X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86%2Fsystem.lisp;h=9b66ca0a565f9ddf44b2a7cf488feb36cdccb050;hb=7deecae2d959173eda6a153d490c752c32050a9e;hp=f3a65a3e0d8b947a304bf7bba284227bb7282e7e;hpb=2e28fe9a277201b4b96f052794b8eeaaccf9aa95;p=sbcl.git diff --git a/src/compiler/x86/system.lisp b/src/compiler/x86/system.lisp index f3a65a3..9b66ca0 100644 --- a/src/compiler/x86/system.lisp +++ b/src/compiler/x86/system.lisp @@ -44,7 +44,7 @@ (inst jmp :ne done) ;; Pick off fixnums. - (inst and al-tn 3) + (inst and al-tn fixnum-tag-mask) (inst jmp :e done) ;; must be an other immediate @@ -85,9 +85,7 @@ (:result-types positive-fixnum) (:generator 6 (move eax type) - (inst mov - (make-ea :byte :base function :disp (- fun-pointer-lowtag)) - al-tn) + (storeb al-tn function 0 fun-pointer-lowtag) (move result eax))) (define-vop (get-header-data) @@ -126,14 +124,16 @@ (storew eax x 0 other-pointer-lowtag) (move res x))) -(define-vop (make-fixnum) +(define-vop (pointer-hash) + (:translate pointer-hash) (:args (ptr :scs (any-reg descriptor-reg) :target res)) (:results (res :scs (any-reg descriptor-reg))) + (:policy :fast-safe) (:generator 1 - ;; Some code (the hash table code) depends on this returning a - ;; positive number so make sure it does. (move res ptr) - (inst shl res 3) + ;; Mask the lowtag, and shift the whole address into a positive + ;; fixnum. + (inst and res (lognot lowtag-mask)) (inst shr res 1))) (define-vop (make-other-immediate-type) @@ -142,7 +142,7 @@ (:results (res :scs (any-reg descriptor-reg) :from (:argument 0))) (:generator 2 (move res val) - (inst shl res (- n-widetag-bits 2)) + (inst shl res (- n-widetag-bits n-fixnum-tag-bits)) (inst or res (sc-case type (unsigned-reg type) (immediate (tn-value type)))))) @@ -240,10 +240,8 @@ (:temporary (:sc any-reg :from (:argument 0) :to :result) temp) (:results (result :scs (descriptor-reg))) (:generator 3 - (inst lea temp - (make-ea :byte :base new-self - :disp (- (ash simple-fun-code-offset word-shift) - fun-pointer-lowtag))) + (inst lea temp (make-ea-for-object-slot new-self simple-fun-code-offset + fun-pointer-lowtag)) (storew temp function simple-fun-self-slot fun-pointer-lowtag) (move result new-self))) @@ -269,8 +267,7 @@ (:arg-types unsigned-num) (:policy :fast-safe) (:generator 2 - (inst fs-segment-prefix) - (inst mov sap (make-ea :dword :disp 0 :index n :scale 4)))) + (inst mov sap (make-ea :dword :disp 0 :index n :scale 4) :fs))) (define-vop (halt) (:generator 1 @@ -286,13 +283,72 @@ (note-next-instruction vop :internal-error) (inst wait))) -;;;; dynamic vop count collection support +;;;; Miscellany + +;;; the RDTSC instruction (present on Pentium processors and +;;; successors) allows you to access the time-stamp counter, a 64-bit +;;; model-specific register that counts executed cycles. The +;;; instruction returns the low cycle count in EAX and high cycle +;;; count in EDX. +;;; +;;; In order to obtain more significant results on out-of-order +;;; processors (such as the Pentium II and later), we issue a +;;; serializing CPUID instruction before reading the cycle counter. +;;; This instruction is used for its side effect of emptying the +;;; processor pipeline, to ensure that the RDTSC instruction is +;;; executed once all pending instructions have been completed. +;;; CPUID writes to EBX and ECX in addition to EAX and EDX, so +;;; they need to be added as temporaries. +;;; +;;; Note that cache effects mean that the cycle count can vary for +;;; different executions of the same code (it counts cycles, not +;;; retired instructions). Furthermore, the results are per-processor +;;; and not per-process, so are unreliable on multiprocessor machines +;;; where processes can migrate between processors. +;;; +;;; This method of obtaining a cycle count has the advantage of being +;;; very fast (around 20 cycles), and of not requiring a system call. +;;; However, you need to know your processor's clock speed to translate +;;; this into real execution time. +;;; +;;; FIXME: This about the WITH-CYCLE-COUNTER interface a bit, and then +;;; perhaps export it from SB-SYS. + +(defknown %read-cycle-counter () (values (unsigned-byte 32) (unsigned-byte 32)) ()) + +(define-vop (%read-cycle-counter) + (:policy :fast-safe) + (:translate %read-cycle-counter) + (:temporary (:sc unsigned-reg :offset eax-offset :target lo) eax) + (:temporary (:sc unsigned-reg :offset edx-offset :target hi) edx) + (:temporary (:sc unsigned-reg :offset ebx-offset) ebx) + (:temporary (:sc unsigned-reg :offset ecx-offset) ecx) + (:ignore ebx ecx) + (:results (hi :scs (unsigned-reg)) + (lo :scs (unsigned-reg))) + (:result-types unsigned-num unsigned-num) + (:generator 5 + (inst xor eax eax) + ;; Intel docs seem quite consistent on only using CPUID before RDTSC, + ;; not both before and after. Go figure. + (inst cpuid) + (inst rdtsc) + (move lo eax) + (move hi edx))) + +(defmacro with-cycle-counter (&body body) + "Returns the primary value of BODY as the primary value, and the +number of CPU cycles elapsed as secondary value. EXPERIMENTAL." + (with-unique-names (hi0 hi1 lo0 lo1) + `(multiple-value-bind (,hi0 ,lo0) (%read-cycle-counter) + (values (locally ,@body) + (multiple-value-bind (,hi1 ,lo1) (%read-cycle-counter) + (+ (ash (- ,hi1 ,hi0) 32) + (- ,lo1 ,lo0))))))) #!+sb-dyncount (define-vop (count-me) (:args (count-vector :scs (descriptor-reg))) (:info index) (:generator 0 - (inst inc (make-ea-for-object-slot count-vector - (+ vector-data-offset index) - other-pointer-lowtag)))) + (inst inc (make-ea-for-vector-data count-vector :offset index))))