https://gcc.gnu.org/g:46a3355c7f165661a048151ce36cf6e08a4e5d9d
commit r16-6918-g46a3355c7f165661a048151ce36cf6e08a4e5d9d Author: Richard Biener <[email protected]> Date: Tue Jan 20 10:57:34 2026 +0100 middle-end/123697 - fix .MASK_LOAD_LANES folding .MASK_LOAD_LANES has an aggregate (array of vectors) return value which is not compatible with the else value used when trying to fold this with all lanes inactive. Instead use an empty CTOR if the else value is zero and otherwise do not simplify. PR middle-end/123697 * gimple-fold.cc (gimple_fold_partial_load_store): Use an empty CTOR for a zero else value in .MASK_LOAD_LANES. * gcc.dg/vect/vect-pr123697.c: New testcase. Diff: --- gcc/gimple-fold.cc | 6 ++++++ gcc/testsuite/gcc.dg/vect/vect-pr123697.c | 13 +++++++++++++ 2 files changed, 19 insertions(+) diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc index b92bf450aba3..4766187e0b9d 100644 --- a/gcc/gimple-fold.cc +++ b/gcc/gimple-fold.cc @@ -5899,6 +5899,12 @@ gimple_fold_partial_load_store (gimple_stmt_iterator *gsi, gcall *call) /* Replace load with else value. */ int else_index = internal_fn_else_index (ifn); tree else_value = gimple_call_arg (call, else_index); + if (!is_gimple_reg (lhs)) + { + if (!zerop (else_value)) + return false; + else_value = build_constructor (TREE_TYPE (lhs), NULL); + } gassign *new_stmt = gimple_build_assign (lhs, else_value); gimple_set_location (new_stmt, gimple_location (call)); gsi_replace (gsi, new_stmt, false); diff --git a/gcc/testsuite/gcc.dg/vect/vect-pr123697.c b/gcc/testsuite/gcc.dg/vect/vect-pr123697.c new file mode 100644 index 000000000000..e1717012e0a3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-pr123697.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-O3" } */ + +struct a { + int c[2]; +}; +struct a d[3]; +double f; +void g() +{ + for (int e = 0; e < 3; ++e) + f += d[e].c[1]; +}
