Changeset 14893

Timestamp:

Jul 20, 2011, 11:04:36 AM (13 years ago)

Author:

Gary Byers

Message:

ACODE-CONSTANT-P returns (values constant-value constant-p), not
what ACODE-CONSTANT-FOLD-BINOP expects. (There was some other
function that did it the other way, but there was a bootstrapping
issue calling that function from old images.)

In ACODE-OPTIMIZE-MUL2, we need to check a constant's sign as well as
use LOGCOUNT to recognize positive powers of two (so that (* 2^{N x)
can be simplified to (ASH X N)).}

File:

• trunk/source/compiler/nx2.lisp (modified) (3 diffs)

trunk/source/compiler/nx2.lisp

@@ -300 +300 @@
 
 (defun acode-constant-fold-binop (seg vreg xfer x y function)
-  (multiple-value-bind (x-p const-x) (acode-constant-p x)
+  (multiple-value-bind (const-x x-p) (acode-constant-p x)
     (when x-p
-      (multiple-value-bind (y-p const-y) (acode-constant-p y)
+      (multiple-value-bind (const-y y-p) (acode-constant-p y)
         (when y-p
           (let* ((result (ignore-errors (funcall function const-x const-y))))
@@ -624 +624 @@
                  t)
                 ((and (eql (logcount f1) 1)
+                      (> f1 0)
                       (acode-form-typep num2 *nx-target-fixnum-type* trust-decls))
                  (backend-use-operator (%nx1-operator ash)
@@ -639 +640 @@
                  (backend-apply-acode num1 seg vreg xfer)
                  t)
-                ((and (eql (logcount f2) 1) (acode-form-typep num1 *nx-target-fixnum-type* trust-decls))
+                ((and (eql (logcount f2) 1)
+                      (> f2 0)
+                      (acode-form-typep num1 *nx-target-fixnum-type* trust-decls))
                  (backend-use-operator (%nx1-operator ash)
                                        seg