;;;; allocation VOPs for the x86-64
;;;; This software is part of the SBCL system. See the README file for
;;;; more information.
;;;;
;;;; This software is derived from the CMU CL system, which was
;;;; written at Carnegie Mellon University and released into the
;;;; public domain. The software is in the public domain and is
;;;; provided with absolutely no warranty. See the COPYING and CREDITS
;;;; files for more information.
(in-package "SB-VM")
;;;; allocation helpers
;;; Most allocation is done by inline code with sometimes help
;;; from the C alloc() function by way of the alloc-tramp
;;; assembly routine.
(defun tagify (result base lowtag)
(if (eql lowtag 0)
(inst mov result base)
(inst lea result (ea lowtag base))))
(defun stack-allocation (size lowtag alloc-tn &optional known-alignedp)
(aver (not (location= alloc-tn rsp-tn)))
(inst sub rsp-tn size)
;; see comment in x86/macros.lisp implementation of this
;; However that comment seems inapplicable here because:
;; - PAD-DATA-BLOCK quite clearly enforces double-word alignment,
;; contradicting "... unfortunately not enforced by ..."
;; - It's not the job of FIXED-ALLOC to realign anything.
;; - The real issue is that it's not obvious that the stack is
;; 16-byte-aligned at *all* times. Maybe it is, maybe it isn't.
(unless known-alignedp ; can skip this AND if we're all good
(inst and rsp-tn #.(lognot lowtag-mask)))
(tagify alloc-tn rsp-tn lowtag)
(values))
#+nil ; was #+avx2
(defun avx-registers-used-p ()
(or (when (and #+sb-xc-host (boundp '*component-being-compiled*))
(let ((comp (component-info *component-being-compiled*)))
(or (sb-c::ir2-component-avx2-used-p comp)
(flet ((used-p (tn)
(do ((tn tn (sb-c::tn-next tn)))
((null tn))
(when (sc-is tn ymm-reg
int-avx2-reg
double-avx2-reg single-avx2-reg)
(return-from avx-registers-used-p
(setf (sb-c::ir2-component-avx2-used-p comp) t))))))
(used-p (sb-c::ir2-component-normal-tns comp))
(used-p (sb-c::ir2-component-wired-tns comp))))))))
(defun alloc-unboxed-p (type)
(case type
((unboxed-array
#.bignum-widetag
#.sap-widetag
#.double-float-widetag
#.complex-single-float-widetag
#.complex-double-float-widetag)
t)))
;;; Insert allocation profiler instrumentation
(eval-when (:compile-toplevel)
(aver (= thread-tot-bytes-alloc-unboxed-slot
(1+ thread-tot-bytes-alloc-boxed-slot))))
;;; the #+allocator metrics histogram contains an exact count
;;; for all sizes up to (* cons-size n-word-bytes histogram-small-bins).
;;; Larger allocations are grouped by the binary log of the size.
;;; It seems that 99.5% of all allocations are less than the small bucket limit,
;;; making the histogram fairly exact except for the tail.
(defparameter *consing-histo* nil)
(defconstant non-small-bucket-offset
(+ histogram-small-bins
(- (integer-length (* sb-vm::histogram-small-bins
sb-vm:cons-size sb-vm:n-word-bytes)))))
;;; Emit counter increments for SB-APROF. SCRATCH-REGISTERS is either a TN
;;; or list of TNs that can be used to store into the profiling data.
;;; We pick one of the available TNs to use for addressing the data buffer.
;;; The TN that we pick can't be R12 because encoding it into an instruction
;;; always requires a SIB byte, which doesn't fit in the reserved bytes
;;; of the instruction stream where hot patching occurs.
(defun instrument-alloc (type size node scratch-registers
&optional thread-temp
&aux (temp
(if (listp scratch-registers)
(dolist (reg scratch-registers
(first scratch-registers))
(unless (location= reg r12-tn) (return reg)))
scratch-registers)))
(declare (ignorable type thread-temp))
(aver (not (location= temp r12-tn)))
;; Each allocation sequence has to call INSTRUMENT-ALLOC,
;; so we may as well take advantage of this fact to load the temp reg
;; here, if provided, rather than spewing more #+gs-seg tests around.
#+gs-seg (when thread-temp (inst rdgsbase thread-temp))
#+allocator-metrics
(let ((use-size-temp (not (typep size '(or (signed-byte 32) tn))))
(tally (gen-label))
(inexact (gen-label)))
(cond ((tn-p type) ; from ALLOCATE-VECTOR-ON-HEAP
;; Constant huge size + unknown type can't occur.
