invoke.texi ([-fsized-deallocation]): Copy-edit to fix verb tense, etc.
2015-01-04 Sandra Loosemore <sandra@codesourcery.com> gcc/ * doc/invoke.texi ([-fsized-deallocation]): Copy-edit to fix verb tense, etc. ([-fvtable-verify], [-fvtv-debug]): Likewise. ([-Wabi]): Likewise. ([-fmessage-length]): Likewise. ([-Wsuggest-final-types], [-Wsuggest-final-methods]): Likewise. ([-Wno-discarded-qualifiers]): Likewise. ([-Wnodiscarded-array-qualifiers]): Likewise. ([-Wno-virtual-move-assign]): Likewise. ([-fsanitize=address], [-fsanitize=thread]): Likewise. ([-fsanitize=leak], [-fsanitize=undefined]): Likewise. ([-fsanitize=unreachable], [-fsanitize-recover]): Likewise. ([-fsanitize-undefined-trap-on-error]): Likewise. ([-floop-interchange]): Likewise. ([-ftree-coalesce-inlined-vars]): Likewise. ([-fvect-cost-model]): Likewise. ([-flto]): Likewise. ([--param]): Likewise. (Spec Files): Likewise. ([-mstrict-align]): Likewise. ([-mfix-cortex-a53-835769]): Likewise. ([-march], [-mtune]): Likewise. ([-mpic-register]): Likewise. ([-munaligned-access]): Likewise. ([-msp8]): Likewise. (EIND and Devices with more than 128 Ki Bytes of Flash): Likewise. (AVR Built-in Macros): Likewise. ([-mpreferred-stack-boundary]): Likewise. ([-mtune-crtl]): Likewise. ([-mashf]): Likewise. ([-mmcu=]): Likewise. ([-minrt]): Likewise. ([-maltivec], [-maltivec=be], [-maltivec=le]): Likewise. ([-mupper-regs]): Likewise. ([-matomic-model]): Likewise. ([-mdiv]): Likewise. ([-mzdcbranch]): Likewise. ([-mdisable-callt]): Likewise. ([-msoft-float]): Likewise. ([-m8byte-align]): Likewise. ([-fstack-reuse]): Likewise. From-SVN: r219176
This commit is contained in:
Sandra Loosemore
Sandra Loosemore
parent
1a78ef4c0e
commit
eaacbd7bbc
@ -1,3 +1,47 @@
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2015-01-04 Sandra Loosemore <sandra@codesourcery.com>
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* doc/invoke.texi ([-fsized-deallocation]): Copy-edit to fix
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verb tense, etc.
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([-fvtable-verify], [-fvtv-debug]): Likewise.
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([-Wabi]): Likewise.
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([-fmessage-length]): Likewise.
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([-Wsuggest-final-types], [-Wsuggest-final-methods]): Likewise.
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([-Wno-discarded-qualifiers]): Likewise.
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([-Wnodiscarded-array-qualifiers]): Likewise.
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([-Wno-virtual-move-assign]): Likewise.
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([-fsanitize=address], [-fsanitize=thread]): Likewise.
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([-fsanitize=leak], [-fsanitize=undefined]): Likewise.
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([-fsanitize=unreachable], [-fsanitize-recover]): Likewise.
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([-fsanitize-undefined-trap-on-error]): Likewise.
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([-floop-interchange]): Likewise.
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([-ftree-coalesce-inlined-vars]): Likewise.
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([-fvect-cost-model]): Likewise.
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([-flto]): Likewise.
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([--param]): Likewise.
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(Spec Files): Likewise.
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([-mstrict-align]): Likewise.
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([-mfix-cortex-a53-835769]): Likewise.
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([-march], [-mtune]): Likewise.
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([-mpic-register]): Likewise.
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([-munaligned-access]): Likewise.
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([-msp8]): Likewise.
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(EIND and Devices with more than 128 Ki Bytes of Flash): Likewise.
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(AVR Built-in Macros): Likewise.
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([-mpreferred-stack-boundary]): Likewise.
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([-mtune-crtl]): Likewise.
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([-mashf]): Likewise.
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([-mmcu=]): Likewise.
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([-minrt]): Likewise.
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([-maltivec], [-maltivec=be], [-maltivec=le]): Likewise.
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([-mupper-regs]): Likewise.
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([-matomic-model]): Likewise.
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([-mdiv]): Likewise.
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([-mzdcbranch]): Likewise.
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([-mdisable-callt]): Likewise.
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([-msoft-float]): Likewise.
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([-m8byte-align]): Likewise.
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([-fstack-reuse]): Likewise.
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2015-01-03 Sandra Loosemore <sandra@codesourcery.com>
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* doc/invoke.texi ([-fprofile-generate], [-fprofile-use]):
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@ -2318,8 +2318,8 @@ void operator delete[] (void *, std::size_t) noexcept;
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as introduced in C++14. This is useful for user-defined replacement
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deallocation functions that, for example, use the size of the object
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to make deallocation faster. Enabled by default under
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@samp{-std=c++14} and above. The flag @option{-Wsized-deallocation} will
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warn about places that might want to add a definition.
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@samp{-std=c++14} and above. The flag @option{-Wsized-deallocation}
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warns about places that might want to add a definition.
