2 files changed, 28 insertions(+), 34 deletions(-)

M fs/doc/hal.txt
M fs/xcomp/i386/kernel.fs

@@ 44,6 44,21 @@ few specialized A-related words.
 The "High HAL" is implemented in the assemblers and complete the API. The API
 of each half is described in the sections below.
 
+### Low HAL and number banks
+
+In addition to having access only to a subset of the High HAL, the Low HAL is
+also limited in the way it handles its operators.
+
+The High HAL, to be able to support arguments to +) and m) in the full 32-bit
+range while also keeping true to its promise that each operand only use one PS
+slot, uses what we call a "rolling number bank" where those parameters go and
+which allows up to 8 operators to "live" at once (that is, exist without being
+consumed by an operation). This makes the HAL very macro-able.
+
+The Low HAL has only a single slot in its number bank. This means that a +) or
+m) has to be consumed before another is created or else those parameters will be
+mixed up.
+
 ### Register allocation
 
 The HAL has 4 virtual registers: W, A, PSP, RSP. Each architecture implementing

@@ 28,9 28,10 @@
 \ Constants and labels
 0 to realmode
 : values ( n -- ) for 0 value next ;
-20 values lblmainalias lblbootptr lblnextword lblcurword lblnextmeta lblret
+21 values lblmainalias lblbootptr lblnextword lblcurword lblnextmeta lblret
           lblsysdict lblparsec lblparseh lblparseud lblerrmsg lblhere lbl[rcnt]
           lblwriterange lblfind lblcompiling lblidt lblmod lblrelwr lblcallwr
+          lblhbank
 $8000 const HERESTART
 $500 to binstart
 $2000 const STACKSZ


@@ 107,32 108,6 @@ xcode abort
   0 jmp,
 
 \ HAL operands
-pc to L1 HBANKCNT CELLSZ * allot
-pc to L2 0 ,
-xcode hbank' ( idx -- a )
-  ax $0f i) and,
-  ax 2 i) shl,
-  ax L1 i) add,
-  ret,
-
-xcode @) ( operand -- n )
-  ax 20 i) shr,
-  wcall, hbank'
-  ax ax 0 d) mov,
-  ret,
-
-xcode hbank! ( operand n -- operand )
-  cx ax mov,      \ cx=n
-  ax L2 m) mov,
-  L2 m) inc,
-  bx ax mov,      \ bx=idx
-  wcall, hbank'    \ ax=a
-  ax 0 d) cx mov,
-  xdrop,          \ ax=operand
-  bx 20 i) shl,
-  ax bx or,
-  ret,
-
 $100 xconst W)
 $107 xconst A)
 $106 xconst PSP)


@@ 140,16 115,18 @@ $104 xconst RSP)
 $4 xconst Z)
 $5 xconst NZ)
 
+pc to lblhbank 0 ,
 xcode m) ( a -- operand )
-  xgrow,
-  si 0 d) $105 i) mov,
-  wjmp, hbank!
+  lblhbank m) ax mov,
+  ax $105 i) mov,
+  ret,
 
 pc to L1 xdrop, ret,
 xcode +) ( operand n -- operand )
   ax ax test, L1 abs>rel jz,
-  si 0 d) $40 i) or, \ disp8 mode
-  wjmp, hbank!
+  lblhbank m) ax mov, xdrop,
+  ax $40 i) or, \ disp8 mode
+  ret,
 
 xcode 8b) ( operand -- operand )
   ax $fffffeff i) and, ret,


@@ 222,10 199,12 @@ xcode W<>A, ( n -- ) \ di ax xchg,
   $97 i) cwrite, ret,
 
 pc to L3 \ ax=opmod disp32
-  wcall, @) ax dwrite,
+  ax lblhbank m) mov,
+  ax dwrite,
   xdrop, ret,
 pc to L2 \ ax=opmod disp8
-  wcall, @) al cwrite,
+  ax lblhbank m) mov,
+  al cwrite,
   xdrop, ret,
 pc to L1 \ ax=opmod
   ax $20000 i) test, forward8 jz, $66 i) cwrite, forward! \ 16b?