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Afternoon all. Here's something that's piqued my curiosity; it's probably owing to some language-lawyerly issue, but it isn't obvious to me. This is on gcc-3.3.3, (cygwin variant, but that's probably not relevant):
-------------------------<snip!>------------------------- dk@mace /test/shift-test> cat foo.c
unsigned int bar (unsigned int baz) { unsigned int quux;
quux = baz >> 32; return quux; }
dk@mace /test/shift-test> gcc -S foo.c -O2 -o foo.s foo.c: In function `bar': foo.c:7: warning: right shift count >= width of type dk@mace /test/shift-test> cat foo.s
Why isn't the shift operation optimised away and replaced with const_int 0?
It's _undefined_. Didn't you make some comment about what undefined meant last week :)
-- Nathan Sidwell :: http://www.codesourcery.com :: CodeSourcery LLC nathan@codesourcery.com :: http://www.planetfall.pwp.blueyonder.co.uk
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