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@item -fstats
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@opindex fstats
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@ -2451,14 +2451,14 @@ shared libraries have been loaded and initialized.
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libraries have been loaded and initialized.
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If this option appears multiple times in the compiler line, with different
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values specified, 'none' will take highest priority over both 'std' and
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'preinit'; 'preinit' will take priority over 'std'.
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values specified, 'none' takes highest priority over both 'std' and
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'preinit'; 'preinit' takes priority over 'std'.
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@item -fvtv-debug
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@opindex fvtv-debug
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Causes debug versions of the runtime functions for the vtable verification
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feature to be called. This assumes the @option{-fvtable-verify=std} or
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@option{-fvtable-verify=preinit} has been used. This flag will also cause the
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@option{-fvtable-verify=preinit} has been used. This flag also causes the
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compiler to keep track of which vtable pointers it found for each class, and
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record that information in the file ``vtv_set_ptr_data.log'', in the dump
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file directory on the user's machine.
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@ -2571,7 +2571,7 @@ These issues were corrected in @option{-fabi-version=6}.
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@item
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Lambdas in default argument scope were mangled incorrectly, and the
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ABI changed the mangling of nullptr_t.
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ABI changed the mangling of @code{nullptr_t}.
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These issues were corrected in @option{-fabi-version=7}.
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@ -3100,8 +3100,8 @@ honor these options.
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@item -fmessage-length=@var{n}
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@opindex fmessage-length
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Try to format error messages so that they fit on lines of about
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@var{n} characters. If @var{n} is zero, then no line-wrapping will be
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done; each error message will appear on a single line. This is the
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@var{n} characters. If @var{n} is zero, then no line-wrapping is
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done; each error message appears on a single line. This is the
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default for all front ends.
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@item -fdiagnostics-show-location=once
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@ -4261,7 +4261,8 @@ appropriate may not be detected.
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@opindex Wno-suggest-final-types
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@opindex Wsuggest-final-types
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Warn about types with virtual methods where code quality would be improved
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if the type was declared with the C++11 final specifier, or, if possible,
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if the type were declared with the C++11 @code{final} specifier,
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or, if possible,
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declared in an anonymous namespace. This allows GCC to more aggressively
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devirtualize the polymorphic calls. This warning is more effective with link
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time optimization, where the information about the class hierarchy graph is
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@ -4271,8 +4272,10 @@ more complete.
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@opindex Wno-suggest-final-methods
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@opindex Wsuggest-final-methods
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Warn about virtual methods where code quality would be improved if the method
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was declared with the C++11 final specifier, or, if possible, its type was
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declared in an anonymous namespace or with the final specifier. This warning is
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were declared with the C++11 @code{final} specifier,
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or, if possible, its type were
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declared in an anonymous namespace or with the @code{final} specifier.
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This warning is
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more effective with link time optimization, where the information about the
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class hierarchy graph is more complete. It is recommended to first consider
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suggestions of @option{-Wsuggest-final-types} and then rebuild with new
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@ -4302,7 +4305,7 @@ This warning is enabled by @option{-Wall}.
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@opindex Wno-discarded-qualifiers
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@opindex Wdiscarded-qualifiers
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Do not warn if type qualifiers on pointers are being discarded.
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Typically, the compiler will warn if a @code{const char *} variable is
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Typically, the compiler warns if a @code{const char *} variable is
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passed to a function that takes a @code{char *} parameter. This option
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can be used to suppress such a warning.
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@ -4310,7 +4313,7 @@ can be used to suppress such a warning.
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@opindex Wno-discarded-array-qualifiers
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@opindex Wdiscarded-array-qualifiers
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Do not warn if type qualifiers on arrays which are pointer targets
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are being discarded. Typically, the compiler will warn if a
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are being discarded. Typically, the compiler warns if a
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@code{const int (*)[]} variable is passed to a function that
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takes a @code{int (*)[]} parameter. This option can be used to
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suppress such a warning.
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@ -4957,7 +4960,7 @@ declaration. This warning is issued even if the definition itself
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provides a prototype. Use this option to detect global functions
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that do not have a matching prototype declaration in a header file.
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This option is not valid for C++ because all function declarations
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provide prototypes and a non-matching declaration will declare an
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provide prototypes and a non-matching declaration declares an
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overload rather than conflict with an earlier declaration.
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Use @option{-Wmissing-declarations} to detect missing declarations in C++.
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@ -5263,7 +5266,7 @@ scalar type.
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@opindex Wno-virtual-move-assign
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Suppress warnings about inheriting from a virtual base with a
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non-trivial C++11 move assignment operator. This is dangerous because
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if the virtual base is reachable along more than one path, it will be
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if the virtual base is reachable along more than one path, it is
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moved multiple times, which can mean both objects end up in the
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moved-from state. If the move assignment operator is written to avoid
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moving from a moved-from object, this warning can be disabled.
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@ -5556,7 +5559,7 @@ many times it is given. This is mainly intended to be used with
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@item -fsanitize=address
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@opindex fsanitize=address
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Enable AddressSanitizer, a fast memory error detector.
