[PATCH v2] ia64: don't use dynamic relocations for local symbols PR other/60465

[PATCH v2] ia64: don't use dynamic relocations for local symbols
	PR other/60465
	* config/ia64/ia64.c (ia64_expand_load_address): Use gprel64
	for local symbolic operands.
	* config/ia64/predicates.md (local_symbolic_operand64): New
	predicate.

        PR other/60465
	* gcc.target/ia64/pr60465-gprel64.c: New test.
	* gcc.target/ia64/pr60465-gprel64-c37.c: New test.

From-SVN: r232080

6 files changed, 86 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 98d6fefe..d54d604 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2016-01-05  Sergei Trofimovich <siarheit@google.com>
+
+	PR other/60465
+	* config/ia64/ia64.c (ia64_expand_load_address): Use gprel64
+	for local symbolic operands.
+	* config/ia64/predicates.md (local_symbolic_operand64): New
+	predicate.
+
 2016-01-05  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR rtl-optimization/68651
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index e0059f8..33ec7a7 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -1105,6 +1105,15 @@ ia64_expand_load_address (rtx dest, rtx src)
     emit_insn (gen_load_fptr (dest, src));
   else if (sdata_symbolic_operand (src, VOIDmode))
     emit_insn (gen_load_gprel (dest, src));
+  else if (local_symbolic_operand64 (src, VOIDmode))
+    {
+      /* We want to use @gprel rather than @ltoff relocations for local
+	 symbols:
+	  - @gprel does not require dynamic linker
+	  - and does not use .sdata section
+	 https://gcc.gnu.org/bugzilla/60465 */
+      emit_insn (gen_load_gprel64 (dest, src));
+    }
   else
     {
       HOST_WIDE_INT addend = 0;
diff --git a/gcc/config/ia64/predicates.md b/gcc/config/ia64/predicates.md
index ddc31b1..02347f7 100644
--- a/gcc/config/ia64/predicates.md
+++ b/gcc/config/ia64/predicates.md
@@ -97,6 +97,32 @@
     }
 })
 
+;; True if OP refers to a local symbol [+any offset].
+;; To be encoded as:
+;;   movl % = @gprel(symbol+offset)
+;;   add  % = %, gp
+(define_predicate "local_symbolic_operand64"
+  (match_code "symbol_ref,const")
+{
+  switch (GET_CODE (op))
+    {
+    case CONST:
+      op = XEXP (op, 0);
+      if (GET_CODE (op) != PLUS
+	  || GET_CODE (XEXP (op, 0)) != SYMBOL_REF
+	  || GET_CODE (XEXP (op, 1)) != CONST_INT)
+	return false;
+      op = XEXP (op, 0);
+      /* FALLTHRU */
+
+    case SYMBOL_REF:
+	return SYMBOL_REF_LOCAL_P (op);
+
+    default:
+      gcc_unreachable ();
+    }
+})
+
 ;; True if OP refers to a symbol in the small address area.
 (define_predicate "small_addr_symbolic_operand" 
   (match_code "symbol_ref,const")
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4ab864e..2075964 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2016-01-05  Sergei Trofimovich <siarheit@google.com>
+
+        PR other/60465
+	* gcc.target/ia64/pr60465-gprel64.c: New test.
+	* gcc.target/ia64/pr60465-gprel64-c37.c: New test.
+
 2016-01-05  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR rtl-optimization/68651
diff --git a/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
new file mode 100644
index 0000000..a7e6809
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia64-*-* } } */
+/* { dg-options "-O2 -fpic" } */
+/* { dg-final { scan-assembler-not "@ltoffx" } } */
+
+/* A bit of https://bugzilla.redhat.com/show_bug.cgi?id=33354
+   where many stores to static variables overflow .sdata */
+
+static const char *s90;
+void f() { s90 = "string 90"; }
+const char * g() { return s90; }
diff --git a/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
new file mode 100644
index 0000000..c00ecc9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
@@ -0,0 +1,27 @@
+/* { dg-do compile { target ia64-*-* } } */
+/* { dg-options "-O2 -fpic" } */
+/* { dg-final { scan-assembler-not "@ltoffx" } } */
+
+/* Test imitates early ld.so setup in glibc
+   where no dynamic relocations must be present. */
+
+struct rtld_global
+{
+    long *p[77];
+};
+
+struct rtld_global _rtld_local __attribute__ ((visibility ("hidden"), section (".sdata")));
+
+static void __attribute__ ((unused, noinline))
+elf_get_dynamic_info (struct rtld_global * g, long * dyn)
+{
+  long **info = g->p;
+
+  info[(0x6ffffeff - *dyn) + 66] = dyn;
+}
+
+void __attribute__ ((unused, noinline))
+_dl_start (long * dyn)
+{
+  elf_get_dynamic_info(&_rtld_local, dyn);
+}