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author | Jakub Jelinek <jakub@redhat.com> | 2011-06-27 18:52:23 +0200 |
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committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2011-06-27 18:52:23 +0200 |
commit | 45d439ac1a9e2df33ac7ef573009749dbebf581b (patch) | |
tree | efa39246412ef14d5214fe10b53a962abeab3d20 /gcc/doc/extend.texi | |
parent | dc2a58daabf95cfac0dd346ff717902bdc6e3d93 (diff) | |
download | gcc-45d439ac1a9e2df33ac7ef573009749dbebf581b.zip gcc-45d439ac1a9e2df33ac7ef573009749dbebf581b.tar.gz gcc-45d439ac1a9e2df33ac7ef573009749dbebf581b.tar.bz2 |
builtin-types.def (BT_FN_PTR_CONST_PTR_SIZE_VAR): New.
* builtin-types.def (BT_FN_PTR_CONST_PTR_SIZE_VAR): New.
* builtins.def (BUILT_IN_ASSUME_ALIGNED): New builtin.
* tree-ssa-structalias.c (find_func_aliases_for_builtin_call,
find_func_clobbers): Handle BUILT_IN_ASSUME_ALIGNED.
* tree-ssa-ccp.c (bit_value_assume_aligned): New function.
(evaluate_stmt, execute_fold_all_builtins): Handle
BUILT_IN_ASSUME_ALIGNED.
* tree-ssa-dce.c (propagate_necessity): Likewise.
* tree-ssa-alias.c (ref_maybe_used_by_call_p_1,
call_may_clobber_ref_p_1): Likewise.
* builtins.c (is_simple_builtin, expand_builtin): Likewise.
(expand_builtin_assume_aligned): New function.
* doc/extend.texi (__builtin_assume_aligned): Document.
* c-common.c (check_builtin_function_arguments): Handle
BUILT_IN_ASSUME_ALIGNED.
* gcc.dg/builtin-assume-aligned-1.c: New test.
* gcc.dg/builtin-assume-aligned-2.c: New test.
* gcc.target/i386/builtin-assume-aligned-1.c: New test.
From-SVN: r175541
Diffstat (limited to 'gcc/doc/extend.texi')
-rw-r--r-- | gcc/doc/extend.texi | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 2d9c689..0e80590 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -7646,6 +7646,28 @@ int g (int c) @end deftypefn +@deftypefn {Built-in Function} void *__builtin_assume_aligned (const void *@var{exp}, size_t @var{align}, ...) +This function returns its first argument, and allows the compiler +to assume that the returned pointer is at least @var{align} bytes +aligned. This built-in can have either two or three arguments, +if it has three, the third argument should have integer type, and +if it is non-zero means misalignment offset. For example: + +@smallexample +void *x = __builtin_assume_aligned (arg, 16); +@end smallexample + +means that the compiler can assume x, set to arg, is at least +16 byte aligned, while: + +@smallexample +void *x = __builtin_assume_aligned (arg, 32, 8); +@end smallexample + +means that the compiler can assume for x, set to arg, that +(char *) x - 8 is 32 byte aligned. +@end deftypefn + @deftypefn {Built-in Function} void __builtin___clear_cache (char *@var{begin}, char *@var{end}) This function is used to flush the processor's instruction cache for the region of memory between @var{begin} inclusive and @var{end} |