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author | dim <dim@FreeBSD.org> | 2015-01-08 19:47:10 +0000 |
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committer | dim <dim@FreeBSD.org> | 2015-01-08 19:47:10 +0000 |
commit | ab328f15cea04a45750ef56019d2b3d971e033f3 (patch) | |
tree | f47eabbd2a48be6d6fec3ddeeefae5b4aeb87dbc /contrib/compiler-rt/lib/builtins/udivmoddi4.c | |
parent | 8189659be8e499f37c87fdd05ef5ec9f88619d56 (diff) | |
parent | 2f1c5cc1039d86db0037cb086bd58f4b90dc6f66 (diff) | |
download | FreeBSD-src-ab328f15cea04a45750ef56019d2b3d971e033f3.zip FreeBSD-src-ab328f15cea04a45750ef56019d2b3d971e033f3.tar.gz |
Update compiler-rt to trunk r224034. This brings a number of new
builtins, and also the various sanitizers. Support for these will be
added in a later commit.
Diffstat (limited to 'contrib/compiler-rt/lib/builtins/udivmoddi4.c')
-rw-r--r-- | contrib/compiler-rt/lib/builtins/udivmoddi4.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/udivmoddi4.c b/contrib/compiler-rt/lib/builtins/udivmoddi4.c new file mode 100644 index 0000000..0c8b4ff --- /dev/null +++ b/contrib/compiler-rt/lib/builtins/udivmoddi4.c @@ -0,0 +1,231 @@ +/* ===-- udivmoddi4.c - Implement __udivmoddi4 -----------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __udivmoddi4 for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +/* Effects: if rem != 0, *rem = a % b + * Returns: a / b + */ + +/* Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide */ + +COMPILER_RT_ABI du_int +__udivmoddi4(du_int a, du_int b, du_int* rem) +{ + const unsigned n_uword_bits = sizeof(su_int) * CHAR_BIT; + const unsigned n_udword_bits = sizeof(du_int) * CHAR_BIT; + udwords n; + n.all = a; + udwords d; + d.all = b; + udwords q; + udwords r; + unsigned sr; + /* special cases, X is unknown, K != 0 */ + if (n.s.high == 0) + { + if (d.s.high == 0) + { + /* 0 X + * --- + * 0 X + */ + if (rem) + *rem = n.s.low % d.s.low; + return n.s.low / d.s.low; + } + /* 0 X + * --- + * K X + */ + if (rem) + *rem = n.s.low; + return 0; + } + /* n.s.high != 0 */ + if (d.s.low == 0) + { + if (d.s.high == 0) + { + /* K X + * --- + * 0 0 + */ + if (rem) + *rem = n.s.high % d.s.low; + return n.s.high / d.s.low; + } + /* d.s.high != 0 */ + if (n.s.low == 0) + { + /* K 0 + * --- + * K 0 + */ + if (rem) + { + r.s.high = n.s.high % d.s.high; + r.s.low = 0; + *rem = r.all; + } + return n.s.high / d.s.high; + } + /* K K + * --- + * K 0 + */ + if ((d.s.high & (d.s.high - 1)) == 0) /* if d is a power of 2 */ + { + if (rem) + { + r.s.low = n.s.low; + r.s.high = n.s.high & (d.s.high - 1); + *rem = r.all; + } + return n.s.high >> __builtin_ctz(d.s.high); + } + /* K K + * --- + * K 0 + */ + sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high); + /* 0 <= sr <= n_uword_bits - 2 or sr large */ + if (sr > n_uword_bits - 2) + { + if (rem) + *rem = n.all; + return 0; + } + ++sr; + /* 1 <= sr <= n_uword_bits - 1 */ + /* q.all = n.all << (n_udword_bits - sr); */ + q.s.low = 0; + q.s.high = n.s.low << (n_uword_bits - sr); + /* r.all = n.all >> sr; */ + r.s.high = n.s.high >> sr; + r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr); + } + else /* d.s.low != 0 */ + { + if (d.s.high == 0) + { + /* K X + * --- + * 0 K + */ + if ((d.s.low & (d.s.low - 1)) == 0) /* if d is a power of 2 */ + { + if (rem) + *rem = n.s.low & (d.s.low - 1); + if (d.s.low == 1) + return n.all; + sr = __builtin_ctz(d.s.low); + q.s.high = n.s.high >> sr; + q.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr); + return q.all; + } + /* K X + * --- + * 0 K + */ + sr = 1 + n_uword_bits + __builtin_clz(d.s.low) - __builtin_clz(n.s.high); + /* 2 <= sr <= n_udword_bits - 1 + * q.all = n.all << (n_udword_bits - sr); + * r.all = n.all >> sr; + */ + if (sr == n_uword_bits) + { + q.s.low = 0; + q.s.high = n.s.low; + r.s.high = 0; + r.s.low = n.s.high; + } + else if (sr < n_uword_bits) // 2 <= sr <= n_uword_bits - 1 + { + q.s.low = 0; + q.s.high = n.s.low << (n_uword_bits - sr); + r.s.high = n.s.high >> sr; + r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr); + } + else // n_uword_bits + 1 <= sr <= n_udword_bits - 1 + { + q.s.low = n.s.low << (n_udword_bits - sr); + q.s.high = (n.s.high << (n_udword_bits - sr)) | + (n.s.low >> (sr - n_uword_bits)); + r.s.high = 0; + r.s.low = n.s.high >> (sr - n_uword_bits); + } + } + else + { + /* K X + * --- + * K K + */ + sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high); + /* 0 <= sr <= n_uword_bits - 1 or sr large */ + if (sr > n_uword_bits - 1) + { + if (rem) + *rem = n.all; + return 0; + } + ++sr; + /* 1 <= sr <= n_uword_bits */ + /* q.all = n.all << (n_udword_bits - sr); */ + q.s.low = 0; + if (sr == n_uword_bits) + { + q.s.high = n.s.low; + r.s.high = 0; + r.s.low = n.s.high; + } + else + { + q.s.high = n.s.low << (n_uword_bits - sr); + r.s.high = n.s.high >> sr; + r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr); + } + } + } + /* Not a special case + * q and r are initialized with: + * q.all = n.all << (n_udword_bits - sr); + * r.all = n.all >> sr; + * 1 <= sr <= n_udword_bits - 1 + */ + su_int carry = 0; + for (; sr > 0; --sr) + { + /* r:q = ((r:q) << 1) | carry */ + r.s.high = (r.s.high << 1) | (r.s.low >> (n_uword_bits - 1)); + r.s.low = (r.s.low << 1) | (q.s.high >> (n_uword_bits - 1)); + q.s.high = (q.s.high << 1) | (q.s.low >> (n_uword_bits - 1)); + q.s.low = (q.s.low << 1) | carry; + /* carry = 0; + * if (r.all >= d.all) + * { + * r.all -= d.all; + * carry = 1; + * } + */ + const di_int s = (di_int)(d.all - r.all - 1) >> (n_udword_bits - 1); + carry = s & 1; + r.all -= d.all & s; + } + q.all = (q.all << 1) | carry; + if (rem) + *rem = r.all; + return q.all; +} |