README.rst

Test programs for FBSTP instructions

Details: http://0x80.pl/notesen.html#note-2013-5

Compilation

$ make

Conversion

Sample output:

$ ./test 0 12 5671245 -143433 334535 4543985349054 999999999999999999999
printf => 0.000000
FBSTP  => 0
printf => 12.000000
FBSTP  => 12
printf => 5671245.000000
FBSTP  => 5671245
printf => -143433.000000
FBSTP  => -143433
printf => 334535.000000
FBSTP  => 334535
printf => 4543985349054.000000
FBSTP  => 4543985349054
printf => 10000000000000000000000.000000
FBSTP  => NaN/overflow

Speed

Results - Pentium M

$ ./speed 
fbstp...
... 2.285 s
simple itoa...
... 0.589 s

Results - Core i5

$ ./speed.exe
FBSTP...
... 1.682 s
simple itoa...
... 0.223 s

Results - Core i7

$ ./speed 
FBSTP...
... 2.165 s
simple itoa...
... 0.419 s