When we vectorize a reduction and the reduction value flows across
an abnormal edge we have to make sure to mark the final SSA properly.
The following serves as a recipie how to avoid blindly copying
SSA_NAME_OCCURS_IN_ABNORMAL_PHI but instead set it when needed during
use replacement.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/123729
* tree-vect-loop.cc (vect_create_epilog_for_reduction): Set
SSA_NAME_OCCURS_IN_ABNORMAL_PHI if the reduction flows
across an abnomal edge.
* g++.dg/torture/pr123729.C: New testcase.
---
gcc/testsuite/g++.dg/torture/pr123729.C | 60 +++++++++++++++++++++++++
gcc/tree-vect-loop.cc | 11 ++++-
2 files changed, 70 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/torture/pr123729.C
diff --git a/gcc/testsuite/g++.dg/torture/pr123729.C
b/gcc/testsuite/g++.dg/torture/pr123729.C
new file mode 100644
index 00000000000..1e12c680f29
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr123729.C
@@ -0,0 +1,60 @@
+// { dg-do compile }
+// { dg-additional-options "-std=gnu++20" }
+
+#include <csetjmp>
+#include <iostream>
+
+template <typename T> struct A { using type = int; };
+template <typename F, typename... G> struct B {};
+template <typename F> struct B<F> { using type = F; };
+struct {
+ template <typename... F,
+ typename Overload = typename B<typename A<F>::type...>::type>
+ int operator()(F...) {
+ int iArrFld_0_0;
+ for (int i = 7; i < 28; ++i)
+ ;
+ int i1 = 3;
+ try {
+ for (int i = 7; i < 28; ++i) {
+ for (int j = 0; j < 7; ++j)
+ if (iArrFld_0_0 == 0) {
+ for (int k = 0; k < 20000; ++k)
+ std::cout << "Hello, world!" << std::endl;
+ }
+ jmp_buf env2;
+ for (int i2 = 16; i2 < 350; ++i2)
+ for (int j2 = 1; j2 < 75; ++j2)
+ for (int k2 = 0; k2 < 16; ++k2) {
+ int temp2 = i2 + j2 + k2;
+ int mod2 = temp2 % 8;
+ {
+ setjmp(env2) == 0;
+ ;
+ }
+ }
+ }
+ } catch (const std::exception &e) {
+ }
+ auto lambda = [](int x) {
+ return [x](int y) {
+ int z = 0;
+ if (y > 0)
+ z = 1;
+ return z + x;
+ };
+ };
+ for (int i = 0; i < 1000; ++i) {
+ int m = 0;
+ auto f = lambda(i);
+ for (int j = 0; j < 100; ++j)
+ m += f(j);
+ i1 += m;
+ }
+ std::cout << "Final value of i1: " << i1 << std::endl;
+ return 0;
+ }
+} a;
+int main() {
+ auto f = a([] {});
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 9c2345ce955..c8b9c6268c8 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6287,8 +6287,17 @@ vect_create_epilog_for_reduction (loop_vec_info
loop_vinfo,
scalar_result = scalar_results[k];
FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name)
{
+ gphi *use_phi = dyn_cast <gphi *> (use_stmt);
FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
- SET_USE (use_p, scalar_result);
+ {
+ if (use_phi
+ && (phi_arg_edge_from_use (use_p)->flags & EDGE_ABNORMAL))
+ {
+ gcc_assert (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig_name));
+ SSA_NAME_OCCURS_IN_ABNORMAL_PHI (scalar_result) = 1;
+ }
+ SET_USE (use_p, scalar_result);
+ }
update_stmt (use_stmt);
}
}
--
2.51.0
