Changeset 14966

Timestamp:

Aug 31, 2011, 1:20:21 PM (13 years ago)

Author:

R. Matthew Emerson

Message:

In arm2-elide-pushes, instead of pushing/popping a double-float register,
copy it to/from an otherwise-unused FPR if possible.

File:

• trunk/source/compiler/ARM/arm2.lisp (modified) (1 diff)

trunk/source/compiler/ARM/arm2.lisp

@@ -2876 +2876 @@
                                       (vinsn-sequence-sets-reg-p
                                        push-vinsn pop-vinsn popped-reg))))
-            (unless (and pushed-reg-is-set popped-reg-is-set)
-              (unless same-reg
-                (let* ((copy (if (eq (hard-regspec-class pushed-reg)
-                                     hard-reg-class-fpr)
-                               (if (eql (get-regspec-mode pushed-reg)
-                                        hard-reg-class-fpr-mode-single)
-                                 (! single-to-single popped-reg pushed-reg)
-                                 (! double-to-double popped-reg pushed-reg))
-                               (! copy-gpr popped-reg pushed-reg))))
-                  (remove-dll-node copy)
-                  (if pushed-reg-is-set
-                    (insert-dll-node-after copy push-vinsn)
-                    (insert-dll-node-before copy push-vinsn))))
-              (elide-vinsn push-vinsn)
-              (elide-vinsn pop-vinsn))))))))
+            (cond
+              ((not (and pushed-reg-is-set popped-reg-is-set))
+               (unless same-reg
+                 (let* ((copy (if (eq (hard-regspec-class pushed-reg)
+                                      hard-reg-class-fpr)
+                                (if (eql (get-regspec-mode pushed-reg)
+                                         hard-reg-class-fpr-mode-single)
+                                  (! single-to-single popped-reg pushed-reg)
+                                  (! double-to-double popped-reg pushed-reg))
+                                (! copy-gpr popped-reg pushed-reg))))
+                   (remove-dll-node copy)
+                   (if pushed-reg-is-set
+                     (insert-dll-node-after copy push-vinsn)
+                     (insert-dll-node-before copy push-vinsn))))
+               (elide-vinsn push-vinsn)
+               (elide-vinsn pop-vinsn))
+              ((and (eql (hard-regspec-class pushed-reg) hard-reg-class-fpr)
+                    (eql (get-regspec-mode pushed-reg)
+                         hard-reg-class-fpr-mode-double))
+               ;; If we're pushing a double-float register that gets
+               ;; set by the intervening vinsns, try to copy it to and
+               ;; from a free FPR instead.
+               (multiple-value-bind (used-gprs used-fprs)
+                   (regs-set-in-vinsn-sequence push-vinsn pop-vinsn)
+                 (declare (ignore used-gprs))
+                 (let* ((nfprs 16)
+                        (free-fpr
+                         (dotimes (r nfprs nil)
+                           (unless (logtest (target-fpr-mask r :double-float)
+                                            used-fprs)
+                             (return r)))))
+                   (when free-fpr
+                     (let* ((reg ($ free-fpr :class :fpr :mode :double-float))
+                            (save (! double-to-double reg pushed-reg))
+                            (restore (! double-to-double popped-reg reg)))
+                       (remove-dll-node save)
+                       (insert-dll-node-after save push-vinsn)
+                       (remove-dll-node restore)
+                       (insert-dll-node-before restore pop-vinsn)
+                       (elide-vinsn push-vinsn)
+                       (elide-vinsn pop-vinsn)))))))))))))