X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fhppa%2Fcall.lisp;h=be8e880b509b3c61a602bce6390878acc765ffc2;hb=69e6aef5e6fb3bd682c7a2cbf774034d2ea58ee8;hp=45bc167ee57fdedc75b51c14585693fdcc5ce2b2;hpb=ca2d58fc8ab92eb5ab50ed4428af4b39866bd5f4;p=sbcl.git diff --git a/src/compiler/hppa/call.lisp b/src/compiler/hppa/call.lisp index 45bc167..be8e880 100644 --- a/src/compiler/hppa/call.lisp +++ b/src/compiler/hppa/call.lisp @@ -1,4 +1,4 @@ -;;;; the VM definition of function call for the HPPA +;;;; the VM definition of function call for HPPA ;;;; This software is part of the SBCL system. See the README file for ;;;; more information. @@ -15,7 +15,7 @@ ;;; Return a wired TN describing the N'th full call argument passing ;;; location. -(!def-vm-support-routine standard-arg-location (n) +(defun standard-arg-location (n) (declare (type unsigned-byte n)) (if (< n register-arg-count) (make-wired-tn *backend-t-primitive-type* @@ -29,7 +29,7 @@ ;;; true, then use the standard (full call) location, otherwise use any legal ;;; location. Even in the non-standard case, this may be restricted by a ;;; desire to use a subroutine call instruction. -(!def-vm-support-routine make-return-pc-passing-location (standard) +(defun make-return-pc-passing-location (standard) (if standard (make-wired-tn *backend-t-primitive-type* register-arg-scn lra-offset) (make-restricted-tn *backend-t-primitive-type* register-arg-scn))) @@ -39,7 +39,7 @@ ;;; standard convention, but is totally unrestricted in non-standard ;;; conventions, since we can always fetch it off of the stack using ;;; the arg pointer. -(!def-vm-support-routine make-old-fp-passing-location (standard) +(defun make-old-fp-passing-location (standard) (if standard (make-wired-tn *fixnum-primitive-type* immediate-arg-scn ocfp-offset) (make-normal-tn *fixnum-primitive-type*))) @@ -47,41 +47,41 @@ ;;; Make the TNs used to hold OLD-FP and RETURN-PC within the current ;;; function. We treat these specially so that the debugger can find ;;; them at a known location. -(!def-vm-support-routine make-old-fp-save-location (env) +(defun make-old-fp-save-location (env) (specify-save-tn (physenv-debug-live-tn (make-normal-tn *fixnum-primitive-type*) env) (make-wired-tn *fixnum-primitive-type* control-stack-arg-scn ocfp-save-offset))) -(!def-vm-support-routine make-return-pc-save-location (env) - (specify-save-tn - (physenv-debug-live-tn (make-normal-tn *backend-t-primitive-type*) env) - (make-wired-tn *backend-t-primitive-type* - control-stack-arg-scn - lra-save-offset))) + +(defun make-return-pc-save-location (env) + (let ((ptype *backend-t-primitive-type*)) + (specify-save-tn + (physenv-debug-live-tn (make-normal-tn ptype) env) + (make-wired-tn ptype control-stack-arg-scn lra-save-offset)))) ;;; Make a TN for the standard argument count passing location. We only ;;; need to make the standard location, since a count is never passed when we ;;; are using non-standard conventions. -(!def-vm-support-routine make-arg-count-location () +(defun make-arg-count-location () (make-wired-tn *fixnum-primitive-type* immediate-arg-scn nargs-offset)) ;;; Make a TN to hold the number-stack frame pointer. This is allocated ;;; once per component, and is component-live. -(!def-vm-support-routine make-nfp-tn () +(defun make-nfp-tn () (component-live-tn (make-wired-tn *fixnum-primitive-type* immediate-arg-scn nfp-offset))) -(!def-vm-support-routine make-stack-pointer-tn () +(defun make-stack-pointer-tn () (make-normal-tn *fixnum-primitive-type*)) -(!def-vm-support-routine make-number-stack-pointer-tn () +(defun make-number-stack-pointer-tn () (make-normal-tn *fixnum-primitive-type*)) ;;; Return a list of TNs that can be used to represent an unknown-values ;;; continuation within a function. -(!def-vm-support-routine make-unknown-values-locations () +(defun make-unknown-values-locations () (list (make-stack-pointer-tn) (make-normal-tn *fixnum-primitive-type*))) @@ -90,7 +90,7 @@ ;;; VM-dependent initialization of the IR2-COMPONENT structure. We push ;;; placeholder entries in the Constants to leave room for additional ;;; noise in the code object header. -(!def-vm-support-routine select-component-format (component) +(defun select-component-format (component) (declare (type component component)) (dotimes (i code-constants-offset) (vector-push-extend nil @@ -98,10 +98,12 @@ (values)) -;;;; Frame hackery: - +;;; bytes-needed-for-non-descriptor-stack-frame is the amount +;;; we grow or shrink the NSP/NFP stack. This stack is used +;;; by C-code so the convention (grow direction, grow size) +;;; is governed by the hpux+hppa ABI or linux+hppa ABI. ;;; Return the number of bytes needed for the current non-descriptor stack. -;;; We have to allocate multiples of 64 bytes. +;;; We have to allocate multiples of 64 bytes (defun bytes-needed-for-non-descriptor-stack-frame () (logandc2 (+ (* (sb-allocated-size 'non-descriptor-stack) n-word-bytes) 63) 63)) @@ -125,6 +127,24 @@ (inst addi (- (bytes-needed-for-non-descriptor-stack-frame)) nfp val))))) +;;; Accessing a slot from an earlier stack frame is definite hackery. +(define-vop (ancestor-frame-ref) + (:args (frame-pointer :scs (descriptor-reg)) + (variable-home-tn :load-if nil)) + (:results (value :scs (descriptor-reg any-reg))) + (:policy :fast-safe) + (:generator 4 + (aver (sc-is variable-home-tn control-stack)) + (loadw value frame-pointer (tn-offset variable-home-tn)))) +(define-vop (ancestor-frame-set) + (:args (frame-pointer :scs (descriptor-reg)) + (value :scs (descriptor-reg any-reg))) + (:results (variable-home-tn :load-if nil)) + (:policy :fast-safe) + (:generator 4 + (aver (sc-is variable-home-tn control-stack)) + (storew value frame-pointer (tn-offset variable-home-tn)))) + (define-vop (xep-allocate-frame) (:info start-lab copy-more-arg-follows) (:ignore copy-more-arg-follows) @@ -137,14 +157,17 @@ (trace-table-entry trace-table-fun-prologue) (emit-label start-lab) ;; Allocate function header. - (inst fun-header-word) + (inst simple-fun-header-word) (dotimes (i (1- simple-fun-code-offset)) (inst word 0)) ;; The start of the actual code. ;; Fix CODE, cause the function object was passed in. (let ((entry-point (gen-label))) (emit-label entry-point) - (inst compute-code-from-lip lip-tn entry-point temp code-tn)) + (inst compute-code-from-lip lip-tn entry-point temp code-tn) + ;; ### We should also save it on the stack so that the garbage + ;; collector won't forget about us if we call anyone else. + ) ;; Build our stack frames. (inst addi (* n-word-bytes (sb-allocated-size 'control-stack)) cfp-tn csp-tn) @@ -152,7 +175,7 @@ (when nfp (move nsp-tn nfp) (inst addi (bytes-needed-for-non-descriptor-stack-frame) - nsp-tn nsp-tn))) + nsp-tn nsp-tn))) (trace-table-entry trace-table-normal))) (define-vop (allocate-frame) @@ -160,13 +183,15 @@ (nfp :scs (any-reg))) (:info callee) (:generator 2 + (trace-table-entry trace-table-fun-prologue) (move csp-tn res) (inst addi (* n-word-bytes (sb-allocated-size 'control-stack)) csp-tn csp-tn) (when (ir2-physenv-number-stack-p callee) (move nsp-tn nfp) (inst addi (bytes-needed-for-non-descriptor-stack-frame) - nsp-tn nsp-tn)))) + nsp-tn nsp-tn)) + (trace-table-entry trace-table-normal))) ;;; Allocate a partial frame for passing stack arguments in a full call. Nargs ;;; is the number of arguments passed. If no stack arguments are passed, then @@ -181,6 +206,7 @@ (inst addi (* nargs n-word-bytes) csp-tn csp-tn)))) +;;; Fix: boil down below notes into something nicer ;;; Emit code needed at the return-point from an unknown-values call for a ;;; fixed number of values. VALUES is the head of the TN-REF list for the ;;; locations that the values are to be received into. NVALS is the number of @@ -245,92 +271,85 @@ default-value-8 br defaulting-done nop |# -;;; + (defun default-unknown-values (vop values nvals move-temp temp lra-label) (declare (type (or tn-ref null) values) - (type unsigned-byte nvals) (type tn move-temp temp)) + (type unsigned-byte nvals) + (type tn move-temp temp)) (cond - ((<= nvals 1) - (assemble () + ((<= nvals 1) ;; Note that this is a single-value return point. This is actually ;; the multiple-value entry point for a single desired value, but ;; the code location has to be here, or the debugger backtrace ;; gets confused. - (note-this-location vop :single-value-return) - (move ocfp-tn csp-tn) - (inst compute-code-from-lra code-tn lra-label temp code-tn))) - ((<= nvals register-arg-count) - (assemble () - ;; Note that this is an unknown-values return point. - (note-this-location vop :unknown-return) - ;; Branch off to the MV case. - (inst b regs-defaulted :nullify t) - - ;; Default any unsupplied values. - (do ((val (tn-ref-across values) (tn-ref-across val))) - ((null val)) - (inst move null-tn (tn-ref-tn val) - (if (tn-ref-across val) - :never - :tr))) - - REGS-DEFAULTED - - ;; Clear the stack. Note: the last move in the single value reg - ;; defaulting nullifies this, so this only happens in the mv case. - (move ocfp-tn csp-tn) - - ;; Fix CODE. - (inst compute-code-from-lra code-tn lra-label temp code-tn))) - (t - (collect ((defaults)) - (assemble (nil nil :labels (default-stack-vals)) - ;; Note that this is an unknown-values return point. - (note-this-location vop :unknown-return) - ;; Branch off to the MV case. - (inst b regs-defaulted :nullify t) - - ;; Default any unsupplied register values. + (without-scheduling () + (note-this-location vop :single-value-return) + (move ocfp-tn csp-tn t) + (inst nop)) + (when lra-label + (inst compute-code-from-lra code-tn lra-label temp code-tn))) + (t + (let ((regs-defaulted (gen-label)) + (defaulting-done (gen-label)) + (default-stack-vals (gen-label))) + (without-scheduling () + ;; Note that this is an unknown-values return point. + (note-this-location vop :unknown-return) + ;; Branch off to the MV case. + (inst b regs-defaulted) ; dont nullify + ;; If there are no stack results, clear the stack before branch. + (if (> nvals register-arg-count) ; what inst to late-branch-exec + (inst addi (fixnumize (- register-arg-count)) nargs-tn temp) + (move ocfp-tn csp-tn t))) + ;; Do the single value case. (do ((i 1 (1+ i)) (val (tn-ref-across values) (tn-ref-across val))) - ((= i register-arg-count)) - (inst move null-tn (tn-ref-tn val))) - (inst b default-stack-vals) - (move ocfp-tn csp-tn) - - REGS-DEFAULTED - - (do ((i register-arg-count (1+ i)) - (val (do ((i 0 (1+ i)) - (val values (tn-ref-across val))) - ((= i register-arg-count) val)) - (tn-ref-across val))) - ((null val)) - - (let ((default-lab (gen-label)) - (tn (tn-ref-tn val))) - (defaults (cons default-lab tn)) - (inst bci :>= nil (fixnumize i) nargs-tn default-lab) - (loadw move-temp ocfp-tn i) - (store-stack-tn tn move-temp))) - - DEFAULTING-DONE - (move ocfp-tn csp-tn) - (inst compute-code-from-lra code-tn lra-label temp code-tn) - - (let ((defaults (defaults))) - (aver defaults) - (assemble (*elsewhere*) - (trace-table-entry trace-table-call-site) - DEFAULT-STACK-VALS - (do ((remaining defaults (cdr remaining))) - ((null remaining)) - (let ((def (car remaining))) - (emit-label (car def)) - (when (null (cdr remaining)) - (inst b defaulting-done)) - (store-stack-tn (cdr def) null-tn))) - (trace-table-entry trace-table-normal))))))) + ((= i (min nvals register-arg-count))) + (move null-tn (tn-ref-tn val))) + (when (> nvals register-arg-count) + (inst b default-stack-vals) + (move csp-tn ocfp-tn t)) + + (emit-label regs-defaulted) + + (when (> nvals register-arg-count) + ;; If there are stack results, we have to default them + ;; and clear the stack. + (collect ((defaults)) + (do ((i register-arg-count (1+ i)) + (val (do ((i 0 (1+ i)) + (val values (tn-ref-across val))) + ((= i register-arg-count) val)) + (tn-ref-across val))) + ((null val)) + + (let ((default-lab (gen-label)) + (tn (tn-ref-tn val))) + (defaults (cons default-lab tn)) + + (inst ldw (* i n-word-bytes) ocfp-tn move-temp) + (inst bc :<= nil temp zero-tn default-lab) + (inst addi (fixnumize -1) temp temp) + (store-stack-tn tn move-temp))) + + (emit-label defaulting-done) + (move ocfp-tn csp-tn) + + (let ((defaults (defaults))) + (aver defaults) + (assemble (*elsewhere*) + (emit-label default-stack-vals) + (trace-table-entry trace-table-fun-prologue) + (do ((remaining defaults (cdr remaining))) + ((null remaining)) + (let ((def (car remaining))) + (emit-label (car def)) + (when (null (cdr remaining)) + (inst b defaulting-done)) + (store-stack-tn (cdr def) null-tn))) + (trace-table-entry trace-table-normal))))) + (when lra-label + (inst compute-code-from-lra code-tn lra-label temp code-tn))))) (values)) @@ -352,30 +371,35 @@ default-value-8 ;;; Args and Nargs are TNs wired to the named locations. We must ;;; explicitly allocate these TNs, since their lifetimes overlap with the ;;; results Start and Count (also, it's nice to be able to target them). -;;; (defun receive-unknown-values (args nargs start count lra-label temp) (declare (type tn args nargs start count temp)) - (assemble (nil nil :labels (variable-values)) - (inst b variable-values :nullify t) - - (inst compute-code-from-lra code-tn lra-label temp code-tn) - (inst move csp-tn start) - (inst stwm (first register-arg-tns) n-word-bytes csp-tn) + (let ((variable-values (gen-label)) + (done (gen-label))) + (without-scheduling () + (inst b variable-values :nullify t) + (inst nop)) ; nop because of emit-return-pc alignment + + (when lra-label + (inst compute-code-from-lra code-tn lra-label temp code-tn)) + (inst addi n-word-bytes csp-tn csp-tn) + (storew (first *register-arg-tns*) csp-tn -1) + (inst addi (- n-word-bytes) csp-tn start) (inst li (fixnumize 1) count) - DONE + (emit-label done) (assemble (*elsewhere*) - (trace-table-entry trace-table-call-site) - VARIABLE-VALUES - (inst compute-code-from-lra code-tn lra-label temp code-tn) - (do ((arg register-arg-tns (rest arg)) + (trace-table-entry trace-table-fun-prologue) + (emit-label variable-values) + (when lra-label + (inst compute-code-from-lra code-tn lra-label temp code-tn)) + (do ((arg *register-arg-tns* (rest arg)) (i 0 (1+ i))) ((null arg)) (storew (first arg) args i)) (move args start) - (move nargs count) - (inst b done :nullify t) + (inst b done) + (move nargs count t) (trace-table-entry trace-table-normal))) (values)) @@ -393,6 +417,15 @@ default-value-8 nvals) (:temporary (:scs (non-descriptor-reg)) temp)) + +;;; This hook in the codegen pass lets us insert code before fall-thru entry +;;; points, local-call entry points, and tail-call entry points. The default +;;; does nothing. +(defun emit-block-header (start-label trampoline-label fall-thru-p alignp) + (declare (ignore fall-thru-p alignp)) + (when trampoline-label + (emit-label trampoline-label)) + (emit-label start-label)) ;;;; Local call with unknown values convention return: @@ -430,7 +463,6 @@ default-value-8 (:temporary (:sc any-reg :offset ocfp-offset :from :eval) ocfp) (:ignore arg-locs args ocfp) (:generator 5 - (trace-table-entry trace-table-call-site) (let ((label (gen-label)) (cur-nfp (current-nfp-tn vop))) (when cur-nfp @@ -439,15 +471,16 @@ default-value-8 (when callee-nfp (maybe-load-stack-tn callee-nfp nfp))) (maybe-load-stack-tn cfp-tn cfp) + (trace-table-entry trace-table-call-site) (inst compute-lra-from-code code-tn label temp (callee-return-pc-tn callee)) (note-this-location vop :call-site) (inst b target :nullify t) + (trace-table-entry trace-table-normal) (emit-return-pc label) (default-unknown-values vop values nvals move-temp temp label) (when cur-nfp - (load-stack-tn cur-nfp nfp-save))) - (trace-table-entry trace-table-normal))) + (load-stack-tn cur-nfp nfp-save))))) ;;; Non-TR local call for a variable number of return values passed according ;;; to the unknown values convention. The results are the start of the values @@ -467,8 +500,8 @@ default-value-8 (:ignore args save) (:vop-var vop) (:temporary (:sc control-stack :offset nfp-save-offset) nfp-save) + (:temporary (:scs (non-descriptor-reg)) temp) (:generator 20 - (trace-table-entry trace-table-call-site) (let ((label (gen-label)) (cur-nfp (current-nfp-tn vop))) (when cur-nfp @@ -477,16 +510,17 @@ default-value-8 (when callee-nfp (maybe-load-stack-tn callee-nfp nfp))) (maybe-load-stack-tn cfp-tn cfp) + (trace-table-entry trace-table-call-site) (inst compute-lra-from-code code-tn label temp (callee-return-pc-tn callee)) (note-this-location vop :call-site) (inst b target :nullify t) + (trace-table-entry trace-table-normal) (emit-return-pc