From: Andrea Corallo <akrl@sdf.org>
Date: Wed, 23 Dec 2020 10:47:36 +0000 (+0100)
Subject: * Follow cstr basic blocks to perform latch recognition
X-Git-Tag: emacs-28.0.90~2727^2~232
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=c90aa68d90b1c5805d3d6327a058098d938ac72f;p=emacs.git

* Follow cstr basic blocks to perform latch recognition

	* lisp/emacs-lisp/comp.el (comp-fwprop-insn): Fix latch
	recognition.
---

diff --git a/lisp/emacs-lisp/comp.el b/lisp/emacs-lisp/comp.el
index 2f8587909e6..485e5dc6ad2 100644
--- a/lisp/emacs-lisp/comp.el
+++ b/lisp/emacs-lisp/comp.el
@@ -2540,9 +2540,12 @@ Fold the call in case."
     (`(phi ,lval . ,rest)
      (let* ((from-latch (cl-some
                          (lambda (x)
-                           (comp-latch-p
-                            (gethash (cdr x)
-                                     (comp-func-blocks comp-func))))
+                           (let* ((bb-name (cadr x))
+                                  (bb (gethash bb-name
+                                               (comp-func-blocks comp-func))))
+                             (or (comp-latch-p bb)
+                                 (when (comp-block-cstr-p bb)
+                                   (comp-latch-p (car (comp-block-preds bb)))))))
                          rest))
             (prop-fn (if from-latch
                          #'comp-cstr-union-no-range