On Fri, 14 Jul 2023, Aldy Hernandez wrote:

> I don't know what you're trying to accomplish here, as I haven't been
> following the PR, but adding all these helper functions to the ranger header
> file seems wrong, especially since there's only one use of them. I see you're
> tweaking the irange API, adding helper functions to range-op (which is only
> for code dealing with implementing range operators for tree codes), etc etc.
> 
> If you need these helper functions, I suggest you put them closer to their
> uses (i.e. wherever the match.pd support machinery goes).

Note I suggested the opposite beacuse I thought these kind of helpers
are closer to value-range support than to match.pd.

But I take away from your answer that there's nothing close in the 
value-range machinery that answers the question whether A op B may
overflow?

Richard.

> Aldy
> 
> On 7/11/23 11:04, Jiufu Guo wrote:
> > Hi,
> > 
> > Integer expression "(X - N * M) / N" can be optimized to "X / N - M"
> > if there is no wrap/overflow/underflow and "X - N * M" has the same
> > sign with "X".
> > 
> > Compare the previous version:
> > https://gcc.gnu.org/pipermail/gcc-patches/2023-June/623028.html
> > - The APIs for checking overflow of range operation are moved to
> > other files: range-op and gimple-range.
> > - Improve the patterns with '(X + C)' for unsigned type.
> > 
> > Bootstrap & regtest pass on ppc64{,le} and x86_64.
> > Is this patch ok for trunk?
> > 
> > BR,
> > Jeff (Jiufu Guo)
> > 
> > 
> >  PR tree-optimization/108757
> > 
> > gcc/ChangeLog:
> > 
> >  * gimple-range.cc (arith_without_overflow_p): New function.
> >  (same_sign_p): New function.
> >  * gimple-range.h (arith_without_overflow_p): New declare.
> >  (same_sign_p): New declare.
> >  * match.pd ((X - N * M) / N): New pattern.
> >  ((X + N * M) / N): New pattern.
> >  ((X + C) div_rshift N): New pattern.
> >  * range-op.cc (plus_without_overflow_p): New function.
> >  (minus_without_overflow_p): New function.
> >  (mult_without_overflow_p): New function.
> >  * range-op.h (plus_without_overflow_p): New declare.
> >  (minus_without_overflow_p): New declare.
> >  (mult_without_overflow_p): New declare.
> >  * value-query.h (get_range): New function
> >  * value-range.cc (irange::nonnegative_p): New function.
> >  (irange::nonpositive_p): New function.
> >  * value-range.h (irange::nonnegative_p): New declare.
> >  (irange::nonpositive_p): New declare.
> > 
> > gcc/testsuite/ChangeLog:
> > 
> >  * gcc.dg/pr108757-1.c: New test.
> >  * gcc.dg/pr108757-2.c: New test.
> >  * gcc.dg/pr108757.h: New test.
> > 
> > ---
> >   gcc/gimple-range.cc               |  50 +++++++
> >   gcc/gimple-range.h                |   2 +
> >   gcc/match.pd                      |  64 ++++++++
> >   gcc/range-op.cc                   |  77 ++++++++++
> >   gcc/range-op.h                    |   4 +
> >   gcc/value-query.h                 |  10 ++
> >   gcc/value-range.cc                |  12 ++
> >   gcc/value-range.h                 |   2 +
> >   gcc/testsuite/gcc.dg/pr108757-1.c |  18 +++
> >   gcc/testsuite/gcc.dg/pr108757-2.c |  19 +++
> >   gcc/testsuite/gcc.dg/pr108757.h   | 233 ++++++++++++++++++++++++++++++
> >   11 files changed, 491 insertions(+)
> >   create mode 100644 gcc/testsuite/gcc.dg/pr108757-1.c
> >   create mode 100644 gcc/testsuite/gcc.dg/pr108757-2.c
> >   create mode 100644 gcc/testsuite/gcc.dg/pr108757.h
