Request for reviews (S): 7063674: Wrong results from basic comparisons after calls to Long.bitCount(long)
vladimir.kozlov at oracle.com
Mon Jun 11 16:14:51 PDT 2012
I looked around and ReverseBytes instructions (which use shifts in addition to
bswap) also missing KILL cr.
Christian Thalinger wrote:
> 7063674: Wrong results from basic comparisons after calls to Long.bitCount(long)
> We are scheduling popcnt instructions between compare and branch/conditional
> move instructions because AD instructs are not defined to kill flags.
> But the Intel Instruction Set Reference says for POPCNT:
> Flags Affected
> OF, SF, ZF, AF, CF, PF are all cleared. ZF is set if SRC = 0, otherwise ZF is cleared
> The fix is to kill the flags in instructs that are using popcnt instructions.
> Tested with test case of CR.
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