Merge pull request JuliaLang#14436 from eschnett/eschnett/avoid-int12…

…8-try

Avoid expensive try-catch for Int128 division

base/int.jl

@@ -376,46 +376,22 @@ if WORD_SIZE == 32
  end
 
  function div(x::Int128, y::Int128)
- try
- Int128(div(BigInt(x),BigInt(y)))
- catch e
- isa(e, InexactError) && throw(DivideError())
- rethrow()
- end
+ (x == typemin(Int128)) & (y == -1) && throw(DivideError())
+ Int128(div(BigInt(x),BigInt(y)))
  end
  function div(x::UInt128, y::UInt128)
- try
- UInt128(div(BigInt(x),BigInt(y)))
- catch e
- isa(e, InexactError) && throw(DivideError())
- rethrow()
- end
+ UInt128(div(BigInt(x),BigInt(y)))
  end
 
  function rem(x::Int128, y::Int128)
- try
- Int128(rem(BigInt(x),BigInt(y)))
- catch e
- isa(e, InexactError) && throw(DivideError())
- rethrow()
- end
+ Int128(rem(BigInt(x),BigInt(y)))
  end
  function rem(x::UInt128, y::UInt128)
- try
- UInt128(rem(BigInt(x),BigInt(y)))
- catch e
- isa(e, InexactError) && throw(DivideError())
- rethrow()
- end
+ UInt128(rem(BigInt(x),BigInt(y)))
  end
 
  function mod(x::Int128, y::Int128)
- try
- Int128(mod(BigInt(x),BigInt(y)))
- catch e
- isa(e, InexactError) && throw(DivideError())
- rethrow()
- end
+ Int128(mod(BigInt(x),BigInt(y)))
  end
 
  <<( x::Int128, y::Int) = y == 0 ? x : box(Int128,shl_int(unbox(Int128,x),unbox(Int,y)))

test/numbers.jl

@@ -1593,6 +1593,22 @@ end
 @test signed(cld(typemax(UInt),typemin(Int)>>1)) == -3
 @test signed(cld(typemax(UInt),(typemin(Int)>>1)+1)) == -4
 
+# Test exceptions and special cases
+for T in (Int8,Int16,Int32,Int64,Int128, UInt8,UInt16,UInt32,UInt64,UInt128)
+ @test_throws DivideError div(T(1), T(0))
+ @test_throws DivideError fld(T(1), T(0))
+ @test_throws DivideError cld(T(1), T(0))
+ @test_throws DivideError rem(T(1), T(0))
+ @test_throws DivideError mod(T(1), T(0))
+end
+for T in (Int8,Int16,Int32,Int64,Int128)
+ @test_throws DivideError div(typemin(T), T(-1))
+ @test_throws DivideError fld(typemin(T), T(-1))
+ @test_throws DivideError cld(typemin(T), T(-1))
+ @test rem(typemin(T), T(-1)) === T(0)
+ @test mod(typemin(T), T(-1)) === T(0)
+end
+
 # Test return types
 for T in (Int8,Int16,Int32,Int64,Int128, UInt8,UInt16,UInt32,UInt64,UInt128)
  z, o = T(0), T(1)