| Message ID | 20100928164913.GB22494@kam.mff.cuni.cz |
|---|---|
| State | New |
| Headers | show |
On Tue, 28 Sep 2010, Jan Hubicka wrote: > Hi, > with recent folding improvements, we now work hard enough to make statement fold to look > into the virtual tables and work out function to be called. Still we don't devirtualize > the call because we never actually substitute the operand of OBJ_TYPE_REF because there is > a NOP_EXPR in a way. > > This patch makes ccp_fold_stmt to do the replacement. I am not 100% sure if we > should not do some type checking and mark call statement uninlinable on > mismatch, but in general C++ should not let us to make mismatches. > > I've bootstrapped/regtested the patch on x86_64 and tested on Mozilla. There it devirutalize > about 900 calls during late ccp and also couple hundred calls before inlining. I am not > attaching a testcase, since I inspected some and think they should be handled by the type > based mahcinery too, but they are not, so I filled in PR for that. Once this is settled we > can decide what has to be handled the busy way. > > OK? > > * tree-ssa-ccp.c (ccp_fold_stmt): Fold OBJ_TYPE_REF away > when destination is known. > > Index: tree-ssa-ccp.c > =================================================================== > --- tree-ssa-ccp.c (revision 164689) > +++ tree-ssa-ccp.c (working copy) > @@ -2307,6 +2307,17 @@ ccp_fold_stmt (gimple_stmt_iterator *gsi > changed = true; > } > } > + if (TREE_CODE (gimple_call_fn (stmt)) == OBJ_TYPE_REF) > + { > + tree expr = OBJ_TYPE_REF_EXPR (gimple_call_fn (stmt)); > + expr = valueize_op (expr); > + if (TREE_CODE (expr) == ADDR_EXPR > + && TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL) > + { > + gimple_call_set_fndecl (stmt, TREE_OPERAND (expr, 0)); Ok with using gimple_call_set_fn (stmt, expr) here (which avoids re-building the addr-expr). Thanks, Richard.
Index: tree-ssa-ccp.c =================================================================== --- tree-ssa-ccp.c (revision 164689) +++ tree-ssa-ccp.c (working copy) @@ -2307,6 +2307,17 @@ ccp_fold_stmt (gimple_stmt_iterator *gsi changed = true; } } + if (TREE_CODE (gimple_call_fn (stmt)) == OBJ_TYPE_REF) + { + tree expr = OBJ_TYPE_REF_EXPR (gimple_call_fn (stmt)); + expr = valueize_op (expr); + if (TREE_CODE (expr) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL) + { + gimple_call_set_fndecl (stmt, TREE_OPERAND (expr, 0)); + changed = true; + } + } return changed; }