Support __builtin_ms_va_list.

Summary:
This change adds support for `__builtin_ms_va_list`, a GCC extension for
variadic `ms_abi` functions. The existing `__builtin_va_list` support is
inadequate for this because `va_list` is defined differently in the Win64
ABI vs. the System V/AMD64 ABI.

Depends on D1622.

Reviewers: rsmith, rnk, rjmccall

CC: cfe-commits

Differential Revision: http://reviews.llvm.org/D1623

llvm-svn: 247941

1 files changed, 131 insertions, 6 deletions

diff --git a/clang/test/CodeGen/ms_abi.c b/clang/test/CodeGen/ms_abi.c
index 7c5c26fc41c..2cca24901b9 100644
--- a/clang/test/CodeGen/ms_abi.c
+++ b/clang/test/CodeGen/ms_abi.c
@@ -1,20 +1,145 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-freebsd10.0 -emit-llvm < %s | FileCheck -check-prefix=FREEBSD %s
 // RUN: %clang_cc1 -triple x86_64-pc-win32 -emit-llvm < %s | FileCheck -check-prefix=WIN64 %s
 
+struct foo {
+  int x;
+  float y;
+  char z;
+};
+// FREEBSD: %[[STRUCT_FOO:.*]] = type { i32, float, i8 }
+// WIN64: %[[STRUCT_FOO:.*]] = type { i32, float, i8 }
+
 void __attribute__((ms_abi)) f1(void);
 void __attribute__((sysv_abi)) f2(void);
 void f3(void) {
-// FREEBSD: define void @f3()
-// WIN64: define void @f3()
+  // FREEBSD-LABEL: define void @f3()
+  // WIN64-LABEL: define void @f3()
   f1();
-// FREEBSD: call x86_64_win64cc void @f1()
-// WIN64: call void @f1()
+  // FREEBSD: call x86_64_win64cc void @f1()
+  // WIN64: call void @f1()
   f2();
-// FREEBSD: call void @f2()
-// WIN64: call x86_64_sysvcc void @f2()
+  // FREEBSD: call void @f2()
+  // WIN64: call x86_64_sysvcc void @f2()
 }
 // FREEBSD: declare x86_64_win64cc void @f1()
 // FREEBSD: declare void @f2()
 // WIN64: declare void @f1()
 // WIN64: declare x86_64_sysvcc void @f2()
 
