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Diffstat (limited to 'src')
| -rw-r--r-- | src/doc/unstable-book/src/compiler-flags/reg-struct-return.md | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/doc/unstable-book/src/compiler-flags/reg-struct-return.md b/src/doc/unstable-book/src/compiler-flags/reg-struct-return.md new file mode 100644 index 00000000000..35b782f38dc --- /dev/null +++ b/src/doc/unstable-book/src/compiler-flags/reg-struct-return.md @@ -0,0 +1,15 @@ +# `reg-struct-return` + +The tracking issue for this feature is: https://github.com/rust-lang/rust/issues/116973. + +------------------------ + +Option -Zreg-struct-return causes the compiler to return small structs in registers +instead of on the stack for extern "C"-like functions. +It is UNSOUND to link together crates that use different values for this flag. +It is only supported on `x86`. + +It is equivalent to [Clang]'s and [GCC]'s `-freg-struct-return`. + +[Clang]: https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-freg-struct-return +[GCC]: https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#index-freg-struct-return |