David Daney <dda...@caviumnetworks.com> writes:
>> but insv is a standard pattern name.
>> the semantics of expression x= (x&0xFF00FFFF) | ((i<<16)&0x00FF0000);
>> is exactly what insv can do.
>> I all tried mips gcc cross compiler, and ins is also not generated.
>
> You must be doing something wrong:
>
> $ cat fanqifei.c
> struct test_foo {
> unsigned int a:18;
> unsigned int b:2;
> unsigned int c:12;
> };
It's relatively easy for gcc to use insv for a bitfield in a struct.
It's quite a bit harder for it to use it for bit manipulation as in
the above example of x = (x&0xFF00FFFF) | ((i<<16)&0x00FF0000). This
case requires recognizing that insv applies at all.
Ian
