diff options
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 27 |
1 files changed, 6 insertions, 21 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 2777d550916..431f8564bd3 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -2118,6 +2118,7 @@ propagate_rhs_into_lhs (tree stmt, tree lhs, tree rhs, bitmap interesting_names) { use_operand_p use_p; imm_use_iterator iter; + tree use_stmt; bool all = true; /* Dump details. */ @@ -2134,10 +2135,8 @@ propagate_rhs_into_lhs (tree stmt, tree lhs, tree rhs, bitmap interesting_names) /* Walk over every use of LHS and try to replace the use with RHS. At this point the only reason why such a propagation would not be successful would be if the use occurs in an ASM_EXPR. */ - repeat: - FOR_EACH_IMM_USE_SAFE (use_p, iter, lhs) + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) { - tree use_stmt = USE_STMT (use_p); /* It's not always safe to propagate into an ASM_EXPR. */ if (TREE_CODE (use_stmt) == ASM_EXPR @@ -2156,7 +2155,8 @@ propagate_rhs_into_lhs (tree stmt, tree lhs, tree rhs, bitmap interesting_names) } /* Propagate the RHS into this use of the LHS. */ - propagate_value (use_p, rhs); + FOR_EACH_IMM_USE_ON_STMT (use_p, iter) + propagate_value (use_p, rhs); /* Special cases to avoid useless calls into the folding routines, operand scanning, etc. @@ -2303,23 +2303,8 @@ propagate_rhs_into_lhs (tree stmt, tree lhs, tree rhs, bitmap interesting_names) } } - /* Due to a bug in the immediate use iterator code, we can - miss visiting uses in some cases when there is more than - one use in a statement. Missing a use can cause a multitude - of problems if we expected to eliminate all uses and remove - the defining statement. - - Until Andrew can fix the iterator, this hack will detect - the cases which cause us problems. Namely if ALL is set - and we still have some immediate uses, then we must have - skipped one or more in the loop above. So just re-execute - the loop. - - The maximum number of times we can re-execute the loop is - bounded by the maximum number of times a given SSA_NAME - appears in a single statement. */ - if (all && !has_zero_uses (lhs)) - goto repeat; + /* Ensure there is nothing else to do. */ + gcc_assert (all && has_zero_uses (lhs)); /* If we were able to propagate away all uses of LHS, then we can remove STMT. */ |
