On Wed, May 15, 2024 at 1:36 PM Li, Pan2 <pan2...@intel.com> wrote:
>
> > LGTM but you'll need an OK from Richard,
> > Thanks for working on this!
>
> Thanks Tamar for help and coaching, let's wait Richard for a while,😊!
OK.
Thanks for the patience,
Richard.
> Pan
>
> -----Original Message-----
> From: Tamar Christina <tamar.christ...@arm.com>
> Sent: Wednesday, May 15, 2024 5:12 PM
> To: Li, Pan2 <pan2...@intel.com>; gcc-patches@gcc.gnu.org
> Cc: juzhe.zh...@rivai.ai; kito.ch...@gmail.com; richard.guent...@gmail.com;
> Liu, Hongtao <hongtao....@intel.com>
> Subject: RE: [PATCH v5 1/3] Internal-fn: Support new IFN SAT_ADD for unsigned
> scalar int
>
> Hi Pan,
>
> Thanks!
>
> > -----Original Message-----
> > From: pan2...@intel.com <pan2...@intel.com>
> > Sent: Wednesday, May 15, 2024 3:14 AM
> > To: gcc-patches@gcc.gnu.org
> > Cc: juzhe.zh...@rivai.ai; kito.ch...@gmail.com; Tamar Christina
> > <tamar.christ...@arm.com>; richard.guent...@gmail.com;
> > hongtao....@intel.com; Pan Li <pan2...@intel.com>
> > Subject: [PATCH v5 1/3] Internal-fn: Support new IFN SAT_ADD for unsigned
> > scalar
> > int
> >
> > From: Pan Li <pan2...@intel.com>
> >
> > This patch would like to add the middle-end presentation for the
> > saturation add. Aka set the result of add to the max when overflow.
> > It will take the pattern similar as below.
> >
> > SAT_ADD (x, y) => (x + y) | (-(TYPE)((TYPE)(x + y) < x))
> >
> > Take uint8_t as example, we will have:
> >
> > * SAT_ADD (1, 254) => 255.
> > * SAT_ADD (1, 255) => 255.
> > * SAT_ADD (2, 255) => 255.
> > * SAT_ADD (255, 255) => 255.
> >
> > Given below example for the unsigned scalar integer uint64_t:
> >
> > uint64_t sat_add_u64 (uint64_t x, uint64_t y)
> > {
> > return (x + y) | (- (uint64_t)((uint64_t)(x + y) < x));
> > }
> >
> > Before this patch:
> > uint64_t sat_add_uint64_t (uint64_t x, uint64_t y)
> > {
> > long unsigned int _1;
> > _Bool _2;
> > long unsigned int _3;
> > long unsigned int _4;
> > uint64_t _7;
> > long unsigned int _10;
> > __complex__ long unsigned int _11;
> >
> > ;; basic block 2, loop depth 0
> > ;; pred: ENTRY
> > _11 = .ADD_OVERFLOW (x_5(D), y_6(D));
> > _1 = REALPART_EXPR <_11>;
> > _10 = IMAGPART_EXPR <_11>;
> > _2 = _10 != 0;
> > _3 = (long unsigned int) _2;
> > _4 = -_3;
> > _7 = _1 | _4;
> > return _7;
> > ;; succ: EXIT
> >
> > }
> >
> > After this patch:
> > uint64_t sat_add_uint64_t (uint64_t x, uint64_t y)
> > {
> > uint64_t _7;
> >
> > ;; basic block 2, loop depth 0
> > ;; pred: ENTRY
> > _7 = .SAT_ADD (x_5(D), y_6(D)); [tail call]
> > return _7;
> > ;; succ: EXIT
> > }
> >
> > The below tests are passed for this patch:
> > 1. The riscv fully regression tests.
> > 3. The x86 bootstrap tests.
> > 4. The x86 fully regression tests.
> >
> > PR target/51492
> > PR target/112600
> >
> > gcc/ChangeLog:
> >
> > * internal-fn.cc (commutative_binary_fn_p): Add type IFN_SAT_ADD
> > to the return true switch case(s).
> > * internal-fn.def (SAT_ADD): Add new signed optab SAT_ADD.
> > * match.pd: Add unsigned SAT_ADD match(es).
> > * optabs.def (OPTAB_NL): Remove fixed-point limitation for
> > us/ssadd.
> > * tree-ssa-math-opts.cc (gimple_unsigned_integer_sat_add): New
> > extern func decl generated in match.pd match.
> > (match_saturation_arith): New func impl to match the saturation arith.
