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From: David Goldberg <goldberg@parc.xerox.com>
To: m3-request
Subject: problem with REAL in 2.07
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Message-Id: <92Aug27.112840pdt.40744@arcturia.parc.xerox.com>
Date: Thu, 27 Aug 1992 11:28:26 PDT

In the following program, z and z1 should have the same value, but
they don't.  THe problem is that C is promoting float to double.

Possible solutions:
(1) when generating code for expressions like (x+y)-z,
turn it into tmp=x+y, tmp-z.  Hopefully the C optimizer make make
this generate efficient C code
(2) For compilers like SunOS that have an -fsingle flag that turns off
automatic promotion, have this be a default flag passed to cc?
(3) other?

	-david
	
============

**************************)

MODULE Bug EXPORTS Main;

IMPORT Test, Wr, Stdio, Fmt;
<*FATAL ANY*>

VAR
  x, y, z, z1, tmp: REAL;
BEGIN
  x := 23.4;
  y := 8388608.0;

  z := (x + y) - y;

  tmp := (x + y);
  z1 := tmp - y;

  Wr.PutText(Stdio.stdout, Fmt.F("%s %s\n", Fmt.Real(z), Fmt.Real(z1)));
  Test.checkR (z, z1);
  Test.done ();
END Bug.