diff options
Diffstat (limited to 'clang/docs/UsersManual.rst')
| -rw-r--r-- | clang/docs/UsersManual.rst | 46 |
1 files changed, 42 insertions, 4 deletions
diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst index 5745e4b..e82b16f 100644 --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2325,7 +2325,7 @@ are listed below. devirtualization and virtual constant propagation, for classes with :doc:`hidden LTO visibility <LTOVisibility>`. Requires ``-flto``. -.. option:: -f[no]split-lto-unit +.. option:: -f[no-]split-lto-unit Controls splitting the :doc:`LTO unit <LTOVisibility>` into regular LTO and :doc:`ThinLTO` portions, when compiling with -flto=thin. Defaults to false @@ -2518,7 +2518,7 @@ are listed below. .. _funique_internal_linkage_names: -.. option:: -f[no]-unique-internal-linkage-names +.. option:: -f[no-]unique-internal-linkage-names Controls whether Clang emits a unique (best-effort) symbol name for internal linkage symbols. When this option is set, compiler hashes the main source @@ -2539,7 +2539,7 @@ are listed below. $ cd $P/bar && clang -c -funique-internal-linkage-names name_conflict.c $ cd $P && clang foo/name_conflict.o && bar/name_conflict.o -.. option:: -f[no]-basic-block-address-map: +.. option:: -f[no-]basic-block-address-map: Emits a ``SHT_LLVM_BB_ADDR_MAP`` section which includes address offsets for each basic block in the program, relative to the parent function address. @@ -2780,6 +2780,25 @@ usual build cycle when using sample profilers for optimization: /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^ code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf + [OPTIONAL] Pseudo instrumentation can be used as the anchor for accurate + profile mapping with the ``-fpseudo-probe-for-profiling`` option. + + On Linux: + + .. code-block:: console + + $ clang++ -O2 -gline-tables-only \ + -fpseudo-probe-for-profiling -funique-internal-linkage-names \ + code.cc -o code + + On Windows: + + .. code-block:: winbatch + + > clang-cl /O2 -gdwarf -gline-tables-only ^ + -fpseudo-probe-for-profiling /clang:-funique-internal-linkage-names ^ + code.cc /Fe:code -fuse-ld=lld /link /debug:dwarf + .. note:: :ref:`-funique-internal-linkage-names <funique_internal_linkage_names>` @@ -2881,6 +2900,25 @@ usual build cycle when using sample profilers for optimization: /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^ -fprofile-sample-use=code.prof code.cc /Fe:code + [OPTIONAL] Pseudo instrumentation can be used as the anchor for accurate + profile mapping with the ``-fpseudo-probe-for-profiling`` option. + + On Linux: + + .. code-block:: console + + $ clang++ -O2 \ + -fpseudo-probe-for-profiling -funique-internal-linkage-names \ + -fprofile-sample-use=code.prof code.cc -o code + + On Windows: + + .. code-block:: winbatch + + > clang-cl /O2 ^ + -fpseudo-probe-for-profiling /clang:-funique-internal-linkage-names ^ + -fprofile-sample-use=code.prof code.cc /Fe:code + [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/ edge counters. The profile inference algorithm (profi) can be used to infer missing blocks and edge counts, and improve the quality of profile data. @@ -4036,7 +4074,7 @@ Controlling implementation limits Sets the limit for the number of full-expressions evaluated in a single constant expression evaluation. This also controls the maximum size of array and dynamic array allocation that can be constant evaluated. - The default is 1048576. + The default is 1048576, and the limit can be disabled with `-fconstexpr-steps=0`. .. option:: -ftemplate-depth=N |