(aver (not use-size-temp))
(inst cmp :byte type simple-vector-widetag)
(inst set :ne temp)
(inst and :dword temp 1)
(inst add :qword
(ea thread-segment-reg
(ash thread-tot-bytes-alloc-boxed-slot word-shift)
thread-tn temp 8)
size))
(t
(inst add :qword
(thread-slot-ea (if (alloc-unboxed-p type)
thread-tot-bytes-alloc-unboxed-slot
thread-tot-bytes-alloc-boxed-slot))
(cond (use-size-temp (inst mov temp size) temp)
(t size)))))
(cond ((tn-p size)
(inst cmp size (* histogram-small-bins 16))
(inst jmp :g inexact)
(inst mov :dword temp size)
(inst shr :dword temp (1+ word-shift))
(inst dec :dword temp)
(inst jmp tally)
(emit-label inexact)
(inst bsr temp size)
;; bsr returns 1 less than INTEGER-LENGTH
(inst add :dword temp (1+ non-small-bucket-offset))
(emit-label tally)
(inst inc :qword (ea thread-segment-reg
(ash thread-obj-size-histo-slot word-shift)
thread-tn temp 8)))
(t
(let* ((n-conses (/ size (* sb-vm:cons-size sb-vm:n-word-bytes)))
(bucket (if (<= n-conses histogram-small-bins)
(1- n-conses)
(+ (integer-length size)
non-small-bucket-offset))))
(inst inc :qword
(thread-slot-ea (+ thread-obj-size-histo-slot bucket)))))))
(when (policy node (> sb-c::instrument-consing 1))
(when (tn-p size)
(aver (not (location= size temp))))
(let ((data temp)
(patch-loc (gen-label))
(skip-instrumentation (gen-label)))
(inst mov data (thread-slot-ea thread-profile-data-slot thread-temp))
(inst test data data)
;; This instruction is modified to "JMP :z" when profiling is
;; partially enabled. After the buffer is assigned, it becomes
;; fully enabled. The unconditional jmp gives minimal performance
;; loss if the profiler is statically disabled. (one memory
;; read and a test whose result is never used, which the CPU
;; is good at ignoring as far as instruction prefetch goes)
(emit-label patch-loc)
(push patch-loc (sb-assem::asmstream-alloc-points sb-assem:*asmstream*))
(inst jmp skip-instrumentation)
(emit-alignment 3 :long-nop)
(let ((helper (if (integerp size)
'enable-alloc-counter
'enable-sized-alloc-counter)))
;; This jump is always encoded as 5 bytes
(inst call (if (or (not node) ; assembly routine
(sb-c::code-immobile-p node))
(make-fixup helper :assembly-routine)
(uniquify-fixup helper))))
(inst nop)
;; Emit "TEST AL, imm" where the immediate value
;; encodes the the data buffer base reg and size reg numbers.
(inst byte #xA8) ; "TEST AL,imm"
(cond ((integerp size)
(inst byte (tn-offset data)))
(t
(inst byte (logior (tn-offset data) (ash (tn-offset size) 4)))
(inst .skip 8 :long-nop)))
(emit-label skip-instrumentation))))
;;; Emit code to allocate an object with a size in bytes given by
;;; SIZE into ALLOC-TN. The size may be an integer of a TN.
;;; NODE may be used to make policy-based decisions.
;;; This function should only be used inside a pseudo-atomic section,
;;; which to the degree needed should also cover subsequent initialization.
;;; CONSP says whether we're allocating conses. But we also need LOWTAG
;;; because the vop could want the CONS to have 0 or list-pointer lowtag.
;;;
;;; A mnemonic device for the argument pattern here:
;;; 1. what to allocate: type, size, lowtag describe the object
;;; 2. where to put the result
;;; 3. node (for determining immobile-space-p) and a scratch register or two
(defun allocation (type size lowtag alloc-tn node temp thread-temp)
(declare (ignorable thread-temp))
(flet ((fallback (size)
;; Call an allocator trampoline and get the result in the proper register.
;; There are 2 choices of trampoline to invoke alloc() or alloc_list()
;; in C. This is chosen by the name of the asm routine.
(let ((consp (eq type 'list)))
(when (typep size 'integer)
(aver (= (align-up size (* 2 n-word-bytes)) size))
(when (neq type 'list)
(incf size) ; the low bit means we're allocating a non-cons object
;; Jump into the cons entry point which saves one instruction because why not.
(setq consp t)))
(cond ((typep size '(and integer (not (signed-byte 32))))
;; MOV accepts large immediate operands, PUSH does not
(inst mov alloc-tn size)
(inst push alloc-tn))
(t
(inst push size)))
(invoke-asm-routine 'call (if consp 'cons->rnn 'alloc->rnn) node t))
(inst pop alloc-tn)))
(let* ((NOT-INLINE (gen-label))
(DONE (gen-label))
(free-pointer #+sb-thread (thread-slot-ea thread-boxed-tlab-slot #+gs-seg thread-temp)
#-sb-thread (ea boxed-region))
(end-addr (ea (sb-x86-64-asm::ea-segment free-pointer)
(+ n-word-bytes (ea-disp free-pointer))
(ea-base free-pointer))))
(cond ((typep size `(integer ,large-object-size))
;; large objects will never be made in a per-thread region
(fallback size)
(when (/= lowtag 0) (inst or :byte alloc-tn lowtag)))
((and (tn-p size) (location= size alloc-tn))
(aver (and temp (not (location= temp size))))
(inst mov temp free-pointer)
;; alloc-tn <- old free ptr and temp <- new free ptr
(inst xadd temp alloc-tn)
(inst cmp temp end-addr)
(inst jmp :a NOT-INLINE)
(inst mov free-pointer temp)
(emit-label DONE)
(when (/= lowtag 0) (inst or :byte alloc-tn lowtag))
(assemble (:elsewhere)
(emit-label NOT-INLINE)
(inst sub temp alloc-tn) ; new-free-ptr - old-free-ptr = size
(fallback temp)
(inst jmp DONE)))
(t
;; fixed-size allocation whose size fits in an imm32 can be done
;; with only one register, the ALLOC-TN. If it doesn't fit in imm32,
;; it would get the first branch of the COND, for large objects.
