From 99788e063016c4f8d87dae3de71c646effac654f Mon Sep 17 00:00:00 2001
From: Alan Hayward <alan.hayward@arm.com>
Date: Mon, 6 Aug 2018 09:54:28 +0000
Subject: cse support for clobber_high

gcc/
	* cse.c (invalidate_reg): New function extracted from...
	(invalidate): ...here.
	(canonicalize_insn): Check for clobber high.
	(invalidate_from_clobbers): invalidate clobber highs.
	(invalidate_from_sets_and_clobbers): Likewise.
	(count_reg_usage): Check for clobber high.
	(insn_live_p): Likewise.
	* cselib.c (cselib_expand_value_rtx_1):Likewise.
	(cselib_invalidate_regno): Check for clobber in setter.
	(cselib_invalidate_rtx): Pass through setter.
	(cselib_invalidate_rtx_note_stores):
	(cselib_process_insn): Check for clobber high.
	* cselib.h (cselib_invalidate_rtx): Add operand.

From-SVN: r263330
---
 gcc/cselib.c | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

(limited to 'gcc/cselib.c')

diff --git a/gcc/cselib.c b/gcc/cselib.c
index 5a978c1f4b8..6d3a4078c68 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -54,7 +54,8 @@ static unsigned int cselib_hash_rtx (rtx, int, machine_mode);
 static cselib_val *new_cselib_val (unsigned int, machine_mode, rtx);
 static void add_mem_for_addr (cselib_val *, cselib_val *, rtx);
 static cselib_val *cselib_lookup_mem (rtx, int);
-static void cselib_invalidate_regno (unsigned int, machine_mode);
+static void cselib_invalidate_regno (unsigned int, machine_mode,
+				     const_rtx = NULL);
 static void cselib_invalidate_mem (rtx);
 static void cselib_record_set (rtx, cselib_val *, cselib_val *);
 static void cselib_record_sets (rtx_insn *);
@@ -1661,6 +1662,7 @@ cselib_expand_value_rtx_1 (rtx orig, struct expand_value_data *evd,
       /* SCRATCH must be shared because they represent distinct values.  */
       return orig;
     case CLOBBER:
+    case CLOBBER_HIGH:
       if (REG_P (XEXP (orig, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig, 0))))
 	return orig;
       break;
@@ -2163,7 +2165,8 @@ cselib_lookup (rtx x, machine_mode mode,
    invalidating call clobbered registers across a call.  */
 
 static void
-cselib_invalidate_regno (unsigned int regno, machine_mode mode)
+cselib_invalidate_regno (unsigned int regno, machine_mode mode,
+			 const_rtx setter)
 {
   unsigned int endregno;
   unsigned int i;
@@ -2186,6 +2189,9 @@ cselib_invalidate_regno (unsigned int regno, machine_mode mode)
 	i = regno - max_value_regs;
 
       endregno = end_hard_regno (mode, regno);
+
+      if (setter && GET_CODE (setter) == CLOBBER_HIGH)
+	gcc_assert (endregno == regno + 1);
     }
   else
     {
@@ -2218,6 +2224,19 @@ cselib_invalidate_regno (unsigned int regno, machine_mode mode)
 	      continue;
 	    }
 
+	  /* Ignore if clobber high and the register isn't clobbered.  */
+	  if (setter && GET_CODE (setter) == CLOBBER_HIGH)
+	    {
+	      gcc_assert (endregno == regno + 1);
+	      const_rtx x = XEXP (setter, 0);
+	      if (!reg_is_clobbered_by_clobber_high (i, GET_MODE (v->val_rtx),
+						     x))
+		{
+		  l = &(*l)->next;
+		  continue;
+		}
+	    }
+
 	  /* We have an overlap.  */
 	  if (*l == REG_VALUES (i))
 	    {
@@ -2352,10 +2371,10 @@ cselib_invalidate_mem (rtx mem_rtx)
   *vp = &dummy_val;
 }
 
-/* Invalidate DEST, which is being assigned to or clobbered.  */
+/* Invalidate DEST, which is being assigned to or clobbered by SETTER.  */
 
 void
-cselib_invalidate_rtx (rtx dest)
+cselib_invalidate_rtx (rtx dest, const_rtx setter)
 {
   while (GET_CODE (dest) == SUBREG
 	 || GET_CODE (dest) == ZERO_EXTRACT
@@ -2363,7 +2382,7 @@ cselib_invalidate_rtx (rtx dest)
     dest = XEXP (dest, 0);
 
   if (REG_P (dest))
-    cselib_invalidate_regno (REGNO (dest), GET_MODE (dest));
+    cselib_invalidate_regno (REGNO (dest), GET_MODE (dest), setter);
   else if (MEM_P (dest))
     cselib_invalidate_mem (dest);
 }
@@ -2371,10 +2390,10 @@ cselib_invalidate_rtx (rtx dest)
 /* A wrapper for cselib_invalidate_rtx to be called via note_stores.  */
 
 static void
-cselib_invalidate_rtx_note_stores (rtx dest, const_rtx ignore ATTRIBUTE_UNUSED,
+cselib_invalidate_rtx_note_stores (rtx dest, const_rtx setter,
 				   void *data ATTRIBUTE_UNUSED)
 {
-  cselib_invalidate_rtx (dest);
+  cselib_invalidate_rtx (dest, setter);
 }
 
 /* Record the result of a SET instruction.  DEST is being set; the source
@@ -2775,9 +2794,12 @@ cselib_process_insn (rtx_insn *insn)
   if (CALL_P (insn))
     {
       for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1))
-	if (GET_CODE (XEXP (x, 0)) == CLOBBER)
-	  cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
-      /* Flush evertything on setjmp.  */
+	{
+	  gcc_assert (GET_CODE (XEXP (x, 0)) != CLOBBER_HIGH);
+	  if (GET_CODE (XEXP (x, 0)) == CLOBBER)
+	    cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
+	}
+      /* Flush everything on setjmp.  */
       if (cselib_preserve_constants
 	  && find_reg_note (insn, REG_SETJMP, NULL))
 	{
-- 
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