backport: re PR tree-optimization/61452 (hang at -O1 and -Os on x86_64-linux-gnu)

2014-09-09  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2014-06-11  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/61452
	* tree-ssa-sccvn.c (visit_phi): Remove pointless setting of
	expr and has_constants in case we found a leader.
	(simplify_binary_expression): Always valueize operands first.
	(simplify_unary_expression): Likewise.

	* gcc.dg/torture/pr61452.c: New testcase.

From-SVN: r215081

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ca399cd3c205fa8fd2c5c521373311a1dd2bdd0f..ecd14a43fabbf4e9e5fffd701f8706d68886d968 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2014-09-09  Richard Biener  <rguenther@suse.de>
+
+       Backport from mainline
+       2014-06-11  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/61452
+       * tree-ssa-sccvn.c (visit_phi): Remove pointless setting of
+       expr and has_constants in case we found a leader.
+       (simplify_binary_expression): Always valueize operands first.
+       (simplify_unary_expression): Likewise.
+
 2014-09-09  Richard Biener  <rguenther@suse.de>
 
        Backport from mainline

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b5af69cfcfcc9a3dddcb8afac6dd0670d100abd6..c459dd0a514930cb7b09fc8a2a84633444c6cd73 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2014-09-09  Richard Biener  <rguenther@suse.de>
+
+       Backport from mainline
+       2014-06-11  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/61452
+       * gcc.dg/torture/pr61452.c: New testcase.
+
 2014-09-09  Richard Biener  <rguenther@suse.de>
 
        Backport from mainline

diff --git a/gcc/testsuite/gcc.dg/torture/pr61452.c b/gcc/testsuite/gcc.dg/torture/pr61452.c
new file mode 100644 (file)
index 0000000..a62de30
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr61452.c
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+
+int a, b;
+short c, d;
+char e, f;
+
+int
+fn1 (int p1, char p2)
+{
+  return p1 || p2 ? 0 : p2;
+}
+
+void
+fn2 ()
+{
+  for (; a;)
+    {
+      int g;
+      g = c = e;
+      for (; a;)
+       b = fn1 (g = d = e, g);
+      f = g; 
+    }
+}
+
+int
+main ()
+{
+  fn2 (); 
+  return 0;
+}

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 5dce65afe851a668e5e271b4145c4abeb4d36168..b2afbcdfea06ed5406d3e3032ec8652471c372ef 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -3015,33 +3015,12 @@ visit_phi (gimple phi)
   /* If all value numbered to the same value, the phi node has that
      value.  */
   if (allsame)
-    {
-      if (is_gimple_min_invariant (sameval))
-       {
-         VN_INFO (PHI_RESULT (phi))->has_constants = true;
-         VN_INFO (PHI_RESULT (phi))->expr = sameval;
-       }
-      else
-       {
-         VN_INFO (PHI_RESULT (phi))->has_constants = false;
-         VN_INFO (PHI_RESULT (phi))->expr = sameval;
-       }
-
-      if (TREE_CODE (sameval) == SSA_NAME)
-       return visit_copy (PHI_RESULT (phi), sameval);
-
-      return set_ssa_val_to (PHI_RESULT (phi), sameval);
-    }
+    return set_ssa_val_to (PHI_RESULT (phi), sameval);
 
   /* Otherwise, see if it is equivalent to a phi node in this block.  */
   result = vn_phi_lookup (phi);
   if (result)
-    {
-      if (TREE_CODE (result) == SSA_NAME)
-       changed = visit_copy (PHI_RESULT (phi), result);
-      else
-       changed = set_ssa_val_to (PHI_RESULT (phi), result);
-    }
+    changed = set_ssa_val_to (PHI_RESULT (phi), result);
   else
     {
       vn_phi_insert (phi, PHI_RESULT (phi));
@@ -3142,24 +3121,18 @@ simplify_binary_expression (gimple stmt)
      catch those with constants.  The goal here is to simultaneously
      combine constants between expressions, but avoid infinite
      expansion of expressions during simplification.  */
-  if (TREE_CODE (op0) == SSA_NAME)
-    {
-      if (VN_INFO (op0)->has_constants
+  op0 = vn_valueize (op0);
+  if (TREE_CODE (op0) == SSA_NAME
+      && (VN_INFO (op0)->has_constants
          || TREE_CODE_CLASS (code) == tcc_comparison
-         || code == COMPLEX_EXPR)
-       op0 = valueize_expr (vn_get_expr_for (op0));
-      else
-       op0 = vn_valueize (op0);
-    }
+         || code == COMPLEX_EXPR))
+    op0 = valueize_expr (vn_get_expr_for (op0));
 
-  if (TREE_CODE (op1) == SSA_NAME)
-    {
-      if (VN_INFO (op1)->has_constants
-         || code == COMPLEX_EXPR)
-       op1 = valueize_expr (vn_get_expr_for (op1));
-      else
-       op1 = vn_valueize (op1);
-    }
+  op1 = vn_valueize (op1);
+  if (TREE_CODE (op1) == SSA_NAME
+      && (VN_INFO (op1)->has_constants
+         || code == COMPLEX_EXPR))
+    op1 = valueize_expr (vn_get_expr_for (op1));
 
   /* Pointer plus constant can be represented as invariant address.
      Do so to allow further propatation, see also tree forwprop.  */
@@ -3217,27 +3190,31 @@ simplify_unary_expression (gimple stmt)
     return NULL_TREE;
 
   orig_op0 = op0;
-  if (VN_INFO (op0)->has_constants)
-    op0 = valueize_expr (vn_get_expr_for (op0));
-  else if (CONVERT_EXPR_CODE_P (code)
-          || code == REALPART_EXPR
-          || code == IMAGPART_EXPR
-          || code == VIEW_CONVERT_EXPR
-          || code == BIT_FIELD_REF)
+  op0 = vn_valueize (op0);
+  if (TREE_CODE (op0) == SSA_NAME)
     {
-      /* We want to do tree-combining on conversion-like expressions.
-         Make sure we feed only SSA_NAMEs or constants to fold though.  */
-      tree tem = valueize_expr (vn_get_expr_for (op0));
-      if (UNARY_CLASS_P (tem)
-         || BINARY_CLASS_P (tem)
-         || TREE_CODE (tem) == VIEW_CONVERT_EXPR
-         || TREE_CODE (tem) == SSA_NAME
-         || TREE_CODE (tem) == CONSTRUCTOR
-         || is_gimple_min_invariant (tem))
-       op0 = tem;
+      if (VN_INFO (op0)->has_constants)
+       op0 = valueize_expr (vn_get_expr_for (op0));
+      else if (CONVERT_EXPR_CODE_P (code)
+              || code == REALPART_EXPR
+              || code == IMAGPART_EXPR
+              || code == VIEW_CONVERT_EXPR
+              || code == BIT_FIELD_REF)
+       {
+         /* We want to do tree-combining on conversion-like expressions.
+            Make sure we feed only SSA_NAMEs or constants to fold though.  */
+         tree tem = valueize_expr (vn_get_expr_for (op0));
+         if (UNARY_CLASS_P (tem)
+             || BINARY_CLASS_P (tem)
+             || TREE_CODE (tem) == VIEW_CONVERT_EXPR
+             || TREE_CODE (tem) == SSA_NAME
+             || TREE_CODE (tem) == CONSTRUCTOR
+             || is_gimple_min_invariant (tem))
+           op0 = tem;
+       }
     }
 
-  /* Avoid folding if nothing changed, but remember the expression.  */
+  /* Avoid folding if nothing changed.  */
   if (op0 == orig_op0)
     return NULL_TREE;