increase powi tolerance further

Author: tgross35

libm-test/src/precision.rs

@@ -19,8 +19,8 @@ pub fn default_ulp(ctx: &CheckCtx) -> u32 {
     let mut ulp = match ctx.base_name {
         // operations from builtins are always precise
         Bn::Add | Bn::Sub | Bn::Mul | Bn::Div => 0,
-        // TODO: is this actually what we want?
-        Bn::Powi => 4,
+        // FIXME: we need a better powi implementation (though this is no worse than C)
+        Bn::Powi => 100,
 
         // Operations that require exact results. This list should correlate with what we
         // have documented at <https://doc.rust-lang.org/std/primitive.f32.html>.