> > 
> > diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
> > index
> > 01e62d3ff3901143bde33dc73c0debf41d0c0fdd..620fe32e85e5fe3847a933554fc656b2939cf02d
> > 100644
> > --- a/gcc/gimple-range.cc
> > +++ b/gcc/gimple-range.cc
> > @@ -926,3 +926,53 @@ assume_query::dump (FILE *f)
> >       }
> >     fprintf (f, "------------------------------\n");
> >   }
> > +
> > +/* Return true if the operation "X CODE Y" in type does not overflow
> > +   underflow or wrap with value range info, otherwise return false.  */
> > +
> > +bool
> > +arith_without_overflow_p (tree_code code, tree x, tree y, tree type)
> > +{
> > +  gcc_assert (INTEGRAL_TYPE_P (type));
> > +
> > +  if (TYPE_OVERFLOW_UNDEFINED (type))
> > +    return true;
> > +
> > +  value_range vr0;
> > +  value_range vr1;
> > +  if (!(get_range (vr0, x) && get_range (vr1, y)))
> > +    return false;
> > +
> > +  switch (code)
> > +    {
> > +    case PLUS_EXPR:
> > +      return plus_without_overflow_p (vr0, vr1, type);
> > +    case MINUS_EXPR:
> > +      return minus_without_overflow_p (vr0, vr1, type);
> > +    case MULT_EXPR:
> > +      return mult_without_overflow_p (vr0, vr1, type);
> > +    default:
> > +      gcc_unreachable ();
> > +    }
> > +
> > +  return false;
> > +}
> > +
> > +/* Return true if "X" and "Y" have the same sign or zero.  */
> > +
> > +bool
> > +same_sign_p (tree x, tree y, tree type)
> > +{
> > +  gcc_assert (INTEGRAL_TYPE_P (type));
> > +
> > +  if (TYPE_UNSIGNED (type))
> > +    return true;
> > +
> > +  value_range vr0;
> > +  value_range vr1;
> > +  if (!(get_range (vr0, x) && get_range (vr1, y)))
> > +    return false;
> > +
> > +  return (vr0.nonnegative_p () && vr1.nonnegative_p ())
> > +    || (vr0.nonpositive_p () && vr1.nonpositive_p ());
> > +}
> > diff --git a/gcc/gimple-range.h b/gcc/gimple-range.h
> > index
> > 6587e4923ff44e10826a697ecced237a0ad23c88..84eac87392b642ed3305011415c804f5b319e09f
> > 100644
> > --- a/gcc/gimple-range.h
> > +++ b/gcc/gimple-range.h
> > @@ -101,5 +101,7 @@ protected:
> >     gori_compute m_gori;
> >   };
> >   
> > +bool arith_without_overflow_p (tree_code code, tree x, tree y, tree type);
> > +bool same_sign_p (tree x, tree y, tree type);
> >   
> >   #endif // GCC_GIMPLE_RANGE_H
> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index
> > 8543f777a28e4f39b2b2a40d0702aed88786bbb3..87e990c5b1ebbd116d7d7efdba62347d3a967cdd
> > 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -942,6 +942,70 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> >   #endif
> >      ))))
> >   +#if GIMPLE
> > +(for div (trunc_div exact_div)
> > + /* Simplify (t + M*N) / N -> t / N + M.  */
> > + (simplify
> > +  (div (plus:c@4 @0 (mult:c@3 @1 @2)) @2)
> > +  (if (INTEGRAL_TYPE_P (type)
> > +       && arith_without_overflow_p (MULT_EXPR, @1, @2, type)
> > +       && arith_without_overflow_p (PLUS_EXPR, @0, @3, type)
> > +       && same_sign_p (@0, @4, type))
> > +  (plus (div @0 @2) @1)))
> > +
> > + /* Simplify (t - M*N) / N -> t / N - M.  */
> > + (simplify
> > +  (div (minus@4 @0 (mult:c@3 @1 @2)) @2)
> > +  (if (INTEGRAL_TYPE_P (type)
> > +       && arith_without_overflow_p (MULT_EXPR, @1, @2, type)
> > +       && arith_without_overflow_p (MINUS_EXPR, @0, @3, type)
> > +       && same_sign_p (@0, @4, type))
> > +  (minus (div @0 @2) @1))))
> > +
> > +/* Simplify
> > +   (t + C) / N -> t / N + C / N where C is multiple of N.
