From: J"orn Rennecke <amylaar@cygnus.co.uk>
Date: Mon, 2 Aug 1999 22:50:49 +0000 (+0000)
Subject: loop.c (strength_reduce): When doing biv->giv conversion, fix up reg_biv_class.
X-Git-Tag: prereleases/libstdc++-2.92~11409
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e76d23764b387e9636b5d568b62531019f7f2273;p=thirdparty%2Fgcc.git

loop.c (strength_reduce): When doing biv->giv conversion, fix up reg_biv_class.

	* loop.c (strength_reduce): When doing biv->giv conversion, fix up
	reg_biv_class.

From-SVN: r28413
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ec354394aa8c..d84431970099 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Mon Aug  2 23:46:45 1999  J"orn Rennecke <amylaar@cygnus.co.uk>
+
+	* loop.c (strength_reduce): When doing biv->giv conversion, fix up
+	reg_biv_class.
+
 1999-08-02  Jakub Jelinek  <jj@ultra.linux.cz>
 
 	* config/float-sparc.h: New file.
diff --git a/gcc/loop.c b/gcc/loop.c
index db50a1862e56..0b02cc2a41c5 100644
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -4072,6 +4072,7 @@ strength_reduce (scan_start, end, loop_top, insn_count,
 		fprintf (loop_dump_stream, "is giv of biv %d\n", bl2->regno);
 	      /* Let this giv be discovered by the generic code.  */
 	      REG_IV_TYPE (bl->regno) = UNKNOWN_INDUCT;
+	      reg_biv_class[bl->regno] = NULL_PTR;
 	      /* We can get better optimization if we can move the giv setting
 		 before the first giv use.  */
 	      if (dominator
@@ -4123,7 +4124,13 @@ strength_reduce (scan_start, end, loop_top, insn_count,
 		}
 	      /* Remove this biv from the chain.  */
 	      if (bl->next)
-		*bl = *bl->next;
+		{
+		  /* We move the following giv from *bl->next into *bl.
+		     We have to update reg_biv_class for that moved biv
+		     to point to its new address.  */
+		  *bl = *bl->next;
+		  reg_biv_class[bl->regno] = bl;
+		}
 	      else
 		{
 		  *backbl = 0;