regcall: Implement regcall Calling Conv in clang

This patch implements the register call calling convention, which ensures
as many values as possible are passed in registers. CodeGen changes
were committed in https://reviews.llvm.org/rL284108.

Differential Revision: https://reviews.llvm.org/D25204

llvm-svn: 285849

1 files changed, 97 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/regcall.cpp b/clang/test/CodeGenCXX/regcall.cpp
new file mode 100644
index 00000000000..0cc6ad00932
--- /dev/null
+++ b/clang/test/CodeGenCXX/regcall.cpp
@@ -0,0 +1,97 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -std=c++11     %s -o - | FileCheck -check-prefix=CHECK-LIN -check-prefix=CHECK-LIN64 %s
+// RUN: %clang_cc1 -triple i386-linux-gnu -emit-llvm -std=c++11     %s -o -   | FileCheck -check-prefix=CHECK-LIN -check-prefix=CHECK-LIN32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++11  %s -o - -DWIN_TEST | FileCheck -check-prefix=CHECK-WIN64 %s
+// RUN: %clang_cc1 -triple i386-windows-msvc -emit-llvm -std=c++11  %s -o - -DWIN_TEST   | FileCheck -check-prefix=CHECK-WIN32 %s
+
+int __regcall foo(int i);
+
+int main()
+{
+  int p = 0, _data;
+  auto lambda = [&](int parameter) -> int {
+    _data = foo(parameter);
+    return _data;
+  };
+  return lambda(p);
+}
+// CHECK-LIN: call x86_regcallcc {{.+}} @_Z15__regcall3__foo
+// CHECK-WIN64: call x86_regcallcc {{.+}} @"\01?foo@@YwHH@Z"
+// CHECK-WIN32: call x86_regcallcc {{.+}} @"\01?foo@@YwHH@Z"
+
+int __regcall foo (int i){
+  return i;
+}
+// CHECK-LIN: define x86_regcallcc {{.+}}@_Z15__regcall3__foo
+// CHECK-WIN64: define x86_regcallcc {{.+}}@"\01?foo@@YwHH@Z"
+// CHECK-WIN32: define x86_regcallcc {{.+}}@"\01?foo@@YwHH@Z"
+
+// used to give a body to test_class functions
+static int x = 0;
+class test_class {
+  int a;
+public:
+#ifndef WIN_TEST
+  __regcall 
+#endif
+    test_class(){++x;}
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_classC1Ev
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_classC2Ev
+  // Windows ignores calling convention on constructor/destructors.
+  // CHECK-WIN64-DAG: define linkonce_odr %class.test_class* @"\01??0test_class@@QEAA@XZ"
+  // CHECK-WIN32-DAG: define linkonce_odr x86_thiscallcc %class.test_class* @"\01??0test_class@@QAE@XZ"
+
+#ifndef WIN_TEST
+  __regcall 
+#endif
+  ~test_class(){--x;}
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_classD2Ev
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_classD1Ev
+  // Windows ignores calling convention on constructor/destructors.
+  // CHECK-WIN64-DAG: define linkonce_odr void @"\01??_Dtest_class@@QEAA@XZ"
+  // CHECK-WIN32-DAG: define linkonce_odr x86_thiscallcc void @"\01??_Dtest_class@@QAE@XZ"
+  
+  test_class& __regcall operator+=(const test_class&){
+    return *this;
+  }
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc dereferenceable(4) %class.test_class* @_ZN10test_classpLERKS_
+  // CHECK-WIN64-DAG: define linkonce_odr x86_regcallcc dereferenceable(4) %class.test_class* @"\01??Ytest_class@@QEAwAEAV0@AEBV0@@Z"
+  // CHECK-WIN32-DAG: define linkonce_odr x86_regcallcc dereferenceable(4) %class.test_class* @"\01??Ytest_class@@QAwAAV0@ABV0@@Z"
+  void __regcall do_thing(){}
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_class20__regcall3__do_thingEv
+  // CHECK-WIN64-DAG: define linkonce_odr x86_regcallcc void @"\01?do_thing@test_class@@QEAwXXZ"
+  // CHECK-WIN32-DAG: define linkonce_odr x86_regcallcc void @"\01?do_thing@test_class@@QAwXXZ"
+  
+  template<typename T>
+  void __regcall tempFunc(T i){}
+  // CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_ZN10test_class20__regcall3__tempFuncIiEEvT_
+  // CHECK-WIN64-DAG: define linkonce_odr x86_regcallcc void @"\01??$freeTempFunc@H@@YwXH@Z"
+  // CHECK-WIN32-DAG: define linkonce_odr x86_regcallcc void @"\01??$freeTempFunc@H@@YwXH@Z"
+};
+
+bool __regcall operator ==(const test_class&, const test_class&){ --x; return false;}
+// CHECK-LIN-DAG: define x86_regcallcc zeroext i1 @_ZeqRK10test_classS1_
+// CHECK-WIN64-DAG: define x86_regcallcc zeroext i1 @"\01??8@Yw_NAEBVtest_class@@0@Z"
+// CHECK-WIN32-DAG: define x86_regcallcc zeroext i1 @"\01??8@Yw_NABVtest_class@@0@Z"
+
+test_class __regcall operator""_test_class (unsigned long long) { ++x; return test_class{};} 
+// CHECK-LIN64-DAG: define x86_regcallcc %class.test_class @_Zli11_test_classy(i64)
+// CHECK-LIN32-DAG: define x86_regcallcc void @_Zli11_test_classy(%class.test_class* inreg noalias sret %agg.result, i64)
+// CHECK-WIN64-DAG: \01??__K_test_class@@Yw?AVtest_class@@_K@Z"
+// CHECK-WIN32-DAG: \01??__K_test_class@@Yw?AVtest_class@@_K@Z"
+
+template<typename T>
+void __regcall freeTempFunc(T i){}
+// CHECK-LIN-DAG: define linkonce_odr x86_regcallcc void @_Z24__regcall3__freeTempFuncIiEvT_
+// CHECK-WIN64-DAG: define linkonce_odr x86_regcallcc void @"\01??$freeTempFunc@H@@YwXH@Z"
+// CHECK-WIN32-DAG: define linkonce_odr x86_regcallcc void @"\01??$freeTempFunc@H@@YwXH@Z"
+
+// class to force generation of functions
+void force_gen() {
+  test_class t;
+  test_class t2 = 12_test_class;
+  t += t2;
+  auto t3 = 100_test_class;
+  t3.tempFunc(1);
+  freeTempFunc(1);
+  t3.do_thing();
+}