diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/adt/numeric.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index 3208789f75e..effc4b886c1 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -8323,7 +8323,7 @@ mul_var(const NumericVar *var1, const NumericVar *var2, NumericVar *result, */ for (i1 = Min(var1ndigits - 1, res_ndigits - 3); i1 >= 0; i1--) { - int var1digit = var1digits[i1]; + NumericDigit var1digit = var1digits[i1]; if (var1digit == 0) continue; @@ -8908,13 +8908,22 @@ div_var_fast(const NumericVar *var1, const NumericVar *var2, * which would make the new value simply div[qi] mod vardigits[0]. * The lower-order terms in qdigit can change this result by not * more than about twice INT_MAX/NBASE, so overflow is impossible. + * + * This inner loop is the performance bottleneck for division, so + * code it in the same way as the inner loop of mul_var() so that + * it can be auto-vectorized. We cast qdigit to NumericDigit + * before multiplying to allow the compiler to generate more + * efficient code (using 16-bit multiplication), which is safe + * since we know that the quotient digit is off by at most one, so + * there is no overflow risk. */ if (qdigit != 0) { int istop = Min(var2ndigits, div_ndigits - qi + 1); + int *div_qi = &div[qi]; for (i = 0; i < istop; i++) - div[qi + i] -= qdigit * var2digits[i]; + div_qi[i] -= ((NumericDigit) qdigit) * var2digits[i]; } } |