https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98914
--- Comment #1 from luoxhu at gcc dot gnu.org ---
The type of k in the case should be "long" to reproduce the issue,
ICE happens at
rs6000_expand_vector_set: gcc_assert (GET_MODE (idx) == E_SImode);
Reason is the vector index variable need be "signed int" for all vec_insert
prototype.
ELFv2 ABI:
vector signed char vec_insert (signed char, vector signed char, signed int);
vector unsigned char vec_insert (unsigned char, vector unsigned char, signed
int);
vector signed int vec_insert (signed int, vector signed int, signed int);
vector unsigned int vec_insert (unsigned int, vector unsigned int, signed int);
vector signed long long vec_insert (signed long long, vector signed long long,
signed int);
Not sure all targets like X86/AArch64 also has some requirements, and whether
below fix reasonable to not generate IFN VEC_SET for stmt like
VIEW_CONVERT_EXPR<unsigned char[16]>(v)[k_7] = 170; ?
diff --git a/gcc/gimple-isel.cc b/gcc/gimple-isel.cc
index 2c78a08d3f1..dbbae270a36 100644
--- a/gcc/gimple-isel.cc
+++ b/gcc/gimple-isel.cc
@@ -77,6 +77,7 @@ gimple_expand_vec_set_expr (gimple_stmt_iterator *gsi)
tree view_op0 = TREE_OPERAND (op0, 0);
machine_mode outermode = TYPE_MODE (TREE_TYPE (view_op0));
if (auto_var_in_fn_p (view_op0, cfun->decl)
+ && TYPE_MODE (TREE_TYPE (pos)) == E_SImode
&& !TREE_ADDRESSABLE (view_op0) && can_vec_set_var_idx_p (outermode))
{
location_t loc = gimple_location (stmt);
