[RFA,PR,tree-optimization/79095,4/4] Tests

This is unchanged from the original posting.  Reposting to make review 
easier.


The tests in g++.dg start with a reduced test from Martin (pr79095-1.C) 
that includes a size check.  With the size != 0 check this testcase 
should not issue any warnings as the path that turns into a 
__builtin_memset should get eliminated.

pr79095-2.C is the same test, but without the size != test.  This test 
should trigger an "exceeds maximum object size" warning.

pr79095-3.C is the original test from the BZ, but with a proper size 
check on the vector.  This test should not produce a warning.

pr79095-4.C is the original test from the BZ, but without a size check 
on the vector.  This should produce *one* warning (trunk currently 
generates 3).  We verify that there's just one __builtin_memset by the 
time VRP2 is done and verify that we do get the desired warning.

pr79095-5.C is another test from Martin which should not produce a warning.

gcc-torture/execute/arith-1.c is updated to test a few more cases.  This 
was mis-compiled at some point during patch development and at that time 
I added the additional tsts.

gcc.dg/tree-ssa/pr79095.c is a new test to verify that VRP can propagate 
constants generated on the true/false arms of an overflow test and that 
constants to _not_ propagate into the wrong arm of the conditional.


These were included in the bootstrap & regression testing of the prior 
patches.  All the tests pass with the prior patches installed.  OK for 
the trunk?
* g++.dg/pr79095-1.C: New test
	* g++.dg/pr79095-2.C: New test
	* g++.dg/pr79095-3.C: New test
	* g++.dg/pr79095-4.C: New test
	* g++.dg/pr79095-5.C: New test
	* gcc.c-torture/execute/arith-1.c: Update with more cases.
	* gcc.dg/tree-ssa/pr79095-1.c: New test.

On Tue, Feb 7, 2017 at 7:32 PM, Jeff Law <law@redhat.com> wrote:
>
> This is unchanged from the original posting.  Reposting to make review
> easier.
>
>
> The tests in g++.dg start with a reduced test from Martin (pr79095-1.C) that
> includes a size check.  With the size != 0 check this testcase should not
> issue any warnings as the path that turns into a __builtin_memset should get
> eliminated.
>
> pr79095-2.C is the same test, but without the size != test.  This test
> should trigger an "exceeds maximum object size" warning.
>
> pr79095-3.C is the original test from the BZ, but with a proper size check
> on the vector.  This test should not produce a warning.
>
> pr79095-4.C is the original test from the BZ, but without a size check on
> the vector.  This should produce *one* warning (trunk currently generates
> 3).  We verify that there's just one __builtin_memset by the time VRP2 is
> done and verify that we do get the desired warning.
>
> pr79095-5.C is another test from Martin which should not produce a warning.
>
> gcc-torture/execute/arith-1.c is updated to test a few more cases.  This was
> mis-compiled at some point during patch development and at that time I added
> the additional tsts.
>
> gcc.dg/tree-ssa/pr79095.c is a new test to verify that VRP can propagate
> constants generated on the true/false arms of an overflow test and that
> constants to _not_ propagate into the wrong arm of the conditional.
>
>
> These were included in the bootstrap & regression testing of the prior
> patches.  All the tests pass with the prior patches installed.  OK for the
> trunk?

Ok.

Richard.

