match.pd: Three new patterns

match.pd: Three new patterns

[Marek Polacek]

This patch brings three new patterns for match.pd.  I think these are
rare, but it shouldn't hurt to have them.
(I suppose you'd be happier if I was moving patterns from fold-const to
match.pd.  I'll work on that as well.)

Given previous discussion, I don't think there's much to say otherwise,
but I'd appreciate if someone could glance over this.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-06-12  Marek Polacek  <polacek@redhat.com>

	* match.pd ((x & y) + (x ^ y) -> x | y,
	(x & y) + (x | y) -> x + y,
	(x | y) - (x ^ y) -> x & y): New patterns.

	* gcc.dg/fold-plus-1.c: New test.
	* gcc.dg/fold-plus-2.c: New test.
	* gcc.dg/fold-minus-2.c: New test.

--- gcc/match.pd
+++ gcc/match.pd
@@ -325,6 +325,21 @@ along with GCC; see the file COPYING3.  If not see
  (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
  (bit_xor @0 @1))
 
+/* (x & y) + (x ^ y) -> x | y */
+(simplify
+ (plus:c (bit_and @0 @1) (bit_xor @0 @1))
+ (bit_ior @0 @1))
+
+/* (x & y) + (x | y) -> x + y */
+(simplify
+ (plus:c (bit_and @0 @1) (bit_ior @0 @1))
+ (plus @0 @1))
+
+/* (x | y) - (x ^ y) -> x & y */
+(simplify
+ (minus (bit_ior @0 @1) (bit_xor @0 @1))
+ (bit_and @0 @1))
+
 (simplify
  (abs (negate @0))
  (abs @0))
--- gcc/testsuite/gcc.dg/fold-plus-1.c
+++ gcc/testsuite/gcc.dg/fold-plus-1.c
@@ -0,0 +1,70 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
--- gcc/testsuite/gcc.dg/fold-plus-2.c
+++ gcc/testsuite/gcc.dg/fold-plus-2.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
--- gcc/testsuite/gcc.dg/fold-minus-2.c
+++ gcc/testsuite/gcc.dg/fold-minus-2.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */

	Marek

Re: match.pd: Three new patterns

[Marc Glisse]

They look fine to me.

> +/* (x & y) + (x ^ y) -> x | y */

This also works if you replace + with | or ^.

> +/* (x | y) - (x ^ y) -> x & y */

For symmetry, you probably also want:
(x | y) - (x & y) -> x ^ y

(they both also work with ^ instead of -)

> +/* (x & y) + (x | y) -> x + y */

Again for symmetry, it seems like this comes with
x + y - (x | y) -> x & y
x + y - (x & y) -> x | y
which seem fine when overflow is undefined or wraps, but not if for 
instance it saturates.

-- 
Marc Glisse

Re: match.pd: Three new patterns

[Richard Biener]

On Sat, 13 Jun 2015, Marc Glisse wrote:

> They look fine to me.
> 
> > +/* (x & y) + (x ^ y) -> x | y */
> 
> This also works if you replace + with | or ^.
>
> > +/* (x | y) - (x ^ y) -> x & y */
> 
> For symmetry, you probably also want:
> (x | y) - (x & y) -> x ^ y
> 
> (they both also work with ^ instead of -)

We already have

/* (x & y) ^ (x | y) -> x ^ y */
(simplify
 (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
 (bit_xor @0 @1))

but of course with minus it doesn't commutate so it's hard to
merge.

> > +/* (x & y) + (x | y) -> x + y */
> 
> Again for symmetry, it seems like this comes with
> x + y - (x | y) -> x & y
> x + y - (x & y) -> x | y
> which seem fine when overflow is undefined or wraps, but not if for instance
> it saturates.

Can you adjust according to Marcs comment and re-submit?  If you like
you can do it as followup as well and thus the original patch is ok
as well.

Thanks,
Richard.

Re: match.pd: Three new patterns

[Marek Polacek]

On Sat, Jun 13, 2015 at 12:05:42PM +0200, Marc Glisse wrote:
> They look fine to me.

Thanks!
 
> >+/* (x & y) + (x ^ y) -> x | y */
> 
> This also works if you replace + with | or ^.

Done.
 
> >+/* (x | y) - (x ^ y) -> x & y */
> 
> For symmetry, you probably also want:
> (x | y) - (x & y) -> x ^ y
 
Done.

> (they both also work with ^ instead of -)

Done (except (x & y) ^ (x | y) -> x ^ y which we already have).

> >+/* (x & y) + (x | y) -> x + y */
> 
> Again for symmetry, it seems like this comes with
> x + y - (x | y) -> x & y
> x + y - (x & y) -> x | y
> which seem fine when overflow is undefined or wraps, but not if for instance
> it saturates.

I'll leave this as a follow-up.

Testing a new patch.  Thanks again.

	Marek

Re: match.pd: Three new patterns (and some more)

[Marek Polacek]

On Tue, Jun 16, 2015 at 03:35:15PM +0200, Richard Biener wrote:
> We already have
> 
> /* (x & y) ^ (x | y) -> x ^ y */
> (simplify
>  (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
>  (bit_xor @0 @1))
> 
> but of course with minus it doesn't commutate so it's hard to
> merge.

Yeah :(.
 
