PR c/52291 - __sync_fetch_and_add and friends poorly specified for pointer
PR c/52291 - __sync_fetch_and_add and friends poorly specified for pointer types 2016-01-20 Martin Sebor <msebor@redhat.com> * extend.texi (__sync Builtins): Clarify the semantics of __sync_fetch_and_OP built-ins on pointers. (__atomic Builtins): Same. From-SVN: r232662
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@ -1,3 +1,10 @@
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2016-01-20 Martin Sebor <msebor@redhat.com>
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PR c/52291
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* extend.texi (__sync Builtins): Clarify the semantics of
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__sync_fetch_and_OP built-ins on pointers.
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(__atomic Builtins): Same.
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2016-01-21 Aditya Kumar <aditya.k7@samsung.com>
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Sebastian Pop <s.pop@samsung.com>
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@ -9262,8 +9262,11 @@ work on multiple types.
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The definition given in the Intel documentation allows only for the use of
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the types @code{int}, @code{long}, @code{long long} or their unsigned
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counterparts. GCC allows any integral scalar or pointer type that is
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1, 2, 4 or 8 bytes in length.
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counterparts. GCC allows any scalar type that is 1, 2, 4 or 8 bytes in
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size other than the C type @code{_Bool} or the C++ type @code{bool}.
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Operations on pointer arguments are performed as if the operands were
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of the @code{uintptr_t} type. That is, they are not scaled by the size
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of the type to which the pointer points.
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These functions are implemented in terms of the @samp{__atomic}
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builtins (@pxref{__atomic Builtins}). They should not be used for new
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@ -9309,7 +9312,11 @@ accessible variables should be protected.
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@findex __sync_fetch_and_xor
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@findex __sync_fetch_and_nand
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These built-in functions perform the operation suggested by the name, and
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returns the value that had previously been in memory. That is,
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returns the value that had previously been in memory. That is, operations
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on integer operands have the following semantics. Operations on pointer
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arguments are performed as if the operands were of the @code{uintptr_t}
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type. That is, they are not scaled by the size of the type to which
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the pointer points.
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@smallexample
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@{ tmp = *ptr; *ptr @var{op}= value; return tmp; @}
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@ -9335,7 +9342,9 @@ as @code{*ptr = ~(tmp & value)} instead of @code{*ptr = ~tmp & value}.
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@findex __sync_xor_and_fetch
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@findex __sync_nand_and_fetch
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These built-in functions perform the operation suggested by the name, and
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return the new value. That is,
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return the new value. That is, operations on integer operands have
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the following semantics. Operations on pointer operands are performed as
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if the operand's type were @code{uintptr_t}.
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@smallexample
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@{ *ptr @var{op}= value; return *ptr; @}
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@ -9592,7 +9601,9 @@ pointer.
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@deftypefnx {Built-in Function} @var{type} __atomic_or_fetch (@var{type} *ptr, @var{type} val, int memorder)
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@deftypefnx {Built-in Function} @var{type} __atomic_nand_fetch (@var{type} *ptr, @var{type} val, int memorder)
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These built-in functions perform the operation suggested by the name, and
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return the result of the operation. That is,
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return the result of the operation. Operations on pointer arguments are
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performed as if the operands were of the @code{uintptr_t} type. That is,
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they are not scaled by the size of the type to which the pointer points.
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@smallexample
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@{ *ptr @var{op}= val; return *ptr; @}
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@ -9610,7 +9621,10 @@ type. It must not be a Boolean type. All memory orders are valid.
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@deftypefnx {Built-in Function} @var{type} __atomic_fetch_or (@var{type} *ptr, @var{type} val, int memorder)
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@deftypefnx {Built-in Function} @var{type} __atomic_fetch_nand (@var{type} *ptr, @var{type} val, int memorder)
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These built-in functions perform the operation suggested by the name, and
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return the value that had previously been in @code{*@var{ptr}}. That is,
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return the value that had previously been in @code{*@var{ptr}}. Operations
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on pointer arguments are performed as if the operands were of
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the @code{uintptr_t} type. That is, they are not scaled by the size of
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the type to which the pointer points.
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@smallexample
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@{ tmp = *ptr; *ptr @var{op}= val; return tmp; @}
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