• Thomas Kuehne (9/9) Oct 13 2004 code:
• Burton Radons (15/26) Oct 13 2004 This is because the first comparison uses float while the second uses
• Thomas Kuehne (3/21) Oct 13 2004 Thanks for the fix - guess I have to read a little about IEEE :)
• Lynn Allan (4/7) Oct 13 2004 Thanks for the time and effort the two of you are putting into making

"Thomas Kuehne" <eisvogel users.sourceforge.net> writes:

code:







The first assertion passes but the second fails.

test case: svn://svn.kuehne.cn/dstress/run/float_literal_dec_02.d

Burton Radons <burton-radons smocky.com> writes:

Thomas Kuehne wrote:

 code:






 
 The first assertion passes but the second fails.
 
 test case: svn://svn.kuehne.cn/dstress/run/float_literal_dec_02.d

This is because the first comparison uses float while the second uses 
real; the float truncates some rounding error in the division that is 
preserved for the comparison in the second assert.  This is a natural 
effect of type promotion.

The real bug is that this doesn't work properly:

    assert(f == cast(float) (a/b));

This should cause the value to be truncated, but it doesn't.

You can cause your code to succeed if you eliminate the rounding error. 
  Divide by a power of 2 instead:

    float f = 0.01171875;
    float a = 12.0;
    float b = 1024.0;

This will then work.  That could probably be considered a correct test 
of the language, as D depends on IEEE being present.

"Thomas Kuehne" <eisvogel users.sourceforge.net> writes:

Burton Radons schrieb:
 code:







 The first assertion passes but the second fails.

 test case: svn://svn.kuehne.cn/dstress/run/float_literal_dec_02.d

 This is because the first comparison uses float while the second uses
 real; the float truncates some rounding error in the division that is
 preserved for the comparison in the second assert.  This is a natural
 effect of type promotion.

 The real bug is that this doesn't work properly:

     assert(f == cast(float) (a/b));

 This should cause the value to be truncated, but it doesn't.

Thanks for the fix - guess I have to read a little about IEEE :)

Thomas

"Lynn Allan" <l_d_allan adelphia.net> writes:

Thanks for the time and effort the two of you are putting into making
'D' an even better tool.

"Burton Radons" <burton-radons smocky.com> wrote in message
news:ckj8ps$2te8$1 digitaldaemon.com...
 Thomas Kuehne wrote:

 code: