Add procedures to generate infinities and a nan.

diff --git a/src/runtime/floenv.scm b/src/runtime/floenv.scm
index 1a1df9cfac3ab4c89e2e15a1bc430e9dfd52f1c6..325b98f1147dfdf67d8291bc90fbcd4c5ee68049 100644 (file)
--- a/src/runtime/floenv.scm
+++ b/src/runtime/floenv.scm
@@ -362,3 +362,34 @@ USA.
    (lambda ()
      (flo:untrap-exceptions! exceptions)
      (procedure))))
+
+(define flo:nan.0)
+(define flo:+inf.0)
+(define flo:-inf.0)
+;;; ZERO can be eliminated after 9.3 is released.  It works around
+;;; overly-aggressive constant folding in SF and LIAR.
+(let ((zero (lambda () (identity-procedure 0.))))
+  (if (flo:have-trap-enable/disable?)
+      (begin
+       (set! flo:nan.0
+             (named-lambda (flo:nan.0)
+               (flo:with-exceptions-untrapped (flo:exception:invalid-operation)
+                 (lambda ()
+                   (flo:/ 0. (zero))))))
+       (set! flo:+inf.0
+             (named-lambda (flo:+inf.0)
+               (flo:with-exceptions-untrapped (flo:exception:divide-by-zero)
+                 (lambda ()
+                   (flo:/ +1. (zero))))))
+       (set! flo:-inf.0
+             (named-lambda (flo:-inf.0)
+               (flo:with-exceptions-untrapped (flo:exception:divide-by-zero)
+                 (lambda ()
+                   (flo:/ -1. (zero))))))
+       unspecific)
+      ;; This works on macOS.  YMMV.
+      (begin
+       (set! flo:nan.0 (named-lambda (flo:nan.0) (flo:/ 0. (zero))))
+       (set! flo:+inf.0 (named-lambda (flo:+inf.0) (flo:/ +1. (zero))))
+       (set! flo:-inf.0 (named-lambda (flo:-inf.0) (flo:/ -1. (zero))))
+       unspecific)))
\ No newline at end of file

diff --git a/src/runtime/runtime.pkg b/src/runtime/runtime.pkg
index 9747d4e4cab2ccf438172758fbc5683c04ff8112..f2564da60d6379f1e11a75a52370fec4c1c14aca 100644 (file)
--- a/src/runtime/runtime.pkg
+++ b/src/runtime/runtime.pkg
@@ -370,6 +370,8 @@ USA.
   (files "floenv")
   (parent (runtime))
   (export ()
+         flo:+inf.0
+         flo:-inf.0
          flo:clear-exceptions!
          flo:default-environment
          flo:default-rounding-mode
@@ -387,6 +389,7 @@ USA.
          flo:have-trap-enable/disable?
          flo:ignoring-exception-traps
          flo:names->exceptions
+         flo:nan.0
          flo:preserving-environment
          flo:raise-exceptions!
          flo:restore-exception-flags!