From e832f8694dff1aa86664554f35ac625561dcbd96 Mon Sep 17 00:00:00 2001 From: Nathan Froyd Date: Sun, 18 Apr 2010 19:28:02 +0000 Subject: [PATCH] 1.0.37.58: micro-optimize x86 lowtag testing Instead of MOV/AND/CMP, use LEA/TEST, which is one byte shorter. Delete AL-LOADED in %TEST-LOWTAG and %TEST-HEADERS as well, since that parameter is unused and attempting to make the above optimization work in the face of that option would be tricky. --- src/compiler/x86/type-vops.lisp | 24 +++++++++++------------- version.lisp-expr | 2 +- 2 files changed, 12 insertions(+), 14 deletions(-) diff --git a/src/compiler/x86/type-vops.lisp b/src/compiler/x86/type-vops.lisp index 1738be3..a8efea6 100644 --- a/src/compiler/x86/type-vops.lisp +++ b/src/compiler/x86/type-vops.lisp @@ -41,10 +41,9 @@ (inst cmp al-tn immediate)))) (inst jmp (if not-p :ne :e) target)) -(defun %test-lowtag (value target not-p lowtag &optional al-loaded) - (unless al-loaded - (move eax-tn value) - (inst and al-tn lowtag-mask)) +(defun %test-lowtag (value target not-p lowtag) + (inst lea eax-tn (make-ea :dword :base value :disp (- lowtag))) + (inst test al-tn lowtag-mask) ;; FIXME: another 'optimization' which doesn't appear to work: ;; prefetching the hypothetically pointed-to version should help, ;; but this is in fact non-ideal in plenty of ways: we emit way too @@ -53,11 +52,10 @@ ;; not too bad. -- CSR, 2004-07-27 (when (member :prefetch *backend-subfeatures*) (inst prefetchnta (make-ea :byte :base value :disp (- lowtag)))) - (inst cmp al-tn lowtag) (inst jmp (if not-p :ne :e) target)) (defun %test-headers (value target not-p function-p headers - &optional (drop-through (gen-label)) al-loaded) + &optional (drop-through (gen-label))) (let ((lowtag (if function-p fun-pointer-lowtag other-pointer-lowtag))) (multiple-value-bind (equal less-or-equal greater-or-equal when-true when-false) ;; EQUAL, LESS-OR-EQUAL and GREATER-OR-EQUAL are the conditions for @@ -67,7 +65,7 @@ (if not-p (values :ne :a :b drop-through target) (values :e :na :nb target drop-through)) - (%test-lowtag value when-false t lowtag al-loaded) + (%test-lowtag value when-false t lowtag) (cond ((and (null (cdr headers)) (numberp (car headers))) @@ -255,9 +253,9 @@ (values target not-target)) (generate-fixnum-test value) (inst jmp :e yep) - (move eax-tn value) - (inst and al-tn lowtag-mask) - (inst cmp al-tn other-pointer-lowtag) + (inst lea eax-tn (make-ea :dword :base value + :disp (- other-pointer-lowtag))) + (inst test al-tn lowtag-mask) (inst jmp :ne nope) (loadw eax-tn value 0 other-pointer-lowtag) (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag)) @@ -271,9 +269,9 @@ value))) (generate-fixnum-test value) (inst jmp :e yep) - (move eax-tn value) - (inst and al-tn lowtag-mask) - (inst cmp al-tn other-pointer-lowtag) + (inst lea eax-tn (make-ea :dword :base value + :disp (- other-pointer-lowtag))) + (inst test al-tn lowtag-mask) (inst jmp :ne nope) (loadw eax-tn value 0 other-pointer-lowtag) (inst cmp eax-tn (+ (ash 1 n-widetag-bits) bignum-widetag)) diff --git a/version.lisp-expr b/version.lisp-expr index afd03dc..c2d58bf 100644 --- a/version.lisp-expr +++ b/version.lisp-expr @@ -17,4 +17,4 @@ ;;; checkins which aren't released. (And occasionally for internal ;;; versions, especially for internal versions off the main CVS ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".) -"1.0.37.57" +"1.0.37.58" -- 1.7.10.4