Re: clobbering of input operands in GCC
- From: Paweł Sikora <spamtrap@xxxxxxxxxx>
- Date: Mon, 20 Mar 2006 10:14:23 +0100
spamtrap@xxxxxxxxxx wrote:
In the GCC manual it says:
"There is no way for you to specify that an input operand is modified
without also specifying it as an output operand..."
But A must NOT be an output operand. Does it mean that you have to
assign the value to some dummy variable?
[ cite gcc.info ]
You may not write a clobber description in a way that overlaps with an
input or output operand. (...)
Variables declared to live in specific registers, and used as asm input
or output operands must have no part mentioned in the clobber description.
[ /cite ]
If you are using registers, which had not been passed as operands,
you need to inform the compiler about this (-> clobber list).
.
- References:
- clobbering of input operands in GCC
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