> > > +/* (x & y) + (x | y) -> x + y */
> > 
> > Again for symmetry, it seems like this comes with
> > x + y - (x | y) -> x & y
> > x + y - (x & y) -> x | y
> > which seem fine when overflow is undefined or wraps, but not if for instance
> > it saturates.
> 
> Can you adjust according to Marcs comment and re-submit?  If you like
> you can do it as followup as well and thus the original patch is ok
> as well.

Sure.  This is a new version with some more patters.  Thanks.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-06-18  Marek Polacek  <polacek@redhat.com>

	* match.pd ((x ^ y) ^ (x | y) -> x & y,
	(x & y) + (x ^ y) -> x | y, (x & y) | (x ^ y) -> x | y,
	(x & y) ^ (x ^ y) -> x | y, (x & y) + (x | y) -> x + y,
	(x | y) - (x ^ y) -> x & y, (x | y) - (x & y) -> x ^ y): New patterns.

	* gcc.dg/fold-ior-1.c: New test.
	* gcc.dg/fold-minus-2.c: New test.
	* gcc.dg/fold-minus-3.c: New test.
	* gcc.dg/fold-plus-1.c: New test.
	* gcc.dg/fold-plus-2.c: New test.
	* gcc.dg/fold-xor-4.c: New test.
	* gcc.dg/fold-xor-5.c: New test.

diff --git gcc/match.pd gcc/match.pd
index 1ab2b1c..badb80a 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -325,6 +325,34 @@ along with GCC; see the file COPYING3.  If not see
  (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
  (bit_xor @0 @1))
 
+/* (x ^ y) ^ (x | y) -> x & y */
+(simplify
+ (bit_xor:c (bit_xor @0 @1) (bit_ior @0 @1))
+ (bit_and @0 @1))
+
+/* (x & y) + (x ^ y) -> x | y */
+/* (x & y) | (x ^ y) -> x | y */
+/* (x & y) ^ (x ^ y) -> x | y */
+(for op (plus bit_ior bit_xor)
+ (simplify
+  (op:c (bit_and @0 @1) (bit_xor @0 @1))
+  (bit_ior @0 @1)))
+
+/* (x & y) + (x | y) -> x + y */
+(simplify
+ (plus:c (bit_and @0 @1) (bit_ior @0 @1))
+ (plus @0 @1))
+
+/* (x | y) - (x ^ y) -> x & y */
+(simplify
+ (minus (bit_ior @0 @1) (bit_xor @0 @1))
+ (bit_and @0 @1))
+
+/* (x | y) - (x & y) -> x ^ y */
+(simplify
+ (minus (bit_ior @0 @1) (bit_and @0 @1))
+ (bit_xor @0 @1))
+
 (simplify
  (abs (negate @0))
  (abs @0))
diff --git gcc/testsuite/gcc.dg/fold-ior-1.c gcc/testsuite/gcc.dg/fold-ior-1.c
index e69de29..0358eb5 100644
--- gcc/testsuite/gcc.dg/fold-ior-1.c
+++ gcc/testsuite/gcc.dg/fold-ior-1.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a ^ b;
+  return tem1 | tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a ^ b;
+  return tem1 | tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b ^ a;
+  return tem1 | tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b ^ a;
+  return tem1 | tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a & b;
+  return tem1 | tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a & b;
+  return tem1 | tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b & a;
+  return tem1 | tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b & a;
+  return tem1 | tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-minus-2.c gcc/testsuite/gcc.dg/fold-minus-2.c
index e69de29..6501f2f 100644
--- gcc/testsuite/gcc.dg/fold-minus-2.c
+++ gcc/testsuite/gcc.dg/fold-minus-2.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-minus-3.c gcc/testsuite/gcc.dg/fold-minus-3.c
index e69de29..e7adce6 100644
--- gcc/testsuite/gcc.dg/fold-minus-3.c
+++ gcc/testsuite/gcc.dg/fold-minus-3.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-plus-1.c gcc/testsuite/gcc.dg/fold-plus-1.c
index e69de29..40d6aa2 100644
--- gcc/testsuite/gcc.dg/fold-plus-1.c
+++ gcc/testsuite/gcc.dg/fold-plus-1.c
@@ -0,0 +1,70 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-plus-2.c gcc/testsuite/gcc.dg/fold-plus-2.c
index e69de29..713abf6 100644
--- gcc/testsuite/gcc.dg/fold-plus-2.c
+++ gcc/testsuite/gcc.dg/fold-plus-2.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-xor-4.c gcc/testsuite/gcc.dg/fold-xor-4.c
index e69de29..b5a2c48 100644
--- gcc/testsuite/gcc.dg/fold-xor-4.c
+++ gcc/testsuite/gcc.dg/fold-xor-4.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a ^ b;
+  return tem1 ^ tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a ^ b;
+  return tem1 ^ tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b ^ a;
+  return tem1 ^ tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b ^ a;
+  return tem1 ^ tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a & b;
+  return tem1 ^ tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a & b;
+  return tem1 ^ tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b & a;
+  return tem1 ^ tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b & a;
+  return tem1 ^ tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-xor-5.c gcc/testsuite/gcc.dg/fold-xor-5.c
index e69de29..15ee76c 100644
--- gcc/testsuite/gcc.dg/fold-xor-5.c
+++ gcc/testsuite/gcc.dg/fold-xor-5.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a ^ b;
+  return tem1 ^ tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a ^ b;
+  return tem1 ^ tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b ^ a;
+  return tem1 ^ tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b ^ a;
+  return tem1 ^ tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a | b;
+  return tem1 ^ tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a | b;
+  return tem1 ^ tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b | a;
+  return tem1 ^ tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b | a;
+  return tem1 ^ tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */


