IDCMP
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The high-order byte, the one containing the 1-bit in a longword $800000, is
at the low address, so "btst #31.,loc" would work as well as "btst #7,loc";
31 mod 8 is 7.
try testing a low-order bit (say, "loc&0x4"), in a longword and see if the
compiler is smart enough to generate a "btst #2,loc+3". while i'm on the
subject, the original questioner (dan lovy?) posted a code fragment showing
his switch from cmp's to btst's; he wondered why his braches were taken in
a strange way.
did anyone mention to him that the sense of the branches change between
"cmp" and "btst"? tst is a compare-against-zero, so where you'd "beq"
after a "cmp", you "bne" after a "btst". wayne ps: add a couple more 0's to
that $800… above.