Hi!

arm_legitimize_address may be called with a TLS symbol referenced, even when
x is not itself a SYMBOL_REF.  Most often it is something like:
(const:SI (plus:SI (symbol_ref:SI "tlsvar") (const_int NNN)))
but generally it can be something else (e.g. from expansion of
TARGET_MEM_REF).  Unfortunately this function legitimizes only the
SYMBOL_REF TLS case as TLS load, but the more complex forms with e.g. -fpic
can e.g. fall thru into legitimize_pic_address -> gen_calculate_pic_address,
which means either wrong-code or ICE later on.
Fixed by legitimizing both the SYMBOL_REF and
CONST+PLUS+SYMBOL_REF+CONST_INT case, and for more complex TLS containing
expressions just returning x (in that case the caller will split the PLUS
on its own).

Kyrill has kindly bootstrapped/regtested this on Chromebook, ok for
trunk/4.8?

2014-03-05  Jakub Jelinek  <ja...@redhat.com>
            Meador Inge  <mead...@codesourcery.com>

        PR target/58595
        * config/arm/arm.c (arm_tls_symbol_p): Remove.
        (arm_legitimize_address): Call legitimize_tls_address for any
        arm_tls_referenced_p expression, handle constant addend.  Call it
        before testing for !TARGET_ARM.
        (thumb_legitimize_address): Don't handle arm_tls_symbol_p here.

        * gcc.dg/tls/pr58595.c: New test.

--- gcc/config/arm/arm.c.jj     2014-03-04 08:51:39.620081210 +0100
+++ gcc/config/arm/arm.c        2014-03-04 14:06:26.776277688 +0100
@@ -235,7 +235,6 @@ static tree arm_gimplify_va_arg_expr (tr
 static void arm_option_override (void);
 static unsigned HOST_WIDE_INT arm_shift_truncation_mask (enum machine_mode);
 static bool arm_cannot_copy_insn_p (rtx);
-static bool arm_tls_symbol_p (rtx x);
 static int arm_issue_rate (void);
 static void arm_output_dwarf_dtprel (FILE *, int, rtx) ATTRIBUTE_UNUSED;
 static bool arm_output_addr_const_extra (FILE *, rtx);
@@ -7336,6 +7335,32 @@ legitimize_tls_address (rtx x, rtx reg)
 rtx
 arm_legitimize_address (rtx x, rtx orig_x, enum machine_mode mode)
 {
+  if (arm_tls_referenced_p (x))
+    {
+      rtx addend = NULL;
+
+      if (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS)
+       {
+         addend = XEXP (XEXP (x, 0), 1);
+         x = XEXP (XEXP (x, 0), 0);
+       }
+
+      if (GET_CODE (x) != SYMBOL_REF)
+       return x;
+
+      gcc_assert (SYMBOL_REF_TLS_MODEL (x) != 0);
+
+      x = legitimize_tls_address (x, NULL_RTX);
+
+      if (addend)
+       {
+         x = gen_rtx_PLUS (SImode, x, addend);
+         orig_x = x;
+       }
+      else
+       return x;
+    }
+
   if (!TARGET_ARM)
     {
       /* TODO: legitimize_address for Thumb2.  */
@@ -7344,9 +7369,6 @@ arm_legitimize_address (rtx x, rtx orig_
       return thumb_legitimize_address (x, orig_x, mode);
     }
 
-  if (arm_tls_symbol_p (x))
-    return legitimize_tls_address (x, NULL_RTX);
-
   if (GET_CODE (x) == PLUS)
     {
       rtx xop0 = XEXP (x, 0);
@@ -7459,9 +7481,6 @@ arm_legitimize_address (rtx x, rtx orig_
 rtx
 thumb_legitimize_address (rtx x, rtx orig_x, enum machine_mode mode)
 {
-  if (arm_tls_symbol_p (x))
-    return legitimize_tls_address (x, NULL_RTX);
-
   if (GET_CODE (x) == PLUS
       && CONST_INT_P (XEXP (x, 1))
       && (INTVAL (XEXP (x, 1)) >= 32 * GET_MODE_SIZE (mode)
@@ -7756,20 +7775,6 @@ thumb_legitimize_reload_address (rtx *x_
 
 /* Test for various thread-local symbols.  */
 
-/* Return TRUE if X is a thread-local symbol.  */
-
-static bool
-arm_tls_symbol_p (rtx x)
-{
-  if (! TARGET_HAVE_TLS)
-    return false;
-
-  if (GET_CODE (x) != SYMBOL_REF)
-    return false;
-
-  return SYMBOL_REF_TLS_MODEL (x) != 0;
-}
-
 /* Helper for arm_tls_referenced_p.  */
 
 static int
--- gcc/testsuite/gcc.dg/tls/pr58595.c.jj       2014-03-04 12:56:48.337915114 
+0100
+++ gcc/testsuite/gcc.dg/tls/pr58595.c  2014-03-04 12:56:48.337915114 +0100
@@ -0,0 +1,28 @@
+/* PR target/58595 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-additional-options "-fpic" { target fpic } } */
+/* { dg-require-effective-target tls } */
+/* { dg-require-effective-target sync_int_long } */
+
+struct S { unsigned long a, b; };
+__thread struct S s;
+void bar (unsigned long *);
+
+__attribute__((noinline)) void
+foo (void)
+{
+  int i;
+  for (i = 0; i < 10; i++)
+    __sync_fetch_and_add (&s.b, 1L);
+}
+
+int
+main ()
+{
+  s.b = 12;
+  foo ();
+  if (s.b != 22)
+    __builtin_abort ();
+  return 0;
+}

        Jakub

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