(inst mov alloc-tn free-pointer)
(cond (temp
(when (tn-p size) (aver (not (location= size temp))))
(inst lea temp (ea size alloc-tn))
(inst cmp temp end-addr)
(inst jmp :a NOT-INLINE)
(inst mov free-pointer temp)
(emit-label DONE)
(when (/= lowtag 0) (inst or :byte alloc-tn lowtag)))
(t
(inst add alloc-tn size)
(inst cmp alloc-tn end-addr)
(inst jmp :a NOT-INLINE)
(inst mov free-pointer alloc-tn)
(cond ((tn-p size)
(inst sub alloc-tn size)
(emit-label DONE)
(when (/= lowtag 0) (inst or :byte alloc-tn lowtag)))
(t
;; SUB can compute the result and tagify it.
;; The fallback also has to tagify.
(inst add alloc-tn (+ (- size) lowtag))
(emit-label DONE)))))
(assemble (:elsewhere)
(emit-label NOT-INLINE)
(fallback size)
(when (and (/= lowtag 0) (not temp) (not (tn-p size)))
(inst or :byte alloc-tn lowtag))
(inst jmp DONE))))))
t)
;;; Allocate an other-pointer object of fixed NWORDS with a single-word
;;; header having the specified WIDETAG value. The result is placed in
;;; RESULT-TN. NWORDS counts the header word.
(defun alloc-other (widetag nwords result-tn node alloc-temp thread-temp
&aux (bytes (pad-data-block nwords)))
(declare (ignorable thread-temp))
(let ((header (compute-object-header nwords widetag)))
#+bignum-assertions
(when (= widetag bignum-widetag) (setq bytes (* bytes 2))) ; use 2x the space
(cond ((and (not alloc-temp) (location= result-tn r12-tn))
;; this is the problematic case for INSTRUMENT-ALLOC.
;; Therefore, allocate into RAX but save it in RESULT-TN
;; and then switch them back.
(inst mov result-tn rax-tn)
(instrument-alloc widetag bytes node rax-tn thread-temp)
(pseudo-atomic (:thread-tn thread-temp)
(allocation nil bytes other-pointer-lowtag rax-tn node nil thread-temp)
(storew* header rax-tn 0 other-pointer-lowtag t))
(inst xchg rax-tn result-tn))
(t
(instrument-alloc widetag bytes node result-tn thread-temp)
(pseudo-atomic ()
(cond (alloc-temp
(allocation nil bytes 0 result-tn node alloc-temp thread-temp)
(storew* header result-tn 0 0 t)
(inst or :byte result-tn other-pointer-lowtag))
(t
(allocation nil bytes other-pointer-lowtag result-tn node nil thread-temp)
(storew* header result-tn 0 other-pointer-lowtag t))))))))
;;;; CONS, LIST and LIST*
(define-vop (list)
(:args (things :more t :scs (descriptor-reg constant immediate)))
(:temporary (:sc unsigned-reg) ptr temp)
(:temporary (:sc unsigned-reg :to (:result 0) :target result) res)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:info star cons-cells)
(:results (result :scs (descriptor-reg)))
(:node-var node)
(:generator 0
(macrolet ((store-slot (tn list &optional (slot cons-car-slot)
(lowtag list-pointer-lowtag))
`(let ((reg
;; FIXME: single-float gets placed in the boxed header
;; rather than just doing an immediate store.
(sc-case ,tn
((control-stack constant)
(move temp ,tn)
temp)
(t
(encode-value-if-immediate ,tn)))))
(storew* reg ,list ,slot ,lowtag (not stack-allocate-p) temp))))
(let ((stack-allocate-p (node-stack-allocate-p node))
(size (* (pad-data-block cons-size) cons-cells))
(lowtag (if (<= cons-cells 2) 0 list-pointer-lowtag)))
(unless stack-allocate-p
(instrument-alloc 'list size node (list ptr temp) thread-tn))
(pseudo-atomic (:elide-if stack-allocate-p :thread-tn thread-tn)
(if stack-allocate-p
(stack-allocation size lowtag res)
(allocation 'list size lowtag res node temp thread-tn))
(multiple-value-bind (last-base-reg lowtag car cdr)
(case cons-cells
(1
(values res 0 cons-car-slot cons-cdr-slot))
(2
;; Note that this does not use the 'ptr' register at all.
;; It would require a different vop to free that register up.
