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Re: use of extended asm on ppc for long long data types


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


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