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[PATCH] Fix PR 55889


Hello,

As we discussed in the PR, the problem here is that the selective scheduler does not expect that renaming a hard register to a pseudo would result in extra dependencies. The dependencies come from implicit clobbers code of sched-deps.c, so I've made a minimal patch that checks only for that case using the same function from IRA and avoids it.

The patch fixes the test case on AIX as reported by David and also bootstraps and tests fine on x86-64 and ia64, ok for trunk?

The second patch is restoring debug printing in the scheduler that was accidentally broken, possibly by Steven's cleanups (now a pattern is expected where an insn was previously). I will commit is as obvious separately.

Andrey

2012-02-19 Andrey Belevantsev <abel@ispras.ru>

PR middle-end/55889

	* sel-sched.c: Include ira.h.
	(implicit_clobber_conflict_p): New function.
	(moveup_expr): Use it.
	* Makefile.in (sel-sched.o): Depend on ira.h.


And the second patch is:


2012-02-19 Andrey Belevantsev <abel@ispras.ru>

	* sel-sched-dump.c (dump_insn_rtx_flags): Explicitly set
	DUMP_INSN_RTX_UID.
	(dump_insn_rtx_1): Pass PATTERN (insn) to str_pattern_slim.
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index f3bb168..557ab08 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -3338,7 +3338,7 @@ sel-sched.o : sel-sched.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
    $(FUNCTION_H) $(INSN_ATTR_H)  $(RECOG_H) $(EXCEPT_H) $(PARAMS_H) \
    $(TM_P_H) output.h $(TARGET_H) $(TREE_PASS_H)  \
    $(SCHED_INT_H) $(GGC_H) $(TREE_H) langhooks.h rtlhooks-def.h \
-   $(SEL_SCHED_IR_H) $(SEL_SCHED_DUMP_H) sel-sched.h $(DBGCNT_H) $(EMIT_RTL_H)
+   $(SEL_SCHED_IR_H) $(SEL_SCHED_DUMP_H) sel-sched.h $(DBGCNT_H) $(EMIT_RTL_H) ira.h
 sel-sched-dump.o : sel-sched-dump.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
    $(RTL_H) $(REGS_H) hard-reg-set.h $(FLAGS_H) insn-config.h \
    $(FUNCTION_H) $(INSN_ATTR_H) $(DIAGNOSTIC_CORE_H) $(RECOG_H) $(EXCEPT_H) $(PARAMS_H) \
diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
index 6f60d70..2944489 100644
--- a/gcc/sel-sched.c
+++ b/gcc/sel-sched.c
@@ -41,6 +41,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "langhooks.h"
 #include "rtlhooks-def.h"
 #include "emit-rtl.h"
+#include "ira.h"
 
 #ifdef INSN_SCHEDULING
 #include "sel-sched-ir.h"
@@ -2101,6 +2102,61 @@ moving_insn_creates_bookkeeping_block_p (insn_t insn,
   return TRUE;
 }
 
+/* Return true when the conflict with newly created implicit clobbers
+   between EXPR and THROUGH_INSN is found because of renaming.  */
+static bool
+implicit_clobber_conflict_p (insn_t through_insn, expr_t expr)
+{
+  HARD_REG_SET temp;
+  rtx insn, reg, rhs, pat;
+  hard_reg_set_iterator hrsi;
+  unsigned regno;
+  bool valid;
+
+  /* Make a new pseudo register.  */
+  reg = gen_reg_rtx (GET_MODE (EXPR_LHS (expr)));
+  max_regno = max_reg_num ();
+  maybe_extend_reg_info_p ();
+
+  /* Validate a change and bail out early.  */
+  insn = EXPR_INSN_RTX (expr);
+  validate_change (insn, &SET_DEST (PATTERN (insn)), reg, 1);
+  valid = verify_changes (0);
+  cancel_changes (0);
+  if (!valid)
+    {
+      if (sched_verbose >= 6)
+	sel_print ("implicit clobbers failed validation, ");
+      return true;
+    }
+
+  /* Make a new insn with it.  */
+  rhs = copy_rtx (VINSN_RHS (EXPR_VINSN (expr)));
+  pat = gen_rtx_SET (VOIDmode, reg, rhs);
+  start_sequence ();
+  insn = emit_insn (pat);
+  end_sequence ();
+
+  /* Calculate implicit clobbers.  */
+  extract_insn (insn);
+  preprocess_constraints ();
+  ira_implicitly_set_insn_hard_regs (&temp);
+  AND_COMPL_HARD_REG_SET (temp, ira_no_alloc_regs);
+
+  /* If any implicit clobber registers intersect with regular ones in
+     through_insn, we have a dependency and thus bail out.  */
+  EXECUTE_IF_SET_IN_HARD_REG_SET (temp, 0, regno, hrsi)
+    {
+      vinsn_t vi = INSN_VINSN (through_insn);
+      if (bitmap_bit_p (VINSN_REG_SETS (vi), regno)
+	  || bitmap_bit_p (VINSN_REG_CLOBBERS (vi), regno)
+	  || bitmap_bit_p (VINSN_REG_USES (vi), regno))
+	return true;
+    }
+
+  return false;
+}
+
 /* Modifies EXPR so it can be moved through the THROUGH_INSN,
    performing necessary transformations.  Record the type of transformation
    made in PTRANS_TYPE, when it is not NULL.  When INSIDE_INSN_GROUP,
@@ -2233,6 +2289,17 @@ moveup_expr (expr_t expr, insn_t through_insn, bool inside_insn_group,
       if (!enable_schedule_as_rhs_p || !EXPR_SEPARABLE_P (expr))
         return MOVEUP_EXPR_NULL;
 
+      /* When renaming a hard register to a pseudo before reload, extra
+	 dependencies can occur from the implicit clobbers of the insn.
+	 Filter out such cases here.  */
+      if (!reload_completed && REG_P (EXPR_LHS (expr))
+	  && HARD_REGISTER_P (EXPR_LHS (expr))
+	  && implicit_clobber_conflict_p (through_insn, expr))
+	{
+	  if (sched_verbose >= 6)
+	    sel_print ("implicit clobbers conflict detected, ");
+	  return MOVEUP_EXPR_NULL;
+	}
       EXPR_TARGET_AVAILABLE (expr) = false;
       was_target_conflict = true;
       as_rhs = true;
diff --git a/gcc/sel-sched-dump.c b/gcc/sel-sched-dump.c
index 4b2be37..0dafe49 100644
--- a/gcc/sel-sched-dump.c
+++ b/gcc/sel-sched-dump.c
@@ -91,7 +91,7 @@ restore_dump (void)
 /* Functions for dumping instructions, av sets, and exprs.  */
 
 /* Default flags for dumping insns.  */
-static int dump_insn_rtx_flags = DUMP_INSN_RTX_PATTERN;
+static int dump_insn_rtx_flags = DUMP_INSN_RTX_UID | DUMP_INSN_RTX_PATTERN;
 
 /* Default flags for dumping vinsns.  */
 static int dump_vinsn_flags = (DUMP_VINSN_INSN_RTX | DUMP_VINSN_TYPE
@@ -136,7 +136,7 @@ dump_insn_rtx_1 (rtx insn, int flags)
     sel_print ("%d;", INSN_UID (insn));
 
   if (flags & DUMP_INSN_RTX_PATTERN)
-    sel_print ("%s;", str_pattern_slim (insn));
+    sel_print ("%s;", str_pattern_slim (PATTERN (insn)));
 
   if (flags & DUMP_INSN_RTX_BBN)
     {

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