	Marek

Re: match.pd: Three new patterns

[Marek Polacek]

On Thu, Jun 18, 2015 at 05:41:18PM +0200, Marek Polacek wrote:
> > Again for symmetry, it seems like this comes with
> > x + y - (x | y) -> x & y
> > x + y - (x & y) -> x | y
> > which seem fine when overflow is undefined or wraps, but not if for instance
> > it saturates.
> 
> I'll leave this as a follow-up.

...here.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-06-19  Marek Polacek  <polacek@redhat.com>

	* match.pd (x + y - (x | y) -> x & y,
	(x + y) - (x & y) -> x | y): New patterns.

	* gcc.dg/fold-minus-4.c: New test.
	* gcc.dg/fold-minus-5.c: New test.

diff --git gcc/match.pd gcc/match.pd
index badb80a..61ff710 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -343,6 +343,18 @@ along with GCC; see the file COPYING3.  If not see
  (plus:c (bit_and @0 @1) (bit_ior @0 @1))
  (plus @0 @1))
 
+/* x + y - (x | y) -> x & y */
+(simplify
+ (minus (plus @0 @1) (bit_ior @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
+  (bit_and @0 @1)))
+
+/* (x + y) - (x & y) -> x | y */
+(simplify
+ (minus (plus @0 @1) (bit_and @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
+  (bit_ior @0 @1)))
+
 /* (x | y) - (x ^ y) -> x & y */
 (simplify
  (minus (bit_ior @0 @1) (bit_xor @0 @1))
diff --git gcc/testsuite/gcc.dg/fold-minus-4.c gcc/testsuite/gcc.dg/fold-minus-4.c
index e69de29..2d76b4f 100644
--- gcc/testsuite/gcc.dg/fold-minus-4.c
+++ gcc/testsuite/gcc.dg/fold-minus-4.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-minus-5.c gcc/testsuite/gcc.dg/fold-minus-5.c
index e69de29..a31e1cc 100644
--- gcc/testsuite/gcc.dg/fold-minus-5.c
+++ gcc/testsuite/gcc.dg/fold-minus-5.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */

	Marek

Re: match.pd: Three new patterns

[Marc Glisse]

On Fri, 19 Jun 2015, Marek Polacek wrote:

> +/* x + y - (x | y) -> x & y */
> +(simplify
> + (minus (plus @0 @1) (bit_ior @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> +  (bit_and @0 @1)))
> +
> +/* (x + y) - (x & y) -> x | y */
> +(simplify
> + (minus (plus @0 @1) (bit_and @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> +  (bit_ior @0 @1)))

It could be macroized so they are handled by the same piece of code, but 
that's not important for a couple lines.

As far as I can tell, TYPE_SATURATING is for fixed point numbers only, are 
we allowed to use bit_ior/bit_and on those? I never know what kind of 
integers are supposed to be supported, so I would have checked 
TYPE_OVERFLOW_UNDEFINED (type) || TYPE_OVERFLOW_WRAPS (type) since those 
are the 2 cases where we know it is safe (for TYPE_OVERFLOW_TRAPS it is 
never clear if we are supposed to preserve traps or just avoid introducing 
new ones). Well, the reviewer will know, I'll shut up :-)

(I still believe that the necessity for TYPE_OVERFLOW_SANITIZED here 
points to a design issue in ubsan, but it is way too late to discuss that)

It is probably not worth the trouble adding the variant:
x+(y-(x&y)) -> x|y
since it decomposes as
y-(x&y) -> y&~x
x+(y&~x) -> x|y
x+(y-(x|y)) -> x-(x&~y) -> x&y is less likely to happen because the first 
transform y-(x|y) -> -(x&~y) increases the number of insns. Bah, we can't 
handle everything...

-- 
Marc Glisse

Re: match.pd: Three new patterns (and some more)

[Richard Biener]

On Thu, 18 Jun 2015, Marek Polacek wrote:

> On Tue, Jun 16, 2015 at 03:35:15PM +0200, Richard Biener wrote:
> > We already have
> > 
> > /* (x & y) ^ (x | y) -> x ^ y */
> > (simplify
> >  (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
> >  (bit_xor @0 @1))
> > 
> > but of course with minus it doesn't commutate so it's hard to
> > merge.
> 
> Yeah :(.
>  
> > > > +/* (x & y) + (x | y) -> x + y */
> > > 
> > > Again for symmetry, it seems like this comes with
> > > x + y - (x | y) -> x & y
> > > x + y - (x & y) -> x | y
> > > which seem fine when overflow is undefined or wraps, but not if for instance
> > > it saturates.
> > 
> > Can you adjust according to Marcs comment and re-submit?  If you like
> > you can do it as followup as well and thus the original patch is ok
> > as well.
> 
> Sure.  This is a new version with some more patters.  Thanks.
> 
> Bootstrapped/regtested on x86_64-linux, ok for trunk?

Ok.

Thanks,
Richard.

