Fix PR9614 for functions with the always_inline attribute. Try to keep

the common case (-O0, no always_inline) fast.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143222 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CodeGenModule.cpp

@@ -901,18 +901,15 @@ bool
 CodeGenModule::shouldEmitFunction(const FunctionDecl *F) {
   if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage)
     return true;
-  if (F->hasAttr<AlwaysInlineAttr>())
-    return true;
-  if (CodeGenOpts.OptimizationLevel == 0)
+  if (CodeGenOpts.OptimizationLevel == 0 &&
+      !F->hasAttr<AlwaysInlineAttr>())
     return false;
   // PR9614. Avoid cases where the source code is lying to us. An available
   // externally function should have an equivalent function somewhere else,
   // but a function that calls itself is clearly not equivalent to the real
   // implementation.
   // This happens in glibc's btowc and in some configure checks.
-  if (isTriviallyRecursiveViaAsm(F))
-    return false;
-  return true;
+  return !isTriviallyRecursiveViaAsm(F);
 }
 
 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {

test/CodeGen/pr9614.c

@@ -1,15 +1,23 @@
 // RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
 
-extern int foo_alias (void) __asm ("foo");
-inline int foo (void) {
+extern void foo_alias (void) __asm ("foo");
+inline void foo (void) {
   return foo_alias ();
 }
-int f(void) {
-  return foo();
+extern void bar_alias (void) __asm ("bar");
+inline __attribute__ ((__always_inline__)) void bar (void) {
+  return bar_alias ();
+}
+void f(void) {
+  foo();
+  bar();
 }
 
-// CHECK-NOT: define
-// CHECK: define i32 @f()
-// CHECK: call i32 @foo()
-// CHECK-NEXT: ret i32
-// CHECK-NOT: define
+// CHECK: define void @f()
+// CHECK-NEXT: entry:
+// CHECK-NEXT: call void @foo()
+// CHECK-NEXT: call void @bar()
+// CHECK-NEXT: ret void
+
+// CHECK: declare void @foo()
+// CHECK: declare void @bar()