(ash -1 (- n-word-bits n-lowtag-bits))
#!+sb-doc
"the fixnum closest in value to negative infinity")
+
+(def!constant most-positive-word (1- (expt 2 n-word-bits))
+ "The most positive integer that is of type SB-EXT:WORD.")
+
+(def!constant most-positive-exactly-single-float-fixnum
+ (min #xffffff sb!xc:most-positive-fixnum))
+(def!constant most-negative-exactly-single-float-fixnum
+ (max #x-ffffff sb!xc:most-negative-fixnum))
+(def!constant most-positive-exactly-double-float-fixnum
+ (min #x1fffffffffffff sb!xc:most-positive-fixnum))
+(def!constant most-negative-exactly-double-float-fixnum
+ (max #x-1fffffffffffff sb!xc:most-negative-fixnum))
+
+;;;; Point where continuous area starting at dynamic-space-start bumps into
+;;;; next space.
+#!+gencgc
+(def!constant max-dynamic-space-end
+ (let ((stop (1- (ash 1 n-word-bits)))
+ (start dynamic-space-start))
+ (dolist (other-start (list read-only-space-start static-space-start linkage-table-space-start))
+ (when (< start other-start)
+ (setf stop (min stop other-start))))
+ stop))