On Tue, May 12, 2026 at 7:47 PM Shivam Gupta <[email protected]> wrote: > > This adds the simplification of: > _1 = ~x_2(D); > t1_4 = _1 & y_3(D); > t2_5 = x_2(D) | y_3(D); > _6 = t1_4 ^ t2_5; > return _6; > > to: > return x_1(D); > > also for ((~x) | y) ^ (x & y) version > _1 = ~x_2(D); > t1_4 = _1 | y_3(D); > t2_5 = x_2(D) & y_3(D); > _6 = t1_4 ^ t2_5; > return _6; > to: > int _1; > _1 = ~x_2(D); > return _1; > > Bootstrapped and tested on aarch64-linux-gnu with > RUNTESTFLAGS="tree-ssa.exp".
OK. Thanks, Richard. > changes since v1: > * v3: Change sf2/sg2 to sf/sg in test case > * v2: > - Update testcase to exercise GIMPLE folding > - Add additional type coverage > - Add vector and _Bool coverage > - Move code above in the file > > PR tree-optimization/112095 > > gcc/ChangeLog: > > * match.pd: Simplify ((~x) & y) ^ (x | y) > to x and ((~x) | y) ^ (x & y) to ~x. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/pr112095.c: New test. > > Signed-off-by: Shivam Gupta <[email protected]> > --- > gcc/match.pd | 9 ++ > gcc/testsuite/gcc.dg/tree-ssa/pr112095.c | 127 +++++++++++++++++++++++ > 2 files changed, 136 insertions(+) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr112095.c > > diff --git a/gcc/match.pd b/gcc/match.pd > index 7b652afb43d..327598bfd63 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -1606,6 +1606,15 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > && TYPE_PRECISION (TREE_TYPE (@0)) == 1) > @2)) > > +/* ((~a) & b) ^ (a | b) --> a */ > +/* ((~a) | b) ^ (a & b) --> ~a */ > +(simplify > + (bit_xor:c (bit_ior:c @0 @1) (bit_and:c @2 @1)) > + (with { bool wascmp; } > + (if (bitwise_inverted_equal_p (@0, @2, wascmp) > + && (!wascmp || element_precision (type) == 1)) > + @0))) > + > /* ~(~a & b) --> a | ~b */ > (simplify > (bit_not (bit_and:cs (bit_not @0) @1)) > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr112095.c > b/gcc/testsuite/gcc.dg/tree-ssa/pr112095.c > new file mode 100644 > index 00000000000..992d0e1f29d > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr112095.c > @@ -0,0 +1,127 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O -fdump-tree-optimized" } */ > + > +typedef signed int s32; > +typedef unsigned char u8; > +typedef unsigned short u16; > +typedef unsigned int u32; > +typedef unsigned long u64; > +typedef __attribute__((vector_size(4 * sizeof (unsigned int)))) unsigned int > v4ui; > + > +s32 > +sf (s32 a, s32 b) > +{ > + s32 t1 = (~a) & b; > + s32 t2 = a | b; > + return t1 ^ t2; > +} > + > +s32 > +sg (s32 a, s32 b) > +{ > + s32 t1 = (~a) | b; > + s32 t2 = a & b; > + return t1 ^ t2; > +} > + > +u8 > +f1 (u8 a, u8 b) > +{ > + u8 t1 = (~a) & b; > + u8 t2 = a | b; > + return t1 ^ t2; > +} > + > +u8 > +g1 (u8 a, u8 b) > +{ > + u8 t1 = (~a) | b; > + u8 t2 = a & b; > + return t1 ^ t2; > +} > + > +u16 > +f2 (u16 a, u16 b) > +{ > + u16 t1 = (~a) & b; > + u16 t2 = a | b; > + return t1 ^ t2; > +} > + > +u16 > +g2 (u16 a, u16 b) > +{ > + u16 t1 = (~a) | b; > + u16 t2 = a & b; > + return t1 ^ t2; > +} > + > +u32 > +f3 (u32 a, u32 b) > +{ > + u32 t1 = (~a) & b; > + u32 t2 = a | b; > + return t1 ^ t2; > +} > + > +u32 > +g3 (u32 a, u32 b) > +{ > + u32 t1 = (~a) | b; > + u32 t2 = a & b; > + return t1 ^ t2; > +} > + > +u64 > +f4 (u64 a, u64 b) > +{ > + u64 t1 = (~a) & b; > + u64 t2 = a | b; > + return t1 ^ t2; > +} > + > +u64 > +g4 (u64 a, u64 b) > +{ > + u64 t1 = (~a) | b; > + u64 t2 = a & b; > + return t1 ^ t2; > +} > + > +_Bool > +bf (_Bool a, _Bool b) > +{ > + _Bool t1 = (~a) & b; > + _Bool t2 = a | b; > + return t1 ^ t2; > +} > + > +_Bool > +bg (_Bool a, _Bool b) > +{ > + _Bool t1 = (~a) | b; > + _Bool t2 = a & b; > + return t1 ^ t2; > +} > + > +v4ui > +vf (v4ui a, v4ui b) > +{ > + v4ui t1 = (~a) & b; > + v4ui t2 = a | b; > + return t1 ^ t2; > +} > + > +v4ui > +vg (v4ui a, v4ui b) > +{ > + v4ui t1 = (~a) | b; > + v4ui t2 = a & b; > + return t1 ^ t2; > +} > + > +/* f* and vf should simplify to return a. */ > +/* { dg-final { scan-tree-dump-times "return a_" 6 "optimized" } } */ > + > +/* g* and vg should simplify to ~a directly. */ > +/* { dg-final { scan-tree-dump-times "= ~a" 6 "optimized" } } */ > -- > 2.34.1 >
