| Message ID | 20231022001232.2713374-1-pinskia@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PATCHv2] move the (a-b) CMP 0 ? (a-b) : (b-a) optimization from fold_cond_expr_with_comparison to match | expand |
On Sun, Oct 22, 2023 at 2:13 AM Andrew Pinski <pinskia@gmail.com> wrote: > > From: Andrew Pinski <apinski@marvell.com> > > This patch moves the `(a-b) CMP 0 ? (a-b) : (b-a)` optimization > from fold_cond_expr_with_comparison to match. > > Bootstrapped and tested on x86_64-linux-gnu. OK. > Changes in: > v2: Removes `(a == b) ? 0 : (b - a)` handling since it was handled > via r14-3606-g3d86e7f4a8ae > Change zerop to integer_zerop for `(a - b) == 0 ? 0 : (b - a)`, > Add `(a - b) != 0 ? (a - b) : 0` handling. > > gcc/ChangeLog: > > * match.pd (`(A - B) CMP 0 ? (A - B) : (B - A)`): > New patterns. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/phi-opt-38.c: New test. > --- > gcc/match.pd | 46 ++++++++++++++++++++-- > gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c | 45 +++++++++++++++++++++ > 2 files changed, 88 insertions(+), 3 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c > > diff --git a/gcc/match.pd b/gcc/match.pd > index a56838fb388..ce8d159d260 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -5650,9 +5650,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > (cnd (logical_inverted_value truth_valued_p@0) @1 @2) > (cnd @0 @2 @1))) > > -/* abs/negative simplifications moved from fold_cond_expr_with_comparison, > - Need to handle (A - B) case as fold_cond_expr_with_comparison does. > - Need to handle UN* comparisons. > +/* abs/negative simplifications moved from fold_cond_expr_with_comparison. > > None of these transformations work for modes with signed > zeros. If A is +/-0, the first two transformations will > @@ -5717,6 +5715,48 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > (convert (negate (absu:utype @0)))) > (negate (abs @0))))) > ) > + > + /* (A - B) == 0 ? (A - B) : (B - A) same as (B - A) */ > + (for cmp (eq uneq) > + (simplify > + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus@3 @2 @1)) > + (if (!HONOR_SIGNED_ZEROS (type)) > + @3)) > + (simplify > + (cnd (cmp (minus@0 @1 @2) integer_zerop) integer_zerop (minus@3 @2 @1)) > + @3) > + ) > + /* (A - B) != 0 ? (A - B) : (B - A) same as (A - B) */ > + (for cmp (ne ltgt) > + (simplify > + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) > + (if (!HONOR_SIGNED_ZEROS (type)) > + @0)) > + (simplify > + (cnd (cmp (minus@0 @1 @2) integer_zerop) @0 integer_zerop) > + @0) > + ) > + /* (A - B) >=/> 0 ? (A - B) : (B - A) same as abs (A - B) */ > + (for cmp (ge gt) > + (simplify > + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) > + (if (!HONOR_SIGNED_ZEROS (type) > + && !TYPE_UNSIGNED (type)) > + (abs @0)))) > + /* (A - B) <=/< 0 ? (A - B) : (B - A) same as -abs (A - B) */ > + (for cmp (le lt) > + (simplify > + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) > + (if (!HONOR_SIGNED_ZEROS (type) > + && !TYPE_UNSIGNED (type)) > + (if (ANY_INTEGRAL_TYPE_P (type) > + && !TYPE_OVERFLOW_WRAPS (type)) > + (with { > + tree utype = unsigned_type_for (type); > + } > + (convert (negate (absu:utype @0)))) > + (negate (abs @0))))) > + ) > ) > > /* -(type)!A -> (type)A - 1. */ > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c > new file mode 100644 > index 00000000000..0f0e3170f8d > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c > @@ -0,0 +1,45 @@ > +/* { dg-options "-O2 -fno-signed-zeros -fdump-tree-phiopt" } */ > +int minus1(int a, int b) > +{ > + int c = a - b; > + if (c == 0) c = b - a; > + return c; > +} > +int minus2(int a, int b) > +{ > + int c = a - b; > + if (c != 0) c = b - a; > + return c; > +} > +int minus3(int a, int b) > +{ > + int c = a - b; > + if (c == 0) c = 0; > + else c = b - a; > + return c; > +} > +int minus4(int a, int b) > +{ > + int c; > + if (a == b) c = 0; > + else > + c = b - a; > + return c; > +} > +int abs0(int a, int b) > +{ > + int c = a - b; > + if (c <= 0) c = b - a; > + return c; > +} > +int negabs(int a, int b) > +{ > + int c = a - b; > + if (c >= 0) c = b - a; > + return c; > +} > + > +/* The above should be optimized at phiopt1 except for negabs which has to wait > + until phiopt2 as -abs is not acceptable in early phiopt. */ > +/* { dg-final { scan-tree-dump-times "if" 1 "phiopt1" } } */ > +/* { dg-final { scan-tree-dump-not "if" "phiopt2" } } */ > -- > 2.39.3 >