(store-slot (tn-ref-tn things) res cons-car-slot 0)
(setf things (tn-ref-across things))
(inst lea temp (ea (+ (* cons-size n-word-bytes) list-pointer-lowtag) res))
(store-slot temp res cons-cdr-slot 0)
(values res 0 (+ cons-size cons-car-slot) (+ cons-size cons-cdr-slot)))
(t
(move ptr res)
(dotimes (i (1- cons-cells))
(store-slot (tn-ref-tn things) ptr)
(setf things (tn-ref-across things))
(inst add ptr (pad-data-block cons-size))
(storew ptr ptr (- cons-cdr-slot cons-size)
list-pointer-lowtag))
(values ptr list-pointer-lowtag cons-car-slot cons-cdr-slot)))
(store-slot (tn-ref-tn things) last-base-reg car lowtag)
(cond (star
(setf things (tn-ref-across things))
(store-slot (tn-ref-tn things) last-base-reg cdr lowtag))
(t
(storew* nil-value last-base-reg cdr lowtag
(not stack-allocate-p))))
(cond ((<= cons-cells 2)
(if (location= result res)
(inst or :byte result list-pointer-lowtag)
(inst lea result (ea list-pointer-lowtag res))))
(t
(move result res)))))))
(aver (null (tn-ref-across things)))))
;;;; special-purpose inline allocators
;;; Special variant of 'storew' which might have a shorter encoding
;;; when storing to the heap (which starts out zero-filled).
;;; This will always write 8 bytes if WORD is a negative number.
(defun storew* (word object slot lowtag zeroed &optional temp)
(cond
((or (not zeroed) (not (typep word '(unsigned-byte 31))))
;; Will use temp reg if WORD can't be encoded as an imm32
(storew word object slot lowtag temp))
((/= word 0)
(let ((size
(cond ((typep word '(unsigned-byte 8))
:byte)
((and (not (logtest word #xff))
(typep (ash word -8) '(unsigned-byte 8)))
;; Array lengths 128 to 16384 which are multiples of 128
(setq word (ash word -8))
(decf lowtag 1) ; increment address by 1
:byte)
((and (not (logtest word #xffff))
(typep (ash word -16) '(unsigned-byte 8)))
;; etc
(setq word (ash word -16))
(decf lowtag 2) ; increment address by 2
:byte)
((typep word '(unsigned-byte 16))
:word)
(t ; must be an (unsigned-byte 31)
:dword))))
(inst mov size (ea (- (* slot n-word-bytes) lowtag) object) word)))))
;;; ALLOCATE-VECTOR
(defun store-string-trailing-null (vector type length words)
;; BASE-STRING needs to have a null terminator. The byte is inaccessible
;; to lisp, so clear it now.
(cond ((and (sc-is type immediate)
(/= (tn-value type) sb-vm:simple-base-string-widetag))) ; do nothing
((and (sc-is type immediate)
(= (tn-value type) sb-vm:simple-base-string-widetag)
(sc-is length immediate))
(inst mov :byte (ea (- (+ (ash vector-data-offset word-shift)
(tn-value length))
other-pointer-lowtag)
vector)
0))
;; Zeroizing the entire final word is easier than using LENGTH now.
((sc-is words immediate)
;; I am not convinced that this case is reachable -
;; we won't DXify a vector of unknown type.
(inst mov :qword
;; Given N data words, write to word N-1
(ea (- (ash (+ (tn-value words) vector-data-offset -1)
word-shift)
other-pointer-lowtag)
vector)
0))
(t
;; This final case is ok with 0 data words - it might clobber the LENGTH
;; slot, but subsequently we rewrite that slot.
;; But strings always have at least 1 word, so no worries either way.
(inst mov :qword
(ea (- (ash (1- vector-data-offset) word-shift)
other-pointer-lowtag)
vector
words (ash 1 (- word-shift n-fixnum-tag-bits)))
0))))
(macrolet ((calc-size-in-bytes (n-words size-tn)
`(cond ((sc-is ,n-words immediate)
(pad-data-block (+ (tn-value ,n-words) vector-data-offset)))
(t
(inst lea ,size-tn
(ea (+ lowtag-mask (* vector-data-offset n-word-bytes))
nil ,n-words (ash 1 (- word-shift n-fixnum-tag-bits))))
(inst and ,size-tn (lognot lowtag-mask))
,size-tn)))
(put-header (vector-tn lowtag type len zeroed temp)
`(let ((len (if (sc-is ,len immediate) (fixnumize (tn-value ,len)) ,len))
(type (if (sc-is ,type immediate) (tn-value ,type) ,type)))
(storew* type ,vector-tn 0 ,lowtag ,zeroed ,temp)
#+ubsan (inst mov :dword (vector-len-ea ,vector-tn ,lowtag) len)
#-ubsan (storew* len ,vector-tn vector-length-slot
,lowtag ,zeroed ,temp)))
(want-shadow-bits ()
`(and poisoned
(if (sc-is type immediate)
(/= (tn-value type) simple-vector-widetag)
:maybe)))
(calc-shadow-bits-size (reg)
`(cond ((sc-is length immediate)
;; Calculate number of dualwords (as 128 bits per dualword)
;; and multiply by 16 to get number of bytes. Also add the 2 header words.
(* 16 (+ 2 (ceiling (tn-value length) 128))))
(t
;; Compute (CEILING length 128) by adding 127, then truncating divide
;; by 128, and untag as part of the divide step.
;; Account for the two fixed words by adding in 128 more bits initially.
(inst lea :dword ,reg (ea (fixnumize (+ 128 127)) length))
(inst shr :dword ,reg 8) ; divide by 128 and untag as one operation
(inst shl :dword ,reg 4) ; multiply by 16 bytes per dualword
,reg)))
(store-originating-pc (vector)
;; Put the current program-counter into the length slot of the shadow bits
;; so that we can ascribe blame to the array's creator.