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Memory access instructions will be instrumented to detect
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Memory access instructions are instrumented to detect
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out-of-bounds and use-after-free bugs.
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See @uref{http://code.google.com/p/address-sanitizer/} for
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more details. The run-time behavior can be influenced using the
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@ -5572,7 +5575,7 @@ See @uref{http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKer
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@item -fsanitize=thread
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@opindex fsanitize=thread
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Enable ThreadSanitizer, a fast data race detector.
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Memory access instructions will be instrumented to detect
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Memory access instructions are instrumented to detect
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data race bugs. See @uref{http://code.google.com/p/thread-sanitizer/} for more
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details. The run-time behavior can be influenced using the @env{TSAN_OPTIONS}
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environment variable; see
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@ -5584,7 +5587,7 @@ supported options.
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Enable LeakSanitizer, a memory leak detector.
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This option only matters for linking of executables and if neither
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@option{-fsanitize=address} nor @option{-fsanitize=thread} is used. In that
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case it will link the executable against a library that overrides @code{malloc}
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case the executable is linked against a library that overrides @code{malloc}
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and other allocator functions. See
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@uref{https://code.google.com/p/address-sanitizer/wiki/LeakSanitizer} for more
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details. The run-time behavior can be influenced using the
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@ -5593,7 +5596,7 @@ details. The run-time behavior can be influenced using the
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@item -fsanitize=undefined
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@opindex fsanitize=undefined
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Enable UndefinedBehaviorSanitizer, a fast undefined behavior detector.
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Various computations will be instrumented to detect undefined behavior
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Various computations are instrumented to detect undefined behavior
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at runtime. Current suboptions are:
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@table @gcctabopt
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@ -5610,7 +5613,7 @@ Detect integer division by zero as well as @code{INT_MIN / -1} division.
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@item -fsanitize=unreachable
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@opindex fsanitize=unreachable
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With this option, the compiler will turn the @code{__builtin_unreachable}
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With this option, the compiler turns the @code{__builtin_unreachable}
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call into a diagnostics message call instead. When reaching the
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@code{__builtin_unreachable} call, the behavior is undefined.
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@ -5724,13 +5727,13 @@ Kernel AddressSanitizer.
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@opindex fno-sanitize-recover
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@option{-fsanitize-recover=} controls error recovery mode for sanitizers
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mentioned in comma-separated list of @var{opts}. Enabling this option
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for a sanitizer component would cause it to attempt to continue
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for a sanitizer component causes it to attempt to continue
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running the program as if no error happened. This means multiple
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runtime errors can be reported in a single program run, and the exit
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code of the program may indicate success even when errors
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have been reported. The @option{-fno-sanitize-recover=} can be used to alter
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this behavior, only the first detected error will be reported
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and program will exit after that with non-zero exit code.
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this behavior: only the first detected error is reported
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and program then exits with a non-zero exit code.
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Currently this feature only works for @option{-fsanitize=undefined} (and its suboptions
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except for @option{-fsanitize=unreachable} and @option{-fsanitize=return}),
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@ -5747,8 +5750,8 @@ Similarly @option{-fno-sanitize-recover} is equivalent to
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The @option{-fsanitize-undefined-trap-on-error} instructs the compiler to
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report undefined behavior using @code{__builtin_trap ()} rather than
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a @code{libubsan} library routine. The advantage of this is that the
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@code{libubsan} library is not needed and will not be linked in, so this
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is usable even for use in freestanding environments.
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@code{libubsan} library is not needed and is not linked in, so this
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is usable even in freestanding environments.
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@item -fdump-final-insns@r{[}=@var{file}@r{]}
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@opindex fdump-final-insns
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@ -8343,6 +8346,7 @@ DO J = 1, M
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ENDDO
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ENDDO
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@end smallexample
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@noindent
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loop interchange transforms the loop as if it were written:
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@smallexample
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DO I = 1, N
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@ -8373,6 +8377,7 @@ DO I = 1, N
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A(I) = A(I) + C
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ENDDO
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@end smallexample
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@noindent
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loop strip mining transforms the loop as if it were written:
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@smallexample
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DO II = 1, N, 51
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@ -8400,6 +8405,7 @@ DO I = 1, N
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ENDDO
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ENDDO
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@end smallexample
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@noindent
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loop blocking transforms the loop as if it were written:
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@smallexample
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DO II = 1, N, 51
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@ -8577,10 +8583,10 @@ is enabled by default at @option{-O} and higher.
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@item -ftree-coalesce-inlined-vars
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@opindex ftree-coalesce-inlined-vars
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||||
Tell the copyrename pass (see @option{-ftree-copyrename}) to attempt to
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combine small user-defined variables too, but only if they were inlined
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combine small user-defined variables too, but only if they are inlined
|
||||
from other functions. It is a more limited form of
|
||||
@option{-ftree-coalesce-vars}. This may harm debug information of such
|
||||
inlined variables, but it will keep variables of the inlined-into
|
||||
inlined variables, but it keeps variables of the inlined-into
|
||||
function apart from each other, such that they are more likely to
|
||||
contain the expected values in a debugging session. This was the
|
||||
default in GCC versions older than 4.7.
