bug#23713: [PATCH 2/6] maint: replace bitwise with logical OR

[Paul Eggert]

Thanks. I see this patch was also installed in June so will close the bug 
report.

I have a bone to pick with it, though. For bool expressions without side 
effects, bitwise ops are logically equivalent to short-circuit ops. On modern 
platforms where operands are trivial, short-circuit ops are often a tad bigger 
and can have more branch-prediction overhead, which is a tiny bit worse for 
performance. In the examples you the short-circuit ops all generate bigger 
machine code on my platform (GCC 6.1 x86-64). So I'm mildly inclined to revert 
the change and have pushed the attached. To some extent this is a style issue; 
yes, there is a long tradition in C of using short-circuit ops for bool, but I 
don't mind too much diverging slightly from the common style in order to make 
the point.

For clarity this patch also uses c_isdigit (which uses a switch) instead of && 
though GCC seems to generate the same code either way.

0001-grep-prefer-bitwise-to-short-circuit-when-shorter.patch
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