Add some MS aliases for existing intrinsics

[rnk]

+Richard for ideas on how to navigate the intel intrinsics

include/clang/Basic/BuiltinsX86.def

304

Part of the idea behind the Intel *mmintrin.h headers is that they define symbols outside of the implementor's namespace. Users should be able to write code that uses these _mm_* names if they don't include those headers. Having this builtin always be available on x86 makes that impossible.

That said, I can see that winnt.h uses these directly, rather than including xmmintrin.h, so we need them to be builtins in MSVC mode, and it's annoying to have them sometimes be builtins and sometimes be functions.

[majnemer]

include/clang/Basic/BuiltinsX86.def

304

We could have the header file use a pragma which turns the _mm intrinsics on along the same lines as #pragma intrinsic. For MSVC compat, we could treat them as-if they were enabled by some similar mechanism.

[rsmith]

include/clang/Basic/BuiltinsX86.def

304

Names starting with an underscore are reserved to the implementation for use in the global namespace. Also, we declare these lazily, on-demand, only if name lookup would otherwise fail, so (outside of odd SFINAE cases in C++) this shouldn't affect the meaning of any valid programs. While I find it distasteful to model these as builtins, the only significant problem I see here is that we'll accept non-portable code that forgets to include the right header if we do so.

Perhaps we could model this somewhat similarly to LIBBUILTIN, so that we allow use of the builtin without a declaration, but produce a diagnostic about the missing #include when we do so?

[rnk]

include/clang/Basic/BuiltinsX86.def

304

+1 for doing something like LIBBUILTIN

[agutowski]

Changed way of handling Intel intrinsics
Removed constant folding

[agutowski]

Separated Intel intrinsics tests

[rnk]

test/Sema/implicit-intel-builtin-decl.c

4

Can you add a C++ test? I think you'll get "undeclared identifier '_mm_getcsr'" instead of this helpful diagnostic.

[agutowski]

test/Sema/implicit-intel-builtin-decl.c

4

This diagnostic works also in C++, although that's not the case with _byteswap functions - if they are LIBBUILTINs, the C++ diagnostic doesn't work, and LANGBUILTINs doesn't have header dependencies. I can create another thing like TARGET_HEADER_BUILTIN, but I don't know if that's a good idea.

[agutowski]

Add test for implicitly declared intel intrinsic diagnostic in C++

[rnk]

lgtm after merging the test back.

test/Sema/implicit-intel-builtin-decl.c

4

OK, it seems fine as is.

Given that there are no diagnostic differences, I would suggest copy-pasting the RUN line at the top of this file and adding -x c++ to avoid duplicating the whole test.

[agutowski]

Merge C and C++ tests

[agutowski]

xmmintrin.h and emmintrin.h broke compilation when included inside extern "C++" block

[agutowski]

Add extern "C" to Intel intrinsics declarations

[rnk]

lgtm We could define a macro that conditionally expands to extern "C", but then we'd have to undef it, and that seems like no good.

[alexander-shaposhnikov]

include/clang/Basic/Builtins.h

142

should the doxygen comment start with /// here ?

[agutowski]

Fix doxygen comment

include/clang/Basic/Builtins.h

     return strchr(getRecord(ID).Attributes, 'f') != nullptr;
   }
 
+  // \brief Returns true if this builtin requires appropriate header in other
+  // compilers. In Clang it will work even without including it, but we can emit
+  // a warning about missing header.
+  bool isHeaderDependentFunction(unsigned ID) const {
+    return strchr(getRecord(ID).Attributes, 'h') != nullptr;
+  }
+
   /// \brief Determines whether this builtin is a predefined compiler-rt/libgcc
   /// function, such as "__clear_cache", where we know the signature a
   /// priori.

include/clang/Basic/Builtins.def

 //  f -> this is a libc/libm function without the '__builtin_' prefix. It can
 //       be followed by ':headername:' to state which header this function
 //       comes from.
+//  h -> this function requires a specific header or an explicit declaration.
 //  i -> this is a runtime library implemented function without the
 //       '__builtin_' prefix. It will be implemented in compiler-rt or libgcc.
 //  p:N: -> this is a printf-like function whose Nth argument is the format

