multi-precision in extended asm

[John S. Yates, Jr.]

Given that GCC provides 64 integers across many architectures
with only 32 bit wide registers I assume there is some general
framework for manipulating these objects.  Is there a way to
write a constraint that says "low order 32 bits of 64 bit
datum" or "high order 32 bits of 64 bit datum"?

In particular how would I express "arithmetic shift right 31
places the high 32 bits of a 64 bit integer to get a register
filled with a copy of the sign bit" on the x86? on the ppc?

--
John S. Yates, Jr.            508 665-6800  x897
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