`(let ((here (gen-label)))
(emit-label here)
(inst lea temp (rip-relative-ea here))
(inst shl temp 4)
(inst mov (ea (- 8 other-pointer-lowtag) ,vector) temp))))
(define-vop (allocate-vector-on-heap)
#+ubsan (:info poisoned)
(:args (type :scs (unsigned-reg immediate))
(length :scs (any-reg immediate))
(words :scs (any-reg immediate)))
;; Result is live from the beginning, like a temp, because we use it as such
;; in 'calc-size-in-bytes'
(:results (result :scs (descriptor-reg) :from :load))
(:arg-types #+ubsan (:constant t)
positive-fixnum positive-fixnum positive-fixnum)
(:temporary (:sc unsigned-reg) temp)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:policy :fast-safe)
(:node-var node)
(:generator 100
#+ubsan
(when (want-shadow-bits)
;; allocate a vector of "written" bits unless the vector is simple-vector-T,
;; which can use unbound-marker as a poison value on reads.
(when (sc-is type unsigned-reg)
(inst cmp :byte type simple-vector-widetag)
(inst push 0)
(inst jmp :e NO-SHADOW-BITS))
;; It would be possible to do this and the array proper
;; in a single pseudo-atomic section, but I don't care to do that.
(let ((nbytes (calc-shadow-bits-size result)))
(pseudo-atomic ()
;; Allocate the bits into RESULT
(allocation nil nbytes 0 result node temp nil)
(inst mov :byte (ea result) simple-bit-vector-widetag)
(inst mov :dword (vector-len-ea result 0)
(if (sc-is length immediate) (fixnumize (tn-value length)) length))
(inst or :byte result other-pointer-lowtag)))
(store-originating-pc result)
(inst push result)) ; save the pointer to the shadow bits
NO-SHADOW-BITS
;; The LET generates instructions that needn't be pseudoatomic
;; so don't move it inside.
;; There are 3 possibilities for correctness of INSTRUMENT-ALLOC:
;; * If WORDS is not immediate, and ALLOC-TEMP is R12, then compute size
;; into ALLOC-TEMP, use RESULT as the instrumentation temp.
;; ALLOCATION receives: input = ALLOC-TEMP, output = RESULT, and no other temp
;; * If WORDS is not immediate and ALLOC-TEMP is not R12, then compute size
;; into RESULT, use ALLOC-TEMP as the instrumentation temp.
;; ALLOCATION receives: input = RESULT, output = RESULT, temp = ALLOC-TEMP.
(multiple-value-bind (size-tn instrumentation-temp alloc-temp)
(cond ((sc-is words immediate)
;; If WORDS is immediate, then let INSTRUMENT-ALLOC choose its temp
(values (calc-size-in-bytes words nil) (list result temp) temp))
((location= temp r12-tn)
;; Compute the size into TEMP, use RESULT for instrumentation.
;; Don't give another temp to ALLOCATION, because its SIZE and temp
;; can not be in the same register (which it AVERs).
(values (calc-size-in-bytes words temp) result nil))
(t
;; Compute the size into RESULT, use TEMP for instrumentation.
;; ALLOCATION needs the temp register in this case,
;; because input and output are in the same register.
(values (calc-size-in-bytes words result) temp temp)))
(instrument-alloc (if (sc-is type immediate)
(case (tn-value type)
(#.simple-vector-widetag 'simple-vector)
(t 'unboxed-array))
type)
size-tn node instrumentation-temp thread-tn)
(pseudo-atomic (:thread-tn thread-tn)
(allocation nil size-tn 0 result node alloc-temp thread-tn)
(put-header result 0 type length t alloc-temp)
(inst or :byte result other-pointer-lowtag)))
#+ubsan
(cond ((want-shadow-bits)
(inst pop temp-reg-tn) ; restore shadow bits
(inst mov (object-slot-ea result 1 other-pointer-lowtag) temp-reg-tn))
(poisoned ; uninitialized SIMPLE-VECTOR
(store-originating-pc result)))))
(define-vop (allocate-vector-on-stack)
#+ubsan (:info poisoned)
(:args (type :scs (unsigned-reg immediate))
(length :scs (any-reg immediate))
(words :scs (any-reg immediate)))
(:results (result :scs (descriptor-reg) :from :load))
(:vop-var vop)
(:arg-types #+ubsan (:constant t)
positive-fixnum positive-fixnum positive-fixnum)
#+ubsan (:temporary (:sc any-reg :offset rax-offset) rax)
#+ubsan (:temporary (:sc any-reg :offset rcx-offset) rcx)
#+ubsan (:temporary (:sc any-reg :offset rdi-offset) rdi)
(:policy :fast-safe)
(:generator 10
#+ubsan
(when (want-shadow-bits)
;; allocate a vector of "written" bits unless the vector is simple-vector-T,
;; which can use unbound-marker as a poison value on reads.
