re PR tree-optimization/32586 (New VN misses FRE opportunities)

2007-09-07  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/32586
        * tree-ssa-sccvn.c (simplify_binary_expression): Avoid
        folding if nothing changed.
        (simplify_unary_expression): New function.  Do tree combining
        on conversion like codes.
        (try_to_simplify): Call it.

        * g++.dg/tree-ssa/pr27090.C: Remove XFAILs.
        * gcc.dg/tree-ssa/ssa-fre-1.c: Likewise.
        * gcc.dg/tree-ssa/ssa-fre-3.c: Likewise.
        * gcc.dg/tree-ssa/ssa-fre-5.c: Likewise.
        * gcc.dg/tree-ssa/ssa-fre-4.c: Likewise, remove scan for
        now obsolete simplification.

From-SVN: r128251

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7d2b14ed7177e820e85782c61153af79455e019a..c6e6daa6a836220c0380e2ed67aac63fcf655bf4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2007-09-07  Richard Guenther  <rguenther@suse.de>
+
+       Reapply
+       2007-09-06  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/32586
+       * tree-ssa-sccvn.c (simplify_binary_expression): Avoid
+       folding if nothing changed.
+       (simplify_unary_expression): New function.  Do tree combining
+       on conversion like codes.
+       (try_to_simplify): Call it.
+
 2007-09-07  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
 
        PR target/33286

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 13ab39940a9fa735988c1c8de748e68690f414b0..f704b279dd1ede95eef3e8cff8f80b4911fc37d8 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,16 @@
+2007-09-07  Richard Guenther  <rguenther@suse.de>
+
+       Reapply
+       2007-09-06  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/32586
+       * g++.dg/tree-ssa/pr27090.C: Remove XFAILs.
+       * gcc.dg/tree-ssa/ssa-fre-1.c: Likewise.
+       * gcc.dg/tree-ssa/ssa-fre-3.c: Likewise.
+       * gcc.dg/tree-ssa/ssa-fre-5.c: Likewise.
+       * gcc.dg/tree-ssa/ssa-fre-4.c: Likewise, remove scan for
+       now obsolete simplification.
+
 2007-09-07  Dorit Nuzman  <dorit@il.ibm.com>
        
        PR tree-optimization/33299

diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr27090.C b/gcc/testsuite/g++.dg/tree-ssa/pr27090.C
index 70ef1e09d57a3a89fab30e83bdd13ee661063e51..a56357a1b52a761e651cb6d68b3f7f2ce6fb0293 100644 (file)
--- a/gcc/testsuite/g++.dg/tree-ssa/pr27090.C
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr27090.C
@@ -17,5 +17,5 @@ int foo(Foo& f)
         return f.get();
 }
 
-/* { dg-final { scan-tree-dump "return f->x;" "optimized" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "return f->x;" "optimized" } } */
 /* { dg-final { cleanup-tree-dump "optimized" } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-1.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-1.c
index e8c57512bbdb56a86ba0acbe250db5779a4b444f..0cb63242c0e9a6f5079d0153e737b34a944596c3 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-1.c
@@ -11,6 +11,6 @@ int f(int *a)
   return *c + t;
 }
 
-/* { dg-final { scan-tree-dump "Replaced \\\(int \\\*\\\) b_.*with a_" "fre" { xfail *-*-* } } } */
-/* { dg-final { scan-tree-dump "Replaced \\\*c_.*with t_" "fre" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "Replaced \\\(int \\\*\\\) b_.*with a_" "fre" } } */
+/* { dg-final { scan-tree-dump "Replaced \\\*c_.*with t_" "fre" } } */
 /* { dg-final { cleanup-tree-dump "fre" } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-3.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-3.c
index e22064624ae298886c17be02e396955da8e18348..ebc91e775183a3726a2b4d371679c3d2c894b8ad 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-3.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-3.c
@@ -11,5 +11,5 @@ foo (int a, int b)
   return aa + bb;
 }
 
-/* { dg-final { scan-tree-dump "Replaced \\\(int\\\) aa_.*with a_" "fre" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "Replaced \\\(int\\\) aa_.*with a_" "fre" } } */
 /* { dg-final { cleanup-tree-dump "fre" } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-4.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-4.c
index 2b2353f33633dca851523019b987804e53c214f2..04208a2290d6309e85e51f3f4ca27a96d3290f06 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-4.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-4.c
@@ -9,6 +9,5 @@ char bar(char f)
         return wrap(f);
 }
 