 // Microsoft builtins.  These are only active with -fms-extensions.
 LANGBUILTIN(_alloca,          "v*z", "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(__assume,         "vb",  "n", ALL_MS_LANGUAGES)
+LIBBUILTIN(_byteswap_ushort, "UsUs",     "fnc", "stdlib.h", ALL_MS_LANGUAGES)
+LIBBUILTIN(_byteswap_ulong,  "ULiULi",   "fnc", "stdlib.h", ALL_MS_LANGUAGES)
+LIBBUILTIN(_byteswap_uint64, "ULLiULLi", "fnc", "stdlib.h", ALL_MS_LANGUAGES)
 LANGBUILTIN(__debugbreak,     "v",   "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(__exception_code, "ULi", "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(_exception_code,  "ULi", "n", ALL_MS_LANGUAGES)

 LANGBUILTIN(_InterlockedExchangePointer, "v*v*D*v*",   "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(_InterlockedIncrement,       "LiLiD*",     "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(__noop,           "i.",  "n", ALL_MS_LANGUAGES)
+LANGBUILTIN(__popcnt16, "UsUs",     "nc", ALL_MS_LANGUAGES)
+LANGBUILTIN(__popcnt,   "UiUi",     "nc", ALL_MS_LANGUAGES)
+LANGBUILTIN(__popcnt64, "ULLiULLi", "nc", ALL_MS_LANGUAGES)
 LANGBUILTIN(__readfsdword,    "ULiULi", "n", ALL_MS_LANGUAGES)
 LANGBUILTIN(__va_start,       "vc**.", "nt", ALL_MS_LANGUAGES)
 

include/clang/Basic/BuiltinsX86.def

 #   define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE) BUILTIN(ID, TYPE, ATTRS)
 #endif
 
+#if defined(BUILTIN) && !defined(TARGET_HEADER_BUILTIN)
+#  define TARGET_HEADER_BUILTIN(ID, TYPE, ATTRS, HEADER, LANG, FEATURE) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
 // FIXME: Are these nothrow/const?
 
 // Miscellaneous builtin for checking x86 cpu features.

 TARGET_BUILTIN(__builtin_ia32_pabsd128, "V4iV4i", "", "ssse3")
 
 TARGET_BUILTIN(__builtin_ia32_ldmxcsr, "vUi", "", "sse")
+TARGET_HEADER_BUILTIN(_mm_setcsr, "vUi", "h","xmmintrin.h", ALL_LANGUAGES, "sse")
 TARGET_BUILTIN(__builtin_ia32_stmxcsr, "Ui", "", "sse")
+TARGET_HEADER_BUILTIN(_mm_getcsr, "Ui", "h", "xmmintrin.h", ALL_LANGUAGES, "sse")
 TARGET_BUILTIN(__builtin_ia32_cvtss2si, "iV4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_cvttss2si, "iV4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_cvtss2si64, "LLiV4f", "", "sse")

 TARGET_BUILTIN(__builtin_ia32_storelps, "vV2i*V4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_movmskps, "iV4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_sfence, "v", "", "sse")
+TARGET_HEADER_BUILTIN(_mm_sfence, "v", "h", "xmmintrin.h", ALL_LANGUAGES, "sse")
 TARGET_BUILTIN(__builtin_ia32_rcpps, "V4fV4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_rcpss, "V4fV4f", "", "sse")
 TARGET_BUILTIN(__builtin_ia32_rsqrtps, "V4fV4f", "", "sse")

 TARGET_BUILTIN(__builtin_ia32_cvtps2dq, "V4iV4f", "", "sse2")
 TARGET_BUILTIN(__builtin_ia32_cvttps2dq, "V4iV4f", "", "sse2")
 TARGET_BUILTIN(__builtin_ia32_clflush, "vvC*", "", "sse2")
+TARGET_HEADER_BUILTIN(_mm_clflush, "vvC*", "h", "emmintrin.h", ALL_LANGUAGES, "sse2")
 TARGET_BUILTIN(__builtin_ia32_lfence, "v", "", "sse2")
+TARGET_HEADER_BUILTIN(_mm_lfence, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2")
 TARGET_BUILTIN(__builtin_ia32_mfence, "v", "", "sse2")
+TARGET_HEADER_BUILTIN(_mm_mfence, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2")
 TARGET_BUILTIN(__builtin_ia32_pause, "v", "", "sse2")
+TARGET_HEADER_BUILTIN(_mm_pause, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2")
 TARGET_BUILTIN(__builtin_ia32_pmuludq128, "V2LLiV4iV4i", "", "sse2")
 TARGET_BUILTIN(__builtin_ia32_psraw128, "V8sV8sV8s", "", "sse2")
 TARGET_BUILTIN(__builtin_ia32_psrad128, "V4iV4iV4i", "", "sse2")