(when (sc-is type unsigned-reg) (bug "vector-on-stack: unknown type"))
(zeroize rax)
(let ((nbytes (calc-shadow-bits-size rcx)))
(stack-allocation nbytes 0 rdi)
(when (sc-is length immediate) (inst mov rcx nbytes)))
(inst rep)
(inst stos :byte) ; RAX was zeroed
(inst lea rax (ea other-pointer-lowtag rsp-tn))
(inst mov :dword (ea (- other-pointer-lowtag) rax) simple-bit-vector-widetag)
(inst mov :dword (vector-len-ea rax)
(if (sc-is length immediate) (fixnumize (tn-value length)) length))
(store-originating-pc rax))
(let ((size (calc-size-in-bytes words result)))
;; Compute tagged pointer sooner than later since access off RSP
;; requires an extra byte in the encoding anyway.
(stack-allocation size other-pointer-lowtag result
;; If already aligned RSP, don't need to do it again.
#+ubsan (want-shadow-bits))
;; NB: store the trailing null BEFORE storing the header,
;; in case the length in words is 0, which stores into the LENGTH slot
;; as if it were element -1 of data (which probably can't happen).
(store-string-trailing-null result type length words)
;; FIXME: It would be good to check for stack overflow here.
(put-header result other-pointer-lowtag type length nil nil)
)
#+ubsan
(cond ((want-shadow-bits)
(inst mov (ea (- (ash vector-length-slot word-shift) other-pointer-lowtag)
result)
rax))
(poisoned ; uninitialized SIMPLE-VECTOR
(store-originating-pc result)))))
#+linux ; unimplemented for others
(define-vop (allocate-vector-on-stack+msan-unpoison)
#+ubsan (:info poisoned)
#+ubsan (:ignore poisoned)
(:args (type :scs (unsigned-reg immediate))
(length :scs (any-reg immediate))
(words :scs (any-reg immediate)))
(:results (result :scs (descriptor-reg) :from :load))
(:arg-types #+ubsan (:constant t)
positive-fixnum positive-fixnum positive-fixnum)
;; This is a separate vop because it needs more temps.
(:temporary (:sc any-reg :offset rcx-offset) rcx)
(:temporary (:sc any-reg :offset rax-offset) rax)
(:temporary (:sc any-reg :offset rdi-offset) rdi)
(:policy :fast-safe)
(:generator 10
(let ((size (calc-size-in-bytes words result)))
;; Compute tagged pointer sooner than later since access off RSP
;; requires an extra byte in the encoding anyway.
(stack-allocation size other-pointer-lowtag result)
(store-string-trailing-null result type length words)
;; FIXME: It would be good to check for stack overflow here.
(put-header result other-pointer-lowtag type length nil nil)
(cond ((sc-is words immediate)
(inst mov rcx (+ (tn-value words) vector-data-offset)))
(t
(inst lea rcx (ea (ash vector-data-offset n-fixnum-tag-bits) words))
(inst shr rcx n-fixnum-tag-bits)))
(inst mov rdi msan-mem-to-shadow-xor-const)
(inst xor rdi rsp-tn) ; compute shadow address
(zeroize rax)
(inst rep)
(inst stos :qword)))))
;;; ALLOCATE-LIST
(macrolet ((calc-size-in-bytes (length answer)
`(cond ((sc-is ,length immediate)
(aver (/= (tn-value ,length) 0))
(* (tn-value ,length) n-word-bytes 2))
(t
(inst mov result nil-value)
(inst test ,length ,length)
(inst jmp :z done)
(inst lea ,answer
(ea nil ,length
(ash 1 (1+ (- word-shift n-fixnum-tag-bits)))))
,answer)))
(compute-end ()
`(let ((size (cond ((typep size '(or (signed-byte 32) tn))
size)
(t
(inst mov limit size)
limit))))
(inst lea limit
(ea (if (fixnump size) size 0) result
(if (fixnump size) nil size))))))
(define-vop (allocate-list-on-stack)
(:args (length :scs (any-reg immediate))
(element :scs (any-reg descriptor-reg)))
(:results (result :scs (descriptor-reg) :from :load))
(:arg-types positive-fixnum *)
(:policy :fast-safe)
(:temporary (:sc descriptor-reg) tail next limit)
(:generator 20
(let ((size (calc-size-in-bytes length next))
(loop (gen-label)))
(stack-allocation size list-pointer-lowtag result)
(compute-end)
(inst mov next result)
(emit-label LOOP)
(inst mov tail next)
(inst add next (* 2 n-word-bytes))
(storew element tail cons-car-slot list-pointer-lowtag)
;; Store the CDR even if it will be smashed to nil.
