PR middle-end/35456

	* fold-const.c (fold_cond_expr_with_comparison): Prevent
	transformations for modes that have signed zeros.
	* ifcvt.c (noce_try_abs): Ditto.

testsuite/ChangeLog:

	PR middle-end/35456
	* gcc.c-torture/execute/pr35456.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@132863 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 459f392..4cbddb6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2008-03-04  Uros Bizjak  <ubizjak@gmail.com>
+
+       PR middle-end/35456
+       * fold-const.c (fold_cond_expr_with_comparison): Prevent
+       transformations for modes that have signed zeros.
+       * ifcvt.c (noce_try_abs): Ditto.
+

 2008-03-04  Joseph Myers  <joseph@codesourcery.com>
 
        * config/i386/i386.c (override_options): Force
 2008-03-04  Joseph Myers  <joseph@codesourcery.com>
 
        * config/i386/i386.c (override_options): Force


@@ -251,7 +258,8 @@
        struct rdg_vertex_info, rdg_vertex_for_stmt): New.
        (create_rdg_edge_for_ddr, create_rdg_vertices): Cleaned up.
        (stmts_from_loop): Skip LABEL_EXPR.
        struct rdg_vertex_info, rdg_vertex_for_stmt): New.
        (create_rdg_edge_for_ddr, create_rdg_vertices): Cleaned up.
        (stmts_from_loop): Skip LABEL_EXPR.

-       (hash_stmt_vertex_info, eq_stmt_vertex_info, hash_stmt_vertex_del): New.
+       (hash_stmt_vertex_info, eq_stmt_vertex_info, hash_stmt_vertex_del):
+       New.

        (build_rdg): Initialize rdg->indices htab.
        (free_rdg, stores_from_loop, ref_base_address,
        rdg_defs_used_in_other_loops_p, have_similar_memory_accesses,
        (build_rdg): Initialize rdg->indices htab.
        (free_rdg, stores_from_loop, ref_base_address,
        rdg_defs_used_in_other_loops_p, have_similar_memory_accesses,


@@ -260,7 +268,8 @@
        * tree-data-ref.h: Depend on tree-chrec.h.
        (debug_data_dependence_relations, free_data_ref): Declared.
        (same_access_functions): ... here.
        * tree-data-ref.h: Depend on tree-chrec.h.
        (debug_data_dependence_relations, free_data_ref): Declared.
        (same_access_functions): ... here.

-       (ddr_is_anti_dependent, ddrs_have_anti_deps, ddr_dependence_level): New.
+       (ddr_is_anti_dependent, ddrs_have_anti_deps, ddr_dependence_level):
+       New.

        (struct rdg_vertex): Add has_mem_write and has_mem_reads.
        (RDGV_HAS_MEM_WRITE, RDGV_HAS_MEM_READS, RDG_STMT,
        RDG_MEM_WRITE_STMT, RDG_MEM_READS_STMT): New.
        (struct rdg_vertex): Add has_mem_write and has_mem_reads.
        (RDGV_HAS_MEM_WRITE, RDGV_HAS_MEM_READS, RDG_STMT,
        RDG_MEM_WRITE_STMT, RDG_MEM_READS_STMT): New.


@@ -270,7 +279,8 @@
        (struct rdg_edge): Add level.
        (RDGE_LEVEL): New.
        (free_rdg, stores_from_loop, remove_similar_memory_refs,
        (struct rdg_edge): Add level.
        (RDGE_LEVEL): New.
        (free_rdg, stores_from_loop, remove_similar_memory_refs,

-       rdg_defs_used_in_other_loops_p, have_similar_memory_accesses): Declared.
+       rdg_defs_used_in_other_loops_p, have_similar_memory_accesses):
+       Declared.

        (rdg_has_similar_memory_accesses): New.
        * tree-vect-analyze.c: Remove unused static decls.
        * lambda.h (dependence_level): New.
        (rdg_has_similar_memory_accesses): New.
        * tree-vect-analyze.c: Remove unused static decls.
        * lambda.h (dependence_level): New.

