From b98b49ac727f969a64be0dcd20d5493cdd325ac8 Mon Sep 17 00:00:00 2001
From: Jeffrey A Law <law@cygnus.com>
Date: Wed, 8 Jul 1998 01:58:58 +0000
Subject: rtlanal.c (reg_overlap_mentioned_p): Handle STRICT_LOW_PART.

        * rtlanal.c (reg_overlap_mentioned_p): Handle STRICT_LOW_PART.  If
        either argument is CONSTANT_P, then return zero.
        * reload.c (reg_overlap_mentioned_for_reload_p): Similarly.

From-SVN: r21005
---
 gcc/rtlanal.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

(limited to 'gcc/rtlanal.c')

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index b410553..8f42391 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -817,7 +817,14 @@ reg_overlap_mentioned_p (x, in)
 {
   int regno, endregno;
 
-  if (GET_CODE (x) == SUBREG)
+  /* Overly conservative.  */
+  if (GET_CODE (x) == STRICT_LOW_PART)
+    x = XEXP (x, 0);
+
+  /* If either argument is a constant, then modifying X can not affect IN.  */
+  if (CONSTANT_P (x) || CONSTANT_P (in))
+    return 0;
+  else if (GET_CODE (x) == SUBREG)
     {
       regno = REGNO (SUBREG_REG (x));
       if (regno < FIRST_PSEUDO_REGISTER)
@@ -825,8 +832,6 @@ reg_overlap_mentioned_p (x, in)
     }
   else if (GET_CODE (x) == REG)
     regno = REGNO (x);
-  else if (CONSTANT_P (x))
-    return 0;
   else if (GET_CODE (x) == MEM)
     {
       char *fmt;
-- 
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