Internal-fn: Introduce new IFN_SAT_MUL for unsigned int

This patch would like to add the middle-end presentation for the
unsigend saturation mul.  Aka set the result of mul to the max
when overflow.

Take uint8_t as example, we will have:

* SAT_MUL (1, 127)   => 127.
* SAT_MUL (2, 127)   => 254.
* SAT_MUL (3, 127)   => 255.
* SAT_MUL (255, 127) => 255.

Given below example for uint16_t from uint128_t

  #define DEF_SAT_U_MUL_FMT_1(NT, WT)             \
  NT __attribute__((noinline))                    \
  sat_u_mul_##NT##_from_##WT##_fmt_1 (NT a, NT b) \
  {                                               \
    WT x = (WT)a * (WT)b;                         \
    NT max = -1;                                  \
    if (x > (WT)(max))                            \
      return max;                                 \
    else                                          \
      return (NT)x;                               \
  }

  DEF_SAT_U_MUL_FMT_1(uint16_t, uint128_t)

Before this patch:
  15   │   <bb 2> [local count: 1073741824]:
  16   │   _1 = (__int128 unsigned) a_4(D);
  17   │   _2 = (__int128 unsigned) b_5(D);
  18   │   _9 = (unsigned long) _1;
  19   │   _10 = (unsigned long) _2;
  20   │   x_6 = _9 w* _10;
  21   │   _7 = MIN_EXPR <x_6, 255>;
  22   │   _3 = (uint8_t) _7;
  23   │   return _3;

After this patch:
   9   │   <bb 2> [local count: 1073741824]:
  10   │   _3 = .SAT_MUL (a_4(D), b_5(D)); [tail call]
  11   │   return _3;

gcc/ChangeLog:

	* internal-fn.cc (commutative_binary_fn_p): Add new case
	for SAT_MUL.
	* internal-fn.def (SAT_MUL): Add new IFN_SAT_MUL.
	* optabs.def (OPTAB_NL): Remove fixed point limitation.

Signed-off-by: Pan Li <pan2.li@intel.com>

diff --git a/gcc/internal-fn.cc b/gcc/internal-fn.cc
index 39048d77d23b3c5422e786f23e4bb98614fef941..ed6ef0e4c647e3257c23e62979249bd689f382ec 100644 (file)
--- a/gcc/internal-fn.cc
+++ b/gcc/internal-fn.cc
@@ -4428,6 +4428,7 @@ commutative_binary_fn_p (internal_fn fn)
     case IFN_ADD_OVERFLOW:
     case IFN_MUL_OVERFLOW:
     case IFN_SAT_ADD:
+    case IFN_SAT_MUL:
     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 8edfa3540f8c96cf7c4379e88465df6e4d040093..914ee9f278cd7f41c277bb470313993cabf62589 100644 (file)
--- a/gcc/internal-fn.def
+++ b/gcc/internal-fn.def
@@ -282,6 +282,7 @@ DEF_INTERNAL_SIGNED_OPTAB_FN (MULHRS, ECF_CONST | ECF_NOTHROW, first,
 
 DEF_INTERNAL_SIGNED_OPTAB_FN (SAT_ADD, ECF_CONST, first, ssadd, usadd, binary)
 DEF_INTERNAL_SIGNED_OPTAB_FN (SAT_SUB, ECF_CONST, first, sssub, ussub, binary)
+DEF_INTERNAL_SIGNED_OPTAB_FN (SAT_MUL, ECF_CONST, first, ssmul, usmul, binary)
 
 DEF_INTERNAL_SIGNED_OPTAB_FN (SAT_TRUNC, ECF_CONST, first, sstrunc, ustrunc, unary_convert)
 

diff --git a/gcc/optabs.def b/gcc/optabs.def
index 0c1435d4ecd78e8a28de06d30706d2913622f3e8..87a8b85da1592646d0a3447572e842ceb158cd97 100644 (file)
--- a/gcc/optabs.def
+++ b/gcc/optabs.def
@@ -134,8 +134,8 @@ OPTAB_NX(smul_optab, "mul$P$a3")
 OPTAB_NX(smul_optab, "mul$F$a3")
 OPTAB_VL(smulv_optab, "mulv$I$a3", MULT, "mul", '3', gen_intv_fp_libfunc)
 OPTAB_VX(smulv_optab, "mul$F$a3")
-OPTAB_NL(ssmul_optab, "ssmul$Q$a3", SS_MULT, "ssmul", '3', gen_signed_fixed_libfunc)
-OPTAB_NL(usmul_optab, "usmul$Q$a3", US_MULT, "usmul", '3', gen_unsigned_fixed_libfunc)
+OPTAB_NL(ssmul_optab, "ssmul$a3", SS_MULT, "ssmul", '3', gen_signed_fixed_libfunc)
+OPTAB_NL(usmul_optab, "usmul$a3", US_MULT, "usmul", '3', gen_unsigned_fixed_libfunc)
 OPTAB_NL(sdiv_optab, "div$a3", DIV, "div", '3', gen_int_fp_signed_fixed_libfunc)
 OPTAB_VL(sdivv_optab, "divv$I$a3", DIV, "divv", '3', gen_int_libfunc)
 OPTAB_VX(sdivv_optab, "div$F$a3")