From dfb65402fa690d8fd47235d8135e7f59eb7d6b7d Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Thu, 31 May 2018 12:29:28 +0200 Subject: [PATCH] documentation: document lto build flags Signed-off-by: Matthias Reichl --- packages/readme.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/packages/readme.md b/packages/readme.md index 109dc27014..2ba73b4676 100644 --- a/packages/readme.md +++ b/packages/readme.md @@ -118,7 +118,10 @@ Set the variable `PKG_BUILD_FLAGS` in the `package.mk` to enable/disable the sin |----------|----------|----------------|-------------| | pic | disabled | target/init | [Position Independent Code](https://en.wikipedia.org/wiki/Position-independent_code) | | pic:host | disabled | host/bootstrap | see above | -| lto | depend on `LTO_SUPPORT` | target/init | can only disabled, use of "Link Time Optimisation" of the compiler | +| lto | disabled | target/init | enable LTO (Link Time optimization) in the compiler and linker unless disabled via `LTO_SUPPORT`. Compiles non-fat LTO objects (only bytecode) and performs single-threaded optimization at link stage | +| lto-parallel | disabled | target/init | same as `lto` but enable parallel optimization at link stage. Only enable this if the package build doesn't run multiple linkers in parallel otherwise this can result in lots of parallel processes! | +| lto-fat | disabled | target/init | same as `lto` but compile fat LTO objects (bytecode plus optimized assembly). This increases compile time but can be useful to create static libraries suitable both for LTO and non-LTO linking | +| lto-off | disabled | target/init | explicitly disable LTO in the compiler and linker | | gold | depend on `GOLD_SUPPORT` | target/init | can only disabled, use of the GOLD-Linker | | parallel | enabled | all | `make` or `ninja` builds with multiple threads/processes (or not) |