From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 25 Oct 2001 17:17:19 +0000 (+0000)
Subject: Add code to reinitialize the floating-point control word on IA-32
X-Git-Tag: 20090517-FFI~2485
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2375e7e0c43dd4fcb5c906dfb658f2f9870ea089;p=mit-scheme.git

Add code to reinitialize the floating-point control word on IA-32
machines when SIGFPE is received.  When this isn't done, all of the
traps are disabled.
---

diff --git a/v7/src/microcode/uxsig.c b/v7/src/microcode/uxsig.c
index 83d700e6e..5ff3e0b9f 100644
--- a/v7/src/microcode/uxsig.c
+++ b/v7/src/microcode/uxsig.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Id: uxsig.c,v 1.36 2001/07/16 02:44:01 cph Exp $
+$Id: uxsig.c,v 1.37 2001/10/25 17:17:19 cph Exp $
 
 Copyright (c) 1990-2001 Massachusetts Institute of Technology
 
@@ -512,11 +512,29 @@ DEFUN_STD_HANDLER (sighnd_terminate,
     ? (find_signal_name (signo))
     : 0)))
 
+#ifdef HAS_COMPILER_SUPPORT
+#  ifdef __IA32__
+
+#define FPE_RESET_TRAPS()						\
+{									\
+  /* Reinitialize the floating-point control word.  */			\
+  extern void EXFUN (i386_interface_initialize, (void));		\
+  i386_interface_initialize ();						\
+}
+
+#  endif
+#endif
+
+#ifndef FPE_RESET_TRAPS
+#  define FPE_RESET_TRAPS()
+#endif
+
 static
 DEFUN_STD_HANDLER (sighnd_fpe,
 {
   if (executing_scheme_primitive_p ())
     error_floating_point_exception ();
+  FPE_RESET_TRAPS ();
   trap_handler ("floating-point exception", signo, info, scp);
 })