Don't treat '=' as simple equality emitting constraints (bug#46812)

Extend assumes allowing the following form

(assume dst (= src1 src2))

to caputure '=' semanting during fwprop handling float integer
conversions.

	* lisp/emacs-lisp/comp.el (comp-equality-fun-p): Don't treat '=' as
	simple equality.
	(comp-arithm-cmp-fun-p, comp-negate-arithm-cmp-fun)
	(comp-reverse-arithm-fun): Rename and add '=' '!='.
	(comp-emit-assume, comp-add-cond-cstrs, comp-fwprop-insn): Update
	for new function nameing and to handle '='.
	* lisp/emacs-lisp/comp-cstr.el (comp-cstr-=): New function.
	* test/src/comp-tests.el (comp-tests-type-spec-tests): Add a bunch
	of '=' specific tests.

1 files changed, 12 insertions, 0 deletions

diff --git a/lisp/emacs-lisp/comp-cstr.el b/lisp/emacs-lisp/comp-cstr.el
index 89815f03b53..bd1e04fb0bb 100644
--- a/lisp/emacs-lisp/comp-cstr.el
+++ b/lisp/emacs-lisp/comp-cstr.el
@@ -859,6 +859,18 @@ Non memoized version of `comp-cstr-intersection-no-mem'."
          (null (neg cstr))
          (equal (typeset cstr) '(cons)))))
 
+(defun comp-cstr-= (dst old-dst src)
+  "Constraint DST being = SRC."
+  (with-comp-cstr-accessors
+    (comp-cstr-intersection dst old-dst src)
+    (cl-loop for v in (valset dst)
+             when (and (floatp v)
+                       (= v (truncate v)))
+               do (push (cons (truncate v) (truncate v)) (range dst)))
+    (cl-loop for (l . h) in (range dst)
+             when (eql l h)
+               do (push (float l) (valset dst)))))
+
 (defun comp-cstr-> (dst old-dst src)
   "Constraint DST being > than SRC.
 SRC can be either a comp-cstr or an integer."