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authordim <dim@FreeBSD.org>2015-01-08 19:47:10 +0000
committerdim <dim@FreeBSD.org>2015-01-08 19:47:10 +0000
commitab328f15cea04a45750ef56019d2b3d971e033f3 (patch)
treef47eabbd2a48be6d6fec3ddeeefae5b4aeb87dbc /contrib/compiler-rt/lib/builtins/floatdisf.c
parent8189659be8e499f37c87fdd05ef5ec9f88619d56 (diff)
parent2f1c5cc1039d86db0037cb086bd58f4b90dc6f66 (diff)
downloadFreeBSD-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/floatdisf.c')
-rw-r--r--contrib/compiler-rt/lib/builtins/floatdisf.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/floatdisf.c b/contrib/compiler-rt/lib/builtins/floatdisf.c
new file mode 100644
index 0000000..3e47580
--- /dev/null
+++ b/contrib/compiler-rt/lib/builtins/floatdisf.c
@@ -0,0 +1,80 @@
+/*===-- floatdisf.c - Implement __floatdisf -------------------------------===
+ *
+ * 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 __floatdisf for the compiler_rt library.
+ *
+ *===----------------------------------------------------------------------===
+ */
+
+/* Returns: convert a to a float, rounding toward even.*/
+
+/* Assumption: float is a IEEE 32 bit floating point type
+ * di_int is a 64 bit integral type
+ */
+
+/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
+
+#include "int_lib.h"
+
+ARM_EABI_FNALIAS(l2f, floatdisf)
+
+COMPILER_RT_ABI float
+__floatdisf(di_int a)
+{
+ if (a == 0)
+ return 0.0F;
+ const unsigned N = sizeof(di_int) * CHAR_BIT;
+ const di_int s = a >> (N-1);
+ a = (a ^ s) - s;
+ int sd = N - __builtin_clzll(a); /* number of significant digits */
+ int e = sd - 1; /* exponent */
+ if (sd > FLT_MANT_DIG)
+ {
+ /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx
+ * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR
+ * 12345678901234567890123456
+ * 1 = msb 1 bit
+ * P = bit FLT_MANT_DIG-1 bits to the right of 1
+ * Q = bit FLT_MANT_DIG bits to the right of 1
+ * R = "or" of all bits to the right of Q
+ */
+ switch (sd)
+ {
+ case FLT_MANT_DIG + 1:
+ a <<= 1;
+ break;
+ case FLT_MANT_DIG + 2:
+ break;
+ default:
+ a = ((du_int)a >> (sd - (FLT_MANT_DIG+2))) |
+ ((a & ((du_int)(-1) >> ((N + FLT_MANT_DIG+2) - sd))) != 0);
+ };
+ /* finish: */
+ a |= (a & 4) != 0; /* Or P into R */
+ ++a; /* round - this step may add a significant bit */
+ a >>= 2; /* dump Q and R */
+ /* a is now rounded to FLT_MANT_DIG or FLT_MANT_DIG+1 bits */
+ if (a & ((du_int)1 << FLT_MANT_DIG))
+ {
+ a >>= 1;
+ ++e;
+ }
+ /* a is now rounded to FLT_MANT_DIG bits */
+ }
+ else
+ {
+ a <<= (FLT_MANT_DIG - sd);
+ /* a is now rounded to FLT_MANT_DIG bits */
+ }
+ float_bits fb;
+ fb.u = ((su_int)s & 0x80000000) | /* sign */
+ ((e + 127) << 23) | /* exponent */
+ ((su_int)a & 0x007FFFFF); /* mantissa */
+ return fb.f;
+}
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