|
||||
@ -8630,9 +8636,9 @@ Alter the cost model used for vectorization. The @var{model} argument
|
||||
should be one of @code{unlimited}, @code{dynamic} or @code{cheap}.
|
||||
With the @code{unlimited} model the vectorized code-path is assumed
|
||||
to be profitable while with the @code{dynamic} model a runtime check
|
||||
will guard the vectorized code-path to enable it only for iteration
|
||||
guards the vectorized code-path to enable it only for iteration
|
||||
counts that will likely execute faster than when executing the original
|
||||
scalar loop. The @code{cheap} model will disable vectorization of
|
||||
scalar loop. The @code{cheap} model disables vectorization of
|
||||
loops where doing so would be cost prohibitive for example due to
|
||||
required runtime checks for data dependence or alignment but otherwise
|
||||
is equal to the @code{dynamic} model.
|
||||
@ -9029,7 +9035,7 @@ optimizations you need to use the GCC driver to perform the link-step.
|
||||
GCC then automatically performs link-time optimization if any of the
|
||||
objects involved were compiled with the @option{-flto}. You generally
|
||||
should specify the optimization options to be used for link-time
|
||||
optimization though GCC will try to be clever at guessing an
|
||||
optimization though GCC tries to be clever at guessing an
|
||||
optimization level to use from the options used at compile-time
|
||||
if you fail to specify one at link-time. You can always override
|
||||
the automatic decision to do link-time optimization at link-time
|
||||
@ -9082,9 +9088,9 @@ stage. Generally options specified at link-time override those
|
||||
specified at compile-time.
|
||||
|
||||
If you do not specify an optimization level option @option{-O} at
|
||||
link-time then GCC will compute one based on the optimization levels
|
||||
link-time then GCC computes one based on the optimization levels
|
||||
used when compiling the object files. The highest optimization
|
||||
level will win here.
|
||||
level wins here.
|
||||
|
||||
Currently, the following options and their setting are take from
|
||||
the first object file that explicitely specified it:
|
||||
@ -9168,7 +9174,7 @@ The current implementation of LTO makes no
|
||||
attempt to generate bytecode that is portable between different
|
||||
types of hosts. The bytecode files are versioned and there is a
|
||||
strict version check, so bytecode files generated in one version of
|
||||
GCC will not work with an older or newer version of GCC.
|
||||
GCC do not work with an older or newer version of GCC.
|
||||
|
||||
Link-time optimization does not work well with generation of debugging
|
||||
information. Combining @option{-flto} with
|
||||
@ -10011,20 +10017,17 @@ the amount of inlining for code having a large abstraction penalty.
|
||||
The default value is 10.
|
||||
|
||||
@item max-early-inliner-iterations
|
||||
@itemx max-early-inliner-iterations
|
||||
Limit of iterations of the early inliner. This basically bounds
|
||||
the number of nested indirect calls the early inliner can resolve.
|
||||
Deeper chains are still handled by late inlining.
|
||||
|
||||
@item comdat-sharing-probability
|
||||
@itemx comdat-sharing-probability
|
||||
Probability (in percent) that C++ inline function with comdat visibility
|
||||
are shared across multiple compilation units. The default value is 20.
|
||||
|
||||
@item profile-func-internal-id
|
||||
@itemx profile-func-internal-id
|
||||
A parameter to control whether to use function internal id in profile
|
||||
database lookup. If the value is 0, the compiler will use id that
|
||||
database lookup. If the value is 0, the compiler uses an id that
|
||||
is based on function assembler name and filename, which makes old profile
|
||||
data more tolerant to source changes such as function reordering etc.
|
||||
The default value is 0.
|
||||
@ -10539,7 +10542,7 @@ pointer parameter.
|
||||
The two Scalar Reduction of Aggregates passes (SRA and IPA-SRA) aim to
|
||||
replace scalar parts of aggregates with uses of independent scalar
|
||||
variables. These parameters control the maximum size, in storage units,
|
||||
of aggregate which will be considered for replacement when compiling for
|
||||
of aggregate which is considered for replacement when compiling for
|
||||
speed
|
||||
(@option{sra-max-scalarization-size-Ospeed}) or size
|
||||
(@option{sra-max-scalarization-size-Osize}) respectively.
|
||||
@ -10608,7 +10611,7 @@ score of the candidate.
|
||||
@item ipa-max-aa-steps
|
||||
During its analysis of function bodies, IPA-CP employs alias analysis
|
||||
in order to track values pointed to by function parameters. In order
|
||||
not spend too much time analyzing huge functions, it will give up and
|
||||
not spend too much time analyzing huge functions, it gives up and
|
||||
consider all memory clobbered after examining
|
||||
@option{ipa-max-aa-steps} statements modifying memory.
|
||||
|
||||
@ -10666,7 +10669,7 @@ See @file{haifa-sched.c} in the GCC sources for more details.
|
||||
The default choice depends on the target.
|
||||
|
||||
@item max-slsr-cand-scan
|
||||
Set the maximum number of existing candidates that will be considered when
|
||||
Set the maximum number of existing candidates that are considered when
|
||||
seeking a basis for a new straight-line strength reduction candidate.
