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| author | Jason Merrill <jason@redhat.com> | 2015-02-12 15:28:41 -0500 |
|---|---|---|
| committer | Jason Merrill <jason@gcc.gnu.org> | 2015-02-12 15:28:41 -0500 |
| commit | f522930c8fe1554c4af6f4d87b6529be1b716ffc (patch) | |
| tree | 2d3f895a3da2356f70340af326c8229b80d19433 /gcc/doc | |
| parent | bc81eb3f77b27d46e25c218cfd9f32c89cc36b3c (diff) | |
| download | gcc-f522930c8fe1554c4af6f4d87b6529be1b716ffc.zip gcc-f522930c8fe1554c4af6f4d87b6529be1b716ffc.tar.gz gcc-f522930c8fe1554c4af6f4d87b6529be1b716ffc.tar.bz2 | |
common.opt (-flifetime-dse): New.
gcc/
* common.opt (-flifetime-dse): New.
gcc/cp/
* decl.c (begin_destructor_body): Condition clobber on
-flifetime-dse.
From-SVN: r220657
Diffstat (limited to 'gcc/doc')
| -rw-r--r-- | gcc/doc/invoke.texi | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 8a04790..5cce4f7 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -7888,6 +7888,16 @@ registers after writing to their lower 32-bit half. Enabled for Alpha, AArch64 and x86 at levels @option{-O2}, @option{-O3}, @option{-Os}. +@item -fno-lifetime-dse +@opindex fno-lifetime-dse +In C++ the value of an object is only affected by changes within its +lifetime: when the constructor begins, the object has an indeterminate +value, and any changes during the lifetime of the object are dead when +the object is destroyed. Normally dead store elimination will take +advantage of this; if your code relies on the value of the object +storage persisting beyond the lifetime of the object, you can use this +flag to disable this optimization. + @item -flive-range-shrinkage @opindex flive-range-shrinkage Attempt to decrease register pressure through register live range |