diff options
Diffstat (limited to 'gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc/tree-ssa-operands.c | 47 |
1 files changed, 19 insertions, 28 deletions
diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index aa56c19..c702ed4 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -1433,13 +1433,12 @@ access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset, get_expr_operands. FULL_REF is a tree that contains the entire pointer dereference expression, if available, or NULL otherwise. OFFSET and SIZE come from the memory access expression that - generated this virtual operand. FOR_CLOBBER is true is this is - adding a virtual operand for a call clobber. */ + generated this virtual operand. */ static void add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, tree full_ref, HOST_WIDE_INT offset, - HOST_WIDE_INT size, bool for_clobber) + HOST_WIDE_INT size) { bitmap aliases = NULL; tree sym; @@ -1514,24 +1513,13 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, append_vdef (al); } - /* If the variable is also an alias tag, add a virtual - operand for it, otherwise we will miss representing - references to the members of the variable's alias set. - This fixes the bug in gcc.c-torture/execute/20020503-1.c. - - It is also necessary to add bare defs on clobbers for - SMT's, so that bare SMT uses caused by pruning all the - aliases will link up properly with calls. In order to - keep the number of these bare defs we add down to the - minimum necessary, we keep track of which SMT's were used - alone in statement vdefs or VUSEs. */ - if (v_ann->is_aliased - || none_added - || (TREE_CODE (var) == SYMBOL_MEMORY_TAG - && for_clobber)) - { - append_vdef (var); - } + /* Even if no aliases have been added, we still need to + establish def-use and use-def chains, lest + transformations think that this is not a memory + reference. For an example of this scenario, see + testsuite/g++.dg/opt/cleanup1.C. */ + if (none_added) + append_vdef (var); } else { @@ -1545,9 +1533,12 @@ add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, append_vuse (al); } - /* Similarly, append a virtual uses for VAR itself, when - it is an alias tag. */ - if (v_ann->is_aliased || none_added) + /* Even if no aliases have been added, we still need to + establish def-use and use-def chains, lest + transformations think that this is not a memory + reference. For an example of this scenario, see + testsuite/g++.dg/opt/cleanup1.C. */ + if (none_added) append_vuse (var); } } @@ -1584,7 +1575,7 @@ add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags) append_use (var_p); } else - add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false); + add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1); } @@ -1631,7 +1622,7 @@ get_indirect_ref_operands (tree stmt, tree expr, int flags, { /* PTR has its own memory tag. Use it. */ add_virtual_operand (pi->name_mem_tag, s_ann, flags, - full_ref, offset, size, false); + full_ref, offset, size); } else { @@ -1660,7 +1651,7 @@ get_indirect_ref_operands (tree stmt, tree expr, int flags, if (v_ann->symbol_mem_tag) add_virtual_operand (v_ann->symbol_mem_tag, s_ann, flags, - full_ref, offset, size, false); + full_ref, offset, size); /* Aliasing information is missing; mark statement as volatile so we won't optimize it out too actively. */ else if (s_ann && !gimple_aliases_computed_p (cfun) @@ -1818,7 +1809,7 @@ add_call_clobber_ops (tree stmt, tree callee) clobber_stats.static_read_clobbers_avoided++; } else - add_virtual_operand (var, s_ann, opf_def, NULL, 0, -1, true); + add_virtual_operand (var, s_ann, opf_def, NULL, 0, -1); } } |