[Clang] Add __builtin_bswapg

Author: clingfei

clang/include/clang/Basic/Builtins.td

@@ -755,6 +755,12 @@ def BSwap : Builtin, Template<["unsigned short", "uint32_t", "uint64_t"],
   let Prototype = "T(T)";
 }
 
+def BSwapg : Builtin {
+  let Spellings = ["__builtin_bswapg"];
+  let Attributes = [NoThrow, Const, Constexpr, CustomTypeChecking];
+  let Prototype = "int(...)";
+}
+
 def Bitreverse : BitInt8_16_32_64BuiltinsTemplate, Builtin {
   let Spellings = ["__builtin_bitreverse"];
   let Attributes = [NoThrow, Const, Constexpr];

clang/lib/AST/ByteCode/InterpBuiltin.cpp

@@ -3288,7 +3288,15 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
   case Builtin::BI__builtin_elementwise_ctzg:
     return interp__builtin_elementwise_countzeroes(S, OpPC, Frame, Call,
                                                    BuiltinID);
-
+  case Builtin::BI__builtin_bswapg: {
+    const APSInt &Val = popToAPSInt(S, Call->getArg(0));
+      assert(Val.getActiveBits() <= 64);
+    if (Val.getBitWidth() == 8)
+        pushInteger(S, Val, Call->getType());
+    else
+        pushInteger(S, Val.byteSwap(), Call->getType());
+    return true;
+  }
   case Builtin::BI__builtin_bswap16:
   case Builtin::BI__builtin_bswap32:
   case Builtin::BI__builtin_bswap64:

clang/lib/AST/ExprConstant.cpp

@@ -13982,6 +13982,17 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
 
     return Success(Val.reverseBits(), E);
   }
+  case Builtin::BI__builtin_bswapg: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+    if (Val.getBitWidth() == 8) {
+        bool ret =  Success(Val, E);
+        return ret;
+    }
+        
+    return Success(Val.byteSwap(), E);
+  }
 
   case Builtin::BI__builtin_bswap16:
   case Builtin::BI__builtin_bswap32:

clang/lib/CodeGen/CGBuiltin.cpp

@@ -3622,6 +3622,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
           Builder.CreateArithmeticFence(ArgValue, ConvertType(ArgType)));
     return RValue::get(ArgValue);
   }
+  case Builtin::BI__builtin_bswapg:
   case Builtin::BI__builtin_bswap16:
   case Builtin::BI__builtin_bswap32:
   case Builtin::BI__builtin_bswap64:

clang/lib/Sema/SemaChecking.cpp

@@ -2200,6 +2200,30 @@ static bool BuiltinCpu(Sema &S, const TargetInfo &TI, CallExpr *TheCall,
   return false;
 }
 
+/// Checks that __builtin_bswapg was called with a single argument, which is an
+/// unsigned integer, and overrides the return value type to the integer type.
+static bool BuiltinBswapg(Sema &S, CallExpr *TheCall) {
+  if (S.checkArgCount(TheCall, 1))
+    return true;
+  ExprResult ArgRes = S.DefaultLvalueConversion(TheCall->getArg(0));
+  if (ArgRes.isInvalid())
+    return true;
+
+  Expr *Arg = ArgRes.get();
+  TheCall->setArg(0, Arg);
+
+  QualType ArgTy = Arg->getType();
+
+  if (!ArgTy->isIntegerType()) {
+    S.Diag(Arg->getBeginLoc(), diag::err_builtin_invalid_arg_type)
+        << 1 << /* scalar */ 1 << /* unsigned integer ty */ 1 << /* no fp */ 0
+        << ArgTy;
+    return true;
+  }
+  TheCall->setType(ArgTy);
+  return false;
+}
+
 /// Checks that __builtin_popcountg was called with a single argument, which is
 /// an unsigned integer.
 static bool BuiltinPopcountg(Sema &S, CallExpr *TheCall) {
@@ -3448,6 +3472,10 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
     }
     break;
   }
+  case Builtin::BI__builtin_bswapg:
+    if (BuiltinBswapg(*this, TheCall))
+        return ExprError();
+    break;
   case Builtin::BI__builtin_popcountg:
     if (BuiltinPopcountg(*this, TheCall))
       return ExprError();

clang/test/AST/ByteCode/builtin-functions.cpp

@@ -824,6 +824,10 @@ namespace bswap {
   int h3 = __builtin_bswap16(0x1234) == 0x3412 ? 1 : f();
   int h4 = __builtin_bswap32(0x1234) == 0x34120000 ? 1 : f();
   int h5 = __builtin_bswap64(0x1234) == 0x3412000000000000 ? 1 : f();
+  int h6 = __builtin_bswapg(0x12) == 0x12 ? 1 : f();
+  int h7 = __builtin_bswapg(0x1234) == 0x3412 ? 1 : f();
+  int h8 = __builtin_bswapg(0x00001234) == 0x34120000 ? 1 : f();
+  int h9 = __builtin_bswapg(0x0000000000001234) == 0x3412000000000000 ? 1 : f();
 }
 
 #define CFSTR __builtin___CFStringMakeConstantString

clang/test/CodeGen/builtins.c

@@ -130,7 +130,7 @@ int main(void) {
   P(object_size, (s0, 3));
 
   // Whatever
-
+  P(bswapg, (N));
   P(bswap16, (N));
   P(bswap32, (N));
   P(bswap64, (N));

clang/test/Sema/constant-builtins-2.c

@@ -479,6 +479,10 @@ int h0 = __builtin_types_compatible_p(int, float);
 int h3 = __builtin_bswap16(0x1234) == 0x3412 ? 1 : f();
 int h4 = __builtin_bswap32(0x1234) == 0x34120000 ? 1 : f();
 int h5 = __builtin_bswap64(0x1234) == 0x3412000000000000 ? 1 : f();
+int h6 = __builtin_bswapg((char)(0x12)) == (char)(0x12) ? 1 : f();
+int h7 = __builtin_bswapg((short)(0x1234)) == (short)(0x3412) ? 1 : f();
+int h8 = __builtin_bswapg(0x00001234) == 0x34120000 ? 1 : f();
+int h9 = __builtin_bswapg(0x0000000000001234ULL) == 0x3412000000000000 ? 1 : f();
 extern long int bi0;
 extern __typeof__(__builtin_expect(0, 0)) bi0;
 

clang/test/Sema/constant-builtins.c

@@ -25,7 +25,10 @@ int h0 = __builtin_types_compatible_p(int,float);
 int h3 = __builtin_bswap16(0x1234) == 0x3412 ? 1 : f();
 int h4 = __builtin_bswap32(0x1234) == 0x34120000 ? 1 : f();
 int h5 = __builtin_bswap64(0x1234) == 0x3412000000000000 ? 1 : f();
-
+int h6 = __builtin_bswapg((char)0x12) == (char)0x12 ? 1 : f();
+int h7 = __builtin_bswapg((short)(0x1234)) == (short)(0x3412) ? 1 : f();
+int h8 = __builtin_bswapg(0x00001234) == 0x34120000 ? 1 : f();
+int h9 = __builtin_bswapg(0x0000000000001234ULL) == 0x3412000000000000 ? 1 : f();
 short somefunc(void);
 
 short t = __builtin_constant_p(5353) ? 42 : somefunc();