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author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
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committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
tree | 65ca85f13617aee1dce474596800950f266a456c /roms/u-boot/lib/ldiv.c | |
download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip |
Diffstat (limited to 'roms/u-boot/lib/ldiv.c')
-rw-r--r-- | roms/u-boot/lib/ldiv.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/roms/u-boot/lib/ldiv.c b/roms/u-boot/lib/ldiv.c new file mode 100644 index 00000000..8e11333a --- /dev/null +++ b/roms/u-boot/lib/ldiv.c @@ -0,0 +1,43 @@ +/* Copyright (C) 1992, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + * SPDX-License-Identifier: LGPL-2.0+ + */ + +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; +} |