>
>         * g++.dg/pr79095-1.C: New test
>         * g++.dg/pr79095-2.C: New test
>         * g++.dg/pr79095-3.C: New test
>         * g++.dg/pr79095-4.C: New test
>         * g++.dg/pr79095-5.C: New test
>         * gcc.c-torture/execute/arith-1.c: Update with more cases.
>         * gcc.dg/tree-ssa/pr79095-1.c: New test.
>
> diff --git a/gcc/testsuite/g++.dg/pr79095-1.C
> b/gcc/testsuite/g++.dg/pr79095-1.C
> new file mode 100644
> index 0000000..4b8043c
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr79095-1.C
> @@ -0,0 +1,40 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -O3" } */
> +
> +typedef long unsigned int size_t;
> +
> +inline void
> +fill (int *p, size_t n, int)
> +{
> +  while (n--)
> +    *p++ = 0;
> +}
> +
> +struct B
> +{
> +  int* p0, *p1, *p2;
> +
> +  size_t size () const {
> +    return size_t (p1 - p0);
> +  }
> +
> +  void resize (size_t n) {
> +    if (n > size())
> +      append (n - size());
> +  }
> +
> +  void append (size_t n)
> +  {
> +    if (size_t (p2 - p1) >= n)          {
> +      fill (p1, n, 0);
> +    }
> +  }
> +};
> +
> +void foo (B &b)
> +{
> +  if (b.size () != 0)
> +    b.resize (b.size () - 1);
> +}
> +
> +
> diff --git a/gcc/testsuite/g++.dg/pr79095-2.C
> b/gcc/testsuite/g++.dg/pr79095-2.C
> new file mode 100644
> index 0000000..9dabc7e
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr79095-2.C
> @@ -0,0 +1,46 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -O3" } */
> +
> +typedef long unsigned int size_t;
> +
> +inline void
> +fill (int *p, size_t n, int)
> +{
> +  while (n--)
> +    *p++ = 0;
> +}
> +
> +struct B
> +{
> +  int* p0, *p1, *p2;
> +
> +  size_t size () const {
> +    return size_t (p1 - p0);
> +  }
> +
> +  void resize (size_t n) {
> +    if (n > size())
> +      append (n - size());
> +  }
> +
> +  void append (size_t n)
> +  {
> +    if (size_t (p2 - p1) >= n)          {
> +      fill (p1, n, 0);
> +    }
> +  }
> +};
> +
> +void foo (B &b)
> +{
> +    b.resize (b.size () - 1);
> +}
> +
> +/* If b.size() == 0, then the argument to b.resize is -1U (it overflowed).
> +   This will result calling "fill" which turns into a memset with a bogus
> +   length argument.  We want to make sure we warn, which multiple
> +   things.  First the ldist pass converted the loop into a memset,
> +   cprop and simplifications made the length a constant and the static
> +   analysis pass determines it's a bogus size to pass to memset.  */
> +/* { dg-warning "exceeds maximum object size" "" { target *-*-* } 0 } */
> +
> diff --git a/gcc/testsuite/g++.dg/pr79095-3.C
> b/gcc/testsuite/g++.dg/pr79095-3.C
> new file mode 100644
> index 0000000..28c8a37
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr79095-3.C
> @@ -0,0 +1,17 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -O3" } */
> +
> +#include <vector>
> +
> +void foo(std::vector<unsigned int> &v);
> +
> +void vtest()
> +{
> +  std::vector<unsigned int> v;
> +  foo (v);
> +  if (v.size() > 0)
> +  {
> +    v.resize (v.size()-1);
> +  }
> +}
> +
> diff --git a/gcc/testsuite/g++.dg/pr79095-4.C
> b/gcc/testsuite/g++.dg/pr79095-4.C
> new file mode 100644
> index 0000000..df55025
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr79095-4.C
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -O3 -fdump-tree-vrp2" } */
> +
> +#include <vector>
> +
> +void foo(std::vector<unsigned int> &v);
> +
> +void vtest()
> +{
> +  std::vector<unsigned int> v;
> +  foo (v);
> +  {
> +    v.resize (v.size()-1);
> +  }
> +}
> +
> +/* As written this testcase should trigger a warning.  We overflow to -1U
> +   if v.size() == 0 in foo().  This results in bogus calls to memset.
> +
> +   The number of clearing loops in the IL can vary depending on the C++
> +   mode used for the test.  But by the end of VRP2, there should be a
> single
> +   clearing loop left and it should be using memcpy.  */
> +/* { dg-final { scan-tree-dump-times  "__builtin_memset \\(_\[0-9\]+, 0,
> \[0-9\]+\\)" 1 "vrp2" } } */
> +
> +/* And that call should trigger a warning.  */
> +/* { dg-warning "exceeds maximum object size" "" { target *-*-* } 0 } */
> diff --git a/gcc/testsuite/g++.dg/pr79095-5.C
> b/gcc/testsuite/g++.dg/pr79095-5.C
> new file mode 100644
> index 0000000..266f4e9
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr79095-5.C
> @@ -0,0 +1,34 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -O3" } */
> +
> +typedef __SIZE_TYPE__ size_t;
> +
> +struct S {
> +  int *p0, *p1, *p2;
> +
> +  size_t size () const { return p1 - p0; }
> +
> +  void f (size_t n) {
> +    if (n > size ())       // can't happen because
> +      foo (n - size ());   //   n is in [1, MIN(size() - 1, 3)]
> +    else if (n < size ())
> +      bar (p0 + n);
> +  }
> +
> +  void foo (size_t n)
> +  {
> +    size_t left = (size_t)(p2 - p1);
> +    if (left >= n)
> +      __builtin_memset (p2, 0, n * sizeof *p2); // { dg-bogus "maximum
> object size" }
> +
> +  }
> +
> +  void bar (int*);
> +};
> +
> +void f (S &s)
> +{
> +  size_t n = s.size ();
> +  if (n > 1 && n < 5)
> +    s.f (n - 1);
> +}
> diff --git a/gcc/testsuite/gcc.c-torture/execute/arith-1.c
> b/gcc/testsuite/gcc.c-torture/execute/arith-1.c
> index 58df322..6168d77 100644
> --- a/gcc/testsuite/gcc.c-torture/execute/arith-1.c
> +++ b/gcc/testsuite/gcc.c-torture/execute/arith-1.c
> @@ -7,9 +7,41 @@ sat_add (unsigned i)
