[multiple changes]

2006-10-24  Richard Guenther  <rguenther@suse.de>

	PR middle-end/27132
	PR middle-end/23295
	* builtins.c (fold_binary): Remove checks for flag_wrapv
	and flag_trapv where negate_expr_p covers these cases.

	* gcc.dg/pr27132.c: New testcase.
	* gcc.dg/pr23295.c: Likewise.
	* gcc.dg/tree-ssa/pr23294.c: Adjust patterns.
	* g++.dg/tree-ssa/pr19807.C: Likewise.

2006-10-23  Richard Guenther  <rguenther@suse.de>

	PR middle-end/29548
	* fold-const.c (fold_plusminus_mult_expr): Check exact power
	of two on the absolute value.
	(fold_binary): Fold x * -C to -x * C if x is easily negatable
	and negating -C does not overflow.

From-SVN: r117969

7 files changed, 58 insertions, 7 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 655596d..568ba2e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,20 @@
 2006-10-23  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/27132
+	PR middle-end/23295
+	* builtins.c (fold_binary): Remove checks for flag_wrapv
+	and flag_trapv where negate_expr_p covers these cases.
+
+2006-10-23  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/29548
+	* fold-const.c (fold_plusminus_mult_expr): Check exact power
+	of two on the absolute value.
+	(fold_binary): Fold x * -C to -x * C if x is easily negatable
+	and negating -C does not overflow.
+
+2006-10-23  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/21032
 	* convert.c (convert_to_real): Fold (float)-x to -(float)x
 	only if not flag_rounding_math.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index b04022e..571a7e8 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -6787,7 +6787,7 @@ fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
       else
 	maybe_same = arg11;
 
-      if (exact_log2 (int11) > 0 && int01 % int11 == 0)
+      if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
         {
 	  alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
 			      build_int_cst (TREE_TYPE (arg00),
@@ -8752,7 +8752,7 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
       /* (-A) - B -> (-B) - A  where B is easily negated and we can swap.  */
       if (TREE_CODE (arg0) == NEGATE_EXPR
 	  && (FLOAT_TYPE_P (type)
-	      || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
+	      || INTEGRAL_TYPE_P (type))
 	  && negate_expr_p (arg1)
 	  && reorder_operands_p (arg0, arg1))
 	return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
@@ -8838,7 +8838,7 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
                /* Avoid this transformation if B is a positive REAL_CST.  */
 	       && (TREE_CODE (arg1) != REAL_CST
 		   ||  REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
-	      || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
+	      || INTEGRAL_TYPE_P (type)))
 	return fold_build2 (PLUS_EXPR, type,
 			    fold_convert (type, arg0),
 			    fold_convert (type, negate_expr (arg1)));
@@ -8923,6 +8923,14 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
 	  /* Transform x * -1 into -x.  */
 	  if (integer_all_onesp (arg1))
 	    return fold_convert (type, negate_expr (arg0));
+	  /* Transform x * -C into -x * C if x is easily negatable.  */
+	  if (TREE_CODE (arg1) == INTEGER_CST
+	      && tree_int_cst_sgn (arg1) == -1
+	      && negate_expr_p (arg0)
+	      && (tem = negate_expr (arg1)) != arg1
+	      && !TREE_OVERFLOW (tem))
+	    return fold_build2 (MULT_EXPR, type,
+	    			negate_expr (arg0), tem);
 
 	  /* (a * (1 << b)) is (a << b)  */
 	  if (TREE_CODE (arg1) == LSHIFT_EXPR
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 06d1abc..b8b1c52 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,14 @@
 2006-10-23  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/27132
+	PR middle-end/23295
+	* gcc.dg/pr27132.c: New testcase.
+	* gcc.dg/pr23295.c: Likewise.
+	* gcc.dg/tree-ssa/pr23294.c: Adjust patterns.
+	* g++.dg/tree-ssa/pr19807.C: Likewise.
+
+2006-10-23  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/21032
 	* gcc.dg/pr21032.c: New testcase.
 
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr19807.C b/gcc/testsuite/g++.dg/tree-ssa/pr19807.C
index 0ff10db..d85b8ad 100644
--- a/gcc/testsuite/g++.dg/tree-ssa/pr19807.C
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr19807.C
@@ -19,6 +19,6 @@ void bar(int i)
 }
 
 /* { dg-final { scan-tree-dump-times "&a\\\[2\\\]" 3 "optimized" } } */
-/* { dg-final { scan-tree-dump-times "&a\\\[.* - 1\\\]" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "&a\\\[.* \\+ -1\\\]" 1 "optimized" } } */
 /* { dg-final { scan-tree-dump-times "&a\\\[.* \\+ 1\\\]" 1 "optimized" } } */
 /* { dg-final { cleanup-tree-dump "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/pr23295.c b/gcc/testsuite/gcc.dg/pr23295.c
new file mode 100644
index 0000000..0418964
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr23295.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-fdump-tree-gimple" } */
+
+int foo(int i)
+{
+  return -i - 5;
+}
+
+/* { dg-final { scan-tree-dump "-5 - i" "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
diff --git a/gcc/testsuite/gcc.dg/pr27132.c b/gcc/testsuite/gcc.dg/pr27132.c
new file mode 100644
index 0000000..272862a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr27132.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-fdump-tree-gimple" } */
+
+int foo(int i)
+{
+  return i - -1;
+}
+
+/* { dg-final { scan-tree-dump "i \\+ 1" "gimple" } } */
+/* { dg-final { cleanup-tree-dump "gimple" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr23294.c b/gcc/testsuite/gcc.dg/tree-ssa/pr23294.c
index 35ab578..d73512d 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr23294.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr23294.c
@@ -32,7 +32,6 @@ int f6(int a, int b)
 }
 
 /* { dg-final { scan-tree-dump-times "a \\\* 5" 3 "optimized" } } */
-/* { dg-final { scan-tree-dump "\\\(b \\\* 3 \\\+ a\\\) \\\* 2" "optimized" } } */
-/* { dg-final { scan-tree-dump "\\\(a - b \\\* 3\\\) \\\* 2" "optimized" } } */
-/* { dg-final { scan-tree-dump "\\\(a \\\* 3 - b\\\) \\\* 2" "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\\) \\\* 2" 3 "optimized" } } */
+/* { dg-final { scan-tree-dump-not "\\\* 6" "optimized" } } */
 /* { dg-final { cleanup-tree-dump "optimized" } } */