Towards PR12457: constant expression evaluation support for __builtin_parity{,l,ll}, __builtin_ffs{,l,ll}, and __builtin_fpclassify.

llvm-svn: 183889

1 files changed, 63 insertions, 14 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 84f7bfdf82b..ad4816a24f8 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -5691,6 +5691,13 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
     return Success(Val.byteSwap(), E);
   }
 
+  case Builtin::BI__builtin_classify_type:
+    return Success(EvaluateBuiltinClassifyType(E), E);
+
+  // FIXME: BI__builtin_clrsb
+  // FIXME: BI__builtin_clrsbl
+  // FIXME: BI__builtin_clrsbll
+
   case Builtin::BI__builtin_clz:
   case Builtin::BI__builtin_clzl:
   case Builtin::BI__builtin_clzll: {
@@ -5703,6 +5710,9 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
     return Success(Val.countLeadingZeros(), E);
   }
 
+  case Builtin::BI__builtin_constant_p:
+    return Success(EvaluateBuiltinConstantP(Info.Ctx, E->getArg(0)), E);
+
   case Builtin::BI__builtin_ctz:
   case Builtin::BI__builtin_ctzl:
   case Builtin::BI__builtin_ctzll: {
@@ -5715,30 +5725,65 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
     return Success(Val.countTrailingZeros(), E);
   }
 
-  case Builtin::BI__builtin_popcount:
-  case Builtin::BI__builtin_popcountl:
-  case Builtin::BI__builtin_popcountll: {
+  case Builtin::BI__builtin_eh_return_data_regno: {
+    int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
+    Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
+    return Success(Operand, E);
+  }
+
+  case Builtin::BI__builtin_expect:
+    return Visit(E->getArg(0));
+
+  case Builtin::BI__builtin_ffs:
+  case Builtin::BI__builtin_ffsl:
+  case Builtin::BI__builtin_ffsll: {
     APSInt Val;
     if (!EvaluateInteger(E->getArg(0), Val, Info))
       return false;
 
-    return Success(Val.countPopulation(), E);
+    unsigned N = Val.countTrailingZeros();
+    return Success(N == Val.getBitWidth() ? 0 : N + 1, E);
   }
 
-  case Builtin::BI__builtin_classify_type:
-    return Success(EvaluateBuiltinClassifyType(E), E);
+  case Builtin::BI__builtin_fpclassify: {
+    APFloat Val(0.0);
+    if (!EvaluateFloat(E->getArg(5), Val, Info))
+      return false;
+    unsigned Arg;
+    switch (Val.getCategory()) {
+    case APFloat::fcNaN: Arg = 0; break;
+    case APFloat::fcInfinity: Arg = 1; break;
+    case APFloat::fcNormal: Arg = Val.isDenormal() ? 3 : 2; break;
+    case APFloat::fcZero: Arg = 4; break;
+    }
+    return Visit(E->getArg(Arg));
+  }
 
-  case Builtin::BI__builtin_constant_p:
-    return Success(EvaluateBuiltinConstantP(Info.Ctx, E->getArg(0)), E);
+  case Builtin::BI__builtin_isinf_sign: {
+    APFloat Val(0.0);
+    return EvaluateFloat(E->getArg(5), Val, Info) &&
+           Success(Val.isInfinity() ? (Val.isNegative() ? -1 : 1) : 0, E);
+  }
 
-  case Builtin::BI__builtin_eh_return_data_regno: {
-    int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
-    Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
-    return Success(Operand, E);
+  case Builtin::BI__builtin_parity:
+  case Builtin::BI__builtin_parityl:
+  case Builtin::BI__builtin_parityll: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+
+    return Success(Val.countPopulation() % 2, E);
   }
 
-  case Builtin::BI__builtin_expect:
-    return Visit(E->getArg(0));
+  case Builtin::BI__builtin_popcount:
+  case Builtin::BI__builtin_popcountl:
+  case Builtin::BI__builtin_popcountll: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+
+    return Success(Val.countPopulation(), E);
+  }
 
   case Builtin::BIstrlen:
     // A call to strlen is not a constant expression.
@@ -6941,6 +6986,10 @@ bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
       Result.changeSign();
     return true;
 
+  // FIXME: Builtin::BI__builtin_powi
+  // FIXME: Builtin::BI__builtin_powif
+  // FIXME: Builtin::BI__builtin_powil
+
   case Builtin::BI__builtin_copysign:
   case Builtin::BI__builtin_copysignf:
   case Builtin::BI__builtin_copysignl: {