From 9e9a2b7031f64e49fcaf28f21a4e70eb1212165f Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Thu, 15 Aug 2024 15:47:31 -0500 Subject: Remove dependence on -fwrapv semantics in a few places. This commit attempts to update a few places, such as the money, numeric, and timestamp types, to no longer rely on signed integer wrapping for correctness. This is intended to move us closer towards removing -fwrapv, which may enable some compiler optimizations. However, there is presently no plan to actually remove that compiler option in the near future. Besides using some of the existing overflow-aware routines in int.h, this commit introduces and makes use of some new ones. Specifically, it adds functions that accept a signed integer and return its absolute value as an unsigned integer with the same width (e.g., pg_abs_s64()). It also adds functions that accept an unsigned integer, store the result of negating that integer in a signed integer with the same width, and return whether the negation overflowed (e.g., pg_neg_u64_overflow()). Finally, this commit adds a couple of tests for timestamps near POSTGRES_EPOCH_JDATE. Author: Joseph Koshakow Reviewed-by: Tom Lane, Heikki Linnakangas, Jian He Discussion: https://postgr.es/m/CAAvxfHdBPOyEGS7s%2Bxf4iaW0-cgiq25jpYdWBqQqvLtLe_t6tw%40mail.gmail.com --- src/backend/utils/adt/cash.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'src/backend/utils/adt/cash.c') diff --git a/src/backend/utils/adt/cash.c b/src/backend/utils/adt/cash.c index ec3c08acfc2..c1a743b2a6b 100644 --- a/src/backend/utils/adt/cash.c +++ b/src/backend/utils/adt/cash.c @@ -387,6 +387,7 @@ Datum cash_out(PG_FUNCTION_ARGS) { Cash value = PG_GETARG_CASH(0); + uint64 uvalue; char *result; char buf[128]; char *bufptr; @@ -429,8 +430,6 @@ cash_out(PG_FUNCTION_ARGS) if (value < 0) { - /* make the amount positive for digit-reconstruction loop */ - value = -value; /* set up formatting data */ signsymbol = (*lconvert->negative_sign != '\0') ? lconvert->negative_sign : "-"; sign_posn = lconvert->n_sign_posn; @@ -445,6 +444,9 @@ cash_out(PG_FUNCTION_ARGS) sep_by_space = lconvert->p_sep_by_space; } + /* make the amount positive for digit-reconstruction loop */ + uvalue = pg_abs_s64(value); + /* we build the digits+decimal-point+sep string right-to-left in buf[] */ bufptr = buf + sizeof(buf) - 1; *bufptr = '\0'; @@ -470,10 +472,10 @@ cash_out(PG_FUNCTION_ARGS) memcpy(bufptr, ssymbol, strlen(ssymbol)); } - *(--bufptr) = ((uint64) value % 10) + '0'; - value = ((uint64) value) / 10; + *(--bufptr) = (uvalue % 10) + '0'; + uvalue = uvalue / 10; digit_pos--; - } while (value || digit_pos >= 0); + } while (uvalue || digit_pos >= 0); /*---------- * Now, attach currency symbol and sign symbol in the correct order. -- cgit v1.2.3