diff options
| author | Andrew Pinski <pinskia@gmail.com> | 2023-10-13 13:27:18 -0700 |
|---|---|---|
| committer | Andrew Pinski <pinskia@gmail.com> | 2023-10-17 08:51:51 -0700 |
| commit | b18d1cabe2f9cccc0cad697e1e0bfd2abebb85f9 (patch) | |
| tree | d3ee416cd553b7861a1c52947a7eccb63e21ed60 | |
| parent | da65efe433f20984bab93335d8f994a6987847e6 (diff) | |
| download | gcc-b18d1cabe2f9cccc0cad697e1e0bfd2abebb85f9.zip gcc-b18d1cabe2f9cccc0cad697e1e0bfd2abebb85f9.tar.gz gcc-b18d1cabe2f9cccc0cad697e1e0bfd2abebb85f9.tar.bz2 | |
MATCH: [PR111432] Simplify `a & (x | CST)` to a when we know that (a & ~CST) == 0
This adds the simplification `a & (x | CST)` to a when we know that
`(a & ~CST) == 0`. In a similar fashion as `a & CST` is handle.
I looked into handling `a | (x & CST)` but that I don't see any decent
simplifications happening.
OK? Bootstrapped and tested on x86_linux-gnu with no regressions.
PR tree-optimization/111432
gcc/ChangeLog:
* match.pd (`a & (x | CST)`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/bitops-7.c: New test.
| -rw-r--r-- | gcc/match.pd | 8 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/bitops-7.c | 24 |
2 files changed, 32 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index dbd554e..067328a 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1550,6 +1550,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) && wi::bit_and_not (get_nonzero_bits (@0), wi::to_wide (@1)) == 0) @0)) + +/* `a & (x | CST)` -> a if we know that (a & ~CST) == 0 */ +(simplify + (bit_and:c SSA_NAME@0 (bit_ior @1 INTEGER_CST@2)) + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && wi::bit_and_not (get_nonzero_bits (@0), wi::to_wide (@2)) == 0) + @0)) + /* x | C -> C if we know that x & ~C == 0. */ (simplify (bit_ior SSA_NAME@0 INTEGER_CST@1) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-7.c b/gcc/testsuite/gcc.dg/tree-ssa/bitops-7.c new file mode 100644 index 0000000..7fb18db --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-7.c @@ -0,0 +1,24 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-optimized-raw" } */ +/* PR tree-optimization/111432 */ + +int +foo3(int c, int bb) +{ + if ((bb & ~3)!=0) __builtin_unreachable(); + return (bb & (c|3)); +} + +int +foo_bool(int c, _Bool bb) +{ + return (bb & (c|7)); +} + +/* Both of these functions should be able to remove the `IOR` and `AND` + as the only bits that are non-zero for bb is set on the other side + of the `AND`. + */ + +/* { dg-final { scan-tree-dump-not "bit_ior_expr, " "optimized" } } */ +/* { dg-final { scan-tree-dump-not "bit_and_expr, " "optimized" } } */ |