 
 BUILTIN(__builtin_ia32_rdpmc, "ULLii", "")
 BUILTIN(__builtin_ia32_rdtsc, "ULLi", "")
+BUILTIN(__rdtsc, "ULLi", "")
 BUILTIN(__builtin_ia32_rdtscp, "ULLiUi*", "")
 // PKU
 TARGET_BUILTIN(__builtin_ia32_rdpkru, "Ui", "", "pku")

 
 #undef BUILTIN
 #undef TARGET_BUILTIN
+#undef TARGET_HEADER_BUILTIN

lib/Basic/Targets.cpp

   { #ID, TYPE, ATTRS, HEADER, ALL_LANGUAGES, nullptr },
 #define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
   { #ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, FEATURE },
+#define TARGET_HEADER_BUILTIN(ID, TYPE, ATTRS, HEADER, LANGS, FEATURE)         \
+  { #ID, TYPE, ATTRS, HEADER, LANGS, FEATURE },
 #include "clang/Basic/BuiltinsX86.def"
 };
 

lib/CodeGen/CGBuiltin.cpp

                                      "cast");
     return RValue::get(Result);
   }
+  case Builtin::BI__popcnt16:
+  case Builtin::BI__popcnt:
+  case Builtin::BI__popcnt64:
   case Builtin::BI__builtin_popcount:
   case Builtin::BI__builtin_popcountl:
   case Builtin::BI__builtin_popcountll: {

     Value *F = CGM.getIntrinsic(Intrinsic::prefetch);
     return Builder.CreateCall(F, {Address, RW, Locality, Data});
   }
+  case X86::BI_mm_clflush: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse2_clflush),
+                              Ops[0]);
+  }
+  case X86::BI_mm_lfence: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse2_lfence));
+  }
+  case X86::BI_mm_mfence: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse2_mfence));
+  }
+  case X86::BI_mm_sfence: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse_sfence));
+  }
+  case X86::BI_mm_pause: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse2_pause));
+  }
+  case X86::BI__rdtsc: {
+    return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_rdtsc));
+  }
   case X86::BI__builtin_ia32_undef128:
   case X86::BI__builtin_ia32_undef256:
   case X86::BI__builtin_ia32_undef512:

   case X86::BI__builtin_ia32_vec_ext_v2si:
     return Builder.CreateExtractElement(Ops[0],
                                   llvm::ConstantInt::get(Ops[1]->getType(), 0));
+  case X86::BI_mm_setcsr:
   case X86::BI__builtin_ia32_ldmxcsr: {
     Address Tmp = CreateMemTemp(E->getArg(0)->getType());
     Builder.CreateStore(Ops[0], Tmp);
     return Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse_ldmxcsr),
                           Builder.CreateBitCast(Tmp.getPointer(), Int8PtrTy));
   }
+  case X86::BI_mm_getcsr:
   case X86::BI__builtin_ia32_stmxcsr: {
     Address Tmp = CreateMemTemp(E->getType());
     Builder.CreateCall(CGM.getIntrinsic(Intrinsic::x86_sse_stmxcsr),

lib/Headers/emmintrin.h

 /// \param __p
 ///    A pointer to the memory location used to identify the cache line to be
 ///    flushed.
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_clflush(void const *__p)
-{
-  __builtin_ia32_clflush(__p);
-}
+void _mm_clflush(void const *);
 
 /// \brief Forces strong memory ordering (serialization) between load
 ///    instructions preceding this instruction and load instructions following

 ///
 /// This intrinsic corresponds to the \c LFENCE instruction.
 ///
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_lfence(void)
-{
-  __builtin_ia32_lfence();
-}
+void _mm_lfence(void);
 
 /// \brief Forces strong memory ordering (serialization) between load and store
 ///    instructions preceding this instruction and load and store instructions

 ///
 /// This intrinsic corresponds to the \c MFENCE instruction.
 ///
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_mfence(void)
-{
-  __builtin_ia32_mfence();
-}
+void _mm_mfence(void);
 
 /// \brief Converts 16-bit signed integers from both 128-bit integer vector
 ///    operands into 8-bit signed integers, and packs the results into the

 ///
 /// This intrinsic corresponds to the \c PAUSE instruction.
 ///
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_pause(void)
-{
-  __builtin_ia32_pause();
-}
+void _mm_pause(void);
 
