[PATCH] Improve handling of COND_EXECs in haifa_classify_insn.

[Alexander Monakov]

Hi.

This patch has been in sel-sched branch for a while.  It makes  
haifa_classify_insn look into predicate and code parts of COND_EXEC to  
decide whether it traps or not, instead of assuming that all COND_EXECs  
trap.  It also factors code duplication in handling of PARALLELs (by using  
recursion).

Bootstrapped and regtested on x64_64 with --disable-multilib and on ia64.

:ADDPATCH scheduler:

Thanks.

	* gcc/haifa-sched.c (haifa_classify_insn): Rename to ...
	(haifa_classify_insn_pat): ... this.  Re-structure.  Improve handling
	of COND_EXECs.  Use it ...
	* gcc/sched-int.h (haifa_classify_insn): ... Here.  Reimplement.

--- gcc/haifa-sched.c	(revision 31645)
+++ gcc/haifa-sched.c	(local)
@@ -405,8 +405,8 @@ may_trap_exp (const_rtx x, int is_store)
      }
  }

-/* Classifies insn for the purpose of verifying that it can be
-   moved speculatively, by examining it's patterns, returning:
+/* Classifies pattern of an insn for the purpose of verifying that it can  
be
+   moved speculatively, by examining it, returning:
     TRAP_RISKY: store, or risky non-load insn (e.g. division by variable).
     TRAP_FREE: non-load insn.
     IFREE: load from a globally safe location.
@@ -415,9 +415,8 @@ may_trap_exp (const_rtx x, int is_store)
     being either PFREE or PRISKY.  */

  int
-haifa_classify_insn (const_rtx insn)
+haifa_classify_insn_pat (rtx pat)
  {
-  rtx pat = PATTERN (insn);
    int tmp_class = TRAP_FREE;
    int insn_class = TRAP_FREE;
    enum rtx_code code;
@@ -428,31 +427,7 @@ haifa_classify_insn (const_rtx insn)

        for (i = len - 1; i >= 0; i--)
  	{
-	  code = GET_CODE (XVECEXP (pat, 0, i));
-	  switch (code)
-	    {
-	    case CLOBBER:
-	      /* Test if it is a 'store'.  */
-	      tmp_class = may_trap_exp (XEXP (XVECEXP (pat, 0, i), 0), 1);
-	      break;
-	    case SET:
-	      /* Test if it is a store.  */
-	      tmp_class = may_trap_exp (SET_DEST (XVECEXP (pat, 0, i)), 1);
-	      if (tmp_class == TRAP_RISKY)
-		break;
-	      /* Test if it is a load.  */
-	      tmp_class
-		= WORST_CLASS (tmp_class,
-			       may_trap_exp (SET_SRC (XVECEXP (pat, 0, i)),
-					     0));
-	      break;
-	    case COND_EXEC:
-	    case TRAP_IF:
-	      tmp_class = TRAP_RISKY;
-	      break;
-	    default:
-	      ;
-	    }
+	  tmp_class = haifa_classify_insn_pat (XVECEXP (pat, 0, i));
  	  insn_class = WORST_CLASS (insn_class, tmp_class);
  	  if (insn_class == TRAP_RISKY || insn_class == IRISKY)
  	    break;
@@ -478,6 +453,12 @@ haifa_classify_insn (const_rtx insn)
  			 may_trap_exp (SET_SRC (pat), 0));
  	  break;
  	case COND_EXEC:
+	  tmp_class = haifa_classify_insn_pat (COND_EXEC_CODE (pat));
+	  if (tmp_class == TRAP_RISKY)
+	    break;
+	  tmp_class = WORST_CLASS (tmp_class,
+				   may_trap_exp (COND_EXEC_TEST (pat), 0));
+	  break;
  	case TRAP_IF:
  	  tmp_class = TRAP_RISKY;
  	  break;
--- gcc/sched-int.h	(revision 31645)
+++ gcc/sched-int.h	(local)
@@ -829,7 +829,14 @@ extern ds_t ds_merge (ds_t, ds_t);
  extern void debug_ds (ds_t);

  /* Functions in haifa-sched.c.  */
-extern int haifa_classify_insn (const_rtx);
+extern int haifa_classify_insn_pat (rtx);
+
+static inline int
+haifa_classify_insn (const_rtx insn)
+{
+  return haifa_classify_insn_pat (PATTERN (insn));
+}
+
  extern void get_ebb_head_tail (basic_block, basic_block, rtx *, rtx *);
  extern int no_real_insns_p (const_rtx, const_rtx);