Remove CC0

This removes CC0 and all directly related infrastructure.

CC_STATUS, CC_STATUS_MDEP, CC_STATUS_MDEP_INIT, and NOTICE_UPDATE_CC
are deleted and poisoned.  CC0 is only deleted (some targets use that
name for something else).  HAVE_cc0 is automatically generated, and we
no longer will do that after this patch.

CC_STATUS_INIT is suggested in final.c to also be useful for ports that
are not CC0, and at least arm seems to use it for something.  So I am
leaving that alone, but most targets that have it could remove it.

2021-05-04  Segher Boessenkool  <segher@kernel.crashing.org>

	* caller-save.c: Remove CC0.
	* cfgcleanup.c: Remove CC0.
	* cfgrtl.c: Remove CC0.
	* combine.c: Remove CC0.
	* compare-elim.c: Remove CC0.
	* conditions.h: Remove CC0.
	* config/h8300/h8300.h: Remove CC0.
	* config/h8300/h8300-protos.h: Remove CC0.
	* config/h8300/peepholes.md: Remove CC0.
	* config/i386/x86-tune-sched.c: Remove CC0.
	* config/m68k/m68k.c: Remove CC0.
	* config/rl78/rl78.c: Remove CC0.
	* config/sparc/sparc.c: Remove CC0.
	* config/xtensa/xtensa.c: Remove CC0.
	(gen_conditional_move):  Use pc_rtx instead of cc0_rtx in a piece of
	RTL where that is used as a placeholder only.
	* cprop.c: Remove CC0.
	* cse.c: Remove CC0.
	* cselib.c: Remove CC0.
	* df-problems.c: Remove CC0.
	* df-scan.c: Remove CC0.
	* doc/md.texi: Remove CC0.  Adjust an example.
	* doc/rtl.texi: Remove CC0.  Adjust an example.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in: Remove CC0.
	* emit-rtl.c: Remove CC0.
	* final.c: Remove CC0.
	* fwprop.c: Remove CC0.
	* gcse-common.c: Remove CC0.
	* gcse.c: Remove CC0.
	* genattrtab.c: Remove CC0.
	* genconfig.c: Remove CC0.
	* genemit.c: Remove CC0.
	* genextract.c: Remove CC0.
	* gengenrtl.c: Remove CC0.
	* genrecog.c: Remove CC0.
	* haifa-sched.c: Remove CC0.
	* ifcvt.c: Remove CC0.
	* ira-costs.c: Remove CC0.
	* ira.c: Remove CC0.
	* jump.c: Remove CC0.
	* loop-invariant.c: Remove CC0.
	* lra-constraints.c: Remove CC0.
	* lra-eliminations.c: Remove CC0.
	* optabs.c: Remove CC0.
	* postreload-gcse.c: Remove CC0.
	* postreload.c: Remove CC0.
	* print-rtl.c: Remove CC0.
	* read-rtl-function.c: Remove CC0.
	* reg-notes.def: Remove CC0.
	* reg-stack.c: Remove CC0.
	* reginfo.c: Remove CC0.
	* regrename.c: Remove CC0.
	* reload.c: Remove CC0.
	* reload1.c: Remove CC0.
	* reorg.c: Remove CC0.
	* resource.c: Remove CC0.
	* rtl.c: Remove CC0.
	* rtl.def: Remove CC0.
	* rtl.h: Remove CC0.
	* rtlanal.c: Remove CC0.
	* sched-deps.c: Remove CC0.
	* sched-rgn.c: Remove CC0.
	* shrink-wrap.c: Remove CC0.
	* simplify-rtx.c: Remove CC0.
	* system.h: Remove CC0.  Poison NOTICE_UPDATE_CC, CC_STATUS_MDEP_INIT,
	CC_STATUS_MDEP, and CC_STATUS.
	* target.def: Remove CC0.
	* valtrack.c: Remove CC0.
	* var-tracking.c: Remove CC0.

1 files changed, 7 insertions, 14 deletions

diff --git a/gcc/cprop.c b/gcc/cprop.c
index 6f34f6b..aca319a 100644
--- a/gcc/cprop.c
+++ b/gcc/cprop.c
@@ -963,10 +963,6 @@ cprop_jump (basic_block bb, rtx_insn *setcc, rtx_insn *jump, rtx from, rtx src)
 	remove_note (jump, note);
      }
 
-  /* Delete the cc0 setter.  */
-  if (HAVE_cc0 && setcc != NULL && CC0_P (SET_DEST (single_set (setcc))))
-    delete_insn (setcc);
-
   global_const_prop_count++;
   if (dump_file != NULL)
     {
@@ -1009,15 +1005,15 @@ constprop_register (rtx from, rtx src, rtx_insn *insn)
   rtx sset;
   rtx_insn *next_insn;
 
-  /* Check for reg or cc0 setting instructions followed by
-     conditional branch instructions first.  */
+  /* Check for reg setting instructions followed by conditional branch
+     instructions first.  */
   if ((sset = single_set (insn)) != NULL
       && (next_insn = next_nondebug_insn (insn)) != NULL
       && any_condjump_p (next_insn)
       && onlyjump_p (next_insn))
     {
       rtx dest = SET_DEST (sset);
-      if ((REG_P (dest) || CC0_P (dest))
+      if (REG_P (dest)
 	  && cprop_jump (BLOCK_FOR_INSN (insn), insn, next_insn,
 			 from, src))
 	return 1;
@@ -1636,8 +1632,7 @@ bypass_block (basic_block bb, rtx_insn *setcc, rtx_insn *jump)
 	  /* Avoid unification of the edge with other edges from original
 	     branch.  We would end up emitting the instruction on "both"
 	     edges.  */
-	  if (dest && setcc && !CC0_P (SET_DEST (PATTERN (setcc)))
-	      && find_edge (e->src, dest))
+	  if (dest && setcc && find_edge (e->src, dest))
 	    dest = NULL;
 
 	  old_dest = e->dest;
@@ -1647,13 +1642,11 @@ bypass_block (basic_block bb, rtx_insn *setcc, rtx_insn *jump)
             {
 	      redirect_edge_and_branch_force (e, dest);
 
-	      /* Copy the register setter to the redirected edge.
-		 Don't copy CC0 setters, as CC0 is dead after jump.  */
+	      /* Copy the register setter to the redirected edge.  */
 	      if (setcc)
 		{
 		  rtx pat = PATTERN (setcc);
-		  if (!CC0_P (SET_DEST (pat)))
-		    insert_insn_on_edge (copy_insn (pat), e);
+		  insert_insn_on_edge (copy_insn (pat), e);
 		}
 
 	      if (dump_file != NULL)
@@ -1719,7 +1712,7 @@ bypass_conditional_jumps (void)
 		  break;
 
 		dest = SET_DEST (PATTERN (insn));
-		if (REG_P (dest) || CC0_P (dest))
+		if (REG_P (dest))
 		  setcc = insn;
 		else
 		  break;