> 2015-06-18  Marek Polacek  <polacek@redhat.com>
> 
> 	* match.pd ((x ^ y) ^ (x | y) -> x & y,
> 	(x & y) + (x ^ y) -> x | y, (x & y) | (x ^ y) -> x | y,
> 	(x & y) ^ (x ^ y) -> x | y, (x & y) + (x | y) -> x + y,
> 	(x | y) - (x ^ y) -> x & y, (x | y) - (x & y) -> x ^ y): New patterns.
> 
> 	* gcc.dg/fold-ior-1.c: New test.
> 	* gcc.dg/fold-minus-2.c: New test.
> 	* gcc.dg/fold-minus-3.c: New test.
> 	* gcc.dg/fold-plus-1.c: New test.
> 	* gcc.dg/fold-plus-2.c: New test.
> 	* gcc.dg/fold-xor-4.c: New test.
> 	* gcc.dg/fold-xor-5.c: New test.
> 
> diff --git gcc/match.pd gcc/match.pd
> index 1ab2b1c..badb80a 100644
> --- gcc/match.pd
> +++ gcc/match.pd
> @@ -325,6 +325,34 @@ along with GCC; see the file COPYING3.  If not see
>   (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
>   (bit_xor @0 @1))
>  
> +/* (x ^ y) ^ (x | y) -> x & y */
> +(simplify
> + (bit_xor:c (bit_xor @0 @1) (bit_ior @0 @1))
> + (bit_and @0 @1))
> +
> +/* (x & y) + (x ^ y) -> x | y */
> +/* (x & y) | (x ^ y) -> x | y */
> +/* (x & y) ^ (x ^ y) -> x | y */
> +(for op (plus bit_ior bit_xor)
> + (simplify
> +  (op:c (bit_and @0 @1) (bit_xor @0 @1))
> +  (bit_ior @0 @1)))
> +
> +/* (x & y) + (x | y) -> x + y */
> +(simplify
> + (plus:c (bit_and @0 @1) (bit_ior @0 @1))
> + (plus @0 @1))
> +
> +/* (x | y) - (x ^ y) -> x & y */
> +(simplify
> + (minus (bit_ior @0 @1) (bit_xor @0 @1))
> + (bit_and @0 @1))
> +
> +/* (x | y) - (x & y) -> x ^ y */
> +(simplify
> + (minus (bit_ior @0 @1) (bit_and @0 @1))
> + (bit_xor @0 @1))
> +
>  (simplify
>   (abs (negate @0))
>   (abs @0))
> diff --git gcc/testsuite/gcc.dg/fold-ior-1.c gcc/testsuite/gcc.dg/fold-ior-1.c
> index e69de29..0358eb5 100644
> --- gcc/testsuite/gcc.dg/fold-ior-1.c
> +++ gcc/testsuite/gcc.dg/fold-ior-1.c
> @@ -0,0 +1,69 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = a ^ b;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = a ^ b;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = b ^ a;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = b ^ a;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn5 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = a & b;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn6 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = a & b;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn7 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = b & a;
> +  return tem1 | tem2;
> +}
> +
> +int
> +fn8 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = b & a;
> +  return tem1 | tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-minus-2.c gcc/testsuite/gcc.dg/fold-minus-2.c
> index e69de29..6501f2f 100644
> --- gcc/testsuite/gcc.dg/fold-minus-2.c
> +++ gcc/testsuite/gcc.dg/fold-minus-2.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = a ^ b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = a ^ b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = b ^ a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = b ^ a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-minus-3.c gcc/testsuite/gcc.dg/fold-minus-3.c
> index e69de29..e7adce6 100644
> --- gcc/testsuite/gcc.dg/fold-minus-3.c
> +++ gcc/testsuite/gcc.dg/fold-minus-3.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-plus-1.c gcc/testsuite/gcc.dg/fold-plus-1.c
> index e69de29..40d6aa2 100644
> --- gcc/testsuite/gcc.dg/fold-plus-1.c
> +++ gcc/testsuite/gcc.dg/fold-plus-1.c
> @@ -0,0 +1,70 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = a ^ b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = a ^ b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = b ^ a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = b ^ a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn5 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = a & b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn6 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = a & b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn7 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = b & a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn8 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = b & a;
> +  return tem1 + tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-plus-2.c gcc/testsuite/gcc.dg/fold-plus-2.c
> index e69de29..713abf6 100644
> --- gcc/testsuite/gcc.dg/fold-plus-2.c
> +++ gcc/testsuite/gcc.dg/fold-plus-2.c
> @@ -0,0 +1,69 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = a | b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = a | b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = b | a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = b | a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn5 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = a & b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn6 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = a & b;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn7 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = b & a;
> +  return tem1 + tem2;
> +}
> +
> +int
> +fn8 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = b & a;
> +  return tem1 + tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-xor-4.c gcc/testsuite/gcc.dg/fold-xor-4.c
> index e69de29..b5a2c48 100644
> --- gcc/testsuite/gcc.dg/fold-xor-4.c
> +++ gcc/testsuite/gcc.dg/fold-xor-4.c
> @@ -0,0 +1,69 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = a ^ b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = a ^ b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a & b;
> +  int tem2 = b ^ a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b & a;
> +  int tem2 = b ^ a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn5 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = a & b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn6 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = a & b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn7 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = b & a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn8 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = b & a;
> +  return tem1 ^ tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-xor-5.c gcc/testsuite/gcc.dg/fold-xor-5.c
> index e69de29..15ee76c 100644
> --- gcc/testsuite/gcc.dg/fold-xor-5.c
> +++ gcc/testsuite/gcc.dg/fold-xor-5.c
> @@ -0,0 +1,69 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = a ^ b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = a ^ b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a | b;
> +  int tem2 = b ^ a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b | a;
> +  int tem2 = b ^ a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn5 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = a | b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn6 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = a | b;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn7 (int a, int b)
> +{
> +  int tem1 = a ^ b;
> +  int tem2 = b | a;
> +  return tem1 ^ tem2;
> +}
> +
> +int
> +fn8 (int a, int b)
> +{
> +  int tem1 = b ^ a;
> +  int tem2 = b | a;
> +  return tem1 ^ tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
> 
> 
> 	Marek
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)

