diff options
Diffstat (limited to 'gcc/tree-ssa-phiprop.c')
| -rw-r--r-- | gcc/tree-ssa-phiprop.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/gcc/tree-ssa-phiprop.c b/gcc/tree-ssa-phiprop.c index d710582..e90ae6a 100644 --- a/gcc/tree-ssa-phiprop.c +++ b/gcc/tree-ssa-phiprop.c @@ -338,8 +338,15 @@ propagate_with_phi (basic_block bb, gphi *phi, struct phiprop_d *phivn, && (!type || types_compatible_p (TREE_TYPE (gimple_assign_lhs (use_stmt)), type)) - /* We cannot replace a load that may throw or is volatile. */ - && !stmt_can_throw_internal (cfun, use_stmt))) + /* We cannot replace a load that may throw or is volatile. + For volatiles the transform can change the number of + executions if the load is inside a loop but the address + computations outside (PR91812). We could relax this + if we guard against that appropriately. For loads that can + throw we could relax things if the moved loads all are + known to not throw. */ + && !stmt_can_throw_internal (cfun, use_stmt) + && !gimple_has_volatile_ops (use_stmt))) continue; /* Check if we can move the loads. The def stmt of the virtual use |