>    return ret;
>  }
>
> +unsigned
> +sat_add2 (unsigned i)
> +{
> +  unsigned ret = i + 1;
> +  if (ret > i)
> +    return ret;
> +  return i;
> +}
> +
> +unsigned
> +sat_add3 (unsigned i)
> +{
> +  unsigned ret = i - 1;
> +  if (ret > i)
> +    ret = i;
> +  return ret;
> +}
> +
> +unsigned
> +sat_add4 (unsigned i)
> +{
> +  unsigned ret = i - 1;
> +  if (ret < i)
> +    return ret;
> +  return i;
> +}
>  main ()
>  {
>    if (sat_add (~0U) != ~0U)
>      abort ();
> +  if (sat_add2 (~0U) != ~0U)
> +    abort ();
> +  if (sat_add3 (0U) != 0U)
> +    abort ();
> +  if (sat_add4 (0U) != 0U)
> +    abort ();
>    exit (0);
>  }
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr79095.c
> b/gcc/testsuite/gcc.dg/tree-ssa/pr79095.c
> new file mode 100644
> index 0000000..f635fca
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr79095.c
> @@ -0,0 +1,436 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fno-ipa-icf -fdump-tree-vrp1" } */
> +
> +extern void arf (unsigned x, unsigned y);
> +extern void baz (unsigned x, unsigned y);
> +
> +unsigned
> +f1 (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (b < a)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f1r (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (a < b)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f1n (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(b < a))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f1nr (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(a < b))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f1o (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (a < b)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f1ro (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (b < a)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f1no (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(a < b))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f1nro (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(b < a))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f2 (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (b <= a)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2r (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (a <= b)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2n (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(b <= a))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2nr (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(a <= b))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f2o (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (a <= b)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2ro (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (b <= a)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2no (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(a <= b))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f2nro (unsigned a, unsigned b)
> +{
> +  b = a + 1;
> +  if (!(b <= a))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f3 (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (b < a)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3r (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (a < b)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3n (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(b < a))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3nr (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(a < b))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f3o (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (a < b)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3ro (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (b < a)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3no (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(a < b))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f3nro (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(b < a))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f4 (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (b <= a)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4r (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (a <= b)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4n (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(b <= a))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4nr (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(a <= b))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +
> +unsigned
> +f4o (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (a <= b)
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4ro (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (b <= a)
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4no (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(a <= b))
> +    {
> +      baz (a, b);
> +      return 42;
> +    }
> +  arf (a, b);
> +  return b;
> +}
> +
> +unsigned
> +f4nro (unsigned a, unsigned b)
> +{
> +  b = a - 1;
> +  if (!(b <= a))
> +    {
> +      arf (a, b);
> +      return 42;
> +    }
> +  baz (a, b);
> +  return b;
> +}
> +
> +/* All calls to baz should still reference a & b as arguments. */
> +/* { dg-final { scan-tree-dump-times "baz \\(a_\[0-9\]+\\(D\\),
> b_\[0-9\]+\\)" 32 "vrp1"} } */
> +
> +
> +/* All calls to arf should have constant arguments.  */
> +/* { dg-final { scan-tree-dump-times "arf \\(\[0-9\]+, \[0-9\]+\\)" 32
> "vrp1"} } */
>