[Bug rtl-optimization/40772] generating rendundant moves from second byte of 32b/64b register

[zsojka at seznam dot cz]

------- Comment #2 from zsojka at seznam dot cz  2009-07-16 15:42 -------
When
                data[j] = ((i + j) & 0xFF00) >> 8;
is replaced by
                data[j] = (i + j) >> 8;

generated asm uses "shr eax, 8" instead of "movzx eax, ah", and runs in 19
ticks in average.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40772