Implement MS read/write barriers and __faststorefence intrinsic

Reviewers: hans, rnk, majnemer

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D25442

llvm-svn: 283793

clang/include/clang/Basic/BuiltinsX86.def

@@ -2071,6 +2071,10 @@ TARGET_BUILTIN(__builtin_ia32_selectpd_512, "V8dUcV8dV8d", "", "")
 TARGET_BUILTIN(__builtin_ia32_monitorx, "vv*UiUi", "", "mwaitx")
 TARGET_BUILTIN(__builtin_ia32_mwaitx, "vUiUiUi", "", "mwaitx")
 
+TARGET_HEADER_BUILTIN(_ReadWriteBarrier, "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+TARGET_HEADER_BUILTIN(_ReadBarrier,      "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+TARGET_HEADER_BUILTIN(_WriteBarrier,     "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+
 TARGET_HEADER_BUILTIN(__emul,  "LLiii",    "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(__emulu, "ULLiUiUi", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
 

clang/include/clang/Basic/BuiltinsX86_64.def

@@ -23,5 +23,8 @@ TARGET_HEADER_BUILTIN(__umulh, "ULLiULLiULLi", "nch", "intrin.h", ALL_MS_LANGUAG
 TARGET_HEADER_BUILTIN(_mul128, "LLiLLiLLiLLi*",      "nh",   "intrin.h", ALL_MS_LANGUAGES, "")
 TARGET_HEADER_BUILTIN(_umul128, "ULLiULLiULLiULLi*", "nh",   "intrin.h", ALL_MS_LANGUAGES, "")
 
+TARGET_HEADER_BUILTIN(__faststorefence, "v", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+
+
 #undef BUILTIN
 #undef TARGET_HEADER_BUILTIN

clang/lib/CodeGen/CGBuiltin.cpp

@@ -7612,6 +7612,17 @@ Value *CodeGenFunction::EmitX86BuiltinExpr(unsigned BuiltinID,
     Builder.CreateStore(HigherBits, HighBitsAddress);
     return Builder.CreateIntCast(MulResult, ResType, IsSigned);
   }
+
+  case X86::BI__faststorefence: {
+    return Builder.CreateFence(llvm::AtomicOrdering::SequentiallyConsistent,
+                               llvm::CrossThread);
+  }
+  case X86::BI_ReadWriteBarrier:
+  case X86::BI_ReadBarrier:
+  case X86::BI_WriteBarrier: {
+    return Builder.CreateFence(llvm::AtomicOrdering::SequentiallyConsistent,
+                               llvm::SingleThread);
+  }
   }
 }
 

clang/lib/Headers/intrin.h

@@ -256,10 +256,12 @@ static __inline__
 unsigned long __cdecl _lrotl(unsigned long, int);
 static __inline__
 unsigned long __cdecl _lrotr(unsigned long, int);
-static __inline__
+static __inline__ void
-void _ReadBarrier(void);
+__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
-static __inline__
+_ReadBarrier(void);
-void _ReadWriteBarrier(void);
+static __inline__ void
+__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
+_ReadWriteBarrier(void);
 static __inline__
 void *_ReturnAddress(void);
 unsigned int _rorx_u32(unsigned int, const unsigned int);
@@ -288,8 +290,9 @@ unsigned int _shrx_u32(unsigned int, unsigned int);
 void _Store_HLERelease(long volatile *, long);
 void _Store64_HLERelease(__int64 volatile *, __int64);
 void _StorePointer_HLERelease(void *volatile *, void *);
-static __inline__
+static __inline__ void
-void _WriteBarrier(void);
+__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
+_WriteBarrier(void);
 unsigned __int32 xbegin(void);
 void _xend(void);
 static __inline__
@@ -1045,30 +1048,6 @@ _InterlockedCompareExchange64_rel(__int64 volatile *_Destination,
 }
 #endif
 /*----------------------------------------------------------------------------*\
-|* Barriers
-\*----------------------------------------------------------------------------*/
-static __inline__ void __DEFAULT_FN_ATTRS
-__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
-_ReadWriteBarrier(void) {
-  __atomic_signal_fence(__ATOMIC_SEQ_CST);
-}
-static __inline__ void __DEFAULT_FN_ATTRS
-__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
-_ReadBarrier(void) {
-  __atomic_signal_fence(__ATOMIC_SEQ_CST);
-}
-static __inline__ void __DEFAULT_FN_ATTRS
-__attribute__((__deprecated__("use other intrinsics or C++11 atomics instead")))
-_WriteBarrier(void) {
-  __atomic_signal_fence(__ATOMIC_SEQ_CST);
-}
-#ifdef __x86_64__
-static __inline__ void __DEFAULT_FN_ATTRS
-__faststorefence(void) {
-  __atomic_thread_fence(__ATOMIC_SEQ_CST);
-}
-#endif
-/*----------------------------------------------------------------------------*\
 |* readfs, readgs
 |* (Pointers in address space #256 and #257 are relative to the GS and FS
 |* segment registers, respectively.)

clang/test/CodeGen/ms-barriers-intrinsics.c

@@ -0,0 +1,39 @@
+// RUN: %clang_cc1 -ffreestanding -fms-extensions -fms-compatibility -fms-compatibility-version=17.00 \
+// RUN:         -triple i686--windows -emit-llvm %s -o - \
+// RUN:         | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-I386
+// RUN: %clang_cc1 -ffreestanding -fms-extensions -fms-compatibility -fms-compatibility-version=17.00 \
+// RUN:         -triple x86_64--windows -emit-llvm %s -o - \
+// RUN:         | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-X64
+
+// intrin.h needs size_t, but -ffreestanding prevents us from getting it from
+// stddef.h.  Work around it with this typedef.
+typedef __SIZE_TYPE__ size_t;
+
+#include <intrin.h>
+
+void test_ReadWriteBarrier() { _ReadWriteBarrier(); }
+// CHECK-LABEL: define void @test_ReadWriteBarrier
+// CHECK:   fence singlethread seq_cst
+// CHECK:   ret void
+// CHECK: }
+
+void test_ReadBarrier() { _ReadBarrier(); }
+// CHECK-LABEL: define void @test_ReadBarrier
+// CHECK:   fence singlethread seq_cst
+// CHECK:   ret void
+// CHECK: }
+
+void test_WriteBarrier() { _WriteBarrier(); }
+// CHECK-LABEL: define void @test_WriteBarrier
+// CHECK:   fence singlethread seq_cst
+// CHECK:   ret void
+// CHECK: }
+
+#if defined(__x86_64__)
+void test__faststorefence() { __faststorefence(); }
+// CHECK-X64-LABEL: define void @test__faststorefence
+// CHECK-X64:   fence seq_cst
+// CHECK-X64:   ret void
+// CHECK-X64: }
+#endif
+