+// Win64 ABI varargs
+void __attribute__((ms_abi)) f4(int a, ...) {
+  // FREEBSD-LABEL: define x86_64_win64cc void @f4
+  // WIN64-LABEL: define void @f4
+  __builtin_ms_va_list ap;
+  __builtin_ms_va_start(ap, a);
+  // FREEBSD: %[[AP:.*]] = alloca i8*
+  // FREEBSD: call void @llvm.va_start
+  // WIN64: %[[AP:.*]] = alloca i8*
+  // WIN64: call void @llvm.va_start
+  int b = __builtin_va_arg(ap, int);
+  // FREEBSD: %[[AP_CUR:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR]], i64 8
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR]] to i32*
+  // WIN64: %[[AP_CUR:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR]], i64 8
+  // WIN64-NEXT: store i8* %[[AP_NEXT]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR]] to i32*
+  double _Complex c = __builtin_va_arg(ap, double _Complex);
+  // FREEBSD: %[[AP_CUR2:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT2:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR2]], i64 16
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT2]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR2]] to { double, double }*
+  // WIN64: %[[AP_CUR2:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT2:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR2]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT2]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR2]] to { double, double }*
+  struct foo d = __builtin_va_arg(ap, struct foo);
+  // FREEBSD: %[[AP_CUR3:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT3:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR3]], i64 16
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT3]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR3]] to %[[STRUCT_FOO]]*
+  // WIN64: %[[AP_CUR3:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT3:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR3]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT3]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR3]] to %[[STRUCT_FOO]]*
+  __builtin_ms_va_list ap2;
+  __builtin_ms_va_copy(ap2, ap);
+  // FREEBSD: %[[AP_VAL:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: store i8* %[[AP_VAL]], i8** %[[AP2:.*]]
+  // WIN64: %[[AP_VAL:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: store i8* %[[AP_VAL]], i8** %[[AP2:.*]]
+  __builtin_ms_va_end(ap);
+  // FREEBSD: call void @llvm.va_end
+  // WIN64: call void @llvm.va_end
+}
+
+// Let's verify that normal va_lists work right on Win64, too.
+void f5(int a, ...) {
+  // WIN64-LABEL: define void @f5
+  __builtin_va_list ap;
+  __builtin_va_start(ap, a);
+  // WIN64: %[[AP:.*]] = alloca i8*
+  // WIN64: call void @llvm.va_start
+  int b = __builtin_va_arg(ap, int);
+  // WIN64: %[[AP_CUR:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR]], i64 8
+  // WIN64-NEXT: store i8* %[[AP_NEXT]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR]] to i32*
+  double _Complex c = __builtin_va_arg(ap, double _Complex);
+  // WIN64: %[[AP_CUR2:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT2:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR2]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT2]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR2]] to { double, double }*
+  struct foo d = __builtin_va_arg(ap, struct foo);
+  // WIN64: %[[AP_CUR3:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT3:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR3]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT3]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR3]] to %[[STRUCT_FOO]]*
+  __builtin_va_list ap2;
+  __builtin_va_copy(ap2, ap);
+  // WIN64: call void @llvm.va_copy
+  __builtin_va_end(ap);
+  // WIN64: call void @llvm.va_end
+}
+
+// Verify that using a Win64 va_list from a System V function works.
+void __attribute__((sysv_abi)) f6(__builtin_ms_va_list ap) {
+  // FREEBSD-LABEL: define void @f6
+  // FREEBSD: store i8* %ap, i8** %[[AP:.*]]
+  // WIN64-LABEL: define x86_64_sysvcc void @f6
+  // WIN64: store i8* %ap, i8** %[[AP:.*]]
+  int b = __builtin_va_arg(ap, int);
+  // FREEBSD: %[[AP_CUR:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR]], i64 8
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR]] to i32*
+  // WIN64: %[[AP_CUR:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR]], i64 8
+  // WIN64-NEXT: store i8* %[[AP_NEXT]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR]] to i32*
+  double _Complex c = __builtin_va_arg(ap, double _Complex);
+  // FREEBSD: %[[AP_CUR2:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT2:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR2]], i64 16
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT2]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR2]] to { double, double }*
+  // WIN64: %[[AP_CUR2:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT2:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR2]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT2]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR2]] to { double, double }*
+  struct foo d = __builtin_va_arg(ap, struct foo);
+  // FREEBSD: %[[AP_CUR3:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: %[[AP_NEXT3:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR3]], i64 16
+  // FREEBSD-NEXT: store i8* %[[AP_NEXT3]], i8** %[[AP]]
+  // FREEBSD-NEXT: bitcast i8* %[[AP_CUR3]] to %[[STRUCT_FOO]]*
+  // WIN64: %[[AP_CUR3:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: %[[AP_NEXT3:.*]] = getelementptr inbounds i8, i8* %[[AP_CUR3]], i64 16
+  // WIN64-NEXT: store i8* %[[AP_NEXT3]], i8** %[[AP]]
+  // WIN64-NEXT: bitcast i8* %[[AP_CUR3]] to %[[STRUCT_FOO]]*
+  __builtin_ms_va_list ap2;
+  __builtin_ms_va_copy(ap2, ap);
+  // FREEBSD: %[[AP_VAL:.*]] = load i8*, i8** %[[AP]]
+  // FREEBSD-NEXT: store i8* %[[AP_VAL]], i8** %[[AP2:.*]]
+  // WIN64: %[[AP_VAL:.*]] = load i8*, i8** %[[AP]]
+  // WIN64-NEXT: store i8* %[[AP_VAL]], i8** %[[AP2:.*]]
+}