i386.md (cmpcc): New.

2009-04-09  Paolo Bonzini  <bonzini@gnu.org>

        * config/i386/i386.md (cmpcc): New.
        * config/i386/sync.md (sync_compare_and_swap*): Set FLAGS_REG.
        (sync_compare_and_swap_cc*): Delete.

        * config/s390/s390.c (s390_compare_emitted): Remove.
        (s390_emit_compare): Handle MODE_CC s390_compare_op0 like
        s390_compare_emitted used to be handled.  Assert that modes match.
        (s390_emit_compare_and_swap): Use s390_emit_compare, do not
        refer to sync_compare_and_swap_ccsi.
        * config/s390/s390.h (s390_compare_emitted): Remove.
        * config/s390/s390.md (seq): Look for MODE_CC s390_compare_op0
        instead of s390_compare_emitted.
        (stack_protect_test, sync_compare_and_swap_cc): Set s390_compare_op0
        instead of s390_compare_emitted.
        * config/s390/s390.md (cmpcc): New.
        (sync_compare_and_swapqi, sync_compare_and_swaphi): Clobber
        CC_REGNUM, do not pretend it's set.
        (sync_compare_and_swap_cc*): Delete.
        * config/s390/predicates.md (cc_reg_operand): New.

        * expr.c (sync_compare_and_swap_cc): Delete.
        * optabs.h (sync_compare_and_swap_cc): Delete.
        * optabs.c (prepare_cmp_insn): Ignore which specific CCmode
        is being used with can_compare_p.
        (emit_cmp_and_jump_insn_1): Likewise when looking in the optab.
        (find_cc_set): New.
        (expand_bool_compare_and_swap): Do not use sync_compare_and_swap_cc,
        look for a MODE_CC set instead.  Use emit_store_flag.
        (expand_compare_and_swap_loop): Likewise, with some additional
        complication to avoid a force_reg when useless.  Use
        emit_cmp_and_jump_insns.
        * genopinit.c (optabs): Delete sync_compare_and_swap_cc.
        * doc/md.texi (sync_compare_and_swap_cc): Merge with
        sync_compare_and_swap documentation.

java:
2009-04-09  Paolo Bonzini  <bonzini@gnu.org>

        * builtins.c (compareAndSwapLong_builtin,
        compareAndSwapInt_builtin, compareAndSwapObject_builtin,
        VMSupportsCS8_builtin): Do not look at sync_compare_and_swap_cc.

From-SVN: r145825

1 files changed, 9 insertions, 13 deletions

diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index 25de8b1..a78233c 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -5091,19 +5091,15 @@ memory operations before the atomic operation occur before the atomic
 operation and all memory operations after the atomic operation occur
 after the atomic operation.
 
-@cindex @code{sync_compare_and_swap_cc@var{mode}} instruction pattern
-@item @samp{sync_compare_and_swap_cc@var{mode}}
-
-This pattern is just like @code{sync_compare_and_swap@var{mode}}, except
-it should act as if compare part of the compare-and-swap were issued via
-@code{cmp@var{m}}.  This comparison will only be used with @code{EQ} and
-@code{NE} branches and @code{setcc} operations.
-
-Some targets do expose the success or failure of the compare-and-swap
-operation via the status flags.  Ideally we wouldn't need a separate
-named pattern in order to take advantage of this, but the combine pass
-does not handle patterns with multiple sets, which is required by
-definition for @code{sync_compare_and_swap@var{mode}}.
+For targets where the success or failure of the compare-and-swap
+operation is available via the status flags, it is possible
+to avoid a separate compare operation and issue the subsequent
+setcc or branch immediately after the compare-and-swap.  To this
+end, GCC will look for a @code{MODE_CC} set in the output of
+@code{sync_compare_and_swap@var{mode}}; if the machine description
+includes such a set, the target should also define a special @code{cmpcc}
+instruction.  GCC will then be able to take the destination of the
+@code{MODE_CC} set and use it as the first operand of @code{cmpcc}.
 
 @cindex @code{sync_add@var{mode}} instruction pattern
 @cindex @code{sync_sub@var{mode}} instruction pattern