[ARC] Use TARGET_USE_ANCHORS_FOR_SYMBOL_P.

We don't want to use anchors for small data: the GP register acts as an anchor in that
case.  We also don't want to use them for PC-relative accesses,
where the PC acts as an anchor.  TLS symbols require special accesses as well, don't use
anchors for such symbols.

gcc/
2017-04-28  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_use_anchors_for_symbol_p): New function.
	(TARGET_USE_ANCHORS_FOR_SYMBOL_P): Define.

gcc/testsuite
2017-04-28  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/pr9001184797.c: New test.

From-SVN: r251586

gcc/ChangeLog

+2017-09-01  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* config/arc/arc.c (arc_use_anchors_for_symbol_p): New function.
+	(TARGET_USE_ANCHORS_FOR_SYMBOL_P): Define.
+
 2017-08-31  Olivier Hainque  <hainque@adacore.com>
 
 	* config.gcc (powerpc-wrs-vxworks|vxworksae|vxworksmils): Now

gcc/config/arc/arc.c

@@ -10566,6 +10566,30 @@ compact_memory_operand_p (rtx op, machine_mode mode,
   return false;
 }
 
+/* Implement TARGET_USE_ANCHORS_FOR_SYMBOL_P.  We don't want to use
+   anchors for small data: the GP register acts as an anchor in that
+   case.  We also don't want to use them for PC-relative accesses,
+   where the PC acts as an anchor.  Prohibit also TLS symbols to use
+   anchors.  */
+
+static bool
+arc_use_anchors_for_symbol_p (const_rtx symbol)
+{
+  if (SYMBOL_REF_TLS_MODEL (symbol))
+    return false;
+
+  if (flag_pic)
+    return false;
+
+  if (SYMBOL_REF_SMALL_P (symbol))
+    return false;
+
+  return default_use_anchors_for_symbol_p (symbol);
+}
+
+#undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
+#define TARGET_USE_ANCHORS_FOR_SYMBOL_P arc_use_anchors_for_symbol_p
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-arc.h"

gcc/testsuite/ChangeLog

+2017-09-01  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* gcc.target/arc/pr9001184797.c: New test.
+
 2017-09-01  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/81887

gcc/testsuite/gcc.target/arc/pr9001184797.c

+/* { dg-do compile } */
+/* { dg-require-effective-target tls } */
+/* { dg-options "-Os -w -mno-ll64" } */
+
+/* This test studies the use of anchors and tls symbols. */
+
+struct a b;
+struct a {
+  long c;
+  long d
+} e() {
+  static __thread struct a f;
+  static __thread g;
+  g = 5;
+  h();
+  if (f.c)
+    g = g & 5;
+  f = b;
+}