> > +   (t + C) >> N -> t >> N + C>>N if low N bits of C is 0.  */
> > +(for op (trunc_div exact_div rshift)
> > + (simplify
> > +  (op (plus@3 @0 INTEGER_CST@1) INTEGER_CST@2)
> > +   (with
> > +    {
> > +      wide_int c = wi::to_wide (@1);
> > +      wide_int n = wi::to_wide (@2);
> > +      bool is_rshift = op == RSHIFT_EXPR;
> > +      bool neg_c = false;
> > +      bool ok = false;
> > +      if (INTEGRAL_TYPE_P (type))
> > +        {
> > +     ok = is_rshift ? wi::ctz (c) >= n.to_shwi ()
> > +                    : wi::multiple_of_p (c, n, TYPE_SIGN (type));
> > +     ok = ok && arith_without_overflow_p (PLUS_EXPR, @0, @1, type)
> > +          && same_sign_p (@0, @3, type);
> > +
> > +     /* Try check 'X + C' as 'X - -C' for unsigned.  */
> > +     if (!ok && TYPE_UNSIGNED (type) && c.sign_mask () < 0)
> > +       {
> > +         neg_c = true;
> > +         c = -c;
> > +         ok = is_rshift ? wi::ctz (c) >= n.to_shwi ()
> > +                        : wi::multiple_of_p (c, n, UNSIGNED);
> > +         value_range vr;
> > +         ok = ok && get_range (vr, @0)
> > +              && wi::geu_p (vr.lower_bound (), c);
> > +       }
> > +   }
> > +    }
> > +   (if (ok)
> > +   (with
> > +    {
> > +      wide_int m;
> > +      m = is_rshift ? wi::rshift (c, n, TYPE_SIGN (type))
> > +               : wi::div_trunc (c, n, TYPE_SIGN (type));
> > +      m = neg_c ? -m : m;
> > +    }
> > +   (plus (op @0 @2) { wide_int_to_tree(type, m); }))))))
> > +#endif
> > +
> >   (for op (negate abs)
> >    /* Simplify cos(-x) and cos(|x|) -> cos(x).  Similarly for cosh.  */
> >    (for coss (COS COSH)
> > diff --git a/gcc/range-op.cc b/gcc/range-op.cc
> > index
> > cb584314f4cfc93aeec50c7f888829997a7dc8eb..487e781a0cdfa39416589983a246327957c14d54
> > 100644
> > --- a/gcc/range-op.cc
> > +++ b/gcc/range-op.cc
> > @@ -4311,6 +4311,83 @@ range_op_table::initialize_integral_ops ()
> >   
> >   }
> >   
> > +bool
> > +plus_without_overflow_p (value_range &vr0, value_range &vr1, tree type)
> > +{
> > +  wi::overflow_type ovf;
> > +  signop sgn = TYPE_SIGN (type);
> > +  wide_int wmax0 = vr0.upper_bound ();
> > +  wide_int wmax1 = vr1.upper_bound ();
> > +  wi::add (wmax0, wmax1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  if (TYPE_UNSIGNED (type))
> > +    return true;
> > +
> > +  wide_int wmin0 = vr0.lower_bound ();
> > +  wide_int wmin1 = vr1.lower_bound ();
> > +  wi::add (wmin0, wmin1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  return true;
> > +}
> > +
> > +bool
> > +minus_without_overflow_p (value_range &vr0, value_range &vr1, tree type)
> > +{
> > +  wi::overflow_type ovf;
> > +  signop sgn = TYPE_SIGN (type);
> > +  wide_int wmin0 = vr0.lower_bound ();
> > +  wide_int wmax1 = vr1.upper_bound ();
> > +  wi::sub (wmin0, wmax1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  if (TYPE_UNSIGNED (type))
> > +    return true;
> > +
> > +  wide_int wmax0 = vr0.upper_bound ();
> > +  wide_int wmin1 = vr1.lower_bound ();
> > +  wi::sub (wmax0, wmin1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  return true;
> > +}
> > +
> > +bool
> > +mult_without_overflow_p (value_range &vr0, value_range &vr1, tree type)
> > +{
> > +  wi::overflow_type ovf;
> > +  signop sgn = TYPE_SIGN (type);
> > +  wide_int wmax0 = vr0.upper_bound ();
> > +  wide_int wmax1 = vr1.upper_bound ();
> > +  wi::mul (wmax0, wmax1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  if (TYPE_UNSIGNED (type))
> > +    return true;
> > +
> > +  wide_int wmin0 = vr0.lower_bound ();
> > +  wide_int wmin1 = vr1.lower_bound ();
> > +  wi::mul (wmin0, wmin1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  wi::mul (wmin0, wmax1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  wi::mul (wmax0, wmin1, sgn, &ovf);
> > +  if (ovf != wi::OVF_NONE)
> > +    return false;
> > +
> > +  return true;
> > +}
> > +
> >   #if CHECKING_P
> >   #include "selftest.h"
> >   
> > diff --git a/gcc/range-op.h b/gcc/range-op.h
> > index
> > af94c2756a74f710aa50aec1ac3b3de5eeb43a8e..1697ce5464c0cc8fbfb86234137ba7cc23e10979
> > 100644
> > --- a/gcc/range-op.h
> > +++ b/gcc/range-op.h
> > @@ -220,6 +220,10 @@ protected:
> >     range_operator *m_operator;
> >   };
> >   
> > +extern bool plus_without_overflow_p (value_range &, value_range &, tree);
> > +extern bool minus_without_overflow_p (value_range &, value_range &, tree);
> > +extern bool mult_without_overflow_p (value_range &, value_range &, tree);
> > +
> >   // Cast the range in R to TYPE if R supports TYPE.
