On Apr 6, 2005, at 2:11 PM, David Edelsohn wrote:
>>>>> Kumar Gala writes:
Kumar> Is there anyway to specify a long long data type as a
constraint to
Kumar> extended asm for powerpc32. If so, how does one specify the
registers
Kumar> that would have the upper and lower bits
The rs6000.md machine description has examples of patterns
implementing 64-bit (DImode) operations in 32-bit mode. The
constraint is
a normal "r" or "b" GPR constraint. GCC allocates pairs of
consecutive
registers to hold the 64-bit value in 32-bit mode.
When operating in big-endian, the MSB is in the first register
and
the LSB is the second register (R+1); in little-endian mode, the two
registers are reversed. The PowerPC port defines a special
print_operand
modifier %L to refer to R+1, e.g., for operand 0, one would write
assembly
code referring to %0 and %L0.
This is great, can I beg of you to update the gcc docs to include this
note for the rs6000 extended asm section.
thanks
- kumar
