(SHRLconst [1] (SHLLconst [1] x))
	=> (ANDLconst [0x7fffffff] x)
(SHRQconst [1] (SHLQconst [1] x))
	=> (BTRQconst [63] x)

// Special case testing first/last bit (with double-shift generated by generic.rules)
((SETNE|SETEQ|NE|EQ) (TESTQ z1:(SHLQconst [63] (SHRQconst [63] x)) z2)) && z1==z2
    => ((SETB|SETAE|ULT|UGE) (BTQconst [63] x))
((SETNE|SETEQ|NE|EQ) (TESTL z1:(SHLLconst [31] (SHRQconst [31] x)) z2)) && z1==z2