(storew next tail cons-cdr-slot list-pointer-lowtag)
(inst cmp next limit)
(inst jmp :ne loop)
(storew nil-value tail cons-cdr-slot list-pointer-lowtag))
done))
(define-vop (allocate-list-on-heap)
(:args (length :scs (any-reg immediate))
(element :scs (any-reg descriptor-reg)
:load-if (not (and (sc-is element immediate)
(eql (tn-value element) 0)))))
(:results (result :scs (descriptor-reg) :from :load))
(:arg-types positive-fixnum *)
(:policy :fast-safe)
(:node-var node)
(:temporary (:sc descriptor-reg) tail next limit)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:generator 20
(let ((size (calc-size-in-bytes length tail))
(entry (gen-label))
(loop (gen-label))
(no-init
(and (sc-is element immediate) (eql (tn-value element) 0))))
(instrument-alloc 'list size node (list next limit) thread-tn)
(pseudo-atomic (:thread-tn thread-tn)
(allocation 'list size list-pointer-lowtag result node limit thread-tn)
(compute-end)
(inst mov next result)
(inst jmp entry)
(emit-label LOOP)
(storew next tail cons-cdr-slot list-pointer-lowtag)
(emit-label ENTRY)
(inst mov tail next)
(inst add next (* 2 n-word-bytes))
(unless no-init ; don't bother writing zeros in the CARs
(storew element tail cons-car-slot list-pointer-lowtag))
(inst cmp next limit)
(inst jmp :ne loop))
(storew nil-value tail cons-cdr-slot list-pointer-lowtag))
done)))
#-immobile-space
(define-vop (make-fdefn)
(:policy :fast-safe)
(:translate make-fdefn)
(:args (name :scs (descriptor-reg) :to :eval))
(:results (result :scs (descriptor-reg) :from :argument))
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:node-var node)
(:generator 37
(alloc-other fdefn-widetag fdefn-size result node nil thread-tn)
(storew name result fdefn-name-slot other-pointer-lowtag)
(storew nil-value result fdefn-fun-slot other-pointer-lowtag)
(storew (make-fixup 'undefined-tramp :assembly-routine)
result fdefn-raw-addr-slot other-pointer-lowtag)))
(define-vop (make-closure)
; (:args (function :to :save :scs (descriptor-reg)))
(:info label length stack-allocate-p)
(:temporary (:sc any-reg) temp)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:results (result :scs (descriptor-reg)))
(:node-var node)
(:generator 10
(let* ((words (+ length closure-info-offset)) ; including header
(bytes (pad-data-block words))
(header (logior (ash (1- words) n-widetag-bits) closure-widetag)))
(unless stack-allocate-p
(instrument-alloc closure-widetag bytes node (list result temp) thread-tn))
(pseudo-atomic (:elide-if stack-allocate-p :thread-tn thread-tn)
(if stack-allocate-p
(stack-allocation bytes fun-pointer-lowtag result)
(allocation nil bytes fun-pointer-lowtag result node temp thread-tn))
(storew* #-immobile-space header ; write the widetag and size
#+immobile-space ; ... plus the layout pointer
(progn (inst mov temp header)
(inst or temp #-sb-thread (static-symbol-value-ea 'function-layout)
#+sb-thread
(thread-slot-ea thread-function-layout-slot))
temp)
result 0 fun-pointer-lowtag (not stack-allocate-p)))
;; Finished with the pseudo-atomic instructions
(when label
(inst lea temp (rip-relative-ea label (ash simple-fun-insts-offset word-shift)))
(storew temp result closure-fun-slot fun-pointer-lowtag)
#+metaspace
(let ((origin (sb-assem::asmstream-data-origin-label sb-assem:*asmstream*)))
(inst lea temp (rip-relative-ea origin :code))
(storew temp result closure-code-slot fun-pointer-lowtag))))))
;;; The compiler likes to be able to directly make value cells.
(define-vop (make-value-cell)
(:args (value :scs (descriptor-reg any-reg) :to :result))
(:results (result :scs (descriptor-reg) :from :eval))
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:info stack-allocate-p)
(:node-var node)
(:generator 10
(cond (stack-allocate-p
(stack-allocation (pad-data-block value-cell-size) other-pointer-lowtag result)
(let ((header (compute-object-header value-cell-size value-cell-widetag)))
(storew header result 0 other-pointer-lowtag)))
(t
(alloc-other value-cell-widetag value-cell-size result node nil thread-tn)))
(storew value result value-cell-value-slot other-pointer-lowtag)))
;;;; automatic allocators for primitive objects
(define-vop (make-funcallable-instance-tramp)
(:args)
(:results (result :scs (any-reg)))
(:vop-var vop)
(:generator 1
(let ((tramp (make-fixup 'funcallable-instance-tramp :assembly-routine)))
(if (sb-c::code-immobile-p vop)
(inst lea result (ea tramp rip-tn))
(inst mov result tramp)))))
(define-vop (fixed-alloc)
(:args)
(:info name words type lowtag stack-allocate-p)
(:results (result :scs (descriptor-reg)))
(:temporary (:sc unsigned-reg) alloc-temp)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:node-var node)
(:generator 50
(let* ((instancep (typep type 'wrapper)) ; is this an instance type?
(bytes (pad-data-block words)))
#+bignum-assertions
(when (eq type bignum-widetag) (setq bytes (* bytes 2))) ; use 2x the space
(progn name) ; possibly not used
(unless stack-allocate-p
(instrument-alloc type bytes node (list result alloc-temp) thread-tn))
(pseudo-atomic (:elide-if stack-allocate-p :thread-tn thread-tn)
;; If storing a header word, defer ORing in the lowtag until after
;; the header is written so that displacement can be 0.
(if stack-allocate-p
(stack-allocation bytes (if type 0 lowtag) result)
(allocation nil bytes (if type 0 lowtag) result node alloc-temp thread-tn))
(when type
(let* ((widetag (if instancep instance-widetag type))
(header (compute-object-header words widetag)))
(if (or #+compact-instance-header
(and (eq name '%make-structure-instance) stack-allocate-p))
;; Write a :DWORD, not a :QWORD, because the high half will be
;; filled in when the layout is stored. Can't use STOREW* though,
;; because it tries to store as few bytes as possible,
;; where this instruction must write exactly 4 bytes.
