From: Walter Lee <walt@tilera.com>
Date: Sat, 25 Jan 2014 22:46:37 +0000 (+0000)
Subject: backport: sync.md (atomic_fetch_sub): Fix negation and avoid clobbering a live register.
X-Git-Tag: releases/gcc-4.7.4~291
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=50b8450bc20856fe4281c67da489f66d1819ad94;p=thirdparty%2Fgcc.git

backport: sync.md (atomic_fetch_sub): Fix negation and avoid clobbering a live register.

2014-01-25  Walter Lee  <walt@tilera.com>

            Backport from mainline
            2014-01-25  Walter Lee  <walt@tilera.com>

            * config/tilegx/sync.md (atomic_fetch_sub): Fix negation and
            avoid clobbering a live register.

From-SVN: r207104
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e3b1c3cdf516..c8e08cf9a40b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2014-01-25  Walter Lee  <walt@tilera.com>
+
+	Backport from mainline
+	2014-01-25  Walter Lee  <walt@tilera.com>
+
+	* config/tilegx/sync.md (atomic_fetch_sub): Fix negation and
+	avoid clobbering a live register.
+
 2014-01-25  Walter Lee  <walt@tilera.com>
 
 	Backport from mainline
diff --git a/gcc/config/tilegx/sync.md b/gcc/config/tilegx/sync.md
index 9bf61d17dbe8..bf62ee638358 100644
--- a/gcc/config/tilegx/sync.md
+++ b/gcc/config/tilegx/sync.md
@@ -151,15 +151,22 @@
    (match_operand:SI 3 "const_int_operand" "")]         ;; model
   ""
 {
+  rtx addend;
   enum memmodel model = (enum memmodel) INTVAL (operands[3]);
 
   if (operands[2] != const0_rtx)
-    emit_move_insn (operands[2], gen_rtx_NEG (<MODE>mode, operands[2]));
+    {
+       addend = gen_reg_rtx (<MODE>mode);
+       emit_move_insn (addend,
+                       gen_rtx_MINUS (<MODE>mode, const0_rtx, operands[2]));
+    }
+  else
+    addend = operands[2];
 
   tilegx_pre_atomic_barrier (model);
   emit_insn (gen_atomic_fetch_add_bare<mode> (operands[0],
                                               operands[1],
-                                              operands[2]));
+                                              addend));
   tilegx_post_atomic_barrier (model);
   DONE;
 })