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Diffstat (limited to 'gcc/doc/md.texi')
| -rw-r--r-- | gcc/doc/md.texi | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi index fc7dc28..19e89ae 100644 --- a/gcc/doc/md.texi +++ b/gcc/doc/md.texi @@ -7918,6 +7918,30 @@ If these patterns are not defined, attempts will be made to use counterparts. If none of these are available a compare-and-swap loop will be used. +@cindex @code{atomic_add_fetch_cmp_0@var{mode}} instruction pattern +@cindex @code{atomic_sub_fetch_cmp_0@var{mode}} instruction pattern +@cindex @code{atomic_and_fetch_cmp_0@var{mode}} instruction pattern +@cindex @code{atomic_or_fetch_cmp_0@var{mode}} instruction pattern +@cindex @code{atomic_xor_fetch_cmp_0@var{mode}} instruction pattern +@item @samp{atomic_add_fetch_cmp_0@var{mode}} +@itemx @samp{atomic_sub_fetch_cmp_0@var{mode}} +@itemx @samp{atomic_and_fetch_cmp_0@var{mode}} +@itemx @samp{atomic_or_fetch_cmp_0@var{mode}} +@itemx @samp{atomic_xor_fetch_cmp_0@var{mode}} +These patterns emit code for an atomic operation on memory with memory +model semantics if the fetch result is used only in a comparison against +zero. +Operand 0 is an output operand which contains a boolean result of comparison +of the value after the operation against zero. Operand 1 is the memory on +which the atomic operation is performed. Operand 2 is the second operand +to the binary operator. Operand 3 is the memory model to be used by the +operation. Operand 4 is an integer holding the comparison code, one of +@code{EQ}, @code{NE}, @code{LT}, @code{GT}, @code{LE} or @code{GE}. + +If these patterns are not defined, attempts will be made to use separate +atomic operation and fetch pattern followed by comparison of the result +against zero. + @cindex @code{mem_thread_fence} instruction pattern @item @samp{mem_thread_fence} This pattern emits code required to implement a thread fence with |