[Bug target/34653] unnecessary REX prefix

[dean at arctic dot org]

------- Comment #4 from dean at arctic dot org  2009-09-17 10:27 -------
(In reply to comment #2)
> 32bit moves and other instructions _SIGN_EXTEND_ results to 64bits on x86_64

wait i just reread your statement.

the amd64 ISA zero-extends 32-bit register writes out to 64-bits.  please go
read the documentation.

-dean


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34653