[clang][Interp] __builtin_copysign

[aaron.ballman]

Missing test coverage for copysign.

clang/lib/AST/Interp/InterpBuiltin.cpp

141

Should split out the fmin functionality into a separate patch.

[tbaeder]

I can add some basic tests for __builtin_copysign here, but there are test added in https://reviews.llvm.org/D155369 as well.

[aaron.ballman]

LGTM

clang/lib/AST/Interp/InterpBuiltin.cpp

static bool interp__builtin_inf(InterpState &S, CodePtr OpPC,
                                 const InterpFrame *Frame, const Function *F) {
   const llvm::fltSemantics &TargetSemantics =
       S.getCtx().getFloatTypeSemantics(F->getDecl()->getReturnType());
 
   S.Stk.push<Floating>(Floating::getInf(TargetSemantics));
   return true;
 }
 
+static bool interp__builtin_copysign(InterpState &S, CodePtr OpPC,
+                                     const InterpFrame *Frame,
+                                     const Function *F) {
+  const Floating &Arg1 = getParam<Floating>(Frame, 0);
+  const Floating &Arg2 = getParam<Floating>(Frame, 1);
+
+  APFloat Copy = Arg1.getAPFloat();
+  Copy.copySign(Arg2.getAPFloat());
+  S.Stk.push<Floating>(Floating(Copy));
+
+  return true;
+}
+
+static bool interp__builtin_fmin(InterpState &S, CodePtr OpPC,
+                                 const InterpFrame *Frame, const Function *F) {
+  const Floating &LHS = getParam<Floating>(Frame, 0);
+  const Floating &RHS = getParam<Floating>(Frame, 1);
+
+  Floating Result;
+
+  // When comparing zeroes, return -0.0 if one of the zeroes is negative.
+  if (LHS.isZero() && RHS.isZero() && RHS.isNegative())
+    Result = RHS;
+  else if (LHS.isNan() || RHS < LHS)
+    Result = RHS;
+  else
+    Result = LHS;
+
+  S.Stk.push<Floating>(Result);
+  return true;
+}
+
 bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F) {
   InterpFrame *Frame = S.Current;
   APValue Dummy;
 
   switch (F->getBuiltinID()) {
   case Builtin::BI__builtin_is_constant_evaluated:
     S.Stk.push<Boolean>(Boolean::from(S.inConstantContext()));
     return Ret<PT_Bool>(S, OpPC, Dummy);
bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const Function *F) {
   case Builtin::BI__builtin_inf:
   case Builtin::BI__builtin_inff:
   case Builtin::BI__builtin_infl:
   case Builtin::BI__builtin_inff16:
   case Builtin::BI__builtin_inff128:
     if (interp__builtin_inf(S, OpPC, Frame, F))
       return Ret<PT_Float>(S, OpPC, Dummy);
     break;
+  case Builtin::BI__builtin_copysign:
+  case Builtin::BI__builtin_copysignf:
+  case Builtin::BI__builtin_copysignl:
+  case Builtin::BI__builtin_copysignf128:
+    if (interp__builtin_copysign(S, OpPC, Frame, F))
+      return Ret<PT_Float>(S, OpPC, Dummy);
+    break;
+
+  case Builtin::BI__builtin_fmin:
+  case Builtin::BI__builtin_fminf:
+  case Builtin::BI__builtin_fminl:
+  case Builtin::BI__builtin_fminf16:
+  case Builtin::BI__builtin_fminf128:
+    if (interp__builtin_fmin(S, OpPC, Frame, F))
+      return Ret<PT_Float>(S, OpPC, Dummy);
+    break;
 
   default:
     return false;
   }
 
   return false;
 }
 
 } // namespace interp
 } // namespace clang