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.
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"}
} */
