diff options
Diffstat (limited to 'vendor/libm/src/math/ilogbf.rs')
-rw-r--r-- | vendor/libm/src/math/ilogbf.rs | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/vendor/libm/src/math/ilogbf.rs b/vendor/libm/src/math/ilogbf.rs new file mode 100644 index 000000000..b384fa4b2 --- /dev/null +++ b/vendor/libm/src/math/ilogbf.rs @@ -0,0 +1,31 @@ +const FP_ILOGBNAN: i32 = -1 - 0x7fffffff; +const FP_ILOGB0: i32 = FP_ILOGBNAN; + +pub fn ilogbf(x: f32) -> i32 { + let mut i = x.to_bits(); + let e = ((i >> 23) & 0xff) as i32; + + if e == 0 { + i <<= 9; + if i == 0 { + force_eval!(0.0 / 0.0); + return FP_ILOGB0; + } + /* subnormal x */ + let mut e = -0x7f; + while (i >> 31) == 0 { + e -= 1; + i <<= 1; + } + e + } else if e == 0xff { + force_eval!(0.0 / 0.0); + if (i << 9) != 0 { + FP_ILOGBNAN + } else { + i32::max_value() + } + } else { + e - 0x7f + } +} |