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| author | Jeff Law <law@redhat.com> | 2006-03-24 00:51:32 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2006-03-24 00:51:32 -0700 |
| commit | 243cc8369be79c5ea217a53b2ab47563e2ea6e02 (patch) | |
| tree | f6d9e217688cbacc0e4fc00e34997e441fd5b063 /gcc/tree-ssa-dom.c | |
| parent | b5b3739a4618fd9769d19ef2fb77eb7e1cbaa04d (diff) | |
| download | gcc-243cc8369be79c5ea217a53b2ab47563e2ea6e02.tar.gz | |
tree-ssa-dom.c (propagate_rhs_into_lhs): Temporarily work around bug in immediate-use iterator.
* tree-ssa-dom.c (propagate_rhs_into_lhs): Temporarily work
around bug in immediate-use iterator.
* gcc.c-torture/compile/pr26833.c: New test.
* gfortran.fortran-torture/compile/pr26806.f90: New test.
From-SVN: r112348
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index daa2f0ea81d..9df59e9dc52 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -2134,6 +2134,7 @@ 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) { tree use_stmt = USE_STMT (use_p); @@ -2264,6 +2265,24 @@ 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 && num_imm_uses (lhs) != 0) + goto repeat; + /* If we were able to propagate away all uses of LHS, then we can remove STMT. */ if (all) |