在 2024-04-10 17:52, Xi Ruoyao via Gcc-help 写道:
No, the OP is still thinking it's a wrong-code.
Would you read the Subject please?
u32 x = a * b;
u64 r = x;
return r;
This is same as
u32 x = (int) a * (int) b;
u64 r = x;
return r;
and
return (u64)(u32) ((int) a * (int) b);
The code requests an `int` be zero-extended to a `u64` (if the result is written to EAX then this is
no-op), but GCC performs sign extension anyway. Do you still consider it not a bug?
-- Best regards, LIU Hao
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