|
||||
|
||||
@item asan-globals
|
||||
@ -11746,8 +11749,8 @@ for each matching switch, with the @code{%*} replaced by the part of
|
||||
that switch matching the @code{*}.
|
||||
|
||||
If @code{%*} appears as the last part of a spec sequence then a space
|
||||
will be added after the end of the last substitution. If there is more
|
||||
text in the sequence however then a space will not be generated. This
|
||||
is added after the end of the last substitution. If there is more
|
||||
text in the sequence, however, then a space is not generated. This
|
||||
allows the @code{%*} substitution to be used as part of a larger
|
||||
string. For example, a spec string like this:
|
||||
|
||||
@ -11755,7 +11758,8 @@ string. For example, a spec string like this:
|
||||
%@{mcu=*:--script=%*/memory.ld@}
|
||||
@end smallexample
|
||||
|
||||
when matching an option like @code{-mcu=newchip} will produce:
|
||||
@noindent
|
||||
when matching an option like @code{-mcu=newchip} produces:
|
||||
|
||||
@smallexample
|
||||
--script=newchip/memory.ld
|
||||
@ -11989,7 +11993,7 @@ statically linked only.
|
||||
|
||||
@item -mstrict-align
|
||||
@opindex mstrict-align
|
||||
Do not assume that unaligned memory references will be handled by the system.
|
||||
Do not assume that unaligned memory references are handled by the system.
|
||||
|
||||
@item -momit-leaf-frame-pointer
|
||||
@itemx -mno-omit-leaf-frame-pointer
|
||||
@ -12013,7 +12017,7 @@ of TLS variables.
|
||||
@opindex mfix-cortex-a53-835769
|
||||
@opindex mno-fix-cortex-a53-835769
|
||||
Enable or disable the workaround for the ARM Cortex-A53 erratum number 835769.
|
||||
This will involve inserting a NOP instruction between memory instructions and
|
||||
This involves inserting a NOP instruction between memory instructions and
|
||||
64-bit integer multiply-accumulate instructions.
|
||||
|
||||
@item -march=@var{name}
|
||||
@ -12031,7 +12035,7 @@ GCC uses this name to determine what kind of instructions it can emit when
|
||||
generating assembly code.
|
||||
|
||||
Where @option{-march} is specified without either of @option{-mtune}
|
||||
or @option{-mcpu} also being specified, the code will be tuned to perform
|
||||
or @option{-mcpu} also being specified, the code is tuned to perform
|
||||
well across a range of target processors implementing the target
|
||||
architecture.
|
||||
|
||||
@ -12046,7 +12050,7 @@ of the code for a big.LITTLE system. The only permissible value is
|
||||
@samp{cortex-a57.cortex-a53}.
|
||||
|
||||
Where none of @option{-mtune=}, @option{-mcpu=} or @option{-march=}
|
||||
are specified, the code will be tuned to perform well across a range
|
||||
are specified, the code is tuned to perform well across a range
|
||||
of target processors.
|
||||
|
||||
This option cannot be suffixed by feature modifiers.
|
||||
@ -12559,7 +12563,7 @@ Expand @code{adddi3} and @code{subdi3} at rtl generation time into
|
||||
@item -mindexed-loads
|
||||
@opindex mindexed-loads
|
||||
Enable the use of indexed loads. This can be problematic because some
|
||||
optimizers will then assume the that indexed stores exist, which is not
|
||||
optimizers then assume that indexed stores exist, which is not
|
||||
the case.
|
||||
|
||||
@item -mlra
|
||||
@ -13040,7 +13044,7 @@ before execution begins.
|
||||
@item -mpic-register=@var{reg}
|
||||
@opindex mpic-register
|
||||
Specify the register to be used for PIC addressing.
|
||||
For standard PIC base case, the default will be any suitable register
|
||||
For standard PIC base case, the default is any suitable register
|
||||
determined by compiler. For single PIC base case, the default is
|
||||
@samp{R9} if target is EABI based or stack-checking is enabled,
|
||||
otherwise the default is @samp{R10}.
|
||||
@ -13157,13 +13161,13 @@ Enables (or disables) reading and writing of 16- and 32- bit values
|
||||
from addresses that are not 16- or 32- bit aligned. By default
|
||||
unaligned access is disabled for all pre-ARMv6 and all ARMv6-M
|
||||
architectures, and enabled for all other architectures. If unaligned
|
||||
access is not enabled then words in packed data structures will be
|
||||
access is not enabled then words in packed data structures are
|
||||
accessed a byte at a time.
|
||||
|
||||
The ARM attribute @code{Tag_CPU_unaligned_access} will be set in the
|
||||
The ARM attribute @code{Tag_CPU_unaligned_access} is set in the
|
||||
generated object file to either true or false, depending upon the
|
||||
setting of this option. If unaligned access is enabled then the
|
||||
preprocessor symbol @code{__ARM_FEATURE_UNALIGNED} will also be
|
||||
preprocessor symbol @code{__ARM_FEATURE_UNALIGNED} is also
|
||||
defined.
|
||||
|
||||
@item -mneon-for-64bits
|
||||
@ -13276,7 +13280,7 @@ This option is used internally by the compiler to select and
|
||||
build multilibs for architectures @code{avr2} and @code{avr25}.