Re: match.pd: Three new patterns

[Richard Biener]

On Fri, 19 Jun 2015, Marek Polacek wrote:

> On Thu, Jun 18, 2015 at 05:41:18PM +0200, Marek Polacek wrote:
> > > Again for symmetry, it seems like this comes with
> > > x + y - (x | y) -> x & y
> > > x + y - (x & y) -> x | y
> > > which seem fine when overflow is undefined or wraps, but not if for instance
> > > it saturates.
> > 
> > I'll leave this as a follow-up.
> 
> ...here.
> 
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
> 
> 2015-06-19  Marek Polacek  <polacek@redhat.com>
> 
> 	* match.pd (x + y - (x | y) -> x & y,

) missing

> 	(x + y) - (x & y) -> x | y): New patterns.
> 
> 	* gcc.dg/fold-minus-4.c: New test.
> 	* gcc.dg/fold-minus-5.c: New test.
> 
> diff --git gcc/match.pd gcc/match.pd
> index badb80a..61ff710 100644
> --- gcc/match.pd
> +++ gcc/match.pd
> @@ -343,6 +343,18 @@ along with GCC; see the file COPYING3.  If not see
>   (plus:c (bit_and @0 @1) (bit_ior @0 @1))
>   (plus @0 @1))
>  
> +/* x + y - (x | y) -> x & y */

Please wrap x + y in () here as well.

Ok with that changes.

Thanks,
Richard.

> +(simplify
> + (minus (plus @0 @1) (bit_ior @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> +  (bit_and @0 @1)))
> +
> +/* (x + y) - (x & y) -> x | y */
> +(simplify
> + (minus (plus @0 @1) (bit_and @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> +  (bit_ior @0 @1)))
> +
>  /* (x | y) - (x ^ y) -> x & y */
>  (simplify
>   (minus (bit_ior @0 @1) (bit_xor @0 @1))
> diff --git gcc/testsuite/gcc.dg/fold-minus-4.c gcc/testsuite/gcc.dg/fold-minus-4.c
> index e69de29..2d76b4f 100644
> --- gcc/testsuite/gcc.dg/fold-minus-4.c
> +++ gcc/testsuite/gcc.dg/fold-minus-4.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-minus-5.c gcc/testsuite/gcc.dg/fold-minus-5.c
> index e69de29..a31e1cc 100644
> --- gcc/testsuite/gcc.dg/fold-minus-5.c
> +++ gcc/testsuite/gcc.dg/fold-minus-5.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = a | b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = a | b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = b | a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = b | a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> 
> 	Marek
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)

Re: match.pd: Three new patterns

[Marek Polacek]

On Fri, Jun 19, 2015 at 05:51:53PM +0200, Marc Glisse wrote:
> On Fri, 19 Jun 2015, Marek Polacek wrote:
> 
> >+/* x + y - (x | y) -> x & y */
> >+(simplify
> >+ (minus (plus @0 @1) (bit_ior @0 @1))
> >+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> >+  (bit_and @0 @1)))
> >+
> >+/* (x + y) - (x & y) -> x | y */
> >+(simplify
> >+ (minus (plus @0 @1) (bit_and @0 @1))
> >+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> >+  (bit_ior @0 @1)))
> 
> It could be macroized so they are handled by the same piece of code, but
> that's not important for a couple lines.
 
Yeah, that could be done, but I didn't see much value in doing that.

> As far as I can tell, TYPE_SATURATING is for fixed point numbers only, are
> we allowed to use bit_ior/bit_and on those? I never know what kind of
> integers are supposed to be supported, so I would have checked
> TYPE_OVERFLOW_UNDEFINED (type) || TYPE_OVERFLOW_WRAPS (type) since those are
> the 2 cases where we know it is safe (for TYPE_OVERFLOW_TRAPS it is never
> clear if we are supposed to preserve traps or just avoid introducing new
> ones). Well, the reviewer will know, I'll shut up :-)
 
I think you're right about TYPE_SATURATING so I've dropped that and instead
replaced it with TYPE_OVERFLOW_TRAPS.  That should do the right thing
together with TYPE_OVERFLOW_SANITIZED.

> (I still believe that the necessity for TYPE_OVERFLOW_SANITIZED here points
> to a design issue in ubsan, but it is way too late to discuss that)

I think delayed folding would help here a bit.  Also, we've been talking
about doing the signed overflow sanitization earlier, but so far I didn't
implement that.  And -ftrapv should be merged into the ubsan infrastructure
some day.

