| Message ID | 20221215165814.1808816-1-siddhesh@gotplt.org |
|---|---|
| State | New |
| Headers | show |
| Series | doc: Fix documentation for __builtin_dynamic_object_size | expand |
On Thu, Dec 15, 2022 at 11:58:14AM -0500, Siddhesh Poyarekar wrote: > --- a/gcc/doc/extend.texi > +++ b/gcc/doc/extend.texi > @@ -14291,8 +14291,14 @@ and GCC does not issue a warning. > @end deftypefn > > @deftypefn {Built-in Function}{size_t} __builtin_object_size (const void * @var{ptr}, int @var{type}) > -Returns the size of an object pointed to by @var{ptr}. @xref{Object Size > -Checking}, for a detailed description of the function. > +Returns a constant size estimate of an object pointed to by @var{ptr}. > +@xref{Object Size Checking}, for a detailed description of the function. > +@end deftypefn > + > +@deftypefn {Built-in Function}{size_t} __builtin_dynamic_object_size (const void * @var{ptr}, int @var{type}) > +Similar to @code{__builtin_object_size} except that the return value > +need not be a constant. @xref{Object Size Checking}, for a detailed > +description of the function. > @end deftypefn > > @deftypefn {Built-in Function} double __builtin_huge_val (void) The above is ok. > diff --git a/gcc/doc/passes.texi b/gcc/doc/passes.texi > index 9e8b4f50ad6..d649db72bbe 100644 > --- a/gcc/doc/passes.texi > +++ b/gcc/doc/passes.texi > @@ -843,12 +843,13 @@ foo()}, this pass tries to change the call so that the address of > pass is located in @code{tree-nrv.cc} and is described by > @code{pass_return_slot}. > > -@item Optimize calls to @code{__builtin_object_size} > +@item Optimize calls to @code{__builtin_object_size} or > +@code{__builtin_dynamic_object_size} > > -This is a propagation pass similar to CCP that tries to remove calls > -to @code{__builtin_object_size} when the size of the object can be > -computed at compile-time. This pass is located in > -@file{tree-object-size.cc} and is described by > +This is a propagation pass similar to CCP that tries to remove calls to > +@code{__builtin_object_size} or @code{__builtin_dynamic_object_size} > +when the size of the object can be computed at compile-time. This pass Can be computed at compile-time is only true for __bos, for __bdos is if it can be computed. > +is located in @file{tree-object-size.cc} and is described by > @code{pass_object_sizes}. > > @item Loop invariant motion Otherwise LGTM. Jakub
On 2022-12-15 12:09, Jakub Jelinek wrote: >> -This is a propagation pass similar to CCP that tries to remove calls >> -to @code{__builtin_object_size} when the size of the object can be >> -computed at compile-time. This pass is located in >> -@file{tree-object-size.cc} and is described by >> +This is a propagation pass similar to CCP that tries to remove calls to >> +@code{__builtin_object_size} or @code{__builtin_dynamic_object_size} >> +when the size of the object can be computed at compile-time. This pass > > Can be computed at compile-time is only true for __bos, for > __bdos is if it can be computed. How about: This is a propagation pass similar to CCP that tries to remove calls to @code{__builtin_object_size} when the size of the object can be computed at compile-time. It also tries to replace calls to @code{__builtin_dynamic_object_size} with an expression that evaluates the size of the object. This pass is located in @file{tree-object-size.cc} and is described by @code{pass_object_sizes}.
On Thu, Dec 15, 2022 at 12:21:21PM -0500, Siddhesh Poyarekar wrote: > On 2022-12-15 12:09, Jakub Jelinek wrote: > > > -This is a propagation pass similar to CCP that tries to remove calls > > > -to @code{__builtin_object_size} when the size of the object can be > > > -computed at compile-time. This pass is located in > > > -@file{tree-object-size.cc} and is described by > > > +This is a propagation pass similar to CCP that tries to remove calls to > > > +@code{__builtin_object_size} or @code{__builtin_dynamic_object_size} > > > +when the size of the object can be computed at compile-time. This pass > > > > Can be computed at compile-time is only true for __bos, for > > __bdos is if it can be computed. > > How about: > > > This is a propagation pass similar to CCP that tries to remove calls to > @code{__builtin_object_size} when the size of the object can be computed at > compile-time. It also tries to replace calls to > > @code{__builtin_dynamic_object_size} with an expression that evaluates > the size of the object. This pass is located in > @file{tree-object-size.cc} and is described by @code{pass_object_sizes}. Without the empty space in between and perhaps with replacing size with upper or lower bound for the size of the object in both cases ok. Jakub
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index d3812fa55b0..608ff54f845 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -14291,8 +14291,14 @@ and GCC does not issue a warning. @end deftypefn @deftypefn {Built-in Function}{size_t} __builtin_object_size (const void * @var{ptr}, int @var{type}) -Returns the size of an object pointed to by @var{ptr}. @xref{Object Size -Checking}, for a detailed description of the function. +Returns a constant size estimate of an object pointed to by @var{ptr}. +@xref{Object Size Checking}, for a detailed description of the function. +@end deftypefn + +@deftypefn {Built-in Function}{size_t} __builtin_dynamic_object_size (const void * @var{ptr}, int @var{type}) +Similar to @code{__builtin_object_size} except that the return value +need not be a constant. @xref{Object Size Checking}, for a detailed +description of the function. @end deftypefn @deftypefn {Built-in Function} double __builtin_huge_val (void) diff --git a/gcc/doc/passes.texi b/gcc/doc/passes.texi index 9e8b4f50ad6..d649db72bbe 100644 --- a/gcc/doc/passes.texi +++ b/gcc/doc/passes.texi @@ -843,12 +843,13 @@ foo()}, this pass tries to change the call so that the address of pass is located in @code{tree-nrv.cc} and is described by @code{pass_return_slot}. -@item Optimize calls to @code{__builtin_object_size} +@item Optimize calls to @code{__builtin_object_size} or +@code{__builtin_dynamic_object_size} -This is a propagation pass similar to CCP that tries to remove calls -to @code{__builtin_object_size} when the size of the object can be -computed at compile-time. This pass is located in -@file{tree-object-size.cc} and is described by +This is a propagation pass similar to CCP that tries to remove calls to +@code{__builtin_object_size} or @code{__builtin_dynamic_object_size} +when the size of the object can be computed at compile-time. This pass +is located in @file{tree-object-size.cc} and is described by @code{pass_object_sizes}. @item Loop invariant motion
__builtin_dynamic_object_size is missing from the full list of builtins, so add it. Also mention it alongside __builtin_object_size in the passes description. gcc/ChangeLog: * doc/extend.texi (__builtin_dynamic_object_size): Document builtin. * doc/passes.texi (Optimize calls to @code{__builtin_object_size}): Also mention __builtin_dynamic_object_size. Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org> --- gcc/doc/extend.texi | 10 ++++++++-- gcc/doc/passes.texi | 11 ++++++----- 2 files changed, 14 insertions(+), 7 deletions(-)