|
||||
These architectures mix devices with and without @code{SPH}.
|
||||
For any setting other than @code{-mmcu=avr2} or @code{-mmcu=avr25}
|
||||
the compiler driver will add or remove this option from the compiler
|
||||
the compiler driver adds or removes this option from the compiler
|
||||
proper's command line, because the compiler then knows if the device
|
||||
or architecture has an 8-bit stack pointer and thus no @code{SPH}
|
||||
register or not.
|
||||
@ -13348,9 +13352,9 @@ generates @emph{stubs}. Stubs are jump pads sometimes also called
|
||||
The stub contains a direct jump to the desired address.
|
||||
|
||||
@item
|
||||
Linker relaxation must be turned on so that the linker will generate
|
||||
the stubs correctly an all situaltion. See the compiler option
|
||||
@code{-mrelax} and the linler option @code{--relax}.
|
||||
Linker relaxation must be turned on so that the linker generates
|
||||
the stubs correctly in all situations. See the compiler option
|
||||
@code{-mrelax} and the linker option @code{--relax}.
|
||||
There are corner cases where the linker is supposed to generate stubs
|
||||
but aborts without relaxation and without a helpful error message.
|
||||
|
||||
@ -13514,7 +13518,7 @@ for @var{mcu}=@code{avr2}, @code{avr25}, @code{avr3},
|
||||
@code{avr6}, @code{avrxmega2}, @code{avrxmega4}, @code{avrxmega5},
|
||||
@code{avrxmega6}, @code{avrxmega7}, respectively.
|
||||
If @var{mcu} specifies a device, this built-in macro is set
|
||||
accordingly. For example, with @code{-mmcu=atmega8} the macro will be
|
||||
accordingly. For example, with @code{-mmcu=atmega8} the macro is
|
||||
defined to @code{4}.
|
||||
|
||||
@item __AVR_@var{Device}__
|
||||
@ -13530,15 +13534,15 @@ the device name as from the AVR user manual. The difference between
|
||||
@code{-mmcu=@var{device}} is that the latter is always lowercase.
|
||||
|
||||
If @var{device} is not a device but only a core architecture like
|
||||
@code{avr51}, this macro will not be defined.
|
||||
@code{avr51}, this macro is not defined.
|
||||
|
||||
@item __AVR_DEVICE_NAME__
|
||||
Setting @code{-mmcu=@var{device}} defines this built-in macro to
|
||||
the device's name. For example, with @code{-mmcu=atmega8} the macro
|
||||
will be defined to @code{atmega8}.
|
||||
is defined to @code{atmega8}.
|
||||
|
||||
If @var{device} is not a device but only a core architecture like
|
||||
@code{avr51}, this macro will not be defined.
|
||||
@code{avr51}, this macro is not defined.
|
||||
|
||||
@item __AVR_XMEGA__
|
||||
The device / architecture belongs to the XMEGA family of devices.
|
||||
@ -15844,11 +15848,11 @@ SSE extensions disabled, @option{-mpreferred-stack-boundary=3} can be
|
||||
used to keep the stack boundary aligned to 8 byte boundary. Since
|
||||
x86-64 ABI require 16 byte stack alignment, this is ABI incompatible and
|
||||
intended to be used in controlled environment where stack space is
|
||||
important limitation. This option will lead to wrong code when functions
|
||||
important limitation. This option leads to wrong code when functions
|
||||
compiled with 16 byte stack alignment (such as functions from a standard
|
||||
library) are called with misaligned stack. In this case, SSE
|
||||
instructions may lead to misaligned memory access traps. In addition,
|
||||
variable arguments will be handled incorrectly for 16 byte aligned
|
||||
variable arguments are handled incorrectly for 16 byte aligned
|
||||
objects (including x87 long double and __int128), leading to wrong
|
||||
results. You must build all modules with
|
||||
@option{-mpreferred-stack-boundary=3}, including any libraries. This
|
||||
@ -16025,8 +16029,8 @@ tuning features and default settings. The names can be used in
|
||||
@opindex mtune-ctrl=@var{feature-list}
|
||||
This option is used to do fine grain control of x86 code generation features.
|
||||
@var{feature-list} is a comma separated list of @var{feature} names. See also
|
||||
@option{-mdump-tune-features}. When specified, the @var{feature} will be turned
|
||||
on if it is not preceded with @code{^}, otherwise, it will be turned off.
|
||||
@option{-mdump-tune-features}. When specified, the @var{feature} is turned
|
||||
on if it is not preceded with @samp{^}, otherwise, it is turned off.
|
||||
@option{-mtune-ctrl=@var{feature-list}} is intended to be used by GCC
|
||||
developers. Using it may lead to code paths not covered by testing and can
|
||||
potentially result in compiler ICEs or runtime errors.
|
||||
@ -16078,7 +16082,7 @@ This option enables generation of @code{SAHF} instructions in 64-bit code.
|
||||
Early Intel Pentium 4 CPUs with Intel 64 support,
|
||||
prior to the introduction of Pentium 4 G1 step in December 2005,
|
||||
lacked the @code{LAHF} and @code{SAHF} instructions
|
||||
which were supported by AMD64.
|
||||
which are supported by AMD64.
