Increase numerical precision of log1p

Karel Král · youknowone · commit 301c32dba090 · 2025-04-30T16:35:04.000+09:00
Use Rust native ln_1p to increase numerical precision matching what is
expected by `test_mtestfile`.
diff --git a/stdlib/src/math.rs b/stdlib/src/math.rs
@@ -147,7 +147,7 @@ mod math {
     fn log1p(x: ArgIntoFloat, vm: &VirtualMachine) -> PyResult<f64> {
         let x = *x;
         if x.is_nan() || x > -1.0_f64 {
-            Ok((x + 1.0_f64).ln())
+            Ok(x.ln_1p())
         } else {
             Err(vm.new_value_error("math domain error".to_owned()))
         }

Original file line number	Diff line number	Diff line change
`@@ -147,7 +147,7 @@ mod math {`
`147`	`147`	`fn log1p(x: ArgIntoFloat, vm: &VirtualMachine) -> PyResult<f64> {`
`148`	`148`	`let x = *x;`
`149`	`149`	`if x.is_nan() \|\| x > -1.0_f64 {`
`150`		`- Ok((x + 1.0_f64).ln())`
	`150`	`+ Ok(x.ln_1p())`
`151`	`151`	`} else {`
`152`	`152`	`Err(vm.new_value_error("math domain error".to_owned()))`
`153`	`153`	`}`