> >   
> >   inline bool
> > diff --git a/gcc/value-query.h b/gcc/value-query.h
> > index
> > d10c3eac1e2e6c477cbab026942a45b4fcc2ddce..cf488c7ea9bfc423fd3de9d2c743f71175804ae2
> > 100644
> > --- a/gcc/value-query.h
> > +++ b/gcc/value-query.h
> > @@ -137,6 +137,16 @@ get_range_query (const struct function *fun)
> >     return (fun && fun->x_range_query) ? fun->x_range_query :
> >   &global_ranges;
> >   }
> >   
> > +/* Return true if there is range for "X" expression at "S" statement,
> > +   and the range is not varying and not undefined.   */
> > +
> > +inline bool
> > +get_range (vrange &r, tree x, gimple *s = NULL)
> > +{
> > +  return get_range_query (cfun)->range_of_expr (r, x, s) && !r.varying_p ()
> > +    && !r.undefined_p ();
> > +}
> > +
> >   // Query the global range of NAME in function F.  Default to cfun.
> >   extern void gimple_range_global (vrange &v, tree name,
> >                              struct function *f = cfun);
> > diff --git a/gcc/value-range.cc b/gcc/value-range.cc
> > index
> > 011bdbdeae62845b5627a8dfa0d261370df7e5db..5ae4e044194326c24aab6babf8e0df3e4b313e98
> > 100644
> > --- a/gcc/value-range.cc
> > +++ b/gcc/value-range.cc
> > @@ -313,6 +313,18 @@ add_vrange (const vrange &v, inchash::hash &hstate,
> >   
> >   } //namespace inchash
> >   
> > +bool
> > +irange::nonnegative_p () const
> > +{
> > +  return wi::ge_p (lower_bound (), 0, TYPE_SIGN (type ()));
> > +}
> > +
> > +bool
> > +irange::nonpositive_p () const
> > +{
> > +  return wi::le_p (upper_bound (), 0, TYPE_SIGN (type ()));
> > +}
> > +
> >   bool
> >   irange::supports_type_p (const_tree type) const
> >   {
> > diff --git a/gcc/value-range.h b/gcc/value-range.h
> > index
> > 0170188201bc9b1c4e117661c9a62819dc1547c5..a12dea514e48cdd04a3cee5dc6304637e501d399
> > 100644
> > --- a/gcc/value-range.h
> > +++ b/gcc/value-range.h
> > @@ -280,6 +280,8 @@ public:
> >     virtual bool singleton_p (tree *result = NULL) const override;
> >     bool singleton_p (wide_int &) const;
> >     bool contains_p (const wide_int &) const;
> > +  bool nonnegative_p () const;
> > +  bool nonpositive_p () const;
> >   
> >     // In-place operators.
