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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/compiler_builtins/libm/src/math/ilogb.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/compiler_builtins/libm/src/math/ilogb.rs')
-rw-r--r-- | vendor/compiler_builtins/libm/src/math/ilogb.rs | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/vendor/compiler_builtins/libm/src/math/ilogb.rs b/vendor/compiler_builtins/libm/src/math/ilogb.rs new file mode 100644 index 000000000..0a380b7ef --- /dev/null +++ b/vendor/compiler_builtins/libm/src/math/ilogb.rs @@ -0,0 +1,31 @@ +const FP_ILOGBNAN: i32 = -1 - 0x7fffffff; +const FP_ILOGB0: i32 = FP_ILOGBNAN; + +pub fn ilogb(x: f64) -> i32 { + let mut i: u64 = x.to_bits(); + let e = ((i >> 52) & 0x7ff) as i32; + + if e == 0 { + i <<= 12; + if i == 0 { + force_eval!(0.0 / 0.0); + return FP_ILOGB0; + } + /* subnormal x */ + let mut e = -0x3ff; + while (i >> 63) == 0 { + e -= 1; + i <<= 1; + } + e + } else if e == 0x7ff { + force_eval!(0.0 / 0.0); + if (i << 12) != 0 { + FP_ILOGBNAN + } else { + i32::max_value() + } + } else { + e - 0x3ff + } +} |