diff --git a/gcc/match.pd b/gcc/match.pd index a56838fb388..ce8d159d260 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -5650,9 +5650,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (cnd (logical_inverted_value truth_valued_p@0) @1 @2) (cnd @0 @2 @1))) -/* abs/negative simplifications moved from fold_cond_expr_with_comparison, - Need to handle (A - B) case as fold_cond_expr_with_comparison does. - Need to handle UN* comparisons. +/* abs/negative simplifications moved from fold_cond_expr_with_comparison. None of these transformations work for modes with signed zeros. If A is +/-0, the first two transformations will @@ -5717,6 +5715,48 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (convert (negate (absu:utype @0)))) (negate (abs @0))))) ) + + /* (A - B) == 0 ? (A - B) : (B - A) same as (B - A) */ + (for cmp (eq uneq) + (simplify + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus@3 @2 @1)) + (if (!HONOR_SIGNED_ZEROS (type)) + @3)) + (simplify + (cnd (cmp (minus@0 @1 @2) integer_zerop) integer_zerop (minus@3 @2 @1)) + @3) + ) + /* (A - B) != 0 ? (A - B) : (B - A) same as (A - B) */ + (for cmp (ne ltgt) + (simplify + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) + (if (!HONOR_SIGNED_ZEROS (type)) + @0)) + (simplify + (cnd (cmp (minus@0 @1 @2) integer_zerop) @0 integer_zerop) + @0) + ) + /* (A - B) >=/> 0 ? (A - B) : (B - A) same as abs (A - B) */ + (for cmp (ge gt) + (simplify + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) + (if (!HONOR_SIGNED_ZEROS (type) + && !TYPE_UNSIGNED (type)) + (abs @0)))) + /* (A - B) <=/< 0 ? (A - B) : (B - A) same as -abs (A - B) */ + (for cmp (le lt) + (simplify + (cnd (cmp (minus@0 @1 @2) zerop) @0 (minus @2 @1)) + (if (!HONOR_SIGNED_ZEROS (type) + && !TYPE_UNSIGNED (type)) + (if (ANY_INTEGRAL_TYPE_P (type) + && !TYPE_OVERFLOW_WRAPS (type)) + (with { + tree utype = unsigned_type_for (type); + } + (convert (negate (absu:utype @0)))) + (negate (abs @0))))) + ) ) /* -(type)!A -> (type)A - 1. */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c new file mode 100644 index 00000000000..0f0e3170f8d --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c @@ -0,0 +1,45 @@ +/* { dg-options "-O2 -fno-signed-zeros -fdump-tree-phiopt" } */ +int minus1(int a, int b) +{ + int c = a - b; + if (c == 0) c = b - a; + return c; +} +int minus2(int a, int b) +{ + int c = a - b; + if (c != 0) c = b - a; + return c; +} +int minus3(int a, int b) +{ + int c = a - b; + if (c == 0) c = 0; + else c = b - a; + return c; +} +int minus4(int a, int b) +{ + int c; + if (a == b) c = 0; + else + c = b - a; + return c; +} +int abs0(int a, int b) +{ + int c = a - b; + if (c <= 0) c = b - a; + return c; +} +int negabs(int a, int b) +{ + int c = a - b; + if (c >= 0) c = b - a; + return c; +} + +/* The above should be optimized at phiopt1 except for negabs which has to wait + until phiopt2 as -abs is not acceptable in early phiopt. */ +/* { dg-final { scan-tree-dump-times "if" 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-not "if" "phiopt2" } } */
From: Andrew Pinski <apinski@marvell.com> This patch moves the `(a-b) CMP 0 ? (a-b) : (b-a)` optimization from fold_cond_expr_with_comparison to match. Bootstrapped and tested on x86_64-linux-gnu. Changes in: v2: Removes `(a == b) ? 0 : (b - a)` handling since it was handled via r14-3606-g3d86e7f4a8ae Change zerop to integer_zerop for `(a - b) == 0 ? 0 : (b - a)`, Add `(a - b) != 0 ? (a - b) : 0` handling. gcc/ChangeLog: * match.pd (`(A - B) CMP 0 ? (A - B) : (B - A)`): New patterns. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/phi-opt-38.c: New test. --- gcc/match.pd | 46 ++++++++++++++++++++-- gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c | 45 +++++++++++++++++++++ 2 files changed, 88 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-38.c