[llvm-branch-commits] [clang] 9afe667 - Function multi-versioning: disable ifunc for ELF targets other than glibc/Android/FreeBSD

[Tobias Hieta via llvm-branch-commits]

Author: Fangrui Song
Date: 2023-08-30T17:00:27+02:00
New Revision: 9afe6676833dc0a554463f82e8d5574a0987aa1e

URL: https://github.com/llvm/llvm-project/commit/9afe6676833dc0a554463f82e8d5574a0987aa1e
DIFF: https://github.com/llvm/llvm-project/commit/9afe6676833dc0a554463f82e8d5574a0987aa1e.diff

LOG: Function multi-versioning: disable ifunc for ELF targets other than glibc/Android/FreeBSD

Generalize D127933 (Fuchsia special case) to other ELF targets. Ensure
that musl, NetBSD, OpenBSD, etc do not get ifunc codegen which is
unsupported in their rtld.

Link: https://discourse.llvm.org/t/does-ifunc-use-from-llvm-require-os-support/67628
Close: https://github.com/llvm/llvm-project/issues/64631
(cherry picked from commit 0c3a02b8c09bb408a74a638a263e51d67c92ca74)

Added: 
    

Modified: 
    clang/include/clang/Basic/TargetInfo.h
    clang/test/CodeGen/attr-target-mv-va-args.c
    clang/test/CodeGen/unique-internal-linkage-names.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
index 41ef47eb565b1c..61be52149341f0 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1414,7 +1414,9 @@ class TargetInfo : public TransferrableTargetInfo,
 
   /// Identify whether this target supports IFuncs.
   bool supportsIFunc() const {
-    return getTriple().isOSBinFormatELF() && !getTriple().isOSFuchsia();
+    return getTriple().isOSBinFormatELF() &&
+           ((getTriple().isOSLinux() && !getTriple().isMusl()) ||
+            getTriple().isOSFreeBSD());
   }
 
   // Validate the contents of the __builtin_cpu_supports(const char*)

diff  --git a/clang/test/CodeGen/attr-target-mv-va-args.c b/clang/test/CodeGen/attr-target-mv-va-args.c
index e75796d7ee0383..96821c610235bd 100644
--- a/clang/test/CodeGen/attr-target-mv-va-args.c
+++ b/clang/test/CodeGen/attr-target-mv-va-args.c
@@ -1,6 +1,8 @@
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck %s --check-prefix=LINUX
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm %s -o - | FileCheck %s --check-prefix=IFUNC-ELF
+// RUN: %clang_cc1 -triple x86_64-pc-freebsd -emit-llvm %s -o - | FileCheck %s --check-prefix=IFUNC-ELF
 // RUN: %clang_cc1 -triple x86_64-windows-pc -emit-llvm %s -o - | FileCheck %s --check-prefixes=NO-IFUNC,WINDOWS
-// RUN: %clang_cc1 -triple x86_64-fuchsia -emit-llvm %s -o - | FileCheck %s --check-prefixes=NO-IFUNC,FUCHSIA
+// RUN: %clang_cc1 -triple x86_64-linux-musl -emit-llvm %s -o - | FileCheck %s --check-prefixes=NO-IFUNC,NO-IFUNC-ELF
+// RUN: %clang_cc1 -triple x86_64-fuchsia -emit-llvm %s -o - | FileCheck %s --check-prefixes=NO-IFUNC,NO-IFUNC-ELF
 int __attribute__((target("sse4.2"))) foo(int i, ...) { return 0; }
 int __attribute__((target("arch=sandybridge"))) foo(int i, ...);
 int __attribute__((target("arch=ivybridge"))) foo(int i, ...) {return 1;}
@@ -10,23 +12,23 @@ int bar(void) {
   return foo(1, 'a', 1.1) + foo(2, 2.2, "asdf");
 }
 
