[gcc r14-9422] Fold: Fix up merge_truthop_with_opposite_arm for NaNs [PR95351]

[gcc r14-9422] Fold: Fix up merge_truthop_with_opposite_arm for NaNs [PR95351]

[Andrew Pinski]

https://gcc.gnu.org/g:31ce2e993d09dcad1ce139a2848a28de5931056d

commit r14-9422-g31ce2e993d09dcad1ce139a2848a28de5931056d
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Sun Mar 10 22:17:09 2024 +0000

    Fold: Fix up merge_truthop_with_opposite_arm for NaNs [PR95351]
    
    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_apinski@quicinc.com>

Diff:
---
 gcc/fold-const.cc                           |  3 ++-
 gcc/testsuite/gcc.dg/float_opposite_arm-1.c | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

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" } } */