> > (math_opts_dom_walker::after_dom_children): Try match saturation
> > arith when IOR expr.
> >
>
> LGTM but you'll need an OK from Richard,
>
> Thanks for working on this!
>
> Tamar
>
> > Signed-off-by: Pan Li <pan2...@intel.com>
> > ---
> > gcc/internal-fn.cc | 1 +
> > gcc/internal-fn.def | 2 ++
> > gcc/match.pd | 51 +++++++++++++++++++++++++++++++++++++++
> > gcc/optabs.def | 4 +--
> > gcc/tree-ssa-math-opts.cc | 32 ++++++++++++++++++++++++
> > 5 files changed, 88 insertions(+), 2 deletions(-)
> >
> > diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
> > index 0a7053c2286..73045ca8c8c 100644
> > --- a/gcc/internal-fn.cc
> > +++ b/gcc/internal-fn.cc
> > @@ -4202,6 +4202,7 @@ commutative_binary_fn_p (internal_fn fn)
> > case IFN_UBSAN_CHECK_MUL:
> > case IFN_ADD_OVERFLOW:
> > case IFN_MUL_OVERFLOW:
> > + case IFN_SAT_ADD:
> > case IFN_VEC_WIDEN_PLUS:
> > case IFN_VEC_WIDEN_PLUS_LO:
> > case IFN_VEC_WIDEN_PLUS_HI:
> > diff --git a/gcc/internal-fn.def b/gcc/internal-fn.def
> > index 848bb9dbff3..25badbb86e5 100644
> > --- a/gcc/internal-fn.def
> > +++ b/gcc/internal-fn.def
> > @@ -275,6 +275,8 @@ DEF_INTERNAL_SIGNED_OPTAB_FN (MULHS, ECF_CONST
> > | ECF_NOTHROW, first,
> > DEF_INTERNAL_SIGNED_OPTAB_FN (MULHRS, ECF_CONST | ECF_NOTHROW,
> > first,
> > smulhrs, umulhrs, binary)
> >
> > +DEF_INTERNAL_SIGNED_OPTAB_FN (SAT_ADD, ECF_CONST, first, ssadd, usadd,
> > binary)
> > +
> > DEF_INTERNAL_COND_FN (ADD, ECF_CONST, add, binary)
> > DEF_INTERNAL_COND_FN (SUB, ECF_CONST, sub, binary)
> > DEF_INTERNAL_COND_FN (MUL, ECF_CONST, smul, binary)
> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index 07e743ae464..0f9c34fa897 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -3043,6 +3043,57 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > || POINTER_TYPE_P (itype))
> > && wi::eq_p (wi::to_wide (int_cst), wi::max_value (itype))))))
> >
> > +/* Unsigned Saturation Add */
> > +(match (usadd_left_part_1 @0 @1)
> > + (plus:c @0 @1)
> > + (if (INTEGRAL_TYPE_P (type)
> > + && TYPE_UNSIGNED (TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@1)))))
> > +
> > +(match (usadd_left_part_2 @0 @1)
> > + (realpart (IFN_ADD_OVERFLOW:c @0 @1))
> > + (if (INTEGRAL_TYPE_P (type)
> > + && TYPE_UNSIGNED (TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@1)))))
> > +
> > +(match (usadd_right_part_1 @0 @1)
> > + (negate (convert (lt (plus:c @0 @1) @0)))
> > + (if (INTEGRAL_TYPE_P (type)
> > + && TYPE_UNSIGNED (TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@1)))))
> > +
> > +(match (usadd_right_part_1 @0 @1)
> > + (negate (convert (gt @0 (plus:c @0 @1))))
> > + (if (INTEGRAL_TYPE_P (type)
> > + && TYPE_UNSIGNED (TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@1)))))
> > +
> > +(match (usadd_right_part_2 @0 @1)
> > + (negate (convert (ne (imagpart (IFN_ADD_OVERFLOW:c @0 @1))
> > integer_zerop)))
> > + (if (INTEGRAL_TYPE_P (type)
> > + && TYPE_UNSIGNED (TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@0))
> > + && types_match (type, TREE_TYPE (@1)))))
> > +
> > +/* We cannot merge or overload usadd_left_part_1 and usadd_left_part_2
> > + because the sub part of left_part_2 cannot work with right_part_1.
