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Information about this build of zuexact

Source: R/info.R
zuexact_info.Rd

Reports the vendored 'xsum' library and how it was built.

Usage

zuexact_info()

Value

A list with elements:

  • xsum: the upstream stable version vendored.

  • xsum_commit: its commit in https://github.com/radfordneal/xsum.

  • large_threshold: vectors with at least this many elements are summed with xsum's large accumulator, shorter ones with the small one. The choice affects speed only, never the result.

  • simd: the SIMD instructions xsum was compiled to use: "avx", "sse2" or "none".

  • fma_hardware: whether the compiler reported a hardware fused multiply-add. Dot products are exact either way: with it, each product's error comes from fma(); without it, from Dekker's splitting algorithm, because some C libraries' software fma() is not exact.

  • long_double: whether this R has long doubles, which is what makes base sum() differ between platforms.

Examples

zuexact_info()
#> $xsum
#> [1] "stable-version-3"
#> 
#> $xsum_commit
#> [1] "b766b3e104cdbd6769c8df033fb430700fce32dd"
#> 
#> $large_threshold
#> [1] 128
#> 
#> $simd
#> [1] "sse2"
#> 
#> $fma_hardware
#> [1] FALSE
#> 
#> $long_double
#> [1] TRUE
#>