diff options
Diffstat (limited to 'gcc/tree-ssa-live.c')
| -rw-r--r-- | gcc/tree-ssa-live.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c index 756fa37..c8b9ce8 100644 --- a/gcc/tree-ssa-live.c +++ b/gcc/tree-ssa-live.c @@ -623,8 +623,8 @@ clear_unused_block_pointer_1 (tree *tp, int *, void *) return NULL_TREE; } -/* Set all block pointer in debug stmt to NULL if the block is unused, - so that they will not be streamed out. */ +/* Set all block pointer in debug or clobber stmt to NULL if the block + is unused, so that they will not be streamed out. */ static void clear_unused_block_pointer (void) @@ -639,7 +639,7 @@ clear_unused_block_pointer (void) tree b; gimple stmt = gsi_stmt (gsi); - if (!is_gimple_debug (stmt)) + if (!is_gimple_debug (stmt) && !gimple_clobber_p (stmt)) continue; b = gimple_block (stmt); if (b && !TREE_USED (b)) @@ -827,7 +827,15 @@ remove_unused_locals (void) if (gimple_clobber_p (stmt)) { tree lhs = gimple_assign_lhs (stmt); - if (TREE_CODE (lhs) == VAR_DECL && !is_used_p (lhs)) + tree base = get_base_address (lhs); + /* Remove clobbers referencing unused vars, or clobbers + with MEM_REF lhs referencing uninitialized pointers. */ + if ((TREE_CODE (base) == VAR_DECL && !is_used_p (base)) + || (TREE_CODE (lhs) == MEM_REF + && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME + && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs, 0)) + && (TREE_CODE (SSA_NAME_VAR (TREE_OPERAND (lhs, 0))) + != PARM_DECL))) { unlink_stmt_vdef (stmt); gsi_remove (&gsi, true); |