[gcc r17-2735] testsuite: Add C++ testcase for PR 126296: `<=>` folding into `<>`.

https://gcc.gnu.org/g:1c69a96d20cbfd4e9a36ee8a6bff8591150424aa

commit r17-2735-g1c69a96d20cbfd4e9a36ee8a6bff8591150424aa
Author: Andrea Pinski <[email protected]>
Date:   Mon Jul 27 15:06:07 2026 -0700

    testsuite: Add C++ testcase for PR 126296: `<=>` folding into `<>`.
    
    This adds 2 testcases for fp: `(i <=> j > 0) | (i <=> j < 0)`.
    The trapping version was fixed by r17-2709-gde8be0eb05d951
    while the non-trapping version was fixed earlier by
    r17-2129-gea8c74c074925b.
    Since we didn't have a testcase for these cases before,
    it would be a good idea to have them.
    
    Pushed as obvious after testing to make sure they work on x86_64-linux-gnu.
    
            PR tree-optimization/126296
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/tree-ssa/pr126296-1.C: New test.
            * g++.dg/tree-ssa/pr126296-2.C: New test.
    
    Signed-off-by: Andrea Pinski <[email protected]>

Diff:
---
 gcc/testsuite/g++.dg/tree-ssa/pr126296-1.C | 20 ++++++++++++++++++++
 gcc/testsuite/g++.dg/tree-ssa/pr126296-2.C | 20 ++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr126296-1.C b/gcc/testsuite/g++.dg/tree-ssa/pr126296-1.C
new file mode 100644
index 000000000000..9859d4ba2d2c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr126296-1.C
@@ -0,0 +1,20 @@
+// PR tree-optimization/126296
+// { dg-do compile { target c++20 } }
+// { dg-options "-O2 -g0 -ftrapping-math -fdump-tree-optimized" }
+// { dg-final { scan-tree-dump-times "\[ij]_\[0-9]+\\(D\\) <> \[ij]_\[0-9]+\\(D\\)" 1 "optimized" } }
+// { dg-final { scan-tree-dump-times "i_\[0-9]+\\(D\\) <> 5\\.0" 1 "optimized" } }
+// { dg-final { scan-tree-dump-not "if " "optimized" } }
+
+#include <compare>
+
+#define A __attribute__((noipa))
+A bool f1 (double i, double j)
+{
+  auto c = i <=> j;
+  return (c < 0) | (c > 0);
+}
+A bool f2 (double i)
+{
+  auto c = i <=> 5.0;
+  return (c < 0) | (c > 0);
+}
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr126296-2.C b/gcc/testsuite/g++.dg/tree-ssa/pr126296-2.C
new file mode 100644
index 000000000000..bbddf885b73c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr126296-2.C
@@ -0,0 +1,20 @@
+// PR tree-optimization/126296
+// { dg-do compile { target c++20 } }
+// { dg-options "-O2 -g0 -fno-trapping-math -fdump-tree-optimized" }
+// { dg-final { scan-tree-dump-times "\[ij]_\[0-9]+\\(D\\) <> \[ij]_\[0-9]+\\(D\\)" 1 "optimized" } }
+// { dg-final { scan-tree-dump-times "i_\[0-9]+\\(D\\) <> 5\\.0" 1 "optimized" } }
+// { dg-final { scan-tree-dump-not "if " "optimized" } }
+
+#include <compare>
+
+#define A __attribute__((noipa))
+A bool f1 (double i, double j)
+{
+  auto c = i <=> j;
+  return (c < 0) | (c > 0);
+}
+A bool f2 (double i)
+{
+  auto c = i <=> 5.0;
+  return (c < 0) | (c > 0);
+}