-// LINUX: @foo.ifunc = weak_odr ifunc i32 (i32, ...), ptr @foo.resolver
-// LINUX: define{{.*}} i32 @foo.sse4.2(i32 noundef %i, ...)
-// LINUX: ret i32 0
-// LINUX: define{{.*}} i32 @foo.arch_ivybridge(i32 noundef %i, ...)
-// LINUX: ret i32 1
-// LINUX: define{{.*}} i32 @foo(i32 noundef %i, ...)
-// LINUX: ret i32 2
-// LINUX: define{{.*}} i32 @bar()
-// LINUX: call i32 (i32, ...) @foo.ifunc(i32 noundef 1, i32 noundef 97, double
-// LINUX: call i32 (i32, ...) @foo.ifunc(i32 noundef 2, double noundef 2.2{{[0-9Ee+]+}}, ptr noundef
+// IFUNC-ELF: @foo.ifunc = weak_odr ifunc i32 (i32, ...), ptr @foo.resolver
+// IFUNC-ELF: define{{.*}} i32 @foo.sse4.2(i32 noundef %i, ...)
+// IFUNC-ELF: ret i32 0
+// IFUNC-ELF: define{{.*}} i32 @foo.arch_ivybridge(i32 noundef %i, ...)
+// IFUNC-ELF: ret i32 1
+// IFUNC-ELF: define{{.*}} i32 @foo(i32 noundef %i, ...)
+// IFUNC-ELF: ret i32 2
+// IFUNC-ELF: define{{.*}} i32 @bar()
+// IFUNC-ELF: call i32 (i32, ...) @foo.ifunc(i32 noundef 1, i32 noundef 97, double
+// IFUNC-ELF: call i32 (i32, ...) @foo.ifunc(i32 noundef 2, double noundef 2.2{{[0-9Ee+]+}}, ptr noundef
 
-// LINUX: define weak_odr ptr @foo.resolver() comdat
-// LINUX: ret ptr @foo.arch_sandybridge
-// LINUX: ret ptr @foo.arch_ivybridge
-// LINUX: ret ptr @foo.sse4.2
-// LINUX: ret ptr @foo
-// LINUX: declare i32 @foo.arch_sandybridge(i32 noundef, ...)
+// IFUNC-ELF: define weak_odr ptr @foo.resolver() comdat
+// IFUNC-ELF: ret ptr @foo.arch_sandybridge
+// IFUNC-ELF: ret ptr @foo.arch_ivybridge
+// IFUNC-ELF: ret ptr @foo.sse4.2
+// IFUNC-ELF: ret ptr @foo
+// IFUNC-ELF: declare i32 @foo.arch_sandybridge(i32 noundef, ...)
 
 // NO-IFUNC: define dso_local i32 @foo.sse4.2(i32 noundef %i, ...)
 // NO-IFUNC: ret i32 0
@@ -39,10 +41,10 @@ int bar(void) {
 // NO-IFUNC: call i32 (i32, ...) @foo.resolver(i32 noundef 2, double noundef 2.2{{[0-9Ee+]+}}, ptr noundef
 
 // WINDOWS: define weak_odr dso_local i32 @foo.resolver(i32 %0, ...) comdat
-// FUCHSIA: define weak_odr i32 @foo.resolver(i32 %0, ...) comdat
+// NO-IFUNC-ELF: define weak_odr i32 @foo.resolver(i32 %0, ...) comdat
 // NO-IFUNC: musttail call i32 (i32, ...) @foo.arch_sandybridge
 // NO-IFUNC: musttail call i32 (i32, ...) @foo.arch_ivybridge
 // NO-IFUNC: musttail call i32 (i32, ...) @foo.sse4.2
 // NO-IFUNC: musttail call i32 (i32, ...) @foo
 // WINDOWS: declare dso_local i32 @foo.arch_sandybridge(i32 noundef, ...)
-// FUCHSIA: declare i32 @foo.arch_sandybridge(i32 noundef, ...)
+// NO-IFUNC-ELF: declare i32 @foo.arch_sandybridge(i32 noundef, ...)

diff  --git a/clang/test/CodeGen/unique-internal-linkage-names.cpp b/clang/test/CodeGen/unique-internal-linkage-names.cpp
index 731c2c143d7b77..65cf9db80b9171 100644
--- a/clang/test/CodeGen/unique-internal-linkage-names.cpp
+++ b/clang/test/CodeGen/unique-internal-linkage-names.cpp
@@ -1,7 +1,7 @@
 // This test checks if internal linkage symbols get unique names with
 // -funique-internal-linkage-names option.
-// RUN: %clang_cc1 -triple x86_64 -x c++ -S -emit-llvm -o - < %s | FileCheck %s --check-prefix=PLAIN
-// RUN: %clang_cc1 -triple x86_64 -x c++  -S -emit-llvm -funique-internal-linkage-names -o - < %s | FileCheck %s --check-prefix=UNIQUE
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -x c++ -S -emit-llvm -o - < %s | FileCheck %s --check-prefix=PLAIN
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -x c++  -S -emit-llvm -funique-internal-linkage-names -o - < %s | FileCheck %s --check-prefix=UNIQUE
 
 static int glob;
 static int foo() {