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target-s390x: Avoid a loop for popcnt 

Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2016-11-21 12:06:26 +01:00
parent 7977000220
commit 250a87d556
1 changed files with 6 additions and 9 deletions
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15
target/s390x/int_helper.c
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@ -137,14 +137,11 @@ uint64_t HELPER(cvd)(int32_t reg)
return dec; return dec;
} }
uint64_t HELPER(popcnt)(uint64_t r2) uint64_t HELPER(popcnt)(uint64_t val)
{ {
uint64_t ret = 0; /* Note that we don't fold past bytes. */
int i; val = (val & 0x5555555555555555ULL) + ((val >> 1) & 0x5555555555555555ULL);
val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
for (i = 0; i < 64; i += 8) { val = (val + (val >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
uint64_t t = ctpop32((r2 >> i) & 0xff); return val;
ret |= t << i;
}
return ret;
} }