Merge pull request #223 from ChrisRackauckas-Claude/fix-double64-julia110-and-downgrade

fix: restore Julia 1.10 support for Double64 intlog2 path + re-enable downgrade CI

Author: ChrisRackauckas

.github/workflows/Downgrade.yml

@@ -12,7 +12,6 @@ on:
       - 'docs/**'
 jobs:
   downgrade:
-    if: false  # Disabled pending fix - see #208 for tracking re-enablement
     name: "Downgrade"
     strategy:
       matrix:

Project.toml

@@ -24,7 +24,7 @@ ExponentialUtilitiesStaticArraysExt = "StaticArrays"
 Adapt = "3.4.0, 4"
 Aqua = "0.8"
 ArrayInterface = "7.1"
-DoubleFloats = "1"
+DoubleFloats = "1.1.14"
 ForwardDiff = "0.10.13"
 GPUArraysCore = "0.1, 0.2"
 GenericSchur = "0.5.3"
@@ -35,7 +35,7 @@ Printf = "1.10"
 Random = "1"
 SafeTestsets = "0.1"
 SparseArrays = "1.10"
-StaticArrays = "1.2"
+StaticArrays = "1.9.8"
 Test = "1"
 julia = "1.10"
 

src/exp_generic.jl

@@ -1,5 +1,9 @@
 intlog2(x::T) where {T <: Integer} = T(8 * sizeof(T) - leading_zeros(x - one(T)))
-intlog2(x) = x > typemax(UInt) ? ceil(Int, log2(x)) : intlog2(ceil(UInt, x)) % Int
+# `ceil(Int, x)` rather than `ceil(UInt, x)` so the integer-conversion path only needs
+# `trunc(::Type{Int}, ::AbstractFloat)`, which extended-precision types such as
+# DoubleFloats.Double64 define, whereas `trunc(::Type{<:Unsigned}, ::AbstractFloat)` is
+# unavailable on Julia 1.10. `x` here is a positive norm, so the signed conversion matches.
+intlog2(x) = x > typemax(Int) ? ceil(Int, log2(x)) : intlog2(ceil(Int, x))
 
 function naivemul!(
         C::StridedMatrix{T}, A::StridedMatrix{T},