The SLP permute optimization rewrite fixed this.
Tested on x86_64-unknown-linux-gnu, pushed to trunk and 13 branch.
PR tree-optimization/113896
* g++.dg/torture/pr113896.C: New testcase.
---
gcc/testsuite/g++.dg/torture/pr113896.C | 35 +++++++++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/torture/pr113896.C
diff --git a/gcc/testsuite/g++.dg/torture/pr113896.C
b/gcc/testsuite/g++.dg/torture/pr113896.C
new file mode 100644
index 00000000000..534c1c2e1cc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr113896.C
@@ -0,0 +1,35 @@
+// { dg-do run }
+// { dg-additional-options "-ffast-math" }
+
+double a1 = 1.0;
+double a2 = 1.0;
+
+void __attribute__((noipa))
+f(double K[2], bool b)
+{
+ double A[] = {
+ b ? a1 : a2,
+ 0,
+ 0,
+ 0
+ };
+
+ double sum{};
+ for(double a : A) sum += a;
+ for(double& a : A) a /= sum;
+
+ if (b) {
+ K[0] = A[0]; // 1.0
+ K[1] = A[1]; // 0.0
+ } else {
+ K[0] = A[0] + A[1];
+ }
+}
+
+int main()
+{
+ double K[2]{};
+ f(K, true);
+ if (K[0] != 1. || K[1] != 0.)
+ __builtin_abort ();
+}
--
2.35.3
