On 6/1/26 16:08, Andrew Pinski wrote:
When I was looking into fixing tree_expr_nonnegative_p not to be recusive,
we should have tree_expr_nonnegative_p use the ranger.
I also didn't realize I wrote this patch before so this is
the updated version of the already approved:
https://gcc.gnu.org/pipermail/gcc-patches/2023-October/634205.html
Updated for the review comments.
Note testsuite/g++.dg/ipa/pure-const-3.C testcase will always fail as we can
use the fact the argument is always non-negative in many different places now.
Since there is no way to test it, let's remove the testcase.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/111959
gcc/ChangeLog:
* fold-const.cc (tree_single_nonnegative_p): Use the range to see
if the SSA_NAME was nonnegative.
gcc/testsuite/ChangeLog:
* gcc.dg/pr80776-1.c: xfail and update comment.
* gcc.dg/tree-ssa/forwprop-44.c: New test.
* testsuite/g++.dg/ipa/pure-const-3.C: Remove.
Signed-off-by: Andrew Pinski <[email protected]>
---
gcc/fold-const.cc | 13 +++++++++++++
gcc/testsuite/g++.dg/ipa/pure-const-3.C | 6 ------
gcc/testsuite/gcc.dg/pr80776-1.c | 10 +++++-----
gcc/testsuite/gcc.dg/tree-ssa/forwprop-44.c | 14 ++++++++++++++
4 files changed, 32 insertions(+), 11 deletions(-)
delete mode 100644 gcc/testsuite/g++.dg/ipa/pure-const-3.C
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/forwprop-44.c
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 179c7e167a3..bc690b24663 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -14576,6 +14576,19 @@ tree_single_nonnegative_p (tree t, int depth)
return RECURSE (TREE_OPERAND (t, 1)) && RECURSE (TREE_OPERAND (t, 2));
case SSA_NAME:
+ /* For integral types, query the range if possible. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (t)))
+ {
+ int_range_max r;
+ get_global_range_query ()->range_of_expr (r, t);
IS there a reason not to use get_range_query() ? get_global_range_query
will only uses ranges from SSA_NAME_RANGE_INFO(ssaname), and is the
fallback if there is no active ranger... You will not get any
contextual info this way, just global values.
+ if (!r.undefined_p () && !r.varying_p())
+ {
+ if (r.nonnegative_p ())
+ return true;
+ if (r.nonpositive_p () && !range_includes_zero_p (r))
+ return false;
+ }
+ }
/* Limit the depth of recursion to avoid quadratic behavior.
This is expected to catch almost all occurrences in practice.
If this code misses important cases that unbounded recursion
diff --git a/gcc/testsuite/g++.dg/ipa/pure-const-3.C
b/gcc/testsuite/g++.dg/ipa/pure-const-3.C
deleted file mode 100644
index 62d355b4ce7..00000000000
--- a/gcc/testsuite/g++.dg/ipa/pure-const-3.C
+++ /dev/null
@@ -1,6 +0,0 @@
-/* { dg-do compile } */
-/* { dg-options "-O2 -fno-ipa-vrp -fdump-tree-optimized -fno-tree-ccp
-fdisable-tree-evrp -fdisable-tree-vrp1 -fdisable-tree-vrp2 -fno-thread-jumps
-fno-tree-dominator-opts" } */
-
-#include "pure-const-3.h"
-
-/* { dg-final { scan-tree-dump "barvar" "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/pr80776-1.c b/gcc/testsuite/gcc.dg/pr80776-1.c
index b9bce62d982..bf0fcd86a65 100644
--- a/gcc/testsuite/gcc.dg/pr80776-1.c
+++ b/gcc/testsuite/gcc.dg/pr80776-1.c
@@ -18,14 +18,14 @@ Foo (void)
if (! (0 <= i && i <= 999999))
__builtin_unreachable ();
- /* Legacy evrp sets the range of i to [0, MAX] *before* the first conditional,
- and to [0,999999] *before* the second conditional. This is because both
- evrp and VRP use trickery to set global ranges when this particular use of
+ /* vrp1 sets the range of i to [0, MAX] *before* the first conditional,
+ and to [0,999999] *before* the second conditional. This is because
+ vrp use trickery to set global ranges when this particular use of
a __builtin_unreachable is in play (see uses of
assert_unreachable_fallthru_edge_p).
- Setting these ranges at the definition site, causes VRP to remove the
+ Setting these ranges at the definition site, causes other to remove the
unreachable code altogether, leaving the following sprintf unguarded.
This
And as a side note, These comments should not be true any more. no
version of VRP does any trickery with regards to builtin_unreachable.
i_4 is VARYING until we get to BB4, at which point it is [0, +INF].
AFTER the conditional :)
=========== BB 2 ============
Imports: i_4
Exports: i_4
<bb 2> :
i_4 = somerandom ();
if (i_4 < 0)
goto <bb 3>; [INV]
else
goto <bb 4>; [INV]
2->3 (T) i_4 : [irange] int [-INF, -1]
2->4 (F) i_4 : [irange] int [0, +INF]
=========== BB 3 ============
<bb 3> :
__builtin_unreachable ();
=========== BB 4 ============
Imports: i_4
Exports: i.0_1 i_4
i.0_1 : i_4(I)
i_4 [irange] int [0, +INF]
Partial equiv (i.0_1 pe32 i_4)
<bb 4> :
i.0_1 = (unsigned int) i_4;
if (i.0_1 > 999999)
goto <bb 5>; [INV]
else
goto <bb 6>; [INV]
i.0_1 : [irange] unsigned int [0, 2147483647] MASK 0x7fffffff VALUE 0x0
4->5 (T) i.0_1 : [irange] unsigned int [1000000, 2147483647] MASK
0x7fffffff VALUE 0x0
4->5 (T) i_4 : [irange] int [1000000, +INF] MASK 0x7fffffff
VALUE 0x0
4->6 (F) i.0_1 : [irange] unsigned int [0, 999999] MASK 0xfffff
VALUE 0x0
4->6 (F) i_4 : [irange] int [0, 999999] MASK 0xfffff VALUE 0x0
=========== BB 5 ============
<bb 5> :
__builtin_unreachable ();
=========== BB 6 ============
i_4 [irange] int [0, 999999] MASK 0xfffff VALUE 0x0
<bb 6> :
_7 = __builtin___sprintf_chk (&number, 1, 7, "%d", i_4);
return;
Non-varying global ranges:
=========================:
i.0_1 : [irange] unsigned int [0, 2147483647] MASK 0x7fffffff VALUE 0x0
Likewise with i.0_1, its only in bb6 that it becomes [0, 999999].
i_4 has a global range of VARYING, and as you can see, i.0_1 is set to
[0, 0x7fffffff]. no trickery!
After VRP2 and the unreachable calls are removed, well then things
change and there is nothing but i_4 with a global range of [0, 999999]
Andrew
