Jonas Maebe wrote:
On 28 May 2012, at 14:41, OBones wrote:
I'm compiling the program at the end of this message
The program is missing.
Bugger, why does this keep happening to me???
Anyway, this time it is at the end.
I really need to have the same instruction set used for floating point maths,
hence the use of SSE3 in both cases.
If your x86-64 target is Win64, using -CfSSE2/-CfSSE3 will not result in
exactly the same fpu instructions on i386 and x86-64 under all circumstances.
The reason is that it is impossible to disable 80 bit extended floating point
support in the i386 version of the compiler (and impossible to enable it in
FPC/Win64). As a result:
a) constants that cannot be represented exactly using double precision will
still be parsed as extended precision by the compiler (and as a result, other
terms in the same expression will be promoted along with it)
b) several run time library functions and constants are declared using the most
precise real type type available on the platform (i.e., extended on i386 and
double on Win64)
Yes, I'm aware of that, but I want to minimize the places where
differences can come from, so using the same instruction set helps doing
that.
==================================================================
program testFPU;
uses
Math;
var
current: Integer;
__VARIABLE: Double;
type
NS = class
class function VARIABLE: Double;
end;
class function NS.VARIABLE: Double;
begin
Result:= __VARIABLE;
end;
function ComputeIt: Double;
begin
if Frac(current/NS.VARIABLE) = current/NS.VARIABLE then
Result := Trunc(current/NS.VARIABLE)
else
Result := Trunc(current/NS.VARIABLE)+1
end;
begin
end.
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