PR gcc/1532

	* cse.c (cse_change_cc_mode): New static function.
	(cse_change_cc_mode_insns, cse_cc_succs): Likewise.
	(cse_condition_code_reg): New function.
	* rtl.h (cse_condition_code_reg): Declare.
	* toplev.c (rest_of_handle_cse2): Call cse_condition_code_reg.
	* target.h (struct gcc_target): Add fixed_condition_code_regs and
	cc_modes_compatible.
	* target-def.h (TARGET_FIXED_CONDITION_CODE_REGS): Define.
	(TARGET_CC_MODES_COMPATIBLE): Define.
	(TARGET_INITIALIZER): Add new initializers.
	* targhooks.c (default_cc_modes_compatible): New function.
	* targhooks.c (default_cc_modes_compatible): Declare.
	* hooks.c (hook_bool_intp_intp_false): New function.
	* hooks.h (hook_bool_intp_intp_false): Declare.
	* config/i386/i386.c (TARGET_FIXED_CONDITION_CODE_REGS): Define.
	(TARGET_CC_MODES_COMPATIBLE): Define.
	(ix86_fixed_condition_code_regs): New static function.
	(ix86_cc_modes_compatible): Likewise.
	* doc/tm.texi (Condition Code): Document new hooks.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@76454 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 17 insertions, 0 deletions

diff --git a/gcc/target.h b/gcc/target.h
index 787d203267c..21a12f0ec3a 100644
--- a/gcc/target.h
+++ b/gcc/target.h
@@ -377,6 +377,23 @@ struct gcc_target
      hook should return NULL_RTX.  */
   rtx (* dwarf_register_span) (rtx);
 
+  /* Fetch the fixed register(s) which hold condition codes, for
+     targets where it makes sense to look for duplicate assignments to
+     the condition codes.  This should return true if there is such a
+     register, false otherwise.  The arguments should be set to the
+     fixed register numbers.  Up to two condition code registers are
+     supported.  If there is only one for this target, the int pointed
+     at by the second argument should be set to -1.  */
+  bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *);
+
+  /* If two condition code modes are compatible, return a condition
+     code mode which is compatible with both, such that a comparison
+     done in the returned mode will work for both of the original
+     modes.  If the condition code modes are not compatible, return
+     VOIDmode.  */
+  enum machine_mode (* cc_modes_compatible) (enum machine_mode,
+					     enum machine_mode);
+
   /* Do machine-dependent code transformations.  Called just before
      delayed-branch scheduling.  */
   void (* machine_dependent_reorg) (void);