src/compiler/arm/pred.lisp

   1 ;;;; predicate VOPs for the ARM VM
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!VM")
  13
  14 \f
  15 ;;;; The Branch VOP.
  16
  17 ;;; The unconditional branch, emitted when we can't drop through to the desired
  18 ;;; destination.  Dest is the continuation we transfer control to.
  19 ;;;
  20 (define-vop (branch)
  21   (:info dest)
  22   (:generator 5
  23     (inst b dest)))
  24
  25 \f
  26 ;;;; Generic conditional VOPs
  27
  28 ;;; The generic conditional branch, emitted immediately after test
  29 ;;; VOPs that only set flags.
  30
  31 ;;; FIXME: Unlike the PPC (from whence this was cribbed), ARM actually
  32 ;;; has flags.  We should take advantage of them here.
  33
  34 (define-vop (branch-if)
  35   (:info dest flags not-p)
  36   (:generator 0
  37     (flet ((negate-condition (name)
  38              (let ((code (logxor 1 (conditional-opcode name))))
  39                (aref *condition-name-vec* code))))
  40       (aver (null (rest flags)))
  41       (inst b
  42             (if not-p
  43                 (negate-condition (first flags))
  44                 (first flags))
  45             dest))))
  46
  47 (defun convert-conditional-move-p (node dst-tn x-tn y-tn)
  48   (declare (ignore node dst-tn x-tn y-tn))
  49   nil)
  50
  51 \f
  52 ;;;; Conditional VOPs:
  53
  54 (define-vop (if-eq)
  55   (:args (x :scs (any-reg descriptor-reg null))
  56          (y :scs (any-reg descriptor-reg null)))
  57   (:conditional)
  58   (:info target not-p)
  59   (:policy :fast-safe)
  60   (:translate eq)
  61   (:generator 3
  62     (inst cmp
  63           (sc-case x
  64             (null null-tn)  ;; FIXME: should it really be like that?
  65             (t x))
  66           (sc-case y
  67             (null null-tn)
  68             (t y)))
  69     (inst b (if not-p :ne :eq) target)))