label) (note-this-location vop :unknown-return) (receive-unknown-values values-start nvals start count label temp) (when cur-nfp - (load-stack-tn cur-nfp nfp-save))) - (trace-table-entry trace-table-normal))) + (load-stack-tn cur-nfp nfp-save))))) ;;;; Local call with known values return: @@ -511,7 +545,6 @@ default-value-8 (:temporary (:sc control-stack :offset nfp-save-offset) nfp-save) (:temporary (:scs (non-descriptor-reg)) temp) (:generator 5 - (trace-table-entry trace-table-call-site) (let ((label (gen-label)) (cur-nfp (current-nfp-tn vop))) (when cur-nfp @@ -520,15 +553,16 @@ default-value-8 (when callee-nfp (maybe-load-stack-tn callee-nfp nfp))) (maybe-load-stack-tn cfp-tn cfp) + (trace-table-entry trace-table-call-site) (inst compute-lra-from-code code-tn label temp (callee-return-pc-tn callee)) (note-this-location vop :call-site) (inst b target :nullify t) + (trace-table-entry trace-table-normal) (emit-return-pc label) (note-this-location vop :known-return) (when cur-nfp - (load-stack-tn cur-nfp nfp-save))) - (trace-table-entry trace-table-normal))) + (load-stack-tn cur-nfp nfp-save))))) ;;; Return from known values call. We receive the return locations as ;;; arguments to terminate their lifetimes in the returning function. We @@ -539,10 +573,10 @@ default-value-8 ;;; MAYBE-LOAD-STACK-TN. ;;; (define-vop (known-return) - (:args (old-fp :target old-fp-temp) + (:args (ocfp :target ocfp-temp) (return-pc :target return-pc-temp) (vals :more t)) - (:temporary (:sc any-reg :from (:argument 0)) old-fp-temp) + (:temporary (:sc any-reg :from (:argument 0)) ocfp-temp) (:temporary (:sc descriptor-reg :from (:argument 1)) return-pc-temp) (:temporary (:scs (interior-reg)) lip) (:move-args :known-return) @@ -551,7 +585,7 @@ default-value-8 (:vop-var vop) (:generator 6 (trace-table-entry trace-table-fun-epilogue) - (maybe-load-stack-tn old-fp-temp old-fp) + (maybe-load-stack-tn ocfp-temp ocfp) (maybe-load-stack-tn return-pc-temp return-pc) (move cfp-tn csp-tn) (let ((cur-nfp (current-nfp-tn vop))) @@ -559,7 +593,7 @@ default-value-8 (move cur-nfp nsp-tn))) (inst addi (- n-word-bytes other-pointer-lowtag) return-pc-temp lip) (inst bv lip) - (move old-fp-temp cfp-tn) + (move ocfp-temp cfp-tn t) (trace-table-entry trace-table-normal))) @@ -603,6 +637,7 @@ default-value-8 ;;; more arg, but there is no new-FP, since the arguments have been set up in ;;; the current frame. ;;; + (macrolet ((define-full-call (name named return variable) (aver (not (and variable (eq return :tail)))) `(define-vop (,name @@ -613,12 +648,12 @@ default-value-8 '((new-fp :scs (any-reg) :to :eval))) ,(if named - '(fdefn :target fdefn-pass) + '(name :target name-pass) '(arg-fun :target lexenv)) ,@(when (eq return :tail) '((ocfp :target ocfp-pass) - (lra :target lra-pass))) + (return-pc :target return-pc-pass))) ,@(unless variable '((args :more t :scs (descriptor-reg))))) @@ -633,185 +668,222 @@ default-value-8 (:vop-var vop) (:info ,@(unless (or variable (eq return :tail)) '(arg-locs)) ,@(unless variable '(nargs)) - ,@(when (eq return :fixed) '(nvals))) + ,@(when (eq return :fixed) '(nvals)) + step-instrumenting) (:ignore - ,@(unless (or variable (eq return :tail)) '(arg-locs)) - ,@(unless variable '(args))) + ,@(unless (or variable (eq return :tail)) '(arg-locs)) + ,@(unless variable '(args))) (:temporary (:sc descriptor-reg :offset ocfp-offset - ,@(when (eq return :tail) - '(:from (:argument 1))) + :from (:argument 1) ,@(unless (eq return :fixed) '(:to :eval))) ocfp-pass) (:temporary (:sc descriptor-reg :offset lra-offset - ,@(when (eq return :tail) - '(:from (:argument 2))) + :from (:argument ,(if (eq return :tail) 2 1)) :to :eval) - lra-pass) + return-pc-pass) ,@(if named `((:temporary (:sc descriptor-reg :offset fdefn-offset :from (:argument ,(if (eq return :tail) 0 1)) :to :eval) - fdefn-pass)) + name-pass)) `((:temporary (:sc descriptor-reg :offset lexenv-offset :from (:argument ,(if (eq return :tail) 0 1)) :to :eval) lexenv) - (:temporary (:scs (descriptor-reg) - :from (:argument ,(if (eq return :tail) 2 1)) - :to :eval) + (:temporary (:scs (descriptor-reg) :from (:argument 0) :to :eval) function))) (:temporary (:sc any-reg :offset nargs-offset :to :eval) nargs-pass) ,@(when variable - (mapcar #'(lambda (name offset) - `(:temporary (:sc descriptor-reg - :offset ,offset - :to :eval) - ,name)) + (mapcar (lambda (name offset) + `(:temporary (:sc descriptor-reg + :offset ,offset + :to :eval) + ,name)) register-arg-names *register-arg-offsets*)) ,@(when (eq return :fixed) '((:temporary (:scs (descriptor-reg) :from :eval) move-temp))) + (:temporary (:scs (descriptor-reg) :to :eval) stepping) + ,@(unless (eq return :tail) '((:temporary (:scs (non-descriptor-reg)) temp) (:temporary (:sc control-stack :offset nfp-save-offset) nfp-save))) - (:temporary (:scs (interior-reg) :type interior) lip) + (:temporary (:sc interior-reg :offset lip-offset) entry-point) (:generator ,(+ (if named 5 0) (if variable 19 1) (if (eq return :tail) 0 10) 15 (if (eq return :unknown) 25 0)) - (trace-table-entry trace-table-call-site) (let* ((cur-nfp (current-nfp-tn vop)) ,@(unless (eq return :tail) '((lra-label (gen-label)))) + (step-done-label (gen-label)) (filler - (list :load-nargs - ,@(if (eq return :tail) - '((unless (location= ocfp ocfp-pass) - :load-ocfp) - (unless (location= lra lra-pass) - :load-lra) - (when cur-nfp - :frob-nfp)) - '((when cur-nfp - :frob-nfp) - :comp-lra - :save-fp - :load-fp))))) - (labels - ((do-next-filler () - (when filler - (ecase (pop filler) - ((nil) (do-next-filler)) - (:load-nargs - ,@(if variable - `((inst sub csp-tn new-fp nargs-pass) - ,@(let ((index -1)) - (mapcar #'(lambda (name) - `(loadw ,name new-fp - ,(incf index))) - register-arg-names))) - '((inst li (fixnumize nargs) nargs-pass)))) - ,@(if (eq return :tail) - '((:load-ocfp - (sc-case ocfp - (any-reg - (inst move ocfp ocfp-pass)) - (control-stack - (loadw ocfp-pass cfp-tn (tn-offset ocfp))))) - (:load-lra - (sc-case lra - (descriptor-reg - (inst move lra lra-pass)) - (control-stack - (loadw lra-pass cfp-tn (tn-offset lra))))) - (:frob-nfp - (inst move cur-nfp nsp-tn))) - `((:frob-nfp - (store-stack-tn nfp-save cur-nfp)) - (:comp-lra - (inst compute-lra-from-code - code-tn lra-label temp lra-pass)) - (:save-fp - (inst move cfp-tn ocfp-pass)) - (:load-fp - ,(if variable - '(move new-fp cfp-tn) - '(if (> nargs register-arg-count) - (move new-fp cfp-tn) - (move csp-tn cfp-tn)))))))))) - + (remove nil + (list :load-nargs + ,@(if (eq return :tail) + '((unless (location= ocfp ocfp-pass) + :load-ocfp) + (unless (location= return-pc + return-pc-pass) + :load-return-pc) + (when cur-nfp + :frob-nfp)) + '(:comp-lra + (when cur-nfp + :frob-nfp) + :save-fp + :load-fp)))))) + (flet ((do-next-filler () + (let* ((next (pop filler)) + (what (if (consp next) (car next) next))) + (ecase what + (:load-nargs + ,@(if variable + `((inst sub csp-tn new-fp nargs-pass) + ,@(let ((index -1)) + (mapcar (lambda (name) + `(inst ldw ,(ash (incf index) + word-shift) + new-fp + ,name)) + register-arg-names))) + '((inst li (fixnumize nargs) nargs-pass)))) + ,@(if (eq return :tail) + '((:load-ocfp + (sc-case ocfp + (any-reg + (move ocfp ocfp-pass t)) + (control-stack + (inst ldw (ash (tn-offset ocfp) + word-shift) + cfp-tn ocfp-pass)))) + (:load-return-pc + (sc-case return-pc + (descriptor-reg + (move return-pc return-pc-pass t)) + (control-stack + (inst ldw (ash (tn-offset return-pc) + word-shift) + cfp-tn return-pc-pass)))) + (:frob-nfp + (inst addi (- (bytes-needed-for-non-descriptor-stack-frame)) + nsp-tn nsp-tn))) + `((:comp-lra + (inst compute-lra-from-code code-tn lra-label + temp return-pc-pass)) + (:frob-nfp + (store-stack-tn nfp-save cur-nfp)) + (:save-fp + (move cfp-tn ocfp-pass t)) + (:load-fp + ,(if variable + '(move new-fp cfp-tn) + '(if (> nargs register-arg-count) + (move new-fp cfp-tn) + (move csp-tn cfp-tn))) + (trace-table-entry trace-table-call-site)))) + ((nil) + (inst nop))))) + (insert-step-instrumenting (callable-tn) + ;; Conditionally insert a conditional trap: + (when step-instrumenting + (load-symbol-value stepping sb!impl::*stepping*) + ;; If it's not NIL, trap. + ;(inst comb := stepping null-tn step-done-label) + (inst comb := null-tn null-tn step-done-label :nullify t) + ;; CONTEXT-PC will be pointing here when the + ;; interrupt is handled, not after the BREAK. + (note-this-location vop :step-before-vop) + ;; Construct a trap code with the low bits from + ;; SINGLE-STEP-AROUND-TRAP and the high bits from + ;; the register number of CALLABLE-TN. + (inst break 0 (logior single-step-around-trap + (ash (reg-tn-encoding callable-tn) + 5))) + (emit-label step-done-label)))) ,@(if named - `((sc-case fdefn - (descriptor-reg (move fdefn fdefn-pass)) + `((sc-case name + (descriptor-reg (move name name-pass)) (control-stack - (loadw fdefn-pass cfp-tn (tn-offset fdefn)) + (inst ldw (ash (tn-offset name) word-shift) + cfp-tn name-pass) (do-next-filler)) (constant - (loadw fdefn-pass code-tn (tn-offset fdefn) - other-pointer-lowtag) + (inst ldw (- (ash (tn-offset name) word-shift) + other-pointer-lowtag) + code-tn name-pass) (do-next-filler))) - (loadw lip fdefn-pass fdefn-raw-addr-slot - other-pointer-lowtag) + ;; The step instrumenting must be done after + ;; FUNCTION is loaded, but before ENTRY-POINT is + ;; calculated. + (insert-step-instrumenting name-pass) + (inst ldw (- (ash fdefn-raw-addr-slot word-shift) + other-pointer-lowtag) + name-pass entry-point) (do-next-filler)) `((sc-case arg-fun - (descriptor-reg (move arg-fun lexenv)) + (descriptor-reg + (move arg-fun lexenv)) (control-stack - (loadw lexenv cfp-tn (tn-offset arg-fun)) + (inst ldw (ash (tn-offset arg-fun) word-shift) + cfp-tn lexenv) (do-next-filler)) (constant - (loadw lexenv code-tn (tn-offset arg-fun) - other-pointer-lowtag) + (inst ldw + (- (ash (tn-offset arg-fun) word-shift) + other-pointer-lowtag) code-tn lexenv) (do-next-filler))) - (loadw function lexenv closure-fun-slot - fun-pointer-lowtag) + (inst ldw (- (ash closure-fun-slot word-shift) + fun-pointer-lowtag) + lexenv function) (do-next-filler) + ;; The step instrumenting must be done before + ;; after FUNCTION is loaded, but before ENTRY-POINT + ;; is calculated. + (insert-step-instrumenting function) (inst addi (- (ash simple-fun-code-offset word-shift) fun-pointer-lowtag) - function lip))) + function entry-point))) (loop - (cond ((null filler) - (return)) - ((null (car filler)) - (pop filler)) - ((null (cdr filler)) - (return)) - (t - (do-next-filler)))) + (if (cdr filler) + (do-next-filler) + (return))) + (do-next-filler) (note-this-location vop :call-site) - (inst bv lip :nullify (null filler)) - (do-next-filler)) + (inst bv entry-point :nullify t)) ,@(ecase return (:fixed - '((emit-return-pc lra-label) + '((trace-table-entry trace-table-normal) + (emit-return-pc lra-label) (default-unknown-values vop values nvals move-temp temp lra-label) (when cur-nfp (load-stack-tn cur-nfp nfp-save)))) (:unknown - '((emit-return-pc lra-label) + '((trace-table-entry trace-table-normal) + (emit-return-pc lra-label) (note-this-location vop :unknown-return) (receive-unknown-values values-start nvals start count lra-label temp) (when cur-nfp (load-stack-tn cur-nfp nfp-save)))) - (:tail))) - (trace-table-entry trace-table-normal))))) + (:tail))))))) (define-full-call call nil :fixed nil) (define-full-call call-named t :fixed nil) @@ -824,48 +896,48 @@ default-value-8 (define-full-call multiple-call-variable nil :unknown t)) -;;; Defined separately, since needs special code that BLT's the arguments +;;; Defined separately, since needs special code that blits the arguments ;;; down. ;;; (define-vop (tail-call-variable) (:args (args-arg :scs (any-reg) :target args) (function-arg :scs (descriptor-reg) :target lexenv) - (old-fp-arg :scs (any-reg) :target old-fp) + (ocfp-arg :scs (any-reg) :target ocfp) (lra-arg :scs (descriptor-reg) :target lra)) (:temporary (:sc any-reg :offset nl0-offset :from (:argument 0)) args) (:temporary (:sc any-reg :offset lexenv-offset :from (:argument 1)) lexenv) - (:temporary (:sc any-reg :offset ocfp-offset :from (:argument 2)) old-fp) + (:temporary (:sc any-reg :offset ocfp-offset :from (:argument 2)) ocfp) (:temporary (:sc any-reg :offset lra-offset :from (:argument 3)) lra) (:temporary (:scs (any-reg) :from (:argument 3)) tmp) - (:vop-var vop) - (:generator 75 - ;; Move these into the passing locations if they are not already there. (move args-arg args) (move function-arg lexenv) - (move old-fp-arg old-fp) + (move ocfp-arg ocfp) (move lra-arg lra) - - ;; Clear the number stack if anything is there. - (let ((cur-nfp (current-nfp-tn vop))) - (when cur-nfp - (inst move cur-nfp nsp-tn))) - ;; And jump to the assembly-routine that does the bliting. (let ((fixup (make-fixup 'tail-call-variable :assembly-routine))) (inst ldil fixup tmp) - (inst be fixup lisp-heap-space tmp :nullify t)))) + (inst be fixup lisp-heap-space tmp)) + ;; Pull the number stack if anything is there. + (let ((cur-nfp (current-nfp-tn vop))) + (if cur-nfp + ;;; NSP is restored by setting it to NSP, + ;;; because stack grows towards higher addresses. + (move cur-nfp nsp-tn) + (inst nop))))) ;;;; Unknown values return: ;;; Return a single value using the unknown-values convention. ;;; +;;; NSP is restored by setting it to NSP, because stack grows +;;; towards higher addresses. (define-vop (return-single) - (:args (old-fp :scs (any-reg)) + (:args (ocfp :scs (any-reg)) (return-pc :scs (descriptor-reg)) (value)) (:ignore value) @@ -875,12 +947,12 @@ default-value-8 (trace-table-entry trace-table-fun-epilogue) (let ((cur-nfp (current-nfp-tn vop))) (when cur-nfp - (inst move cur-nfp nsp-tn))) + (move cur-nfp nsp-tn))) ;; Clear the control stack, and restore the frame pointer. (move cfp-tn csp-tn) - (move old-fp cfp-tn) + (move ocfp cfp-tn) ;; Out of here. - (lisp-return return-pc :offset 1) + (lisp-return return-pc :offset 2) (trace-table-entry trace-table-normal))) ;;; Do unknown-values return of a fixed number of values. The Values are @@ -897,10 +969,9 @@ default-value-8 ;;; current frame.) ;;; (define-vop (return) - (:args - (old-fp :scs (any-reg)) - (return-pc :scs (descriptor-reg) :to (:eval 1)) - (values :more t)) + (:args (ocfp :scs (any-reg)) + (return-pc :scs (descriptor-reg) :to (:eval 1)) + (values :more t)) (:ignore values) (:info nvals) (:temporary (:sc descriptor-reg :offset a0-offset :from (:eval 0)) a0) @@ -911,26 +982,35 @@ default-value-8 (:temporary (:sc descriptor-reg :offset a5-offset :from (:eval 0)) a5) (:temporary (:sc any-reg :offset nargs-offset) nargs) (:temporary (:sc any-reg :offset ocfp-offset) val-ptr) + (:vop-var vop) (:generator 6 ;; Clear the number stack. (trace-table-entry trace-table-fun-epilogue) (let ((cur-nfp (current-nfp-tn vop))) (when cur-nfp - (inst move cur-nfp nsp-tn))) - ;; Establish the values pointer and values count. - (move cfp-tn val-ptr) - (inst li (fixnumize nvals) nargs) - ;; restore the frame pointer and clear as much of the control - ;; stack as possible. - (move old-fp cfp-tn) - (inst addi (* nvals n-word-bytes) val-ptr csp-tn) - ;; pre-default any argument register that need it. - (when (< nvals register-arg-count) - (dolist (reg (subseq (list a0 a1 a2 a3 a4 a5) nvals)) - (move null-tn reg))) - ;; And away we go. - (lisp-return return-pc) + (move cur-nfp nsp-tn))) + (cond + ((= nvals 1) ;; Clear the control stack, and restore the frame pointer + (move cfp-tn csp-tn) + (move ocfp cfp-tn) + ;; Out of here. + (lisp-return return-pc :offset 2)) + (t + ;; Establish the values pointer and values count. + (move cfp-tn val-ptr) + (inst li (fixnumize nvals) nargs) + ;; restore the frame pointer and clear as much of the control + ;; stack as possible. + (move ocfp cfp-tn) + (inst addi (* nvals n-word-bytes) val-ptr csp-tn) + (aver (= (* nvals n-word-bytes) (fixnumize nvals))) + ;; pre-default any argument register that need it. + (when (< nvals register-arg-count) + (dolist (reg (subseq (list a0 a1 a2 a3 a4 a5) nvals)) + (move null-tn reg))) + ;; And away we go. + (lisp-return return-pc))) (trace-table-entry trace-table-normal))) ;;; Do unknown-values return of an arbitrary number of values (passed on the @@ -939,51 +1019,46 @@ default-value-8 ;;; branch off to code that calls an assembly-routine. ;;; (define-vop (return-multiple) - (:args - (old-fp-arg :scs (any-reg) :to (:eval 1)) - (lra-arg :scs (descriptor-reg) :to (:eval 1)) - (vals-arg :scs (any-reg) :target vals) - (nvals-arg :scs (any-reg) :target nvals)) + (:args (ocfp-arg :scs (any-reg) :target ocfp) + (lra-arg :scs (descriptor-reg) :target lra) + (vals-arg :scs (any-reg) :target vals) + (nvals-arg :scs (any-reg) :target nvals)) - (:temporary (:sc any-reg :offset nl1-offset :from (:argument 0)) old-fp) + (:temporary (:sc any-reg :offset nl1-offset :from (:argument 0)) ocfp) (:temporary (:sc descriptor-reg :offset lra-offset :from (:argument 1)) lra) (:temporary (:sc any-reg :offset nl0-offset :from (:argument 2)) vals) (:temporary (:sc any-reg :offset nargs-offset :from (:argument 3)) nvals) (:temporary (:sc descriptor-reg :offset a0-offset) a0) (:temporary (:scs (any-reg) :from (:eval 0)) tmp) - (:vop-var vop) - (:node-var node) - (:generator 13 (trace-table-entry trace-table-fun-epilogue) - ;; Clear the number stack. - (let ((cur-nfp (current-nfp-tn vop))) - (when cur-nfp - (inst move cur-nfp nsp-tn))) - - (unless (policy node (> space speed)) + (let ((not-single (gen-label))) + ;; Clear the number stack. + (let ((cur-nfp (current-nfp-tn vop))) + (when cur-nfp + (move cur-nfp nsp-tn))) ;; Check for the single case. (inst comib :<> (fixnumize 1) nvals-arg not-single) (loadw a0 vals-arg) - ;; Return with one value. (move cfp-tn csp-tn) - (move old-fp-arg cfp-tn) - (lisp-return lra-arg :offset 1)) - - ;; Nope, not the single case. - NOT-SINGLE - (move old-fp-arg old-fp) - (move lra-arg lra) - (move vals-arg vals) - (move nvals-arg nvals) - (let ((fixup (make-fixup 'return-multiple :assembly-routine))) - (inst ldil fixup tmp) - (inst be fixup lisp-heap-space tmp :nullify t)) + (move ocfp-arg cfp-tn) + (lisp-return lra-arg :offset 2) + ;; Nope, not the single case. + (emit-label not-single) + ;; most of these moves will not be emitted and therefor + ;; isn't suitable to put in the delay slot below. But if + ;; you do, dont forget to force-emit as in (move src dst t) + (move ocfp-arg ocfp) + (move lra-arg lra) + (move vals-arg vals) + (move nvals-arg nvals) + (let ((fixup (make-fixup 'return-multiple :assembly-routine))) + (inst ldil fixup tmp) + (inst be fixup lisp-heap-space tmp :nullify t))) (trace-table-entry trace-table-normal))) - ;;;; XEP hackery: @@ -996,7 +1071,7 @@ default-value-8 ;; Don't bother doing anything. )) -;;; Get the lexical environment from it's passing location. +;;; Get the lexical environment from its passing location. ;;; (define-vop (setup-closure-environment) (:temporary (:sc descriptor-reg :offset lexenv-offset :target closure @@ -1011,7 +1086,7 @@ default-value-8 ;;; Copy a more arg from the argument area to the end of the current frame. ;;; Fixed is the number of non-more arguments. -;;; +;;; FIXME-lav: old hppa code look smarter. (define-vop (copy-more-arg) (:temporary (:sc any-reg :offset nl0-offset) result) (:temporary (:sc any-reg :offset nl1-offset) count) @@ -1020,104 +1095,112 @@ default-value-8 (:temporary (:sc descriptor-reg :offset l0-offset) temp) (:info fixed) (:generator 20 - ;; Figure out how many things we are going to copy. - (unless (zerop fixed) - (inst addi (- (fixnumize fixed)) nargs-tn count)) - - ;; Blow out of here if is nothing to copy. - (inst comb :<= (if (zerop fixed) nargs-tn count) zero-tn done :nullify t) - - (when (< fixed register-arg-count) - ;; Save a pointer to the results so we can fill in register args. - ;; We don't need this if there are more fixed args than reg args. - (move csp-tn result)) - - ;; Allocate the space on the stack. - (inst add csp-tn (if (zerop fixed) nargs-tn count) csp-tn) - - (when (< fixed register-arg-count) - ;; We must stop when we run out of stack args, not when we run out of - ;; args in general. - (inst addi (fixnumize (- register-arg-count)) nargs-tn count) + (let ((loop (gen-label)) + (do-regs (gen-label)) + (done (gen-label))) + (when (< fixed register-arg-count) + ;; Save a pointer to the results so we can fill in register args. + ;; We don't need this if there are more fixed args than reg args. + (move csp-tn result)) + ;; Allocate the space on the stack. + (cond ((zerop fixed) + (inst comb := nargs-tn zero-tn done) + (inst add nargs-tn csp-tn csp-tn)) + (t + (inst addi (fixnumize (- fixed)) nargs-tn count) + (inst comb :<= count zero-tn done :nullify t) + (inst add count csp-tn csp-tn))) + (when (< fixed register-arg-count) + ;; We must stop when we run out of stack args, not when we run out of + ;; more args. + (inst addi (fixnumize (- register-arg-count)) nargs-tn count)) ;; Everything of interest in registers. - (inst comb :<= count zero-tn do-regs)) - ;; Initialize dst to be end of stack. - (move csp-tn dst) - - ;; Initialize src to be end of args. - (inst add cfp-tn nargs-tn src) - - LOOP - ;; *--dst = *--src, --count - (inst ldwm (- n-word-bytes) src temp) - (inst addib :> (fixnumize -1) count loop) - (inst stwm temp (- n-word-bytes) dst) - - DO-REGS - (when (< fixed register-arg-count) - ;; Now we have to deposit any more args that showed up in registers. - ;; We know there is at least one more arg, otherwise we would have - ;; branched to done up at the top. - (inst addi (fixnumize (- fixed)) nargs-tn count) - (do ((i fixed (1+ i))) - ((>= i register-arg-count)) - ;; Is this the last one? - (inst addib :<= (fixnumize -1) count done) - ;; Store it relative to the pointer saved at the start. - (storew (nth i register-arg-tns) result (- i fixed)))) - DONE)) + (inst comb :<= count zero-tn do-regs) + ;; Initialize dst to be end of stack. + (move csp-tn dst t) + ;; Initialize