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-rw-r--r--lib/builtins/floattidf.c100
1 files changed, 47 insertions, 53 deletions
diff --git a/lib/builtins/floattidf.c b/lib/builtins/floattidf.c
index 7c87f57be..9fc5783dc 100644
--- a/lib/builtins/floattidf.c
+++ b/lib/builtins/floattidf.c
@@ -21,62 +21,56 @@
* ti_int is a 128 bit integral type
*/
-/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
+/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+ * mmmm */
-COMPILER_RT_ABI double
-__floattidf(ti_int a)
-{
- if (a == 0)
- return 0.0;
- const unsigned N = sizeof(ti_int) * CHAR_BIT;
- const ti_int s = a >> (N-1);
- a = (a ^ s) - s;
- int sd = N - __clzti2(a); /* number of significant digits */
- int e = sd - 1; /* exponent */
- if (sd > DBL_MANT_DIG)
- {
- /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx
- * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR
- * 12345678901234567890123456
- * 1 = msb 1 bit
- * P = bit DBL_MANT_DIG-1 bits to the right of 1
- * Q = bit DBL_MANT_DIG bits to the right of 1
- * R = "or" of all bits to the right of Q
- */
- switch (sd)
- {
- case DBL_MANT_DIG + 1:
- a <<= 1;
- break;
- case DBL_MANT_DIG + 2:
- break;
- default:
- a = ((tu_int)a >> (sd - (DBL_MANT_DIG+2))) |
- ((a & ((tu_int)(-1) >> ((N + DBL_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 DBL_MANT_DIG or DBL_MANT_DIG+1 bits */
- if (a & ((tu_int)1 << DBL_MANT_DIG))
- {
- a >>= 1;
- ++e;
- }
- /* a is now rounded to DBL_MANT_DIG bits */
+COMPILER_RT_ABI double __floattidf(ti_int a) {
+ if (a == 0)
+ return 0.0;
+ const unsigned N = sizeof(ti_int) * CHAR_BIT;
+ const ti_int s = a >> (N - 1);
+ a = (a ^ s) - s;
+ int sd = N - __clzti2(a); /* number of significant digits */
+ int e = sd - 1; /* exponent */
+ if (sd > DBL_MANT_DIG) {
+ /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx
+ * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR
+ * 12345678901234567890123456
+ * 1 = msb 1 bit
+ * P = bit DBL_MANT_DIG-1 bits to the right of 1
+ * Q = bit DBL_MANT_DIG bits to the right of 1
+ * R = "or" of all bits to the right of Q
+ */
+ switch (sd) {
+ case DBL_MANT_DIG + 1:
+ a <<= 1;
+ break;
+ case DBL_MANT_DIG + 2:
+ break;
+ default:
+ a = ((tu_int)a >> (sd - (DBL_MANT_DIG + 2))) |
+ ((a & ((tu_int)(-1) >> ((N + DBL_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 DBL_MANT_DIG or DBL_MANT_DIG+1 bits */
+ if (a & ((tu_int)1 << DBL_MANT_DIG)) {
+ a >>= 1;
+ ++e;
}
- else
- {
- a <<= (DBL_MANT_DIG - sd);
- /* a is now rounded to DBL_MANT_DIG bits */
- }
- double_bits fb;
- fb.u.s.high = ((su_int)s & 0x80000000) | /* sign */
- ((e + 1023) << 20) | /* exponent */
+ /* a is now rounded to DBL_MANT_DIG bits */
+ } else {
+ a <<= (DBL_MANT_DIG - sd);
+ /* a is now rounded to DBL_MANT_DIG bits */
+ }
+ double_bits fb;
+ fb.u.s.high = ((su_int)s & 0x80000000) | /* sign */
+ ((e + 1023) << 20) | /* exponent */
((su_int)(a >> 32) & 0x000FFFFF); /* mantissa-high */
- fb.u.s.low = (su_int)a; /* mantissa-low */
- return fb.f;
+ fb.u.s.low = (su_int)a; /* mantissa-low */
+ return fb.f;
}
#endif /* CRT_HAS_128BIT */