This patch fixes PR 49169, where GCC is incorrectly optimising away
a test for whether a function is Thumb rather than ARM. The patch
was posted by Richard in the PR:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49169
See the PR for a discussion about whether a target hook is better
(or not, IMO).
Tested on arm-linux-gnueabi, where it fixes the attached testcase.
OK to install?
Richard
gcc/
2011-07-24 Richard Guenther <rguent...@suse.de>
PR tree-optimization/49169
* fold-const.c (get_pointer_modulus_and_residue): Don't rely on
the alignment of function decls.
gcc/testsuite/
2011-07-24 Michael Hope <michael.h...@linaro.org>
Richard Sandiford <richard.sandif...@linaro.org>
PR tree-optimization/49169
* gcc.dg/torture/pr49169.c: New test.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c 2011-06-22 16:48:38.000000000 +0100
+++ gcc/fold-const.c 2011-06-23 17:50:33.000000000 +0100
@@ -9216,7 +9216,8 @@ get_pointer_modulus_and_residue (tree ex
*residue = 0;
code = TREE_CODE (expr);
- if (code == ADDR_EXPR)
+ if (code == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (expr, 0)) != FUNCTION_DECL)
{
unsigned int bitalign;
bitalign = get_object_alignment_1 (TREE_OPERAND (expr, 0), residue);
Index: gcc/testsuite/gcc.dg/torture/pr49169.c
===================================================================
--- /dev/null 2011-06-20 08:31:41.268810499 +0100
+++ gcc/testsuite/gcc.dg/torture/pr49169.c 2011-06-23 17:52:24.000000000
+0100
@@ -0,0 +1,13 @@
+#include <stdlib.h>
+#include <stdint.h>
+
+int
+main (void)
+{
+ void *p = main;
+ if ((intptr_t) p & 1)
+ abort ();
+ return 0;
+}
+
+/* { dg-final { scan-assembler "abort" } } */
