[COMMITTED] Fold: Fix up merge_truthop_with_opposite_arm for NaNs [PR95351]

[Andrew Pinski]

The problem here is that merge_truthop_with_opposite_arm would
use the type of the result of the comparison rather than the operands
of the comparison to figure out if we are honoring NaNs.
This fixes that oversight and now we get the correct results in this
case.

Committed as obvious after a bootstrap/test on x86_64-linux-gnu.

        PR middle-end/95351

gcc/ChangeLog:

        * fold-const.cc (merge_truthop_with_opposite_arm): Use
        the type of the operands of the comparison and not the type
        of the comparison.

gcc/testsuite/ChangeLog:

        * gcc.dg/float_opposite_arm-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
 gcc/fold-const.cc                           |  3 ++-
 gcc/testsuite/gcc.dg/float_opposite_arm-1.c | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/float_opposite_arm-1.c

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 43105d20be3..299c22bf391 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -6420,7 +6420,6 @@ static tree
 merge_truthop_with_opposite_arm (location_t loc, tree op, tree cmpop,
                                 bool rhs_only)
 {
-  tree type = TREE_TYPE (cmpop);
   enum tree_code code = TREE_CODE (cmpop);
   enum tree_code truthop_code = TREE_CODE (op);
   tree lhs = TREE_OPERAND (op, 0);
@@ -6436,6 +6435,8 @@ merge_truthop_with_opposite_arm (location_t loc, tree op, 
tree cmpop,
   if (TREE_CODE_CLASS (code) != tcc_comparison)
     return NULL_TREE;
 
+  tree type = TREE_TYPE (TREE_OPERAND (cmpop, 0));
+
   if (rhs_code == truthop_code)
     {
       tree newrhs = merge_truthop_with_opposite_arm (loc, rhs, cmpop, 
rhs_only);
diff --git a/gcc/testsuite/gcc.dg/float_opposite_arm-1.c 
b/gcc/testsuite/gcc.dg/float_opposite_arm-1.c
new file mode 100644
index 00000000000..d2dbff35066
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/float_opposite_arm-1.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-original -fdump-tree-optimized" } */
+/* { dg-add-options ieee } */
+/* PR middle-end/95351 */
+
+int Foo(double possiblyNAN, double b, double c)
+{
+    return (possiblyNAN <= 2.0) || ((possiblyNAN  > 2.0) && (b > c));
+}
+
+/* Make sure we don't remove either >/<=  */
+
+/* { dg-final { scan-tree-dump "possiblyNAN > 2.0e.0" "original" } } */
+/* { dg-final { scan-tree-dump "possiblyNAN_\[0-9\]+.D. > 2.0e.0" "optimized" 
} } */
+
+/* { dg-final { scan-tree-dump "possiblyNAN <= 2.0e.0" "original" } } */
+/* { dg-final { scan-tree-dump "possiblyNAN_\[0-9\]+.D. <= 2.0e.0" "optimized" 
} } */
-- 
2.43.0