* Jan Beulich <[email protected]> wrote:
> This generally allows better code to be generated, since the zero-
> extension during 32-bit operations comes for free (needed when the
> result is used as array index or similar), whereas sign extension must
> be done explicitly and frequently requires a one byte larger
> instruction due to the necessary rex64 prefix.
good catch! Applied your patch to x86.git - queued it up for v2.6.25. I
bet there are tons of other instances where we use signed instead of
unsigned and get worse code generation.
Ingo
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