 #undef __DEFAULT_FN_ATTRS
 

lib/Headers/ia32intrin.h

   return __builtin_ia32_rdpmc(__A);
 }
 
-/* __rdtsc */
-static __inline__ unsigned long long __attribute__((__always_inline__, __nodebug__))
-__rdtsc(void) {
-  return __builtin_ia32_rdtsc();
-}
-
 /* __rdtscp */
 static __inline__ unsigned long long __attribute__((__always_inline__, __nodebug__))
 __rdtscp(unsigned int *__A) {

lib/Headers/intrin.h

   *_Index = 31 - __builtin_clzl(_Mask);
   return 1;
 }
-static __inline__ unsigned short __DEFAULT_FN_ATTRS
-__popcnt16(unsigned short _Value) {
-  return __builtin_popcount((int)_Value);
-}
-static __inline__ unsigned int __DEFAULT_FN_ATTRS
-__popcnt(unsigned int _Value) {
-  return __builtin_popcount(_Value);
-}
 static __inline__ unsigned char __DEFAULT_FN_ATTRS
 _bittest(long const *_BitBase, long _BitPos) {
   return (*_BitBase >> _BitPos) & 1;

   *_Index = 63 - __builtin_clzll(_Mask);
   return 1;
 }
-static __inline__
-unsigned __int64 __DEFAULT_FN_ATTRS
-__popcnt64(unsigned __int64 _Value) {
-  return __builtin_popcountll(_Value);
-}
 static __inline__ unsigned char __DEFAULT_FN_ATTRS
 _bittest64(__int64 const *_BitBase, __int64 _BitPos) {
   return (*_BitBase >> _BitPos) & 1;

lib/Headers/xmmintrin.h

 ///
 /// This intrinsic corresponds to the \c SFENCE instruction.
 ///
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_sfence(void)
-{
-  __builtin_ia32_sfence();
-}
+void _mm_sfence(void);
 
 /// \brief Extracts 16-bit element from a 64-bit vector of [4 x i16] and
 ///    returns it, as specified by the immediate integer operand.

 ///
 /// \returns A 32-bit unsigned integer containing the contents of the MXCSR
 ///    register.
-static __inline__ unsigned int __DEFAULT_FN_ATTRS
-_mm_getcsr(void)
-{
-  return __builtin_ia32_stmxcsr();
-}
+unsigned int _mm_getcsr(void);
 
 /// \brief Sets the MXCSR register with the 32-bit unsigned integer value. There
 ///    are several groups of macros associated with this intrinsic, including:

 ///
 /// \param __i
 ///    A 32-bit unsigned integer value to be written to the MXCSR register.
-static __inline__ void __DEFAULT_FN_ATTRS
-_mm_setcsr(unsigned int __i)
-{
-  __builtin_ia32_ldmxcsr(__i);
-}
+void _mm_setcsr(unsigned int);
 
 /// \brief Selects 4 float values from the 128-bit operands of [4 x float], as
 ///    specified by the immediate value operand.

lib/Sema/SemaDecl.cpp

     return nullptr;
   }
 
-  if (!ForRedeclaration && Context.BuiltinInfo.isPredefinedLibFunction(ID)) {
+  if (!ForRedeclaration &&
+      (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
+       Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
     Diag(Loc, diag::ext_implicit_lib_function_decl)
         << Context.BuiltinInfo.getName(ID) << R;
     if (Context.BuiltinInfo.getHeaderName(ID) &&

test/CodeGen/builtins-x86.c

   tmp_i = __builtin_ia32_vec_ext_v2si(tmp_V2i, 0);
 
   (void) __builtin_ia32_ldmxcsr(tmp_Ui);
+  (void) _mm_setcsr(tmp_Ui);
   tmp_Ui = __builtin_ia32_stmxcsr();
+  tmp_Ui = _mm_getcsr();
   (void)__builtin_ia32_fxsave(tmp_vp);
   (void)__builtin_ia32_fxsave64(tmp_vp);
   (void)__builtin_ia32_fxrstor(tmp_vp);

   tmp_i = __builtin_ia32_cvttss2si(tmp_V4f);
 
   tmp_i = __builtin_ia32_rdtsc();
+  tmp_i = __rdtsc();
   tmp_i = __builtin_ia32_rdtscp(&tmp_Ui);
   tmp_LLi = __builtin_ia32_rdpmc(tmp_i);
 #ifdef USE_64