> >     virtual bool union_ (const vrange &) override;
> > diff --git a/gcc/testsuite/gcc.dg/pr108757-1.c
> > b/gcc/testsuite/gcc.dg/pr108757-1.c
> > new file mode 100644
> > index
> > 0000000000000000000000000000000000000000..7908f4bdcb8e225fe311b668efbe8f6db525b4d5
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/pr108757-1.c
> > @@ -0,0 +1,18 @@
> > +/* PR tree-optimization/108757 */
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -fdump-tree-optimized" } */
> > +
> > +#include <limits.h>
> > +#define N 5
> > +#define M 3
> > +#define GAP 0
> > +typedef unsigned int UINT;
> > +typedef int INT;
> > +#define UMAX UINT_MAX
> > +#define IMAX INT_MAX
> > +#define IMIN INT_MIN
> > +#include "pr108757.h"
> > +
> > +/* { dg-final { scan-tree-dump-not " = x_\[0-9\]+\\(D\\) \\+ " "optimized"
> > } } *
> > +/* { dg-final { scan-tree-dump-not " = x_\[0-9\]+\\(D\\) \\- " "optimized"
> > } } */
> > +/* { dg-final { scan-tree-dump-not " = b_\[0-9\]+ \\+ " "optimized" } } */
> > diff --git a/gcc/testsuite/gcc.dg/pr108757-2.c
> > b/gcc/testsuite/gcc.dg/pr108757-2.c
> > new file mode 100644
> > index
> > 0000000000000000000000000000000000000000..82bebd09944f0be2e0690c604723bfe6182acec3
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/pr108757-2.c
> > @@ -0,0 +1,19 @@
> > +/* PR tree-optimization/108757 */
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -fdump-tree-optimized -fwrapv" } */
> > +
> > +#include <limits.h>
> > +#define N 4
> > +#define M 3
> > +#define GAP 2
> > +typedef unsigned int UINT;
> > +typedef int INT;
> > +#define UMAX UINT_MAX
> > +#define IMAX INT_MAX
> > +#define IMIN INT_MIN
> > +#include "pr108757.h"
> > +
> > +/* { dg-final { scan-tree-dump-times " = x_\[0-9\]+\\(D\\) \\+ " 16
> > "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times " = x_\[0-9\]+\\(D\\) \\- " 3
> > "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times " \\+ x_\[0-9\]+\\(D\\)" 3 "optimized"
> > } } */
> > +
> > diff --git a/gcc/testsuite/gcc.dg/pr108757.h
> > b/gcc/testsuite/gcc.dg/pr108757.h
> > new file mode 100644
> > index
> > 0000000000000000000000000000000000000000..5550199c1ef952f54eaa83087cec25e992057c34
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/pr108757.h
> > @@ -0,0 +1,233 @@
> > +#define NOINLINE __attribute__ ((noinline))
> > +UINT NOINLINE
> > +opt_u1 (UINT x)
> > +{
> > +  if (x < (M * N) - GAP)
> > +    return 0;
> > +  UINT a = x - (M * N);
> > +  UINT b = a / N;
> > +  return b + M;
> > +}
> > +
> > +UINT NOINLINE
> > +opt_u2 (UINT x)
> > +{
> > +  if (x > (UMAX - (M * N) + GAP))
> > +    return 0;
> > +  UINT a = x + (M * N);
> > +  UINT b = a / N;
> > +  return b - M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s1 (INT x)
> > +{
> > +  if (x < (M * N) - GAP)
> > +    return 0;
> > +  INT a = x - (M * N);
> > +  INT b = a / N;
> > +  return b + M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s2 (INT x)
> > +{
> > +  if (x < IMIN + (M * N) - GAP || x > 0)
> > +    return 0;
> > +  INT a = x - (M * N);
> > +  INT b = a / N;
> > +  return b + M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s3 (INT x)
> > +{
> > +  if (x < (M * N) - GAP)
> > +    return 0;
> > +  INT a = x - (M * N);
> > +  INT b = a / -N;
> > +  return b + -M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s4 (INT x)
> > +{
> > +  if (x < IMIN + (M * N) - GAP || x > 0)
> > +    return 0;
> > +  INT a = x - (M * N);
> > +  INT b = a / -N;
> > +  return b + -M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s5 (INT x)
> > +{
> > +  if (x > (-M * N) + GAP)
