Merge pull request #22644 from angusmoore/anm/ranges-32bit-#22613

Handle 32 bit architecture when creating float ranges (#22613)

Author: timholy

base/docs/helpdb/Base.jl

@@ -1143,7 +1143,15 @@ bswap
 
 The largest integer losslessly representable by the given floating-point DataType `T`.
 """
-maxintfloat
+maxintfloat(T)
+
+"""
+    maxintfloat(T, S)
+
+The largest integer losslessly representable by the given floating-point DataType `T` that
+also does not exceed the maximum integer representable by the integer DataType `S`.
+"""
+maxintfloat(T, S)
 
 """
     delete!(collection, key)

base/floatfuncs.jl

@@ -20,6 +20,7 @@ maxintfloat(::Type{Float64}) = 9007199254740992.
 maxintfloat(::Type{Float32}) = Float32(16777216.)
 maxintfloat(::Type{Float16}) = Float16(2048f0)
 maxintfloat(x::T) where {T<:AbstractFloat} = maxintfloat(T)
+maxintfloat(::Type{S}, ::Type{T}) where {S<:AbstractFloat, T<:Integer} = min(maxintfloat(S), S(typemax(T)))
 maxintfloat() = maxintfloat(Float64)
 
 isinteger(x::AbstractFloat) = (x - trunc(x) == 0)

base/twiceprecision.jl

@@ -106,7 +106,7 @@ end
 
 function floatrange(a::AbstractFloat, st::AbstractFloat, len::Real, divisor::AbstractFloat)
     T = promote_type(typeof(a), typeof(st), typeof(divisor))
-    m = maxintfloat(T)
+    m = maxintfloat(T, Int)
     if abs(a) <= m && abs(st) <= m && abs(divisor) <= m
         ia, ist, idivisor = round(Int, a), round(Int, st), round(Int, divisor)
         if ia == a && ist == st && idivisor == divisor
@@ -131,7 +131,7 @@ function colon(start::T, step::T, stop::T) where T<:Union{Float16,Float32,Float6
         if start_d != 0 && stop_d != 0 &&
                 T(start_n/start_d) == start && T(stop_n/stop_d) == stop
             den = lcm(start_d, step_d) # use same denominator for start and step
-            m = maxintfloat(T)
+            m = maxintfloat(T, Int)
             if den != 0 && abs(start*den) <= m && abs(step*den) <= m &&  # will round succeed?
                     rem(den, start_d) == 0 && rem(den, step_d) == 0      # check lcm overflow
                 start_n = round(Int, start*den)
@@ -167,7 +167,7 @@ function range(a::T, st::T, len::Integer) where T<:Union{Float16,Float32,Float64
     if start_d != 0 && step_d != 0 &&
             T(start_n/start_d) == a && T(step_n/step_d) == st
         den = lcm(start_d, step_d)
-        m = maxintfloat(T)
+        m = maxintfloat(T, Int)
         if abs(den*a) <= m && abs(den*st) <= m &&
                 rem(den, start_d) == 0 && rem(den, step_d) == 0
             start_n = round(Int, den*a)
@@ -257,7 +257,7 @@ function _convertSRL(::Type{StepRangeLen{T,R,S}}, r::Range{U}) where {T,R,S,U}
     if start_d != 0 && step_d != 0 &&
             U(start_n/start_d) == f && U(step_n/step_d) == s
         den = lcm(start_d, step_d)
-        m = maxintfloat(T)
+        m = maxintfloat(T, Int)
         if den != 0 && abs(f*den) <= m && abs(s*den) <= m &&
                 rem(den, start_d) == 0 && rem(den, step_d) == 0
             start_n = round(Int, f*den)
@@ -326,7 +326,7 @@ function linspace(start::T, stop::T, len::Integer) where T<:Union{Float16,Float3
     stop_n, stop_d = rat(stop)
     if start_d != 0 && stop_d != 0
         den = lcm(start_d, stop_d)
-        m = maxintfloat(T)
+        m = maxintfloat(T, Int)
         if den != 0 && abs(den*start) <= m && abs(den*stop) <= m
             start_n = round(Int, den*start)
             stop_n = round(Int, den*stop)

test/floatfuncs.jl

@@ -14,11 +14,15 @@ end
 
 # maxintfloat
 
-@test maxintfloat(Float16) == Float16(2048f0)
+@test maxintfloat(Float16) === Float16(2048f0)
 for elty in (Float16,Float32,Float64)
-    @test maxintfloat(rand(elty)) == maxintfloat(elty)
+    @test maxintfloat(rand(elty)) === maxintfloat(elty)
 end
-@test maxintfloat() == maxintfloat(Float64)
+@test maxintfloat() === maxintfloat(Float64)
+@test maxintfloat(Float64, Int32) === 2147483647.0
+@test maxintfloat(Float32, Int32) === maxintfloat(Float32)
+@test maxintfloat(Float64, Int16) === 32767.0
+@test maxintfloat(Float64, Int64) === maxintfloat(Float64)
 
 # isinteger
 for elty in (Float16,Float32,Float64)

test/ranges.jl

@@ -356,15 +356,18 @@ for T = (Float32, Float64,), i = 1:2^15, n = 1:5
     # FIXME: these fail some small portion of the time
     @test_skip start == first(r)
     @test_skip stop  == last(r)
-    # FIXME: linspace construction fails on 32-bit
-    Sys.WORD_SIZE == 64 || continue
     l = linspace(start,stop,n)
     @test n == length(l)
     # FIXME: these fail some small portion of the time
     @test_skip start == first(l)
     @test_skip stop  == last(l)
 end
 
+# Inexact errors on 32 bit architectures. #22613
+@test first(linspace(log(0.2), log(10.0), 10)) == log(0.2)
+@test last(linspace(log(0.2), log(10.0), 10)) == log(10.0)
+@test length(Base.floatrange(-3e9, 1.0, 1, 1.0)) == 1
+
 # linspace & ranges with very small endpoints
 for T = (Float32, Float64)
     z = zero(T)