|
||||
These are load and store instructions, respectively, for certain status flags.
|
||||
In 64-bit mode, the @code{SAHF} instruction is used to optimize @code{fmod},
|
||||
@code{drem}, and @code{remainder} built-in functions;
|
||||
@ -18943,20 +18947,20 @@ testsuite and/or aesthetic purposes.
|
||||
@opindex mmcu=
|
||||
Select the MCU to target. This is used to create a C preprocessor
|
||||
symbol based upon the MCU name, converted to upper case and pre- and
|
||||
post- fixed with @code{__}. This in turn will be used by the
|
||||
@code{msp430.h} header file to select an MCU specific supplimentary
|
||||
post-fixed with @samp{__}. This in turn is used by the
|
||||
@code{msp430.h} header file to select an MCU-specific supplementary
|
||||
header file.
|
||||
|
||||
The option also sets the ISA to use. If the MCU name is one that is
|
||||
known to only support the 430 ISA then that is selected, otherwise the
|
||||
430X ISA is selected. A generic MCU name of @code{msp430} can also be
|
||||
used to select the 430 ISA. Similarly the generic @code{msp430x} MCU
|
||||
name will select the 430X ISA.
|
||||
name selects the 430X ISA.
|
||||
|
||||
In addition an MCU specific linker script will be added to the linker
|
||||
In addition an MCU-specific linker script is added to the linker
|
||||
command line. The script's name is the name of the MCU with
|
||||
@code{.ld} appended. Thus specifying @option{-mmcu=xxx} on the gcc
|
||||
command line will define the C preprocessor symbol @code{__XXX__} and
|
||||
@file{.ld} appended. Thus specifying @option{-mmcu=xxx} on the @command{gcc}
|
||||
command line defines the C preprocessor symbol @code{__XXX__} and
|
||||
cause the linker to search for a script called @file{xxx.ld}.
|
||||
|
||||
This option is also passed on to the assembler.
|
||||
@ -19012,7 +19016,7 @@ them safe to use inside interrupt handlers as well as in normal code.
|
||||
@opindex minrt
|
||||
Enable the use of a minimum runtime environment - no static
|
||||
initializers or constructors. This is intended for memory-constrained
|
||||
devices. The compiler will include special symbols in some objects
|
||||
devices. The compiler includes special symbols in some objects
|
||||
that tell the linker and runtime which code fragments are required.
|
||||
|
||||
@end table
|
||||
@ -19764,7 +19768,7 @@ enhancements.
|
||||
|
||||
When @option{-maltivec} is used, rather than @option{-maltivec=le} or
|
||||
@option{-maltivec=be}, the element order for Altivec intrinsics such
|
||||
as @code{vec_splat}, @code{vec_extract}, and @code{vec_insert} will
|
||||
as @code{vec_splat}, @code{vec_extract}, and @code{vec_insert}
|
||||
match array element order corresponding to the endianness of the
|
||||
target. That is, element zero identifies the leftmost element in a
|
||||
vector register when targeting a big-endian platform, and identifies
|
||||
@ -19779,7 +19783,7 @@ the default when targeting a big-endian platform.
|
||||
|
||||
The element order is used to interpret element numbers in Altivec
|
||||
intrinsics such as @code{vec_splat}, @code{vec_extract}, and
|
||||
@code{vec_insert}. By default, these will match array element order
|
||||
@code{vec_insert}. By default, these match array element order
|
||||
corresponding to the endianness for the target.
|
||||
|
||||
@item -maltivec=le
|
||||
@ -19791,7 +19795,7 @@ currently ignored when targeting a big-endian platform.
|
||||
|
||||
The element order is used to interpret element numbers in Altivec
|
||||
intrinsics such as @code{vec_splat}, @code{vec_extract}, and
|
||||
@code{vec_insert}. By default, these will match array element order
|
||||
@code{vec_insert}. By default, these match array element order
|
||||
corresponding to the endianness for the target.
|
||||
|
||||
@item -mvrsave
|
||||
@ -19940,7 +19944,7 @@ Generate code that uses (does not use) the scalar
|
||||
instructions that target all 64 registers in the vector/scalar
|
||||
floating point register set, depending on the model of the machine.
|
||||
|
||||
If the @option{-mno-upper-regs} option was used, it will turn off both
|
||||
If the @option{-mno-upper-regs} option is used, it turns off both
|
||||
@option{-mupper-regs-sf} and @option{-mupper-regs-df} options.
|
||||
|
||||
@item -mfloat-gprs=@var{yes/single/double/no}
|
||||
@ -21420,7 +21424,7 @@ built-in functions. The generated atomic sequences require additional support
|
||||
from the interrupt/exception handling code of the system and are only suitable
|
||||
for SH3* and SH4* single-core systems. This option is enabled by default when
|
||||
the target is @code{sh*-*-linux*} and SH3* or SH4*. When the target is SH4A,
|
||||
this option will also partially utilize the hardware atomic instructions
|
||||
this option also partially utilizes the hardware atomic instructions
|
||||
@code{movli.l} and @code{movco.l} to create more efficient code, unless
|
||||
@samp{strict} is specified.
