On Sat, Jun 20, 2020 at 1:54 PM Yichao Yu <yyc1...@gmail.com> wrote: > > > > The current logic seems to be comparing the whole attribute tree between > > > the callee > > > and caller (or at least the tree starting from the target attribute). > > > This is unnecessary and causes strange dependency of the indirection > > > elimination on unrelated properties like `noinline`(PR95780) and > > > `visibility`(PR95778). > > > > Does it fix PR95780 and PR95778? Can you include testcases for them?
OK so replacing https://github.com/gcc-mirror/gcc/commit/b8ce8129a560f64f8b2855c4a3812b7c3c0ebf3f#diff-e2d535917af8555baad2e9c8749e96a5 with/adding to the test the following one should work. I still couldn't get test to run though...... ``` /* { dg-do compile } */ /* { dg-require-ifunc "" } */ /* { dg-options "-O2 -fdump-tree-optimized" } */ __attribute__ ((flatten,target ("default"),cold)) static unsigned foo(const char *buf, unsigned size) { return 1; } __attribute__ ((flatten,target ("avx"),cold)) static unsigned foo(const char *buf, unsigned size) { return 2; } __attribute__ ((target ("default"))) unsigned bar() { char buf[4096]; unsigned acc = 0; for (int i = 0; i < sizeof(buf); i++) { acc += foo(&buf[i], 1); } return acc; } __attribute__ ((target ("avx"))) unsigned bar() { char buf[4096]; unsigned acc = 0; for (int i = 0; i < sizeof(buf); i++) { acc += foo(&buf[i], 1); } return acc; } /* { dg-final { scan-tree-dump-times "return 4096;" 1 "optimized" } } */ /* { dg-final { scan-tree-dump-times "return 8192;" 1 "optimized" } } */ ``` > > Yes it at least partially fixes them. As mentioned in the other email, > this still does not allow inlining but maybe that should be reported > as another issue? > > I need to work on the test and might need some help. > Right now I'm not sure how to write such a test (I assume blaming on > the old implementation should tell me where the right test is though). > Also, make -k check somehow gives me some segfaults from LLVM. I was > wondering if it is related to that I was using an out-of-tree non > bootstrap build so I'm recompiling a bootstrap in-source build... > > > > > > This changes the comparison to be only on the `target` attribute which > > > should be > > > the intent of the code. > > > --- > > > gcc/multiple_target.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/gcc/multiple_target.c b/gcc/multiple_target.c > > > index c1cfe8ff978..9eb0afd58cc 100644 > > > --- a/gcc/multiple_target.c > > > +++ b/gcc/multiple_target.c > > > @@ -483,7 +483,7 @@ redirect_to_specific_clone (cgraph_node *node) > > > DECL_ATTRIBUTES > > > (e->callee->decl)); > > > > > > /* Function is not calling proper target clone. */ > > > - if (!attribute_list_equal (attr_target, attr_target2)) > > > + if (attr_target2 == NULL_TREE || !attribute_value_equal > > > (attr_target, attr_target2)) > > > { > > > while (fv2->prev != NULL) > > > fv2 = fv2->prev; > > > @@ -494,7 +494,7 @@ redirect_to_specific_clone (cgraph_node *node) > > > cgraph_node *callee = fv2->this_node; > > > attr_target2 = lookup_attribute ("target", > > > DECL_ATTRIBUTES > > > (callee->decl)); > > > - if (attribute_list_equal (attr_target, attr_target2)) > > > + if (attr_target2 != NULL_TREE && attribute_value_equal > > > (attr_target, attr_target2)) > > > { > > > e->redirect_callee (callee); > > > cgraph_edge::redirect_call_stmt_to_callee (e); > > > -- > > > 2.27.0 > > > > > > > > > -- > > H.J.