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 6a70e17..f6466f7 100644 (file)
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -5072,9 +5072,10 @@ fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
 
      Note that all these transformations are correct if A is
      NaN, since the two alternatives (A and -A) are also NaNs.  */
 
      Note that all these transformations are correct if A is
      NaN, since the two alternatives (A and -A) are also NaNs.  */

-  if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
-       ? real_zerop (arg01)
-       : integer_zerop (arg01))
+  if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+      && (FLOAT_TYPE_P (TREE_TYPE (arg01))
+         ? real_zerop (arg01)
+         : integer_zerop (arg01))

       && ((TREE_CODE (arg2) == NEGATE_EXPR
           && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
             /* In the case that A is of the form X-Y, '-A' (arg2) may
       && ((TREE_CODE (arg2) == NEGATE_EXPR
           && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
             /* In the case that A is of the form X-Y, '-A' (arg2) may


@@ -5127,7 +5128,8 @@ fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
      both transformations are correct when A is NaN: A != 0
      is then true, and A == 0 is false.  */
 
      both transformations are correct when A is NaN: A != 0
      is then true, and A == 0 is false.  */
 

-  if (integer_zerop (arg01) && integer_zerop (arg2))
+  if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+      && integer_zerop (arg01) && integer_zerop (arg2))

     {
       if (comp_code == NE_EXPR)
        return pedantic_non_lvalue (fold_convert (type, arg1));
     {
       if (comp_code == NE_EXPR)
        return pedantic_non_lvalue (fold_convert (type, arg1));


@@ -5161,7 +5163,8 @@ fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
      a number and A is not.  The conditions in the original
      expressions will be false, so all four give B.  The min()
      and max() versions would give a NaN instead.  */
      a number and A is not.  The conditions in the original
      expressions will be false, so all four give B.  The min()
      and max() versions would give a NaN instead.  */

-  if (operand_equal_for_comparison_p (arg01, arg2, arg00)
+  if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
+      && operand_equal_for_comparison_p (arg01, arg2, arg00)

       /* Avoid these transformations if the COND_EXPR may be used
         as an lvalue in the C++ front-end.  PR c++/19199.  */
       && (in_gimple_form
       /* Avoid these transformations if the COND_EXPR may be used
         as an lvalue in the C++ front-end.  PR c++/19199.  */
       && (in_gimple_form

diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 4fd98d0..cab4fbd 100644 (file)
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1738,6 +1738,10 @@ noce_try_abs (struct noce_if_info *if_info)
   rtx cond, earliest, target, seq, a, b, c;
   int negate;
 
   rtx cond, earliest, target, seq, a, b, c;
   int negate;
 

+  /* Reject modes with signed zeros.  */
+  if (HONOR_SIGNED_ZEROS (GET_MODE (if_info->x)))
+    return FALSE;
+

   /* Recognize A and B as constituting an ABS or NABS.  The canonical
      form is a branch around the negation, taken when the object is the
      first operand of a comparison against 0 that evaluates to true.  */
   /* Recognize A and B as constituting an ABS or NABS.  The canonical
      form is a branch around the negation, taken when the object is the
      first operand of a comparison against 0 that evaluates to true.  */

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7aeb040..7b62ebf 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-03-04  Uros Bizjak  <ubizjak@gmail.com>
+
+       PR middle-end/35456
+       * gcc.c-torture/execute/pr35456.c: New test.
+

 2008-03-04  Joseph Myers  <joseph@codesourcery.com>
 
        * gcc.target/i386/sse-10.c: Don't use
 2008-03-04  Joseph Myers  <joseph@codesourcery.com>
 
        * gcc.target/i386/sse-10.c: Don't use

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr35456.c b/gcc/testsuite/gcc.c-torture/execute/pr35456.c
new file mode 100644 (file)
index 0000000..175a0b2
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr35456.c
@@ -0,0 +1,21 @@
+extern void abort (void);
+
+double
+__attribute__ ((noinline))
+not_fabs (double x)
+{
+  return x >= 0.0 ? x : -x;
+}
+
+int main()
+{
+  double x = -0.0;
+  double y;
+
+  y = not_fabs (x);
+
+  if (!__builtin_signbit (y))
+    abort();
+
+  return 0;
+}