From owner-freebsd-current  Tue Mar 21  0:47:11 2000
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To: current@freebsd.org
Subject: Floating point exceptions.
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Date: Tue, 21 Mar 2000 08:47:00 +0000
From: David Malone <dwmalone@maths.tcd.ie>
Message-ID:  <200003210847.aa00165@salmon.maths.tcd.ie>
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Floating point exceptions seem to have been turned off by default:

	gonzo 13% uname -r
	5.0-CURRENT
	gonzo 14% cat a.c
	double div(double x,double y) { return x/y; }
	int main() { double x; x = div(1.0,0.0); printf("%f\n",x); }
	gonzo 15% gcc -o a a.c
	gonzo 16% ./a
	Inf

This seems to produce an SIGFPE on 3.0, which I would have thought
was the correct thing to do:

	walton 12% uname -r
	3.4-STABLE
	walton 13% cat a.c
	double div(double x,double y) { return x/y; }
	int main() { double x; x = div(1.0,0.0); printf("%f\n",x); }
	walton 14% gcc -o a a.c
	walton 15% ./a
	Floating exception (core dumped)

There was a discussion on one of the list about what to do for
floating point excpetions recently, and I thought people decided
that causing a signal by default was a right thing? I presume this
was caused by the commit below?

	David.

cracauer    2000/03/10 09:56:33 PST

  Modified files:
    sys/i386/include     npx.h 
  Log:
  Change the default FPU control word so that exceptions for new
  processes are now masked until set by fpsetmask(3).
  
  Submitted by: bde
  Approved by:  jkh, bde
  
  Revision  Changes    Path
  1.18      +5 -35     src/sys/i386/include/npx.h



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