From 00e90d3d4cb51fd0fae7b2dbd4bab1db26d6676e Mon Sep 17 00:00:00 2001
From: Yichao Yu <yyc1992@gmail.com>
Date: Fri, 26 Jun 2020 15:46:15 -0600
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 (redirect_to_specific_clone): Fix tests
	to check individual attribute rather than an attribute list.

gcc/testsuite

	* gcc.target/i386/pr95778-1.c: New test.
	* gcc.target/i386/pr95778-2.c: New test.
---
 gcc/multiple_target.c                     |  6 ++++--
 gcc/testsuite/gcc.target/i386/pr95778-1.c | 21 +++++++++++++++++++++
 gcc/testsuite/gcc.target/i386/pr95778-2.c | 21 +++++++++++++++++++++
 3 files changed, 46 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..b15d004fa4e 100644
--- a/gcc/multiple_target.c
+++ b/gcc/multiple_target.c
@@ -483,7 +483,8 @@ 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 +495,8 @@ 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" } } */
-- 
2.30.2