This fixes PR3713 by properly propagating ->has_constants in SCCVN.
With that we are able to simplify (unsigned) Bar & 1 properly.
Only copyprop later turns the call into a direct one though,
so I'm testing the important fact - that Bar is inlined and eliminated
by IPA inlining.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Unless this is somehow a regression (which I doubt) this has to
wait for stage1 (even though it's pretty safe and at most exposes
existing bugs in SCCVN).
Richard.
2013-01-16 Richard Biener <rguent...@suse.de>
PR tree-optimization/3713
* tree-ssa-sccvn.c (visit_copy): Simplify. Always propagate
has_constants and expr.
(stmt_has_constants): Properly valueize SSA names when deciding
whether the stmt has constants.
* g++.dg/ipa/devirt-11.C: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 195240)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** static tree valueize_expr (tree expr);
*** 2653,2670 ****
static bool
visit_copy (tree lhs, tree rhs)
{
- /* Follow chains of copies to their destination. */
- while (TREE_CODE (rhs) == SSA_NAME
- && SSA_VAL (rhs) != rhs)
- rhs = SSA_VAL (rhs);
-
/* The copy may have a more interesting constant filled expression
(we don't, since we know our RHS is just an SSA name). */
! if (TREE_CODE (rhs) == SSA_NAME)
! {
! VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
! VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
! }
return set_ssa_val_to (lhs, rhs);
}
--- 2653,2665 ----
static bool
visit_copy (tree lhs, tree rhs)
{
/* The copy may have a more interesting constant filled expression
(we don't, since we know our RHS is just an SSA name). */
! VN_INFO (lhs)->has_constants = VN_INFO (rhs)->has_constants;
! VN_INFO (lhs)->expr = VN_INFO (rhs)->expr;
!
! /* And finally valueize. */
! rhs = SSA_VAL (rhs);
return set_ssa_val_to (lhs, rhs);
}
*************** expr_has_constants (tree expr)
*** 3063,3087 ****
static bool
stmt_has_constants (gimple stmt)
{
if (gimple_code (stmt) != GIMPLE_ASSIGN)
return false;
switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
{
! case GIMPLE_UNARY_RHS:
! return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
case GIMPLE_BINARY_RHS:
! return (is_gimple_min_invariant (gimple_assign_rhs1 (stmt))
! || is_gimple_min_invariant (gimple_assign_rhs2 (stmt)));
! case GIMPLE_TERNARY_RHS:
! return (is_gimple_min_invariant (gimple_assign_rhs1 (stmt))
! || is_gimple_min_invariant (gimple_assign_rhs2 (stmt))
! || is_gimple_min_invariant (gimple_assign_rhs3 (stmt)));
case GIMPLE_SINGLE_RHS:
/* Constants inside reference ops are rarely interesting, but
it can take a lot of looking to find them. */
! return is_gimple_min_invariant (gimple_assign_rhs1 (stmt));
default:
gcc_unreachable ();
}
--- 3058,3095 ----
static bool
stmt_has_constants (gimple stmt)
{
+ tree tem;
+
if (gimple_code (stmt) != GIMPLE_ASSIGN)
return false;
switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt)))
{
! case GIMPLE_TERNARY_RHS:
! tem = gimple_assign_rhs3 (stmt);
! if (TREE_CODE (tem) == SSA_NAME)
! tem = SSA_VAL (tem);
! if (is_gimple_min_invariant (tem))
! return true;
! /* Fallthru. */
case GIMPLE_BINARY_RHS:
! tem = gimple_assign_rhs2 (stmt);
! if (TREE_CODE (tem) == SSA_NAME)
! tem = SSA_VAL (tem);
! if (is_gimple_min_invariant (tem))
! return true;
! /* Fallthru. */
!
case GIMPLE_SINGLE_RHS:
/* Constants inside reference ops are rarely interesting, but
it can take a lot of looking to find them. */
! case GIMPLE_UNARY_RHS:
! tem = gimple_assign_rhs1 (stmt);
! if (TREE_CODE (tem) == SSA_NAME)
! tem = SSA_VAL (tem);
! return is_gimple_min_invariant (tem);
!
default:
gcc_unreachable ();
}
Index: gcc/testsuite/g++.dg/ipa/devirt-11.C
===================================================================
*** gcc/testsuite/g++.dg/ipa/devirt-11.C (revision 0)
--- gcc/testsuite/g++.dg/ipa/devirt-11.C (working copy)
***************
*** 0 ****
--- 1,22 ----
+ // { dg-do compile }
+ // { dg-options "-std=c++11 -O -fdump-ipa-inline" }
+
+ class Foo
+ {
+ public:
+ void Bar() const
+ {
+ __builtin_puts ("Howdy!");
+ }
+ };
+
+ int main()
+ {
+ Foo x;
+ auto y = &Foo::Bar;
+ (x.*y)();
+ return 0;
+ }
+
+ // { dg-final { scan-ipa-dump "Inlined 1 calls, eliminated 1 functions"
"inline" } }
+ // { dg-final { cleanup-ipa-dump "inline" } }