(inst mov :dword (ea 0 result) header)
(storew* header result 0 0 (not stack-allocate-p)))
(inst or :byte result lowtag))))
(when instancep ; store its layout
(inst mov :dword (ea (+ 4 (- lowtag)) result)
(make-fixup type :layout))))))
;;; Allocate a non-vector variable-length object.
;;; Exactly 4 allocators are rendered via this vop:
;;; BIGNUM (%ALLOCATE-BIGNUM)
;;; FUNCALLABLE-INSTANCE (%MAKE-FUNCALLABLE-INSTANCE)
;;; CLOSURE (%ALLOC-CLOSURE)
;;; INSTANCE (%MAKE-INSTANCE)
;;; WORDS accounts for the mandatory slots *including* the header.
;;; EXTRA is the variable payload, also measured in words.
(define-vop (var-alloc)
(:args (extra :scs (any-reg)))
(:arg-types positive-fixnum)
(:info name words type lowtag stack-allocate-p)
(:ignore name)
(:results (result :scs (descriptor-reg) :from (:eval 1)))
(:temporary (:sc unsigned-reg :from :eval :to (:eval 1)) bytes)
(:temporary (:sc unsigned-reg :from :eval :to :result) header)
;; KLUDGE: wire to RAX so that it doesn't get R12
(:temporary (:sc unsigned-reg :offset 0) alloc-temp)
#+gs-seg (:temporary (:sc unsigned-reg :offset 15) thread-tn)
(:node-var node)
(:generator 50
;; With the exception of bignums, these objects have effectively
;; 32-bit headers because the high 4 byes contain a layout pointer.
(let ((operand-size (if (= type bignum-widetag) :qword :dword)))
(inst lea operand-size bytes
(ea (* (1+ words) n-word-bytes) nil
extra (ash 1 (- word-shift n-fixnum-tag-bits))))
(inst mov operand-size header bytes)
(inst shl operand-size header (- (length-field-shift type) word-shift)) ; w+1 to length field
(inst lea operand-size header ; (w-1 << 8) | type
(ea (+ (ash -2 (length-field-shift type)) type) header))
(inst and operand-size bytes (lognot lowtag-mask)))
#+bignum-assertions
(when (= type bignum-widetag) (inst shl :dword bytes 1)) ; use 2x the space
(cond (stack-allocate-p
(stack-allocation bytes lowtag result)
(storew header result 0 lowtag))
(t
;; can't pass RESULT as a possible choice of scratch register
;; because it might be in the same physical reg as BYTES.
;; Yup, the lifetime specs in this vop are pretty confusing.
(instrument-alloc type bytes node alloc-temp thread-tn)
(pseudo-atomic (:thread-tn thread-tn)
(allocation nil bytes lowtag result node alloc-temp thread-tn)
(storew header result 0 lowtag))))))
(macrolet ((c-call (name)
`(let ((c-fun (make-fixup ,name :foreign)))
(inst call (cond ((sb-c::code-immobile-p node) c-fun)
(t (progn (inst mov rax c-fun) rax)))))))
#+immobile-space
(define-vop (alloc-immobile-fixedobj)
(:args (size-class :scs (any-reg) :target c-arg1)
(nwords :scs (any-reg) :target c-arg2)
(header :scs (any-reg) :target c-arg3))
(:temporary (:sc unsigned-reg :from (:argument 0) :to :eval :offset rdi-offset) c-arg1)
(:temporary (:sc unsigned-reg :from (:argument 1) :to :eval :offset rsi-offset) c-arg2)
(:temporary (:sc unsigned-reg :from (:argument 2) :to :eval :offset rdx-offset) c-arg3)
(:temporary (:sc unsigned-reg :from :eval :to (:result 0) :offset rax-offset) rax)
(:results (result :scs (descriptor-reg)))
(:node-var node)
(:generator 50
(inst mov c-arg1 size-class)
(inst mov c-arg2 nwords)
(inst mov c-arg3 header)
;; RSP needn't be restored because the allocators all return immediately
;; which has that effect
(inst and rsp-tn -16)
(pseudo-atomic ()
(c-call "alloc_immobile_fixedobj")
(move result rax))))
(define-vop (alloc-dynamic-space-code)
(:args (total-words :scs (signed-reg) :target c-arg1))
(:temporary (:sc unsigned-reg :from (:argument 0) :to :eval :offset rdi-offset) c-arg1)
(:temporary (:sc unsigned-reg :from :eval :to (:result 0) :offset rax-offset) rax)
(:results (result :scs (descriptor-reg)))
(:node-var node)
(:generator 50
(inst mov c-arg1 total-words)
;; RSP needn't be restored because the allocators all return immediately
;; which has that effect
(inst and rsp-tn -16)
(pseudo-atomic () (c-call "alloc_code_object"))
;; RESULT is a tagged ptr. MOV doesn't need to be inside the PSEUDO-ATOMIC.
(inst mov result rax)))
) ; end MACROLET