Hi, while updating compute_points_to_sets I missed that the code not only sets the nonlocal/escaped flags but also initializes pt. With my previous change if uses_global_memory is false pt is not updated correctly which may lead to wrong code.
This is fixed by the following patch I comitted to avoid strange misoptimizations. Bootstrapped/regtested x86_64-linux and also tested with LTO. Honza gcc/ChangeLog: PR tree-optimization/102720 * tree-ssa-structalias.c (compute_points_to_sets): Fix producing of call used and clobbered sets. diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c index 6f12a66ee0d..2e6513bb72a 100644 --- a/gcc/tree-ssa-structalias.c +++ b/gcc/tree-ssa-structalias.c @@ -7541,17 +7541,18 @@ compute_points_to_sets (void) determine_global_memory_access (stmt, NULL, &reads_global_memory, &uses_global_memory); - if (!uses_global_memory) - ; - else if ((vi = lookup_call_use_vi (stmt)) != NULL) + if ((vi = lookup_call_use_vi (stmt)) != NULL) { *pt = find_what_var_points_to (cfun->decl, vi); /* Escaped (and thus nonlocal) variables are always implicitly used by calls. */ /* ??? ESCAPED can be empty even though NONLOCAL always escaped. */ - pt->nonlocal = uses_global_memory; - pt->escaped = uses_global_memory; + if (uses_global_memory) + { + pt->nonlocal = uses_global_memory; + pt->escaped = uses_global_memory; + } } else if (uses_global_memory) { @@ -7572,17 +7573,18 @@ compute_points_to_sets (void) determine_global_memory_access (stmt, &writes_global_memory, NULL, NULL); - if (!writes_global_memory) - ; - else if ((vi = lookup_call_clobber_vi (stmt)) != NULL) + if ((vi = lookup_call_clobber_vi (stmt)) != NULL) { *pt = find_what_var_points_to (cfun->decl, vi); /* Escaped (and thus nonlocal) variables are always implicitly clobbered by calls. */ /* ??? ESCAPED can be empty even though NONLOCAL always escaped. */ - pt->nonlocal = writes_global_memory; - pt->escaped = writes_global_memory; + if (writes_global_memory) + { + pt->nonlocal = writes_global_memory; + pt->escaped = writes_global_memory; + } } else if (writes_global_memory) {