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-rw-r--r--src/math/ilogb.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/src/math/ilogb.c b/src/math/ilogb.c
index 5a1819d8..64d40154 100644
--- a/src/math/ilogb.c
+++ b/src/math/ilogb.c
@@ -3,22 +3,24 @@
int ilogb(double x)
{
- union dshape u = {x};
- int e = u.bits>>52 & 0x7ff;
+ #pragma STDC FENV_ACCESS ON
+ union {double f; uint64_t i;} u = {x};
+ uint64_t i = u.i;
+ int e = i>>52 & 0x7ff;
if (!e) {
- u.bits <<= 12;
- if (u.bits == 0) {
+ i <<= 12;
+ if (i == 0) {
FORCE_EVAL(0/0.0f);
return FP_ILOGB0;
}
/* subnormal x */
- for (e = -0x3ff; u.bits < (uint64_t)1<<63; e--, u.bits<<=1);
+ for (e = -0x3ff; i>>63 == 0; e--, i<<=1);
return e;
}
if (e == 0x7ff) {
FORCE_EVAL(0/0.0f);
- return u.bits<<12 ? FP_ILOGBNAN : INT_MAX;
+ return i<<12 ? FP_ILOGBNAN : INT_MAX;
}
return e - 0x3ff;
}