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| author | Sandra Loosemore <sandra@codesourcery.com> | 2024-01-18 23:19:39 +0000 |
|---|---|---|
| committer | Sandra Loosemore <sandra@codesourcery.com> | 2024-01-18 23:26:42 +0000 |
| commit | 9b6b7d615543d73381cb1f994825d9bca024c838 (patch) | |
| tree | efd3ede0a355cda632e74d96f9edfeccc8c27cf3 /gcc/doc | |
| parent | 0c7c65c4c359f8bfa1ebcb7b1c409af314064da2 (diff) | |
| download | gcc-9b6b7d615543d73381cb1f994825d9bca024c838.zip gcc-9b6b7d615543d73381cb1f994825d9bca024c838.tar.gz gcc-9b6b7d615543d73381cb1f994825d9bca024c838.tar.bz2 | |
Improve documentation of noinline and noipa attributes [PR108470]
gcc/ChangeLog
PR ipa/108470
* doc/extend.texi (Common Function Attributes): Document that
noinline also disables some interprocedural optimizations and
improve flow to the part about using inline asm instead to
disable calls from being optimized away completely. Remove the
sentence that says noipa is mainly for internal compiler testing.
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/extend.texi | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index d879ad5..616e26d 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -3666,13 +3666,17 @@ propagation. @cindex @code{noinline} function attribute @item noinline This function attribute prevents a function from being considered for -inlining. +inlining. It also disables some other interprocedural optimizations; it's +preferable to use the more comprehensive @code{noipa} attribute instead +if that is your goal. + @c Don't enumerate the optimizations by name here; we try to be @c future-compatible with this mechanism. -If the function does not have side effects, there are optimizations -other than inlining that cause function calls to be optimized away, -although the function call is live. To keep such calls from being -optimized away, put +Even if a function is declared with the @code{noinline} attribute, +there are optimizations other than inlining that can cause calls to be +optimized away if it does not have side effects, although the function +call is live. To keep such calls from being optimized away, put + @smallexample asm (""); @end smallexample @@ -3691,8 +3695,7 @@ the body. This attribute implies @code{noinline}, @code{noclone} and to a combination of other attributes, because its purpose is to suppress existing and future optimizations employing interprocedural analysis, including those that do not have an attribute suitable for disabling -them individually. This attribute is supported mainly for the purpose -of testing the compiler. +them individually. @cindex @code{nonnull} function attribute @cindex functions with non-null pointer arguments |