Ported random to lisp.

PRIMITIVES.md

@@ -162,8 +162,6 @@ added to them too.
     * Print the specified integer.
   * `printstr`
     * Print the given string.
-  * `random`
-    * Return a random integer between zero and N.
   * `split`
     * Split a string by the given character, and return a list of "(before after)".  Return nil if the character isn't found.
   * `split-all`
@@ -301,6 +299,8 @@ The implementation of these primitives can be found in the file [stdlib.slisp](s
   * Print "anything".
 * `println`
   * Print "anything" by invoking `print`, then outputting a newline.
+* `random`
+  * Return a random integer between zero and N-1.
 * `range`
   * Return a list of numbers between the given start/end, using the specified step-size.
 * `read-line`

compiler/template.tmpl

@@ -87,7 +87,6 @@ SYS_wait4         equ  61
 SYS_getdents64    equ 217
 SYS_clock_gettime equ 228
 SYS_prlimit64     equ 302
-SYS_getrandom     equ 318
 
 ;; (entries)
 O_RDONLY        equ 0
@@ -2395,34 +2394,6 @@ FUNC fn_sys_putc
     ret
 
 
-
-;; Generate a random number 0-N
-FUNC fn_sys_random
-    mov rbx, rdi             ; type-check arg1
-    GET_TAG_BITS rbx
-    cmp rbx, TAG_ID_INTEGER
-    jne type_error
-
-    UNTAG_REG rdi
-    push rdi                        ; push the limit
-
-    mov rax, SYS_getrandom
-    lea rdi, [random_buffer]   ; random value location
-    mov rsi, 4                 ; number of bytes
-    xor rdx, rdx               ; flags = 0
-    syscall
-
-    pop rcx                    ; limit the value
-    mov eax, [random_buffer]
-    xor edx, edx
-    div ecx
-
-    mov rax, rdx
-    TAG_INTEGER_REG rax
-    ret
-
-
-
 ;; system helper
 FUNC fn_sys_run
     mov rbx, rdi               ; type check

inception.lisp

@@ -330,7 +330,6 @@
   (register-builtin "sys_packages" (lambda (args) (sys_packages )))
   (register-builtin "sys_plus" (lambda (args) (sys_plus (car args) (cadr args))))
   (register-builtin "sys_putc" (lambda (args) (sys_putc (car args))))
-  (register-builtin "sys_random" (lambda (args) (sys_random (car args))))
   (register-builtin "sys_run" (lambda (args) (sys_run (car args) (cadr args))))
   (register-builtin "sys_split" (lambda (args) (sys_split (car args) (cadr args))))
   (register-builtin "sys_sqrt" (lambda (args) (sys_sqrt (car args))))

stdlib.slisp

@@ -174,10 +174,6 @@ It is assumed the filehandle came from fopen, but nil is also accepted."
   "Write the single specified character to STDOUT."
   (sys_putc c))
 
-(defun random (n)
-  "Return a random number 0-N."
-  (sys_random n))
-
 ;; NOP: This is a special form in our compiler
 ;; However if we make this then we can pretend
 ;; we load packages.
@@ -1035,6 +1031,15 @@ Uses (environment) to get all environmental variables, and filters."
             (getenv-loop name (cdr xs))))
       nil))
 
+
+(defconst SYS_getrandom 318)
+
+(defun random (n)
+  "Return a random number between zero and N-1, (both zero and N-1 are valid return values.)"
+  (let ((buf "skx/slisp"))
+    (syscall SYS_getrandom buf 8)
+    (% (abs (u64 buf 0)) n)))
+
 (defun read-line ()
   "Read and return a line of text from STDIN"
   (let ((text "")