> > +    return 0;
> > +  INT a = x - (-M * N);
> > +  INT b = a / N;
> > +  return b + -M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s6 (INT x)
> > +{
> > +  if (x > IMAX - (M * N) + GAP || x < 0)
> > +    return 0;
> > +  INT a = x - (-M * N);
> > +  INT b = a / N;
> > +  return b + -M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s7 (INT x)
> > +{
> > +  if (x > (M * -N) + GAP)
> > +    return 0;
> > +  INT a = x - (M * -N);
> > +  INT b = a / -N;
> > +  return b + M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s8 (INT x)
> > +{
> > +  if (x > IMAX - (M * N) + GAP || x < 0)
> > +    return 0;
> > +  INT a = x - (M * -N);
> > +  INT b = a / -N;
> > +  return b + M;
> > +}
> > +
> > +UINT NOINLINE
> > +opt_u3 (UINT x)
> > +{
> > +  if (x < (M << N) - GAP)
> > +    return 0;
> > +  UINT a = x - (M << N);
> > +  UINT b = a >> N;
> > +  return b + M;
> > +}
> > +
> > +UINT NOINLINE
> > +opt_u4 (UINT x)
> > +{
> > +  if (x > (UMAX - (M << N)) + GAP)
> > +    return 0;
> > +  UINT a = x + (M << N);
> > +  UINT b = a >> N;
> > +  return b - M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s9 (INT x)
> > +{
> > +  if (x < (M << N) - GAP)
> > +    return 0;
> > +  INT a = x - (M << N);
> > +  INT b = a >> N;
> > +  return b + M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s10 (INT x)
> > +{
> > +  if (x < IMIN + (M << N) - GAP || x > 0)
> > +    return 0;
> > +  INT a = x - (M << N);
> > +  INT b = a >> N;
> > +  return b + M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s11 (INT x)
> > +{
> > +  if (x > (-M << N) + GAP)
> > +    return 0;
> > +  INT a = x - (-M << N);
> > +  INT b = a >> N;
> > +  return b + -M;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s12 (INT x)
> > +{
> > +  if (x > IMAX - (M << N) + GAP || x < 0)
> > +    return 0;
> > +  INT a = x - (-M << N);
> > +  INT b = a >> N;
> > +  return b + -M;
> > +}
> > +
> > +UINT NOINLINE
> > +opt_u5 (UINT x, UINT n, UINT m)
> > +{
> > +  if (n > N || m > M)
> > +    return 0;
> > +  if (x < (M*N) - GAP)
> > +    return 0;
> > +  UINT a = x - (m * n);
> > +  UINT b = a / n;
> > +  return b + m;
> > +}
> > +
> > +UINT NOINLINE
> > +opt_u6 (UINT x, UINT n, UINT m)
> > +{
> > +  if (n > N || m > M)
> > +    return 0;
> > +  if (x > (UMAX - M*N) + GAP)
> > +    return 0;
> > +  UINT a = x + (m * n);
> > +  UINT b = a / n;
> > +  return b - m;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s13 (INT x, INT n, INT m)
> > +{
> > +  if (n > N || m > M || n < 0 || m < 0)
> > +    return 0;
> > +  if (x < (M*N) - GAP)
> > +    return 0;
> > +  INT a = x - (m * n);
> > +  INT b = a / n;
> > +  return b + m;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s14 (INT x, INT n, INT m)
> > +{
> > +  if (n > N || m > M || n < 0 || m < 0)
> > +    return 0;
> > +  if (x > -M*N + GAP)
> > +    return 0;
> > +  INT a = x + (m * n);
> > +  INT b = a / n;
> > +  return b - m;
> > +}
> > +
> > +INT
> > +opt_s15 (INT x, INT n, INT m)
> > +{
> > +  if (n > 0 || m > 0 || n < -N || m < -M)
> > +    return 0;
> > +  if (x < (M*N) - GAP)
> > +    return 0;
> > +  INT a = x - (m * n);
> > +  INT b = a / n;
> > +  return b + m;
> > +}
> > +
> > +INT NOINLINE
> > +opt_s16 (INT x, INT n, INT m)
> > +{
> > +  if (n > 0 || m > 0 || n < -N || m < -M)
> > +    return 0;
> > +  if (x < 0 || x > (IMAX - M*N) + GAP)
> > +    return 0;
> > +  INT a = x + (m * n);
> > +  INT b = a / n;
> > +  return b - m;
> > +}
> > +
> 
> 
> 

-- 
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)

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