re PR tree-optimization/66952 (wrong code at -O2 and -O3 on x86_64-linux-gnu)

2015-07-22  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66952
	* tree-ssa-ifcombine.c (pass_tree_ifcombine::execute): For
	blocks we end up executing unconditionally reset all SSA
	info such as range and alignment.
	* tree-ssanames.h (reset_flow_sensitive_info): Declare.
	* tree-ssanames.c (reset_flow_sensitive_info): New function.

	* gcc.dg/torture/pr66952.c: New testcase.

From-SVN: r226062

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8f2771eeec525f063fa9e2a9ba6e844da45d7da3..c1838eac3539ac209b88fee1334b9448dc5f39f9 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2015-07-22  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/66952
+       * tree-ssa-ifcombine.c (pass_tree_ifcombine::execute): For
+       blocks we end up executing unconditionally reset all SSA
+       info such as range and alignment.
+       * tree-ssanames.h (reset_flow_sensitive_info): Declare.
+       * tree-ssanames.c (reset_flow_sensitive_info): New function.
+
 2015-07-22  Charles Baylis  <charles.baylis@linaro.org>
 
        * config/aarch64/aarch64-simd.md (vec_store_lanesoi_lane<mode>): Fix

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 80803088961df48ed528e491f8172d9dbcb36a29..f4eb4c9f94c1afd031dc5f9a1b955febc05177a7 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-22  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/66952
+       * gcc.dg/torture/pr66952.c: New testcase.
+
 2015-07-22  Charles Baylis  <charles.baylis@linaro.org>
 
         * gcc.target/aarch64/advsimd-intrinsics/vld2_lane_f32_indices_1.c: New

diff --git a/gcc/testsuite/gcc.dg/torture/pr66952.c b/gcc/testsuite/gcc.dg/torture/pr66952.c
new file mode 100644 (file)
index 0000000..2a98d2e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr66952.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+
+int a = 128, b;
+
+static int
+fn1 (char p1, int p2)
+{
+  return p1 < 0 || p1 > 1 >> p2 ? 0 : p1 << 1;
+}
+
+static int
+fn2 ()
+{
+  char c = a;
+  b = fn1 (c, 1);
+  if ((128 | c) < 0 ? 1 : 0)
+    return 1;
+  return 0;
+}
+
+int
+main ()
+{
+  if (fn2 () != 1)
+    __builtin_abort ();
+
+  return 0;
+}

diff --git a/gcc/tree-ssa-ifcombine.c b/gcc/tree-ssa-ifcombine.c
index e199689bdf30ee34ead2aba8ae8c97b70f3079ab..ef3d16de4120c2311d6dd448da2ff86b849220b7 100644 (file)
--- a/gcc/tree-ssa-ifcombine.c
+++ b/gcc/tree-ssa-ifcombine.c
@@ -765,7 +765,22 @@ pass_tree_ifcombine::execute (function *fun)
 
       if (stmt
          && gimple_code (stmt) == GIMPLE_COND)
-       cfg_changed |= tree_ssa_ifcombine_bb (bb);
+       if (tree_ssa_ifcombine_bb (bb))
+         {
+           /* Clear range info from all stmts in BB which is now executed
+              conditional on a always true/false condition.  */
+           for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
+                !gsi_end_p (gsi); gsi_next (&gsi))
+             {
+               gimple stmt = gsi_stmt (gsi);
+               ssa_op_iter i;
+               tree op;
+               FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
+                 reset_flow_sensitive_info (op);
+             }
+
+           cfg_changed |= true;
+         }
     }
 
   free (bbs);

diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index 4dd881ae0c40bd5293e5b0c6160aff4f3bfe7e30..910cb19b8d14dc64e232c176497a4ffe05b24846 100644 (file)
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -528,6 +528,23 @@ duplicate_ssa_name_fn (struct function *fn, tree name, gimple stmt)
 }
 
 
+/* Reset all flow sensitive data on NAME such as range-info, nonzero
+   bits and alignment.  */
+
+void
+reset_flow_sensitive_info (tree name)
+{
+  if (POINTER_TYPE_P (TREE_TYPE (name)))
+    {
+      /* points-to info is not flow-sensitive.  */
+      if (SSA_NAME_PTR_INFO (name))
+       mark_ptr_info_alignment_unknown (SSA_NAME_PTR_INFO (name));
+    }
+  else
+    SSA_NAME_RANGE_INFO (name) = NULL;
+}
+
+
 /* Release all the SSA_NAMEs created by STMT.  */
 
 void

diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h
index a7eeb8f2319d06df6ca3dcf8e947d985f37d4689..c6db57e9660ea4b32f329f36cb7f87cebb70ff92 100644 (file)
--- a/gcc/tree-ssanames.h
+++ b/gcc/tree-ssanames.h
@@ -94,6 +94,7 @@ extern void duplicate_ssa_name_ptr_info (tree, struct ptr_info_def *);
 extern tree duplicate_ssa_name_fn (struct function *, tree, gimple);
 extern void duplicate_ssa_name_range_info (tree, enum value_range_type,
                                           struct range_info_def *);
+extern void reset_flow_sensitive_info (tree);
 extern void release_defs (gimple);
 extern void replace_ssa_name_symbol (tree, tree);