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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/lib/ldiv.c | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/lib/ldiv.c')
-rw-r--r-- | roms/u-boot/lib/ldiv.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/roms/u-boot/lib/ldiv.c b/roms/u-boot/lib/ldiv.c new file mode 100644 index 000000000..5b1a25f28 --- /dev/null +++ b/roms/u-boot/lib/ldiv.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* Copyright (C) 1992, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + */ + +typedef struct { + long quot; + long rem; +} ldiv_t; +/* Return the `ldiv_t' representation of NUMER over DENOM. */ +ldiv_t +ldiv (long int numer, long int denom) +{ + ldiv_t result; + + result.quot = numer / denom; + result.rem = numer % denom; + + /* The ANSI standard says that |QUOT| <= |NUMER / DENOM|, where + NUMER / DENOM is to be computed in infinite precision. In + other words, we should always truncate the quotient towards + zero, never -infinity. Machine division and remainer may + work either way when one or both of NUMER or DENOM is + negative. If only one is negative and QUOT has been + truncated towards -infinity, REM will have the same sign as + DENOM and the opposite sign of NUMER; if both are negative + and QUOT has been truncated towards -infinity, REM will be + positive (will have the opposite sign of NUMER). These are + considered `wrong'. If both are NUM and DENOM are positive, + RESULT will always be positive. This all boils down to: if + NUMER >= 0, but REM < 0, we got the wrong answer. In that + case, to get the right answer, add 1 to QUOT and subtract + DENOM from REM. */ + + if (numer >= 0 && result.rem < 0) + { + ++result.quot; + result.rem -= denom; + } + + return result; +} |