> It is probably not worth the trouble adding the variant:
> x+(y-(x&y)) -> x|y
> since it decomposes as
> y-(x&y) -> y&~x
> x+(y&~x) -> x|y
> x+(y-(x|y)) -> x-(x&~y) -> x&y is less likely to happen because the first
> transform y-(x|y) -> -(x&~y) increases the number of insns. Bah, we can't
> handle everything...

That sounds about right ;).  Thanks!

So, Richi, is this variant ok as well?  I also added one ubsan test.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-06-22  Marek Polacek  <polacek@redhat.com>

	* match.pd ((x + y) - (x | y) -> x & y,
	(x + y) - (x & y) -> x | y): New patterns.

	* gcc.dg/fold-minus-4.c: New test.
	* gcc.dg/fold-minus-5.c: New test.
	* c-c++-common/ubsan/overflow-add-5.c: New test.

diff --git gcc/match.pd gcc/match.pd
index badb80a..6d520ef 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -343,6 +343,18 @@ along with GCC; see the file COPYING3.  If not see
  (plus:c (bit_and @0 @1) (bit_ior @0 @1))
  (plus @0 @1))
 
+/* (x + y) - (x | y) -> x & y */
+(simplify
+ (minus (plus @0 @1) (bit_ior @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type))
+  (bit_and @0 @1)))
+
+/* (x + y) - (x & y) -> x | y */
+(simplify
+ (minus (plus @0 @1) (bit_and @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type))
+  (bit_ior @0 @1)))
+
 /* (x | y) - (x ^ y) -> x & y */
 (simplify
  (minus (bit_ior @0 @1) (bit_xor @0 @1))
diff --git gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
index e69de29..905a60a 100644
--- gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
+++ gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=signed-integer-overflow" } */
+
+int __attribute__ ((noinline))
+foo (int i, int j)
+{
+  return (i + j) - (i | j);
+}
+
+/* { dg-output "signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 2147483647 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+
+int __attribute__ ((noinline))
+bar (int i, int j)
+{
+  return (i + j) - (i & j);
+}
+
+/* { dg-output "\[^\n\r]*signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'" } */
+
+int
+main ()
+{
+  int r = foo (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  r = bar (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  return 0;
+}
diff --git gcc/testsuite/gcc.dg/fold-minus-4.c gcc/testsuite/gcc.dg/fold-minus-4.c
index e69de29..2d76b4f 100644
--- gcc/testsuite/gcc.dg/fold-minus-4.c
+++ gcc/testsuite/gcc.dg/fold-minus-4.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-minus-5.c gcc/testsuite/gcc.dg/fold-minus-5.c
index e69de29..a31e1cc 100644
--- gcc/testsuite/gcc.dg/fold-minus-5.c
+++ gcc/testsuite/gcc.dg/fold-minus-5.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */

	Marek

Re: match.pd: Three new patterns

[Richard Biener]

On Mon, 22 Jun 2015, Marek Polacek wrote:

> On Fri, Jun 19, 2015 at 05:51:53PM +0200, Marc Glisse wrote:
> > On Fri, 19 Jun 2015, Marek Polacek wrote:
> > 
> > >+/* x + y - (x | y) -> x & y */
> > >+(simplify
> > >+ (minus (plus @0 @1) (bit_ior @0 @1))
> > >+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> > >+  (bit_and @0 @1)))
> > >+
> > >+/* (x + y) - (x & y) -> x | y */
> > >+(simplify
> > >+ (minus (plus @0 @1) (bit_and @0 @1))
> > >+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_SATURATING (type))
> > >+  (bit_ior @0 @1)))
> > 
> > It could be macroized so they are handled by the same piece of code, but
> > that's not important for a couple lines.
>  
> Yeah, that could be done, but I didn't see much value in doing that.
> 
> > As far as I can tell, TYPE_SATURATING is for fixed point numbers only, are
> > we allowed to use bit_ior/bit_and on those? I never know what kind of
> > integers are supposed to be supported, so I would have checked
> > TYPE_OVERFLOW_UNDEFINED (type) || TYPE_OVERFLOW_WRAPS (type) since those are
> > the 2 cases where we know it is safe (for TYPE_OVERFLOW_TRAPS it is never
> > clear if we are supposed to preserve traps or just avoid introducing new
> > ones). Well, the reviewer will know, I'll shut up :-)
>  
> I think you're right about TYPE_SATURATING so I've dropped that and instead
> replaced it with TYPE_OVERFLOW_TRAPS.  That should do the right thing
> together with TYPE_OVERFLOW_SANITIZED.

Are you sure?  The point is that if the minus or the plus in the original
expression saturate the result isn't correct, no?

> > (I still believe that the necessity for TYPE_OVERFLOW_SANITIZED here points
> > to a design issue in ubsan, but it is way too late to discuss that)
> 
> I think delayed folding would help here a bit.  Also, we've been talking
> about doing the signed overflow sanitization earlier, but so far I didn't
> implement that.  And -ftrapv should be merged into the ubsan infrastructure
> some day.
> 
> > It is probably not worth the trouble adding the variant:
> > x+(y-(x&y)) -> x|y
> > since it decomposes as
> > y-(x&y) -> y&~x
> > x+(y&~x) -> x|y
> > x+(y-(x|y)) -> x-(x&~y) -> x&y is less likely to happen because the first
> > transform y-(x|y) -> -(x&~y) increases the number of insns. Bah, we can't
> > handle everything...
> 
> That sounds about right ;).  Thanks!
> 
> So, Richi, is this variant ok as well?  I also added one ubsan test.

