Skip to content

fix expm1f overflow threshold #1043

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
quaternic wants to merge 1 commit into
base: main
Choose a base branch
from
+2 −23
Open

fix expm1f overflow threshold #1043

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 0 additions & 21 deletions libm-test/src/precision.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -218,27 +218,6 @@ impl MaybeOverride<(f16,)> for SpecialCase {}

impl MaybeOverride<(f32,)> for SpecialCase {
fn check_float<F: Float>(input: (f32,), actual: F, expected: F, ctx: &CheckCtx) -> CheckAction {
if ctx.base_name == BaseName::Expm1
&& !input.0.is_infinite()
&& input.0 > 80.0
&& actual.is_infinite()
&& !expected.is_infinite()
{
// we return infinity but the number is representable
if ctx.basis == CheckBasis::Musl {
return XFAIL_NOCHECK;
}
return XFAIL("expm1 representable numbers");
}

if ctx.base_name == BaseName::Sinh && input.0.abs() > 80.0 && actual.is_nan() {
// we return some NaN that should be real values or infinite
if ctx.basis == CheckBasis::Musl {
return XFAIL_NOCHECK;
}
return XFAIL("sinh unexpected NaN");
}

if (ctx.base_name == BaseName::Lgamma || ctx.base_name == BaseName::LgammaR)
&& input.0 > 4e36
&& expected.is_infinite()
Expand Down
4 changes: 2 additions & 2 deletions libm/src/math/expm1f.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,6 @@
* ====================================================
*/

const O_THRESHOLD: f32 = 8.8721679688e+01; /* 0x42b17180 */
const LN2_HI: f32 = 6.9313812256e-01; /* 0x3f317180 */
const LN2_LO: f32 = 9.0580006145e-06; /* 0x3717f7d1 */
const INV_LN2: f32 = 1.4426950216e+00; /* 0x3fb8aa3b */
Expand Down Expand Up @@ -50,7 +49,8 @@ pub fn expm1f(mut x: f32) -> f32 {
if sign {
return -1.;
}
if x > O_THRESHOLD {
if hx > 0x42b17217 {
/* x > log(FLT_MAX) */
x *= x1p127;
return x;
}
Expand Down
Loading