From ba43793e0351ee798d912bfb77d14d8f28edda9c Mon Sep 17 00:00:00 2001
From: Nathan Froyd <froydnj@cs.rice.edu>
Date: Wed, 6 Jan 2010 05:05:43 +0000
Subject: [PATCH] 1.0.34.4: micro-optimize widetag checking on x86oids

If we are checking a range of widetags and there are no more widetags to
check, we can tweak the widetag and do a single, unsigned comparison.
---
 src/compiler/x86-64/type-vops.lisp |   42 +++++++++++++++++++++++++-----------
 src/compiler/x86/type-vops.lisp    |   34 ++++++++++++++++++-----------
 version.lisp-expr                  |    2 +-
 3 files changed, 52 insertions(+), 26 deletions(-)

diff --git a/src/compiler/x86-64/type-vops.lisp b/src/compiler/x86-64/type-vops.lisp
index d8e49e0..0735c08 100644
--- a/src/compiler/x86-64/type-vops.lisp
+++ b/src/compiler/x86-64/type-vops.lisp
@@ -83,13 +83,14 @@
 (defun %test-headers (value target not-p function-p headers
                             &optional (drop-through (gen-label)))
   (let ((lowtag (if function-p fun-pointer-lowtag other-pointer-lowtag)))
-    (multiple-value-bind (equal less-or-equal when-true when-false)
-        ;; EQUAL and LESS-OR-EQUAL are the conditions for branching to TARGET.
-        ;; WHEN-TRUE and WHEN-FALSE are the labels to branch to when we know
-        ;; it's true and when we know it's false respectively.
+    (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 branching to TARGET.  WHEN-TRUE and WHEN-FALSE are the
+        ;; labels to branch to when we know it's true and when we know
+        ;; it's false respectively.
         (if not-p
-            (values :ne :a drop-through target)
-            (values :e :na target drop-through))
+            (values :ne :a :b drop-through target)
+            (values :e :na :nb target drop-through))
       (%test-lowtag value when-false t lowtag)
       (inst mov al-tn (make-ea :byte :base value :disp (- lowtag)))
       (do ((remaining headers (cdr remaining)))
@@ -105,13 +106,28 @@
            (t
              (let ((start (car header))
                    (end (cdr header)))
-               (unless (= start bignum-widetag)
-                 (inst cmp al-tn start)
-                 (inst jmp :b when-false)) ; was :l
-               (inst cmp al-tn end)
-               (if last
-                   (inst jmp less-or-equal target)
-                   (inst jmp :be when-true))))))) ; was :le
+               (cond
+                 ((= start bignum-widetag)
+                  (inst cmp al-tn end)
+                  (if last
+                      (inst jmp less-or-equal target)
+                      (inst jmp :be when-true)))
+                 ((= end complex-array-widetag)
+                  (inst cmp al-tn start)
+                  (if last
+                      (inst jmp greater-or-equal target)
+                      (inst jmp :b when-false)))
+                 ((not last)
+                  (inst cmp al-tn start)
+                  (inst jmp :b when-false)
+                  (inst cmp al-tn end)
+                  (if last
+                      (inst jmp less-or-equal target)
+                      (inst jmp :be when-true)))
+                 (t
+                  (inst sub al-tn start)
+                  (inst cmp al-tn (- end start))
+                  (inst jmp less-or-equal target))))))))
       (emit-label drop-through))))
 
 
diff --git a/src/compiler/x86/type-vops.lisp b/src/compiler/x86/type-vops.lisp
index 0284ae4..1738be3 100644
--- a/src/compiler/x86/type-vops.lisp
+++ b/src/compiler/x86/type-vops.lisp
@@ -127,18 +127,28 @@
                      ;; was true.
                      (return))
                     (t
-                     (unless (= start bignum-widetag)
-                       (inst cmp al-tn start)
-                       (if (= end complex-array-widetag)
-                           (progn
-                             (aver last)
-                             (inst jmp greater-or-equal target))
-                           (inst jmp :b when-false))) ; was :l
-                     (unless (= end complex-array-widetag)
-                       (inst cmp al-tn end)
-                       (if last
-                           (inst jmp less-or-equal target)
-                           (inst jmp :be when-true)))))))))))) ; was :le
+                     (cond
+                       ((= start bignum-widetag)
+                        (inst cmp al-tn end)
+                        (if last
+                            (inst jmp less-or-equal target)
+                            (inst jmp :be when-true)))
+                       ((= end complex-array-widetag)
+                        (inst cmp al-tn start)
+                        (if last
+                            (inst jmp greater-or-equal target)
+                            (inst jmp :b when-false)))
+                       ((not last)
+                        (inst cmp al-tn start)
+                        (inst jmp :b when-false)
+                        (inst cmp al-tn end)
+                        (if last
+                            (inst jmp less-or-equal target)
+                            (inst jmp :be when-true)))
+                       (t
+                        (inst sub al-tn start)
+                        (inst cmp al-tn (- end start))
+                        (inst jmp less-or-equal target))))))))))))
       (emit-label drop-through))))
 
 ;;;; type checking and testing
diff --git a/version.lisp-expr b/version.lisp-expr
index e8a3822..0274c6f 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".)
-"1.0.34.3"
+"1.0.34.4"
-- 
1.7.10.4