MATCH: Add `(x | c) & ~(y | c)` and `x & ~(y | x)` patterns [PR98710]
Checks
Commit Message
Adding some more simple bit_and/bit_ior patterns.
How often these show up, I have no idea.
This was tested on top of
https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629174.html .
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
PR tree-optimization/98710
* match.pd (`(x | c) & ~(y | c)`, `(x & c) | ~(y & c)`): New pattern.
(`x & ~(y | x)`, `x | ~(y & x)`): New patterns.
gcc/testsuite/ChangeLog:
PR tree-optimization/98710
* gcc.dg/tree-ssa/andor-7.c: New test.
* gcc.dg/tree-ssa/andor-8.c: New test.
---
gcc/match.pd | 14 +++++++++++++-
gcc/testsuite/gcc.dg/tree-ssa/andor-7.c | 16 ++++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/andor-8.c | 19 +++++++++++++++++++
3 files changed, 48 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/andor-7.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/andor-8.c
Comments
On 9/3/23 19:25, Andrew Pinski via Gcc-patches wrote:
> Adding some more simple bit_and/bit_ior patterns.
> How often these show up, I have no idea.
>
> This was tested on top of
> https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629174.html .
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> gcc/ChangeLog:
>
> PR tree-optimization/98710
> * match.pd (`(x | c) & ~(y | c)`, `(x & c) | ~(y & c)`): New pattern.
> (`x & ~(y | x)`, `x | ~(y & x)`): New patterns.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/98710
> * gcc.dg/tree-ssa/andor-7.c: New test.
> * gcc.dg/tree-ssa/andor-8.c: New test.
OK
jeff
@@ -1995,7 +1995,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* (x & y) | (x | z) -> (x | z) */
(simplify
(bitop:c (rbitop:c @0 @1) (bitop:c@3 @0 @2))
- @3))
+ @3)
+ /* (x | c) & ~(y | c) -> x & ~(y | c) */
+ /* (x & c) | ~(y & c) -> x | ~(y & c) */
+ (simplify
+ (bitop:c (rbitop:c @0 @1) (bit_not@3 (rbitop:c @1 @2)))
+ (bitop @0 @3))
+ /* x & ~(y | x) -> 0 */
+ /* x | ~(y & x) -> -1 */
+ (simplify
+ (bitop:c @0 (bit_not (rbitop:c @0 @1)))
+ (if (bitop == BIT_AND_EXPR)
+ { build_zero_cst (type); }
+ { build_minus_one_cst (type); })))
/* ((x | y) & z) | x -> (z & y) | x
((x ^ y) & z) | x -> (z & y) | x */
new file mode 100644
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-original" } */
+/* PR tree-optimization/98710 */
+
+signed foo(signed x, signed y, signed z)
+{
+ return (x | z) & ~(y | z); // x & ~(y | z);
+}
+// Note . here is `(` or `)`
+/* { dg-final { scan-tree-dump "return x \& ~.y \\| z.;|return ~.y \\| z. \& x;" "original" } } */
+
+signed foo_or(signed a, signed b, signed c)
+{
+ return (a & c) | ~(b & c); // a | ~(b & c);
+}
+/* { dg-final { scan-tree-dump "return a \\| ~.b \& c.;|return ~.b \& c. \\| a;" "original" } } */
new file mode 100644
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-original" } */
+/* PR tree-optimization/98710 */
+
+signed foo2(signed a, signed b, signed c)
+{
+ return (a & ~(b | a)) & c; // 0
+}
+/* { dg-final { scan-tree-dump "return 0;" "original" } } */
+signed foo2_or(signed x, signed y, signed z)
+{
+ return (x | ~(y & x)) & z; // -1 & z -> z
+}
+
+/* { dg-final { scan-tree-dump "return z;" "original" } } */
+/* All | and & should have been removed. */
+/* { dg-final { scan-tree-dump-not "~" "original" } } */
+/* { dg-final { scan-tree-dump-not " \& " "original" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "original" } } */