1.0.20.14: align loops on x86-64

 * Intel recommends 16 byte alignment for branch target, and since
   code objects are 16 byte aligned on x86-64, we can get it.

diff --git a/src/compiler/codegen.lisp b/src/compiler/codegen.lisp
index e35909d..da07167 100644 (file)
--- a/src/compiler/codegen.lisp
+++ b/src/compiler/codegen.lisp
@@ -133,6 +133,18 @@
         (when (and (eq (block-info 1block) block)
                    (block-start 1block))
           (sb!assem:assemble (*code-segment*)
+            ;; Align first emitted block of each loop: x86 and x86-64 both
+            ;; like 16 byte alignment, however, since x86 aligns code objects
+            ;; on 8 byte boundaries we cannot guarantee proper loop alignment
+            ;; there (yet.)
+            #!+x86-64
+            (let ((cloop (sb!c::block-loop 1block)))
+              (when (and cloop
+                         (sb!c::loop-tail cloop)
+                         (not (sb!c::loop-info cloop)))
+                (sb!assem:align sb!vm:n-lowtag-bits #x90)
+                ;; Mark the loop as aligned by saving the IR1 block aligned.
+                (setf (sb!c::loop-info cloop) 1block)))
             (sb!assem:emit-label (block-label 1block)))
           (let ((env (block-physenv 1block)))
             (unless (eq env prev-env)

diff --git a/src/compiler/vop.lisp b/src/compiler/vop.lisp
index fbd0056..9f7ace3 100644 (file)
--- a/src/compiler/vop.lisp
+++ b/src/compiler/vop.lisp
@@ -430,7 +430,7 @@
   ;;
   ;;    :STRANGE
   ;;        A segment of a "strange loop" in a non-reducible flow graph.
-  (kind (required-argument) :type (member :outer :natural :strange))
+  (kind (missing-arg) :type (member :outer :natural :strange))
   ;; The first and last blocks in the loop.  There may be more than one tail,
   ;; since there may be multiple back branches to the same head.
   (head nil :type (or cblock null))
@@ -446,7 +446,9 @@
   (depth 0 :type fixnum)
   ;; The head of the list of blocks directly within this loop.  We must recurse
   ;; on INFERIORS to find all the blocks.
-  (blocks nil :type (or null cblock)))
+  (blocks nil :type (or null cblock))
+  ;; Backend saves the first emitted block of each loop here.
+  (info nil))
 
 (defprinter (cloop :conc-name loop-)
   kind

diff --git a/version.lisp-expr b/version.lisp-expr
index 9d5513a..babdc8f 100644 (file)
--- 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".)
-"1.0.20.13"
+"1.0.20.14"