On Mon, May 8, 2023 at 7:27 AM Andrew Pinski via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > This patch adds the support for match that was implemented for PR 87913 in > phiopt. > It implements it by adding support to minmax_from_comparison for the check. > It uses the range information if available which allows to produce MIN/MAX > expression > when comparing against the lower/upper bound of the range instead of > lower/upper > of the type. > > minmax-20.c is the new testcase which tests the ranges part. > > OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
OK. > gcc/ChangeLog: > > * fold-const.cc (minmax_from_comparison): Add support for NE_EXPR. > * match.pd ((cond (cmp (convert1? x) c1) (convert2? x) c2) pattern): > Add ne as a possible cmp. > ((a CMP b) ? minmax<a, c> : minmax<b, c> pattern): Likewise. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/minmax-20.c: New test. > --- > gcc/fold-const.cc | 26 +++++++++++++++++++++++ > gcc/match.pd | 4 ++-- > gcc/testsuite/gcc.dg/tree-ssa/minmax-20.c | 12 +++++++++++ > 3 files changed, 40 insertions(+), 2 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/minmax-20.c > > diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc > index db54bfc5662..d90671b9975 100644 > --- a/gcc/fold-const.cc > +++ b/gcc/fold-const.cc > @@ -173,6 +173,19 @@ minmax_from_comparison (tree_code cmp, tree exp0, tree > exp1, tree exp2, tree exp > /* X > Y - 1 equals to X >= Y. */ > if (cmp == GT_EXPR) > code = GE_EXPR; > + /* a != MIN_RANGE<a> ? a : MIN_RANGE<a>+1 -> > MAX_EXPR<MIN_RANGE<a>+1, a> */ > + if (cmp == NE_EXPR && TREE_CODE (exp0) == SSA_NAME) > + { > + value_range r; > + get_range_query (cfun)->range_of_expr (r, exp0); > + if (r.undefined_p ()) > + r.set_varying (TREE_TYPE (exp0)); > + > + widest_int min = widest_int::from (r.lower_bound (), > + TYPE_SIGN (TREE_TYPE > (exp0))); > + if (min == wi::to_widest (exp1)) > + code = MAX_EXPR; > + } > } > if (wi::to_widest (exp1) == (wi::to_widest (exp3) + 1)) > { > @@ -182,6 +195,19 @@ minmax_from_comparison (tree_code cmp, tree exp0, tree > exp1, tree exp2, tree exp > /* X >= Y + 1 equals to X > Y. */ > if (cmp == GE_EXPR) > code = GT_EXPR; > + /* a != MAX_RANGE<a> ? a : MAX_RANGE<a>-1 -> > MIN_EXPR<MIN_RANGE<a>-1, a> */ > + if (cmp == NE_EXPR && TREE_CODE (exp0) == SSA_NAME) > + { > + value_range r; > + get_range_query (cfun)->range_of_expr (r, exp0); > + if (r.undefined_p ()) > + r.set_varying (TREE_TYPE (exp0)); > + > + widest_int max = widest_int::from (r.upper_bound (), > + TYPE_SIGN (TREE_TYPE > (exp0))); > + if (max == wi::to_widest (exp1)) > + code = MIN_EXPR; > + } > } > } > if (code != ERROR_MARK > diff --git a/gcc/match.pd b/gcc/match.pd > index a55ede838cd..95f7e9a6abc 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -4751,7 +4751,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > > Case 2) > (cond (eq (convert1? x) c1) (convert2? x) c2) -> (cond (eq x c1) c1 c2). > */ > -(for cmp (lt le gt ge eq) > +(for cmp (lt le gt ge eq ne) > (simplify > (cond (cmp (convert1? @1) INTEGER_CST@3) (convert2? @1) INTEGER_CST@2) > (with > @@ -4942,7 +4942,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > /* Optimize (a CMP b) ? minmax<a, c> : minmax<b, c> > to minmax<min/max<a, b>, c> */ > (for minmax (min max) > - (for cmp (lt le gt ge) > + (for cmp (lt le gt ge ne) > (simplify > (cond (cmp @1 @3) (minmax:c @1 @4) (minmax:c @2 @4)) > (with > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-20.c > b/gcc/testsuite/gcc.dg/tree-ssa/minmax-20.c > new file mode 100644 > index 00000000000..481c375f5f9 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-20.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-phiopt2" } */ > + > +int f(int num) > +{ > + if (num < 3) __builtin_unreachable(); > + return num != 3 ? num : 4; > +} > + > +/* In phiopt2 with the range information, this should be turned into > + a MAX_EXPR. */ > +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt2" } } */ > -- > 2.31.1 >