Odd bit shifting behavior

Question

I have the following C code which works:

int ex(unsigned int x) {     int mask  = 0x55555555;     int a = ((x >> 0) & mask );     return a + ((x >> 1) & mask ); } 

However, when I expand it to this, I get a different result:

int ex(unsigned int x) {     int mask  = 0x55555555;     int a = ((x >> 0) & mask );     int b = ((x >> 1) & mask );     return a + b; } 

What is the reason for this difference?

EDIT: Note, I'm compiling this for 32bit.

Answer 1

What is the reason for this difference?

The 1^st snippet returns the result of adding two unsigneds with the result being (implicitly) converted to an int.

The 2^nd snippet returns the result of adding two ints .

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