boulder: Enable cached incremental LTO support for GNU & LLVM toolchains - #870
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boulder: Enable cached incremental LTO support for GNU & LLVM toolchains#870joebonrichie wants to merge 1 commit into
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September 1, 2026 19:47
Cache LTO artefacts by default when ccache is enabled. Note that LLVM's fat LTO is not supported. This can compliment ccache/sccache. Benchmarks (ccache disabled): zlib-ng (llvm, thin-lto): Uncached (warm first run) : 3.21s Cached (second run) : 2.51s emacs (gcc, lto): Uncached (warm first run) : 4m04.47s Cached (second run) : 3m45.09s starship (rust, thin-lto): no LTO cache, no sccache : 2m37.31s LTO uncached, sccache disabled : 2m36.88s LTO cached, sccache disabled : 1m58.47s LTO cached, sccache uncached : 2m11.85s LTO cached, sccache cached: : 12.70s no LTO cache, sccache uncached : 3m03.27s no LTO cache, sscache cached : 1m02.44s
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Cache LTO artefacts by default when ccache is enabled. Note that LLVM's fat LTO is not supported. This can compliment ccache/sccache.
Benchmarks
(sccache enabled):
starship (rust, thin-lto):
no LTO cache, no sccache : 2m37.31s
LTO uncached, sccache disabled : 2m36.88s
LTO cached, sccache disabled : 1m58.47s
LTO cached, sccache uncached : 2m11.85s
LTO cached, sccache cached: : 12.70s
no LTO cache, sccache uncached : 3m03.27s
no LTO cache, sscache cached : 1m02.44s
(ccache disabled):
zlib-ng (llvm, thin-lto):
Uncached (warm first run) : 3.21s
Cached (second run) : 2.51s
emacs (gcc, lto):
Uncached (warm first run) : 4m04.47s
Cached (second run) : 3m45.09s