|
||||
|
||||
@ -21445,7 +21449,7 @@ Generate hardware atomic sequences using the @code{movli.l} and @code{movco.l}
|
||||
instructions only. This is only available on SH4A and is suitable for
|
||||
multi-core systems. Since the hardware instructions support only 32 bit atomic
|
||||
variables access to 8 or 16 bit variables is emulated with 32 bit accesses.
|
||||
Code compiled with this option will also be compatible with other software
|
||||
Code compiled with this option is also compatible with other software
|
||||
atomic model interrupt/exception handling systems if executed on an SH4A
|
||||
system. Additional support from the interrupt/exception handling code of the
|
||||
system is not required for this model.
|
||||
@ -21458,8 +21462,8 @@ parameter is ignored. The specified value must be an integer multiple of four
|
||||
and in the range 0-1020.
|
||||
|
||||
@item strict
|
||||
This parameter prevents mixed usage of multiple atomic models, even though they
|
||||
would be compatible, and will make the compiler generate atomic sequences of the
|
||||
This parameter prevents mixed usage of multiple atomic models, even if they
|
||||
are compatible, and makes the compiler generate atomic sequences of the
|
||||
specified model only.
|
||||
|
||||
@end table
|
||||
@ -21567,18 +21571,18 @@ SH2A and SHcompact.
|
||||
Calls a library function that performs the operation in double precision
|
||||
floating point. Division by zero causes a floating-point exception. This is
|
||||
the default for SHcompact with FPU. Specifying this for targets that do not
|
||||
have a double precision FPU will default to @code{call-div1}.
|
||||
have a double precision FPU defaults to @code{call-div1}.
|
||||
|
||||
@item call-table
|
||||
Calls a library function that uses a lookup table for small divisors and
|
||||
the @code{div1} instruction with case distinction for larger divisors. Division
|
||||
by zero calculates an unspecified result and does not trap. This is the default
|
||||
for SH4. Specifying this for targets that do not have dynamic shift
|
||||
instructions will default to @code{call-div1}.
|
||||
instructions defaults to @code{call-div1}.
|
||||
|
||||
@end table
|
||||
|
||||
When a division strategy has not been specified the default strategy will be
|
||||
When a division strategy has not been specified the default strategy is
|
||||
selected based on the current target. For SH2A the default strategy is to
|
||||
use the @code{divs} and @code{divu} instructions instead of library function
|
||||
calls.
|
||||
@ -21669,7 +21673,7 @@ is being compiled for.
|
||||
@opindex mno-zdcbranch
|
||||
Assume (do not assume) that zero displacement conditional branch instructions
|
||||
@code{bt} and @code{bf} are fast. If @option{-mzdcbranch} is specified, the
|
||||
compiler will try to prefer zero displacement branch code sequences. This is
|
||||
compiler prefers zero displacement branch code sequences. This is
|
||||
enabled by default when generating code for SH4 and SH4A. It can be explicitly
|
||||
disabled by specifying @option{-mno-zdcbranch}.
|
||||
|
||||
@ -22456,7 +22460,7 @@ architecture.
|
||||
This option is enabled by default when the RH850 ABI is
|
||||
in use (see @option{-mrh850-abi}), and disabled by default when the
|
||||
GCC ABI is in use. If @code{CALLT} instructions are being generated
|
||||
then the C preprocessor symbol @code{__V850_CALLT__} will be defined.
|
||||
then the C preprocessor symbol @code{__V850_CALLT__} is defined.
|
||||
|
||||
@item -mrelax
|
||||
@itemx -mno-relax
|
||||
@ -22479,8 +22483,8 @@ Disable (or re-enable) the generation of hardware floating point
|
||||
instructions. This option is only significant when the target
|
||||
architecture is @samp{V850E2V3} or higher. If hardware floating point
|
||||
instructions are being generated then the C preprocessor symbol
|
||||
@code{__FPU_OK__} will be defined, otherwise the symbol
|
||||
@code{__NO_FPU__} will be defined.
|
||||
@code{__FPU_OK__} is defined, otherwise the symbol
|
||||
@code{__NO_FPU__} is defined.
|
||||
|
||||
@item -mloop
|
||||
@opindex mloop
|
||||
@ -22555,7 +22559,7 @@ Enables support for @code{doubles} and @code{long long} types to be
|
||||
aligned on 8-byte boundaries. The default is to restrict the
|
||||
alignment of all objects to at most 4-bytes. When
|
||||
@option{-m8byte-align} is in effect the C preprocessor symbol
|
||||
@code{__V850_8BYTE_ALIGN__} will be defined.
|
||||
@code{__V850_8BYTE_ALIGN__} is defined.
|
||||
|
||||
@item -mbig-switch
|
||||
@opindex mbig-switch
|
||||
@ -22823,7 +22827,7 @@ temporary beyond the end point defined by the language. When a lifetime of
|
||||
a variable ends, and if the variable lives in memory, the optimizing compiler
|
||||
has the freedom to reuse its stack space with other temporaries or scoped
|
||||
local variables whose live range does not overlap with it. Legacy code extending
|
||||
local lifetime will likely to break with the stack reuse optimization.
|
||||
local lifetime is likely to break with the stack reuse optimization.
|
||||
|
||||
For example,
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user