[PATCH] Fix target clone indirection elimination.
Yichao Yu
yyc1992@gmail.com
Sun Jun 21 00:31:13 GMT 2020
On Sat, Jun 20, 2020 at 8:16 PM Yichao Yu <yyc1992@gmail.com> wrote:
>
> On Sat, Jun 20, 2020 at 3:41 PM Yichao Yu <yyc1992@gmail.com> wrote:
> >
> > On Sat, Jun 20, 2020 at 3:26 PM Yichao Yu <yyc1992@gmail.com> wrote:
> > >
> > > On Sat, Jun 20, 2020 at 3:25 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > >
> > > > On Sat, Jun 20, 2020 at 12:20 PM Yichao Yu <yyc1992@gmail.com> wrote:
> > > > >
> > > > > On Sat, Jun 20, 2020 at 3:12 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > > > >
> > > > > > On Sat, Jun 20, 2020 at 11:37 AM Yichao Yu <yyc1992@gmail.com> wrote:
> > > > > > >
> > > > > > > On Sat, Jun 20, 2020 at 1:54 PM Yichao Yu <yyc1992@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......
> > > > > > >
> > > > > > Can you try the enclosed testcases?
> > > > >
> > > > >
> > > > > The assembly produced are the following with my patch and if I
> > > > > understand it correctly those should work. Unfortunately I don't know
> > > > > how to actually run the test as a test (if that makes sense....).
> > > > >
> > > >
> > > > Place 2 files under gcc/testsuite/gcc.target/i386 and in GCC build directory, do
> > > >
> > > > $ make check-gcc RUNTESTFLAGS="--target_board='unix{-m32,}'
> > > > i386.exp=pr95778-*.c"
> > > >
> >
> > Finally got it start running after installing dejagnu...
> > It seems to be runing something unrelated though....
> >
> > e.g. Running /home/yuyichao/projects/contrib/gcc/gcc/testsuite/gcc.c-torture/execute/builtins/builtins.exp
> > ...
> > Running /home/yuyichao/projects/contrib/gcc/gcc/testsuite/gcc.c-torture/execute/execute.exp
>
> OK it seems that the `-*.c` syntax doesn't work for me somehow, there
> are still a lot of unrelated outputs but when I replaced the * with 1
> and 2 separately I can confirm that there are only expected pass with
> my patch and there are some unexpected failures when the patch is
> reverted.
And the updated patch is
>From b219facb0960cd09bbcef72e9c03cc045474a8e6 Mon Sep 17 00:00:00 2001
From: Yichao Yu <yyc1992@gmail.com>
Date: Sat, 20 Jun 2020 11:59:36 -0400
Subject: [PATCH] Fix target clone indirection elimination.
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).
This changes the comparison to be only on the `target` attribute which should be
the intent of the code.
---
gcc/multiple_target.c | 4 ++--
gcc/testsuite/gcc.target/i386/pr95778-1.c | 21 +++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr95778-2.c | 21 +++++++++++++++++++++
3 files changed, 44 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr95778-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr95778-2.c
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);
diff --git a/gcc/testsuite/gcc.target/i386/pr95778-1.c
b/gcc/testsuite/gcc.target/i386/pr95778-
1.c
new file mode 100644
index 00000000000..3238303d696
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr95778-1.c
@@ -0,0 +1,21 @@
+/* { dg-do compile { target fpic } } */
+/* { dg-options "-O3 -fPIC -fno-asynchronous-unwind-tables" } */
+/* { dg-require-ifunc "" } */
+
+__attribute__((target_clones("default,avx2")))
+static int
+f2(int *p)
+{
+ asm volatile ("" :: "r"(p) : "memory");
+ return *p;
+}
+
+__attribute__((target_clones("default,avx2")))
+int
+g2(int *p)
+{
+ return f2(p);
+}
+
+/* { dg-final { scan-assembler "g2.default.1:\n\tjmp\tf2.default.1\n" } } */
+/* { dg-final { scan-assembler "g2.avx2.0:\n\tjmp\tf2.avx2.0\n" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr95778-2.c
b/gcc/testsuite/gcc.target/i386/pr95778-
2.c
new file mode 100644
index 00000000000..e88702d2b82
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr95778-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile { target fpic } } */
+/* { dg-options "-O3 -fPIC -fno-asynchronous-unwind-tables" } */
+/* { dg-require-ifunc "" } */
+
+__attribute__((visibility("internal"),target_clones("default,avx2")))
+int
+f2(int *p)
+{
+ asm volatile ("" :: "r"(p) : "memory");
+ return *p;
+}
+
+__attribute__((target_clones("default,avx2")))
+int
+g2(int *p)
+{
+ return f2(p);
+}
+
+/* { dg-final { scan-assembler "g2.default.1:\n\tjmp\tf2.default.1\n" } } */
+/* { dg-final { scan-assembler "g2.avx2.0:\n\tjmp\tf2.avx2.0\n" } } */
--
2.27.0
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