   tmp_i = __builtin_ia32_pmovmskb(tmp_V8c);
   (void) __builtin_ia32_movntq(tmp_V1LLip, tmp_V1LLi);
   (void) __builtin_ia32_sfence();
+  (void) _mm_sfence();
 
   tmp_V4s = __builtin_ia32_psadbw(tmp_V8c, tmp_V8c);
   tmp_V4f = __builtin_ia32_rcpps(tmp_V4f);

   tmp_V4i = __builtin_ia32_cvtps2dq(tmp_V4f);
   tmp_V4i = __builtin_ia32_cvttps2dq(tmp_V4f);
   (void) __builtin_ia32_clflush(tmp_vCp);
+  (void) _mm_clflush(tmp_vCp);
   (void) __builtin_ia32_lfence();
+  (void) _mm_lfence();
   (void) __builtin_ia32_mfence();
+  (void) _mm_mfence();
+  (void) __builtin_ia32_pause();
+  (void) _mm_pause();
   tmp_V4s = __builtin_ia32_psllwi(tmp_V4s, tmp_i);
   tmp_V2i = __builtin_ia32_pslldi(tmp_V2i, tmp_i);
   tmp_V1LLi = __builtin_ia32_psllqi(tmp_V1LLi, tmp_i);

test/Sema/implicit-intel-builtin-decl.c

+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -target-feature +sse2 -fsyntax-only -verify %s
+
+void f() {
+  (void)_mm_getcsr(); // expected-warning{{implicitly declaring library function '_mm_getcsr'}} \
+  // expected-note{{include the header <xmmintrin.h> or explicitly provide a declaration for '_mm_getcsr'}}
+  _mm_setcsr(1); // expected-warning{{implicitly declaring library function '_mm_setcsr'}} \
+  // expected-note{{include the header <xmmintrin.h> or explicitly provide a declaration for '_mm_setcsr'}}
+  _mm_sfence(); // expected-warning{{implicitly declaring library function '_mm_sfence'}} \
+  // expected-note{{include the header <xmmintrin.h> or explicitly provide a declaration for '_mm_sfence'}}
+
+  _mm_clflush((void*)0); // expected-warning{{implicitly declaring library function '_mm_clflush'}} \
+  // expected-note{{include the header <emmintrin.h> or explicitly provide a declaration for '_mm_clflush'}}
+  _mm_lfence(); // expected-warning{{implicitly declaring library function '_mm_lfence'}} \
+  // expected-note{{include the header <emmintrin.h> or explicitly provide a declaration for '_mm_lfence'}}
+  _mm_mfence(); // expected-warning{{implicitly declaring library function '_mm_mfence'}} \
+  // expected-note{{include the header <emmintrin.h> or explicitly provide a declaration for '_mm_mfence'}}
+  _mm_pause(); // expected-warning{{implicitly declaring library function '_mm_pause'}} \
+  // expected-note{{include the header <emmintrin.h> or explicitly provide a declaration for '_mm_pause'}}
+}
+
+unsigned int _mm_getcsr();
+void _mm_setcsr(unsigned int);
+void _mm_sfence();
+
+void _mm_clflush(void const *);
+void _mm_lfence();
+void _mm_mfence();
+void _mm_pause();
+
+void g() {
+  (void)_mm_getcsr();
+  _mm_setcsr(1);
+  _mm_sfence();
+
+  _mm_clflush((void*)0);
+  _mm_lfence();
+  _mm_mfence();
+  _mm_pause();
+}

test/Sema/implicit-ms-builtin-decl.c

+// RUN: %clang_cc1 -fsyntax-only -verify %s -fms-extensions
+
+void f() {
+  (void)_byteswap_ushort(42); // expected-warning{{implicitly declaring library function '_byteswap_ushort}} \
+  // expected-note{{include the header <stdlib.h> or explicitly provide a declaration for '_byteswap_ushort'}}
+  (void)_byteswap_uint64(42LL); // expected-warning{{implicitly declaring library function '_byteswap_uint64}} \
+  // expected-note{{include the header <stdlib.h> or explicitly provide a declaration for '_byteswap_uint64'}}
+}
+
+void _byteswap_ulong(); // expected-warning{{incompatible redeclaration of library function '_byteswap_ulong'}} \
+// expected-note{{'_byteswap_ulong' is a builtin}}
+
+unsigned short _byteswap_ushort(unsigned short);
+unsigned long long _byteswap_uint64(unsigned long long);
+
+void g() {
+  (void)_byteswap_ushort(42);
+  (void)_byteswap_uint64(42LL);
+}