[Sbcl-commits] CVS: sbcl/src/compiler/x86 insts.lisp,1.30,1.31 type-vops.lisp,1.16,1.17

[Christophe R. <cr...@us...>]

Update of /cvsroot/sbcl/sbcl/src/compiler/x86
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv14330/src/compiler/x86

Modified Files:
	insts.lisp type-vops.lisp 
Log Message:
0.8.13.7:
	Just for fun: implement the Intel prefetch instructions, and 
	conditionally use (one of) them in typetag checking
	... no, it doesn't make anything noticeably faster; why do you 
		ask?


Index: insts.lisp
===================================================================
RCS file: /cvsroot/sbcl/sbcl/src/compiler/x86/insts.lisp,v
retrieving revision 1.30
retrieving revision 1.31
diff -u -d -r1.30 -r1.31
--- insts.lisp	15 Apr 2004 17:47:13 -0000	1.30
+++ insts.lisp	27 Jul 2004 17:56:35 -0000	1.31
@@ -615,6 +615,14 @@
   (disp :field (byte 16 8))
   (level :field (byte 8 24)))
 
+(sb!disassem:define-instruction-format (prefetch 24
+						 :default-printer
+						 '(:name ", " reg/mem))
+  (prefix :field (byte 8 0) :value #b00001111)
+  (op :field (byte 8 8) :value #b00011000)
+  (reg/mem :fields (list (byte 2 22) (byte 3 16)) :type 'byte-reg/mem)
+  (reg :field (byte 3 19) :type 'reg))
+
 ;;; Single byte instruction with an immediate byte argument.
 (sb!disassem:define-instruction-format (byte-imm 16
 				     :default-printer '(:name :tab code))
@@ -1840,6 +1848,43 @@
   (:emitter
    (emit-byte segment #b11001001)))
 
+;;;; prefetch
+(define-instruction prefetchnta (segment ea)
+  (:printer prefetch ((op #b00011000) (reg #b000)))
+  (:emitter
+   (aver (typep ea 'ea))
+   (aver (eq :byte (ea-size ea)))
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b00011000)
+   (emit-ea segment ea #b000)))
+
+(define-instruction prefetcht0 (segment ea)
+  (:printer prefetch ((op #b00011000) (reg #b001)))
+  (:emitter
+   (aver (typep ea 'ea))
+   (aver (eq :byte (ea-size ea)))
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b00011000)
+   (emit-ea segment ea #b001)))
+
+(define-instruction prefetcht1 (segment ea)
+  (:printer prefetch ((op #b00011000) (reg #b010)))
+  (:emitter
+   (aver (typep ea 'ea))
+   (aver (eq :byte (ea-size ea)))
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b00011000)
+   (emit-ea segment ea #b010)))
+
+(define-instruction prefetcht2 (segment ea)
+  (:printer prefetch ((op #b00011000) (reg #b011)))
+  (:emitter
+   (aver (typep ea 'ea))
+   (aver (eq :byte (ea-size ea)))
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b00011000)
+   (emit-ea segment ea #b011)))
+
 ;;;; interrupt instructions
 
 (defun snarf-error-junk (sap offset &optional length-only)

Index: type-vops.lisp
===================================================================
RCS file: /cvsroot/sbcl/sbcl/src/compiler/x86/type-vops.lisp,v
retrieving revision 1.16
retrieving revision 1.17
diff -u -d -r1.16 -r1.17
--- type-vops.lisp	1 Mar 2004 23:22:26 -0000	1.16
+++ type-vops.lisp	27 Jul 2004 17:56:35 -0000	1.17
@@ -62,6 +62,14 @@
   (unless al-loaded
     (move eax-tn value)
     (inst and 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
+  ;; many of these prefetch instructions; pointed-to objects are very
+  ;; often in the cache anyway; etc. etc.  Still, as proof-of-concept,
+  ;; 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))