> > + For example, left_part_2 pattern focus one .ADD_OVERFLOW but the
> > + right_part_1 has nothing to do with .ADD_OVERFLOW. */
> > +
> > +/* Unsigned saturation add, case 1 (branchless):
> > + SAT_U_ADD = (X + Y) | - ((X + Y) < X) or
> > + SAT_U_ADD = (X + Y) | - (X > (X + Y)). */
> > +(match (unsigned_integer_sat_add @0 @1)
> > + (bit_ior:c (usadd_left_part_1 @0 @1) (usadd_right_part_1 @0 @1)))
> > +
> > +/* Unsigned saturation add, case 2 (branchless with .ADD_OVERFLOW). */
> > +(match (unsigned_integer_sat_add @0 @1)
> > + (bit_ior:c (usadd_left_part_2 @0 @1) (usadd_right_part_2 @0 @1)))
> > +
> > /* x > y && x != XXX_MIN --> x > y
> > x > y && x == XXX_MIN --> false . */
> > (for eqne (eq ne)
> > diff --git a/gcc/optabs.def b/gcc/optabs.def
> > index ad14f9328b9..3f2cb46aff8 100644
> > --- a/gcc/optabs.def
> > +++ b/gcc/optabs.def
> > @@ -111,8 +111,8 @@ OPTAB_NX(add_optab, "add$F$a3")
> > OPTAB_NX(add_optab, "add$Q$a3")
> > OPTAB_VL(addv_optab, "addv$I$a3", PLUS, "add", '3', gen_intv_fp_libfunc)
> > OPTAB_VX(addv_optab, "add$F$a3")
> > -OPTAB_NL(ssadd_optab, "ssadd$Q$a3", SS_PLUS, "ssadd", '3',
> > gen_signed_fixed_libfunc)
> > -OPTAB_NL(usadd_optab, "usadd$Q$a3", US_PLUS, "usadd", '3',
> > gen_unsigned_fixed_libfunc)
> > +OPTAB_NL(ssadd_optab, "ssadd$a3", SS_PLUS, "ssadd", '3',
> > gen_signed_fixed_libfunc)
> > +OPTAB_NL(usadd_optab, "usadd$a3", US_PLUS, "usadd", '3',
> > gen_unsigned_fixed_libfunc)
> > OPTAB_NL(sub_optab, "sub$P$a3", MINUS, "sub", '3',
> > gen_int_fp_fixed_libfunc)
> > OPTAB_NX(sub_optab, "sub$F$a3")
> > OPTAB_NX(sub_optab, "sub$Q$a3")
> > diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
> > index e8c804f09b7..62da1c5ee08 100644
> > --- a/gcc/tree-ssa-math-opts.cc
> > +++ b/gcc/tree-ssa-math-opts.cc
> > @@ -4086,6 +4086,36 @@ arith_overflow_check_p (gimple *stmt, gimple
> > *cast_stmt, gimple *&use_stmt,
> > return 0;
> > }
> >
> > +extern bool gimple_unsigned_integer_sat_add (tree, tree*, tree (*)(tree));
> > +
> > +/*
> > + * Try to match saturation arith pattern(s).
> > + * 1. SAT_ADD (unsigned)
> > + * _7 = _4 + _6;
> > + * _8 = _4 > _7;
> > + * _9 = (long unsigned int) _8;
> > + * _10 = -_9;
> > + * _12 = _7 | _10;
> > + * =>
> > + * _12 = .SAT_ADD (_4, _6); */
> > +static void
> > +match_saturation_arith (gimple_stmt_iterator *gsi, gassign *stmt)
> > +{
> > + gcall *call = NULL;
> > +
> > + tree ops[2];
> > + tree lhs = gimple_assign_lhs (stmt);
> > +
> > + if (gimple_unsigned_integer_sat_add (lhs, ops, NULL)
> > + && direct_internal_fn_supported_p (IFN_SAT_ADD, TREE_TYPE (lhs),
> > + OPTIMIZE_FOR_BOTH))
> > + {
> > + call = gimple_build_call_internal (IFN_SAT_ADD, 2, ops[0], ops[1]);
> > + gimple_call_set_lhs (call, lhs);
> > + gsi_replace (gsi, call, true);
> > + }
> > +}
> > +
> > /* Recognize for unsigned x
> > x = y - z;
> > if (x > y)
> > @@ -6048,6 +6078,8 @@ math_opts_dom_walker::after_dom_children
> > (basic_block bb)
> > break;
> >
> > case BIT_IOR_EXPR:
> > + match_saturation_arith (&gsi, as_a<gassign *> (stmt));
> > + /* fall-through */
> > case BIT_XOR_EXPR:
> > match_uaddc_usubc (&gsi, stmt, code);
> > break;
> > --
> > 2.34.1
>
