X-Git-Url: http://git.subgeniuskitty.com/vvhitespace/.git/blobdiff_plain/0425a4c688d837e65ccbece82a8987ac41dcee3f..b6bea2cfd080c66a11074dd47484711482a2907a:/stdlib/README.md diff --git a/stdlib/README.md b/stdlib/README.md index 00d0fb5..eb92964 100644 --- a/stdlib/README.md +++ b/stdlib/README.md @@ -2,7 +2,8 @@ This folder contains a library of useful functions written in VVhitespace. Standard include guards are used with `cpp` to include the stdlib in user -programs. For an example, see `examples/hello-stdlib`. +programs. For an example, see `examples/hello-stdlib`. This also means +`cpp` syntax must be respected. # Reservations # @@ -12,16 +13,16 @@ following reservations: ## Label ## 00000000 0xxxxxxx - reserved for stdlib function entry points - 00000000 1xxxxxxx - unassigned + 00000000 1xxxxxxx - available for use in user programs 0xxxxxxx xxxxxxxx - reserved for private use by stdlib 1xxxxxxx xxxxxxxx - available for use in user programs ## Heap and Pointers ## The first 16 heap addresses (`0-15`) are reserved when using the stdlib. -Within that reservation, heap[0] is used by `random` and heap[15] is used -by `spewreg`. The remaining 14 locations, heap[1]-heap[14] are used as -general-purpose registers. +Within that reservation, heap[0] is used by `random` and the block +heap[1]-heap[15] by the stack rotation subroutines which time-share +pseudo-registers between the various stdlib subroutines. By convention, functions which return a pointer will use the address `0` to represent a `NULL` pointer. @@ -32,13 +33,16 @@ The following labels are entry points to stdlib functions. Read the header comment for each function to learn the call and return stack. 000xxx - reserved - 001xxx - print functions - 1000 ----- print string from stack (stdio.pvvs) - 1001 ----- print string from heap (stdio.pvvs) - 1010 ----- print number from stack (stdio.pvvs) + 001xxx - core functions + 1000 ----- printf (stdio.pvvs) + 1001 ----- print number from stack (stdio.pvvs) + 1010 ----- stackrotate (stack.pvvs) + 1011 ----- stackrotatereverse (stack.pvvs) + 1100 ----- deepdup (stack.pvvs) 010xxx - math functions 10000 ----- random (math.pvvs) 10001 ----- absolute value (math.pvvs) + 10010 ----- greatest common divisor (math.pvvs) 011xxx - heap functions 11000 ----- memset (heap.pvvs) 11001 ----- memcpy (heap.pvvs) @@ -50,22 +54,48 @@ header comment for each function to learn the call and return stack. 11111 ----- spew (heap.pvvs) 100xxx - string functions 100000 ----- strlen (string.pvvs) - 101xxx - unassigned + 100001 ----- isdigit (string.pvvs) + 101xxx - logic functions + 101000 ----- not (logic.pvvs) + 101001 ----- and (logic.pvvs) + 101010 ----- or (logic.pvvs) + 101011 ----- xor (logic.pvvs) + 101100 ----- rshift (logic.pvvs) + 101101 ----- lshift (logic.pvvs) 110xxx - conversion functions + 110000 ----- atoi (convert.pvvs) 111xxx - debug functions 111000 ----- dump heap (debug.pvvs) 111001 ----- dump stack (debug.pvvs) + 111010 ----- print sign (debug.pvvs) + 111011 ----- print magnitude (debug.pvvs) + 111100 ----- print string (debug.pvvs) + 111101 ----- print signed number (debug.pvvs) 1xxxxxx - reserved for less common entry points - 1000000 ----- slurp registers (heap.pvvs) - 1000001 ----- spew registers (heap.pvvs) + 1000000 ----- lowbitand (logic.pvvs) + 1000001 ----- 1000010 ----- print sign of number (stdio.pvvs) 1000011 ----- print magnitude of number (stdio.pvvs) + 1000100 ----- print string from stack (stdio.pvvs) + 1000101 ----- print string from heap (stdio.pvvs) # Misc # -By convention, each public stdlib label will have 8 bits of -private label space associated with it, formed as follows: +## Private Label Space ## + +By convention, each public stdlib label will have 8 bits of private label space +associated with it, formed as follows: 00001000 xxxxxxxx - for use by 1000 00001001 xxxxxxxx - for use by 1001 ...etc + +## Extending Heap Reservation ## + +By default, the stdlib uses the first 16 heap addresses. All heap access (other +than heap[0] as a seed) occurs through `stackrotate` and `stackrotatereverse`. +Edit these functions to increase the stdlib's heap reservation. + +The remainder of the stdlib is written to automatically use the new allocation. +Functions like `printf`, for example, allow more substitutions when the heap +allocation is increased.