p++,q=filename[filename_count];*p && *p!='\"';p++,q++) *q=*p;
+    for (p++,k=0;*p && *p!='\"' && k<FILENAME_MAX; p++,k++)
+      filename[filename_count][k]=*p;
+    if (k==FILENAME_MAX) panic("Capacity exceeded: File name too long");
     if (*p=='\"' && *(p-1)!='\"') { /* yes, it's a line directive */
-      *q='\0';
+      filename[filename_count][k]='\0';
       for (k=0;strcmp(filename[k],filename[filename_count])!=0;k++);
-      if (k==filename_count) filename_count++;
+      if (k==filename_count) {
+        if (filename_count==256)
+          panic("Capacity exceeded: More than 256 file names");
+        filename_count++;
+      }
       cur_file=k;
       line_no=j-1;
     }
@@ -2448,7 +2454,7 @@ switch(*p++) {
  case '%': rt_op=mod;@+break;
  case '<': rt_op=shl;@+goto sh_check;
  case '>': rt_op=shr;
-  sh_check:@+if (*p++==*(p-1)) break;
+  sh_check: p++;@+if (*(p-1)==*(p-2)) break;
   derr("syntax error at `%c'",*(p-2));
 @.syntax error...@>
  case '&': rt_op=and;@+break;
@@ -2557,7 +2563,7 @@ case shl: case shr: binary_check("compute a bitwise shift of");
  if (top_val.equiv.h || top_val.equiv.l>63) next_val.equiv=zero_octa;
  else if (op_stack[op_ptr]==shl)
    next_val.equiv=shift_left(next_val.equiv,top_val.equiv.l);
- else next_val.equiv=shift_right(next_val.equiv,top_val.equiv.l,true);
+ else next_val.equiv=shift_right(next_val.equiv,top_val.equiv.l,1);
  goto fin_bin;
 case and: binary_check("compute bitwise and of");
  next_val.equiv.h&=top_val.equiv.h, next_val.equiv.l&=top_val.equiv.l;
@@ -2813,7 +2819,11 @@ case 2:@+if (!(op_bits&two_arg_bit))
     if (op_bits&one_arg_bit)
       derr("opcode `%s' must not have two operands",op_field)@;
     else derr("opcode `%s' must have more than two operands",op_field);
+  if ((op_bits&(three_arg_bit+mem_bit))==three_arg_bit) goto make_two_three;
   @<Do a two-operand operation@>;
+make_two_three: val_stack[2]=val_stack[1], val_ptr=3;
+  val_stack[1].equiv=zero_octa, val_stack[1].link=NULL,
+    val_stack[1].status=pure; /* insert \.0 as the second operand */
 case 3:@+if (!(op_bits&three_arg_bit))
     derr("opcode `%s' must not have three operands",op_field);
   @<Do a three-operand operation@>;