From: Segher Boessenkool <segher@kernel.crashing.org>
Date: Wed, 14 Mar 2018 12:24:21 +0000 (+0100)
Subject: combine: Don't make log_links for pc_rtx (PR84780 #c10)
X-Git-Tag: basepoints/gcc-9~686
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=def703386a1efb5e48b24b1457ce679667e137c9;p=thirdparty%2Fgcc.git

combine: Don't make log_links for pc_rtx (PR84780 #c10)

distribute_links tries to place a log_link for whatever the destination
of the modified instruction is.  It shouldn't do that when that dest
is pc_rtx, which isn't actually a register.


	* combine.c (distribute_links): Don't make a link based on pc_rtx.

From-SVN: r258523
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 104e44255e6b..fcd11eb7db37 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-14  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR rtl-optimization/84780
+	* combine.c (distribute_links): Don't make a link based on pc_rtx.
+
 2018-03-14  Martin Liska  <mliska@suse.cz>
 
 	* tree.c (record_node_allocation_statistics): Use
diff --git a/gcc/combine.c b/gcc/combine.c
index 06a9ddde8586..ff672ad2adbe 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -14778,6 +14778,9 @@ distribute_links (struct insn_link *links)
 	     || GET_CODE (reg) == SUBREG)
 	reg = XEXP (reg, 0);
 
+      if (reg == pc_rtx)
+	continue;
+
       /* A LOG_LINK is defined as being placed on the first insn that uses
 	 a register and points to the insn that sets the register.  Start
 	 searching at the next insn after the target of the link and stop