src/compiler/codegen.lisp

   1 ;;;; the implementation-independent parts of the code generator. We use
   2 ;;;; functions and information provided by the VM definition to convert
   3 ;;;; IR2 into assembly code. After emitting code, we finish the
   4 ;;;; assembly and then do the post-assembly phase.
   5
   6 ;;;; This software is part of the SBCL system. See the README file for
   7 ;;;; more information.
   8 ;;;;
   9 ;;;; This software is derived from the CMU CL system, which was
  10 ;;;; written at Carnegie Mellon University and released into the
  11 ;;;; public domain. The software is in the public domain and is
  12 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  13 ;;;; files for more information.
  14
  15 (in-package "SB!C")
  16 \f
  17 ;;;; utilities used during code generation
  18
  19 ;;; the number of bytes used by the code object header
  20 (defun component-header-length (&optional
  21                                 (component *component-being-compiled*))
  22   (let* ((2comp (component-info component))
  23          (constants (ir2-component-constants 2comp))
  24          (num-consts (length constants)))
  25     (ash (logandc2 (1+ num-consts) 1) sb!vm:word-shift)))
  26
  27 ;;; the size of the NAME'd SB in the currently compiled component.
  28 ;;; This is useful mainly for finding the size for allocating stack
  29 ;;; frames.
  30 (defun sb-allocated-size (name)
  31   (finite-sb-current-size (sb-or-lose name)))
  32
  33 ;;; the TN that is used to hold the number stack frame-pointer in
  34 ;;; VOP's function, or NIL if no number stack frame was allocated
  35 (defun current-nfp-tn (vop)
  36   (unless (zerop (sb-allocated-size 'non-descriptor-stack))
  37     (let ((block (ir2-block-block (vop-block vop))))
  38     (when (ir2-physenv-number-stack-p
  39            (physenv-info
  40             (block-physenv block)))
  41       (ir2-component-nfp (component-info (block-component block)))))))
  42
  43 ;;; the TN that is used to hold the number stack frame-pointer in the
  44 ;;; function designated by 2ENV, or NIL if no number stack frame was
  45 ;;; allocated
  46 (defun callee-nfp-tn (2env)
  47   (unless (zerop (sb-allocated-size 'non-descriptor-stack))
  48     (when (ir2-physenv-number-stack-p 2env)
  49       (ir2-component-nfp (component-info *component-being-compiled*)))))
  50
  51 ;;; the TN used for passing the return PC in a local call to the function
  52 ;;; designated by 2ENV
  53 (defun callee-return-pc-tn (2env)
  54   (ir2-physenv-return-pc-pass 2env))
  55 \f
  56 ;;;; specials used during code generation
  57
  58 (defvar *trace-table-info*)
  59 (defvar *code-segment* nil)
  60 (defvar *elsewhere* nil)
  61 (defvar *elsewhere-label* nil)
  62 \f
  63 ;;;; noise to emit an instruction trace
  64
  65 (defvar *prev-segment*)
  66 (defvar *prev-vop*)
  67
  68 (defun trace-instruction (segment vop inst args)
  69   (let ((*standard-output* *compiler-trace-output*))
  70     (unless (eq *prev-segment* segment)
  71       (format t "in the ~A segment:~%" (sb!assem:segment-name segment))
  72       (setf *prev-segment* segment))
  73     (unless (eq *prev-vop* vop)
  74       (when vop
  75         (format t "~%VOP ")
  76         (if (vop-p vop)
  77             (print-vop vop)
  78             (format *compiler-trace-output* "~S~%" vop)))
  79       (terpri)
  80       (setf *prev-vop* vop))
  81     (case inst
  82       (:label
  83        (format t "~A:~%" args))
  84       (:align
  85        (format t "~0,8T.align~0,8T~A~%" args))
  86       (t
  87        (format t "~0,8T~A~@[~0,8T~{~A~^, ~}~]~%" inst args))))
  88   (values))
  89 \f
  90 ;;;; GENERATE-CODE and support routines
  91
  92 ;;; standard defaults for slots of SEGMENT objects
  93 (defun default-segment-run-scheduler ()
  94   (and *assembly-optimize*
  95         (policy (lambda-bind
  96                  (block-home-lambda
  97                   (block-next (component-head *component-being-compiled*))))
  98                 (or (> speed compilation-speed) (> space compilation-speed)))))
  99 (defun default-segment-inst-hook ()
 100   (and *compiler-trace-output*
 101        #'trace-instruction))
 102
 103 (defun init-assembler ()
 104   (setf *code-segment*
 105         (sb!assem:make-segment :name "regular"
 106                                :run-scheduler (default-segment-run-scheduler)
 107                                :inst-hook (default-segment-inst-hook)))
 108   #!+sb-dyncount
 109   (setf (sb!assem:segment-collect-dynamic-statistics *code-segment*)
 110         *collect-dynamic-statistics*)
 111   (setf *elsewhere*
 112         (sb!assem:make-segment :name "elsewhere"
 113                                :run-scheduler (default-segment-run-scheduler)
 114                                :inst-hook (default-segment-inst-hook)))
 115   (values))
 116
 117 (defun generate-code (component)
 118   (when *compiler-trace-output*
 119     (format *compiler-trace-output*
 120             "~|~%assembly code for ~S~2%"
 121             component))
 122   (let ((prev-env nil)
 123         (*trace-table-info* nil)
 124         (*prev-segment* nil)
 125         (*prev-vop* nil)
 126         (*fixup-notes* nil))
 127     (let ((label (sb!assem:gen-label)))
 128       (setf *elsewhere-label* label)
 129       (sb!assem:assemble (*elsewhere*)
 130         (sb!assem:emit-label label)))
 131     (do-ir2-blocks (block component)
 132       (let ((1block (ir2-block-block block)))
 133         (when (and (eq (block-info 1block) block)
 134                    (block-start 1block))
 135           (sb!assem:assemble (*code-segment*)
 136             (sb!assem:emit-label (block-label 1block)))
 137           (let ((env (block-physenv 1block)))
 138             (unless (eq env prev-env)
 139               (let ((lab (gen-label)))
 140                 (setf (ir2-physenv-elsewhere-start (physenv-info env))
 141                       lab)
 142                 (emit-label-elsewhere lab))
 143               (setq prev-env env)))))
 144       (do ((vop (ir2-block-start-vop block) (vop-next vop)))
 145           ((null vop))
 146         (let ((gen (vop-info-generator-function (vop-info vop))))
 147           (if gen
 148             (funcall gen vop)
 149             (format t
 150                     "missing generator for ~S~%"
 151                     (template-name (vop-info vop)))))))
 152     (sb!assem:append-segment *code-segment* *elsewhere*)
 153     (setf *elsewhere* nil)
 154     (values (sb!assem:finalize-segment *code-segment*)
 155             (nreverse *trace-table-info*)
 156             *fixup-notes*)))
 157
 158 (defun emit-label-elsewhere (label)
 159   (sb!assem:assemble (*elsewhere*)
 160     (sb!assem:emit-label label)))
 161
 162 (defun label-elsewhere-p (label-or-posn)
 163   (<= (label-position *elsewhere-label*)
 164       (etypecase label-or-posn
 165         (label
 166          (label-position label-or-posn))
 167         (index
 168          label-or-posn))))