As said, removing TYPE_SATURATING doesn't sound correct.  I'm not sure
about TYPE_OVERFLOW_TRAPS - we're certainly removing traps elsewhere
(look for the scarce use of this flag in fold-const.c and match.pd
where I only preserved those that were originally in fold-const.c).

So, TYPE_OVERFLOW_TRAPS is your choice but TYPE_SATURATING is
required IMHO.

Richard.

> Bootstrapped/regtested on x86_64-linux, ok for trunk?
> 
> 2015-06-22  Marek Polacek  <polacek@redhat.com>
> 
> 	* match.pd ((x + y) - (x | y) -> x & y,
> 	(x + y) - (x & y) -> x | y): New patterns.
> 
> 	* gcc.dg/fold-minus-4.c: New test.
> 	* gcc.dg/fold-minus-5.c: New test.
> 	* c-c++-common/ubsan/overflow-add-5.c: New test.
> 
> diff --git gcc/match.pd gcc/match.pd
> index badb80a..6d520ef 100644
> --- gcc/match.pd
> +++ gcc/match.pd
> @@ -343,6 +343,18 @@ along with GCC; see the file COPYING3.  If not see
>   (plus:c (bit_and @0 @1) (bit_ior @0 @1))
>   (plus @0 @1))
>  
> +/* (x + y) - (x | y) -> x & y */
> +(simplify
> + (minus (plus @0 @1) (bit_ior @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type))
> +  (bit_and @0 @1)))
> +
> +/* (x + y) - (x & y) -> x | y */
> +(simplify
> + (minus (plus @0 @1) (bit_and @0 @1))
> + (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type))
> +  (bit_ior @0 @1)))
> +
>  /* (x | y) - (x ^ y) -> x & y */
>  (simplify
>   (minus (bit_ior @0 @1) (bit_xor @0 @1))
> diff --git gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
> index e69de29..905a60a 100644
> --- gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
> +++ gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
> @@ -0,0 +1,30 @@
> +/* { dg-do run } */
> +/* { dg-options "-fsanitize=signed-integer-overflow" } */
> +
> +int __attribute__ ((noinline))
> +foo (int i, int j)
> +{
> +  return (i + j) - (i | j);
> +}
> +
> +/* { dg-output "signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 2147483647 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
> +
> +int __attribute__ ((noinline))
> +bar (int i, int j)
> +{
> +  return (i + j) - (i & j);
> +}
> +
> +/* { dg-output "\[^\n\r]*signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
> +/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'" } */
> +
> +int
> +main ()
> +{
> +  int r = foo (__INT_MAX__, 1);
> +  asm volatile ("" : "+g" (r));
> +  r = bar (__INT_MAX__, 1);
> +  asm volatile ("" : "+g" (r));
> +  return 0;
> +}
> diff --git gcc/testsuite/gcc.dg/fold-minus-4.c gcc/testsuite/gcc.dg/fold-minus-4.c
> index e69de29..2d76b4f 100644
> --- gcc/testsuite/gcc.dg/fold-minus-4.c
> +++ gcc/testsuite/gcc.dg/fold-minus-4.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = a & b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = b & a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
> diff --git gcc/testsuite/gcc.dg/fold-minus-5.c gcc/testsuite/gcc.dg/fold-minus-5.c
> index e69de29..a31e1cc 100644
> --- gcc/testsuite/gcc.dg/fold-minus-5.c
> +++ gcc/testsuite/gcc.dg/fold-minus-5.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-cddce1" } */
> +
> +int
> +fn1 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = a | b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn2 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = a | b;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn3 (int a, int b)
> +{
> +  int tem1 = a + b;
> +  int tem2 = b | a;
> +  return tem1 - tem2;
> +}
> +
> +int
> +fn4 (int a, int b)
> +{
> +  int tem1 = b + a;
> +  int tem2 = b | a;
> +  return tem1 - tem2;
> +}
> +
> +/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
> +/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
> 
> 	Marek
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)

Re: match.pd: Three new patterns

[Marek Polacek]

On Tue, Jun 23, 2015 at 09:56:33AM +0200, Richard Biener wrote:
> > I think you're right about TYPE_SATURATING so I've dropped that and instead
> > replaced it with TYPE_OVERFLOW_TRAPS.  That should do the right thing
> > together with TYPE_OVERFLOW_SANITIZED.
> 
> Are you sure?  The point is that if the minus or the plus in the original
> expression saturate the result isn't correct, no?
 
Yes, but I thought that TYPE_SATURATING is only true for fixed-point, i.e.
those _Accum/_Sat/_Fract (?), and you can't do bitwise & or | on them, which
means that the TYPE_SATURATING check wouldn't be necessary.

> As said, removing TYPE_SATURATING doesn't sound correct.  I'm not sure
> about TYPE_OVERFLOW_TRAPS - we're certainly removing traps elsewhere
> (look for the scarce use of this flag in fold-const.c and match.pd
> where I only preserved those that were originally in fold-const.c).
> 
> So, TYPE_OVERFLOW_TRAPS is your choice but TYPE_SATURATING is
> required IMHO.