-/* { dg-final { scan-tree-dump "Replaced \\\(char\\\) .*with " "fre" { xfail *-*-* } } } */
-/* { dg-final { scan-tree-dump "Replaced \\\(int\\\) .*with " "fre" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "Replaced \\\(char\\\) .*with " "fre" } } */
 /* { dg-final { cleanup-tree-dump "fre" } } */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-5.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-5.c
index db6346cc2e77c927d3353fa16a6d7b16e5af4f2d..7ef20c2214d01fa54e029832936fde372d221138 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-5.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-5.c
@@ -10,5 +10,5 @@ bar (unsigned int t)
   return a == t;
 }
 
-/* { dg-final { scan-tree-dump "Replaced \\\(unsigned int\\\) a_.*with t_" "fre" { xfail *-*-* } } } */
+/* { dg-final { scan-tree-dump "Replaced \\\(unsigned int\\\) a_.*with t_" "fre" } } */
 /* { dg-final { cleanup-tree-dump "fre" } } */

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index 855f42af9952e8a3cbad732259d7d96c5b980e1e..bca0e8473aeb347cb0624ff23b23d8d0f2cf1f1d 100644 (file)
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -1411,6 +1411,11 @@ simplify_binary_expression (tree rhs)
        op1 = SSA_VAL (op1);
     }
 
+  /* Avoid folding if nothing changed.  */
+  if (op0 == TREE_OPERAND (rhs, 0)
+      && op1 == TREE_OPERAND (rhs, 1))
+    return NULL_TREE;
+
   result = fold_binary (TREE_CODE (rhs), TREE_TYPE (rhs), op0, op1);
 
   /* Make sure result is not a complex expression consisting
@@ -1423,6 +1428,50 @@ simplify_binary_expression (tree rhs)
   return NULL_TREE;
 }
 
+/* Simplify the unary expression RHS, and return the result if
+   simplified. */
+
+static tree
+simplify_unary_expression (tree rhs)
+{
+  tree result = NULL_TREE;
+  tree op0 = TREE_OPERAND (rhs, 0);
+
+  if (TREE_CODE (op0) != SSA_NAME)
+    return NULL_TREE;
+
+  if (VN_INFO (op0)->has_constants)
+    op0 = valueize_expr (VN_INFO (op0)->expr);
+  else if (TREE_CODE (rhs) == NOP_EXPR
+          || TREE_CODE (rhs) == CONVERT_EXPR
+          || TREE_CODE (rhs) == REALPART_EXPR
+          || TREE_CODE (rhs) == IMAGPART_EXPR)
+    {
+      /* 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_INFO (op0)->expr);
+      if (UNARY_CLASS_P (tem)
+         || BINARY_CLASS_P (tem)
+         || TREE_CODE (tem) == SSA_NAME
+         || is_gimple_min_invariant (tem))
+       op0 = tem;
+    }
+
+  /* Avoid folding if nothing changed, but remember the expression.  */
+  if (op0 == TREE_OPERAND (rhs, 0))
+    return rhs;
+
+  result = fold_unary (TREE_CODE (rhs), TREE_TYPE (rhs), op0);
+  if (result)
+    {
+      STRIP_USELESS_TYPE_CONVERSION (result);
+      if (valid_gimple_expression_p (result))
+        return result;
+    }
+
+  return rhs;
+}
+
 /* Try to simplify RHS using equivalences and constant folding.  */
 
 static tree
@@ -1457,21 +1506,14 @@ try_to_simplify (tree stmt, tree rhs)
            if (result)
              return result;
          }
-         break;
+         /* Fallthrough for some codes.  */
+         if (!(TREE_CODE (rhs) == REALPART_EXPR
+               || TREE_CODE (rhs) == IMAGPART_EXPR))
+           break;
          /* We could do a little more with unary ops, if they expand
             into binary ops, but it's debatable whether it is worth it. */
        case tcc_unary:
-         {
-           tree result = NULL_TREE;
-           tree op0 = TREE_OPERAND (rhs, 0);
-           if (TREE_CODE (op0) == SSA_NAME && VN_INFO (op0)->has_constants)
-             op0 = VN_INFO (op0)->expr;
-           else if (TREE_CODE (op0) == SSA_NAME && SSA_VAL (op0) != op0)
-             op0 = SSA_VAL (op0);
-           result = fold_unary (TREE_CODE (rhs), TREE_TYPE (rhs), op0);
-           if (result)
-             return result;
-         }
+         return simplify_unary_expression (rhs);
          break;
        case tcc_comparison:
        case tcc_binary: