PTR-PLUS merge into the mainline
Roman Zippel
zippel@linux-m68k.org
Thu Jul 5 16:57:00 GMT 2007
Hi,
On Thu, 5 Jul 2007, I wrote:
> Exactly and that's why I think this transformation is done far too early.
> It doesn't make sense that these two examples produce different code:
>
> int foo1(int x)
> {
> return (x * 4) + 4;
> }
> int foo2(int x)
> {
> int y = x * 4;
> return y + 4;
> }
Another example:
int foo3(int x, int y)
{
return (x * y) + (y * 5);
}
int foo4(int x, int y)
{
x *= y;
return x + (y * 5);
}
Here the generated code depends on how the constant multiply is expanded,
so that combine can do the optimization.
bye, Roman
More information about the Gcc
mailing list