Ok, I guess I'll add TYPE_SATURATING back, even though I'm not clear
on that one, and commit.

Thanks,

	Marek

Re: match.pd: Three new patterns

[Richard Biener]

On Tue, 23 Jun 2015, Marek Polacek wrote:

> On Tue, Jun 23, 2015 at 09:56:33AM +0200, Richard Biener wrote:
> > > I think you're right about TYPE_SATURATING so I've dropped that and instead
> > > replaced it with TYPE_OVERFLOW_TRAPS.  That should do the right thing
> > > together with TYPE_OVERFLOW_SANITIZED.
> > 
> > Are you sure?  The point is that if the minus or the plus in the original
> > expression saturate the result isn't correct, no?
>  
> Yes, but I thought that TYPE_SATURATING is only true for fixed-point, i.e.
> those _Accum/_Sat/_Fract (?), and you can't do bitwise & or | on them, which
> means that the TYPE_SATURATING check wouldn't be necessary.

Who says you can't do bitwise ops on them?  I can't see that being
enforced in the GIMPLE checking in tree-cfg.c.  Yes, there is no
such thing as a "saturating" bitwise and but bitwise and should
just work fine.

You can check with a arm cross what the C FE does when you use
bitwise ops but I believe the regular and/ior md patterns work
just fine (there are no special modes/registers but they seem
to be shared with regular registers, just special operations
are available).

Richard.

> 
> > As said, removing TYPE_SATURATING doesn't sound correct.  I'm not sure
> > about TYPE_OVERFLOW_TRAPS - we're certainly removing traps elsewhere
> > (look for the scarce use of this flag in fold-const.c and match.pd
> > where I only preserved those that were originally in fold-const.c).
> > 
> > So, TYPE_OVERFLOW_TRAPS is your choice but TYPE_SATURATING is
> > required IMHO.
> 
> Ok, I guess I'll add TYPE_SATURATING back, even though I'm not clear
> on that one, and commit.
> 
> Thanks,
> 
> 	Marek
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)

Re: match.pd: Three new patterns

[Marek Polacek]

On Tue, Jun 23, 2015 at 10:22:35AM +0200, Richard Biener wrote:
> Who says you can't do bitwise ops on them?  I can't see that being
> enforced in the GIMPLE checking in tree-cfg.c.  Yes, there is no
> such thing as a "saturating" bitwise and but bitwise and should
> just work fine.
> 
> You can check with a arm cross what the C FE does when you use
> bitwise ops but I believe the regular and/ior md patterns work
> just fine (there are no special modes/registers but they seem
> to be shared with regular registers, just special operations
> are available).

Ok ;).  Applied the following then.

2015-06-23  Marek Polacek  <polacek@redhat.com>

	* match.pd ((x + y) - (x | y) -> x & y,
	(x + y) - (x & y) -> x | y): New patterns.

	* gcc.dg/fold-minus-4.c: New test.
	* gcc.dg/fold-minus-5.c: New test.
	* c-c++-common/ubsan/overflow-add-5.c: New test.

diff --git gcc/match.pd gcc/match.pd
index badb80a..9c88e3e 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -343,6 +343,20 @@ along with GCC; see the file COPYING3.  If not see
  (plus:c (bit_and @0 @1) (bit_ior @0 @1))
  (plus @0 @1))
 
+/* (x + y) - (x | y) -> x & y */
+(simplify
+ (minus (plus @0 @1) (bit_ior @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
+      && !TYPE_SATURATING (type))
+  (bit_and @0 @1)))
+
+/* (x + y) - (x & y) -> x | y */
+(simplify
+ (minus (plus @0 @1) (bit_and @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
+      && !TYPE_SATURATING (type))
+  (bit_ior @0 @1)))
+
 /* (x | y) - (x ^ y) -> x & y */
 (simplify
  (minus (bit_ior @0 @1) (bit_xor @0 @1))
diff --git gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
index e69de29..905a60a 100644
--- gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
+++ gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=signed-integer-overflow" } */
+
+int __attribute__ ((noinline))
+foo (int i, int j)
+{
+  return (i + j) - (i | j);
+}
+
+/* { dg-output "signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 2147483647 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+
+int __attribute__ ((noinline))
+bar (int i, int j)
+{
+  return (i + j) - (i & j);
+}
+
+/* { dg-output "\[^\n\r]*signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'" } */
+
+int
+main ()
+{
+  int r = foo (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  r = bar (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  return 0;
+}
diff --git gcc/testsuite/gcc.dg/fold-minus-4.c gcc/testsuite/gcc.dg/fold-minus-4.c
index e69de29..2d76b4f 100644
--- gcc/testsuite/gcc.dg/fold-minus-4.c
+++ gcc/testsuite/gcc.dg/fold-minus-4.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a & b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b & a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
diff --git gcc/testsuite/gcc.dg/fold-minus-5.c gcc/testsuite/gcc.dg/fold-minus-5.c
index e69de29..a31e1cc 100644
--- gcc/testsuite/gcc.dg/fold-minus-5.c
+++ gcc/testsuite/gcc.dg/fold-minus-5.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = a | b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a + b;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b + a;
+  int tem2 = b | a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */

	Marek