src to be end of args. + (inst add nargs-tn cfp-tn src) + + (emit-label loop) + ;; decrease src, then load src into temp + (inst ldwm (- n-word-bytes) src temp) + ;; increase, compare if count >= to zero, if true, jump + (inst addib :>= (fixnumize -1) count loop) + ;; decrease dst, then store temp at dst + (inst stwm temp (- n-word-bytes) dst) + + (emit-label do-regs) + (when (< fixed register-arg-count) + ;; Now we have to deposit any more args that showed up in registers. + ;; We know there is at least one more arg, otherwise we would have + ;; branched to done up at the top. + (inst addi (- (fixnumize (1+ fixed))) nargs-tn count) + (do ((i fixed (1+ i))) + ((>= i register-arg-count)) + ;; Is this the last one? + (inst comb := count zero-tn done) + ;; Store it relative to the pointer saved at the start. + (storew (nth i *register-arg-tns*) result (- i fixed)) + ;; Decrement count. + (inst addi (- (fixnumize 1)) count count))) + (emit-label done)))) ;;; More args are stored consequtively on the stack, starting immediately at ;;; the context pointer. The context pointer is not typed, so the lowtag is 0. ;;; (define-full-reffer more-arg * 0 0 (descriptor-reg any-reg) * %more-arg) - ;;; Turn more arg (context, count) into a list. -;;; (define-vop (listify-rest-args) + (:translate %listify-rest-args) (:args (context-arg :target context :scs (descriptor-reg)) (count-arg :target count :scs (any-reg))) (:arg-types * tagged-num) (:temporary (:scs (any-reg) :from (:argument 0)) context) (:temporary (:scs (any-reg) :from (:argument 1)) count) - (:temporary (:scs (descriptor-reg) :from :eval) temp) - (:temporary (:scs (non-descriptor-reg) :from :eval) dst) + (:temporary (:scs (descriptor-reg) :from :eval) temp dst) (:results (result :scs (descriptor-reg))) - (:translate %listify-rest-args) (:policy :safe) + (:node-var node) (:generator 20 - (move context-arg context) - (move count-arg count) - ;; Check to see if there are any arguments. - (inst comb := count zero-tn done) - (move null-tn result) - - ;; We need to do this atomically. - (pseudo-atomic () - (assemble () + (let* ((enter (gen-label)) + (loop (gen-label)) + (done (gen-label)) + (dx-p (node-stack-allocate-p node)) + (alloc-area-tn (if dx-p csp-tn alloc-tn))) + (move context-arg context) + (move count-arg count) + ;; Check to see if there are any arguments. + (inst comb := count zero-tn done) + (move null-tn result t) + + ;; We need to do this atomically. + (pseudo-atomic () + (when dx-p + (align-csp temp)) ;; Allocate a cons (2 words) for each item. - (inst move alloc-tn result) - (inst dep list-pointer-lowtag 31 3 result) + (set-lowtag list-pointer-lowtag alloc-area-tn result) (move result dst) (inst sll count 1 temp) - (inst add alloc-tn temp alloc-tn) + (inst b enter) + (inst add temp alloc-area-tn alloc-area-tn) - LOOP - ;; Grab one value and stash it in the car of this cons. - (inst ldwm n-word-bytes context temp) - (storew temp dst 0 list-pointer-lowtag) - - ;; Dec count, and if != zero, go back for more. + ;; Store the current cons in the cdr of the previous cons. + (emit-label loop) (inst addi (* 2 n-word-bytes) dst dst) - (inst addib :> (fixnumize -1) count loop :nullify t) (storew dst dst -1 list-pointer-lowtag) + (emit-label enter) + ;; Grab one value. + (inst ldwm n-word-bytes context temp) + ;; Dec count, and if != zero, go back for more. + (inst addib :<> (fixnumize -1) count loop) + ;; Store the value in the car (in delay slot) + (storew temp dst 0 list-pointer-lowtag) + ;; NIL out the last cons. - (storew null-tn dst -1 list-pointer-lowtag) - ;; Clear out dst, because it points past the last cons. - (move null-tn dst))) - DONE)) + (storew null-tn dst 1 list-pointer-lowtag)) + (emit-label done)))) ;;; Return the location and size of the more arg glob created by Copy-More-Arg. ;;; Supplied is the total number of arguments supplied (originally passed in @@ -1129,10 +1212,6 @@ default-value-8 ;;; supplied - fixed, and return a pointer that many words below the current ;;; stack top. ;;; - -;;; WTF? FIXME -- CSR -;;;(setf (info function source-transform 'c::%more-arg-context) nil) -;;; (define-vop (more-arg-context) (:policy :fast-safe) (:translate sb!c::%more-arg-context) @@ -1147,7 +1226,6 @@ default-value-8 (inst addi (fixnumize (- fixed)) supplied count) (inst sub csp-tn count context))) - ;;; Signal wrong argument count error if Nargs isn't = to Count. ;;; (define-vop (verify-arg-count) @@ -1166,7 +1244,7 @@ default-value-8 (t (inst bci :<> nil (fixnumize count) nargs err-lab)))))) -;;; Signal an argument count error. +;;; Signal argument errors. ;;; (macrolet ((frob (name error translate &rest args) `(define-vop (,name) @@ -1191,3 +1269,22 @@ default-value-8 (frob unknown-key-arg-error unknown-key-arg-error sb!c::%unknown-key-arg-error key) (frob nil-fun-returned-error nil-fun-returned-error nil fun)) + +;;; Single-stepping + +(define-vop (step-instrument-before-vop) + (:temporary (:scs (descriptor-reg)) stepping) + (:policy :fast-safe) + (:vop-var vop) + (:generator 3 + (load-symbol-value stepping sb!impl::*stepping*) + ;; If it's not NIL, trap. + (inst comb := stepping null-tn DONE :nullify t) + ;; CONTEXT-PC will be pointing here when the interrupt is handled, + ;; not after the BREAK. + (note-this-location vop :step-before-vop) + ;; CALLEE-REGISTER-OFFSET isn't needed for before-traps, so we + ;; can just use a bare SINGLE-STEP-BEFORE-TRAP as the code. + (inst break 0 single-step-before-trap) + DONE)) +