Performance fix: avoid unnecessary convert on setindex!、copy when type is same.
#38
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NHDaly
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Nov 8, 2018
This fixes unnecessary copies on `setindex!`, etc.
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@@ Coverage Diff @@
## master #38 +/- ##
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+ Coverage 98.82% 98.83% +<.01%
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Files 1 1
Lines 170 171 +1
==========================================
+ Hits 168 169 +1
Misses 2 2
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The "copy constructor" is no longer necessary now that a no-op
`convert` is added, since by default construction falls back to convert.
To verify, after this change, the performance is still correct:
```
julia> f = FixedPointDecimals.FixedDecimal{Int128,2}(3.25)
FixedDecimal{Int128,2}(3.25)
julia> @Btime x = FixedPointDecimals.FixedDecimal{Int128, 2}($f)
0.036 ns (0 allocations: 0 bytes)
FixedDecimal{Int128,2}(3.25)
```
And `@code_native` shows this to be a simple reinterpret.
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(I've also removed the copy constructor that I added in #36, since this is the more general and correct fix.) And verified that the performance is unchanged: julia> f = FixedPointDecimals.FixedDecimal{Int128,2}(3.25)
FixedDecimal{Int128,2}(3.25)
julia> @btime x = FixedPointDecimals.FixedDecimal{Int128, 2}($f)
0.036 ns (0 allocations: 0 bytes)
FixedDecimal{Int128,2}(3.25) |
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Add
convert(::Type{T}, x::T) where {T<:FD} = xThis fixes unnecessary copies on
setindex!, etc.Fixes the allocations issue for
identityfrom this table, by preventing the widening toBigInt:#37
This is the same situation as this issue:
JuliaLang/julia#17559