Hi!
GCC before r237607 used to mishandle TLS in -mcmodel=large - forcing
TLS symbols in constant pool, which obviously doesn't work, because they
aren't constant. For all other models aarch64_tls_symbol_p is checked
first.
The following patch backports just the bug fix for this PR part to 6.x,
the whole patch has not been declared as a bugfix, came with no testcases,
so I have no idea on what it actually fixes.
I want to roll GCC 6.3rc1 today, is this ok for 6.3 before that, or do you
prefer to backport it yourself later (post 6.3)? Bootstrapped/regtested
successfully on aarch64-linux on 6 branch.
Is the testcase alone ok for trunk (additionally I've included it in my
x86_64-linux and i686-linux bootstraps)?
2016-12-14 Wilco Dijkstra <wdijk...@arm.com>
Jakub Jelinek <ja...@redhat.com>
PR target/78796
* config/aarch64/aarch64.c (aarch64_classify_symbol): Merge large
model checks into switch.
* gcc.dg/tls/pr78796.c: New test.
--- gcc/config/aarch64/aarch64.c.jj 2016-08-12 18:05:00.000000000 +0200
+++ gcc/config/aarch64/aarch64.c 2016-12-13 17:13:24.372394957 +0100
@@ -9280,18 +9280,6 @@ aarch64_classify_symbol (rtx x, rtx offs
if (GET_CODE (x) == SYMBOL_REF)
{
- if (aarch64_cmodel == AARCH64_CMODEL_LARGE)
- {
- /* This is alright even in PIC code as the constant
- pool reference is always PC relative and within
- the same translation unit. */
- if (nopcrelative_literal_loads
- && CONSTANT_POOL_ADDRESS_P (x))
- return SYMBOL_SMALL_ABSOLUTE;
- else
- return SYMBOL_FORCE_TO_MEM;
- }
-
if (aarch64_tls_symbol_p (x))
return aarch64_classify_tls_symbol (x);
@@ -9332,6 +9320,16 @@ aarch64_classify_symbol (rtx x, rtx offs
? SYMBOL_SMALL_GOT_28K : SYMBOL_SMALL_GOT_4G);
return SYMBOL_SMALL_ABSOLUTE;
+ case AARCH64_CMODEL_LARGE:
+ /* This is alright even in PIC code as the constant
+ pool reference is always PC relative and within
+ the same translation unit. */
+ if (nopcrelative_literal_loads
+ && CONSTANT_POOL_ADDRESS_P (x))
+ return SYMBOL_SMALL_ABSOLUTE;
+ else
+ return SYMBOL_FORCE_TO_MEM;
+
default:
gcc_unreachable ();
}
--- gcc/testsuite/gcc.dg/tls/pr78796.c.jj 2016-12-13 17:15:17.135966420
+0100
+++ gcc/testsuite/gcc.dg/tls/pr78796.c 2016-12-13 17:15:13.939006921 +0100
@@ -0,0 +1,32 @@
+/* PR target/78796 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-additional-options "-mcmodel=large" { target aarch64-*-* } } */
+/* { dg-require-effective-target tls } */
+
+struct S { int a, b, c, d, e; };
+struct S t;
+__thread struct S s;
+
+__attribute__((used, noinline, noclone)) void
+foo (int *x, int *y)
+{
+ asm volatile ("" : : "g" (x), "g" (y) : "memory");
+ if (*x != 1 || *y != 2)
+ __builtin_abort ();
+}
+
+__attribute__((used, noinline, noclone)) void
+bar (void)
+{
+ foo (&t.c, &s.c);
+}
+
+int
+main ()
+{
+ t.c = 1;
+ s.c = 2;
+ bar ();
+ return 0;
+}
Jakub
