[InstSimplify] Add basic constant folding for `llvm.sincos` (#114527)

This calls into the existing constant folding for `llvm.sin` and
`llvm.cos`, which currently does not fold for any non-finite values, so
most tests are negative tests at the moment.

Note: The constant folding does not consider the `afn` fast-math flag
and will produce the same result regardless of if the flag is set.

1 files changed, 35 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index efbccee..0233d31 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1632,6 +1632,7 @@ bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
   case Intrinsic::sqrt:
   case Intrinsic::sin:
   case Intrinsic::cos:
+  case Intrinsic::sincos:
   case Intrinsic::pow:
   case Intrinsic::powi:
   case Intrinsic::ldexp:
@@ -3534,6 +3535,40 @@ ConstantFoldStructCall(StringRef Name, Intrinsic::ID IntrinsicID,
       return nullptr;
     return ConstantStruct::get(StTy, Result0, Result1);
   }
+  case Intrinsic::sincos: {
+    Type *Ty = StTy->getContainedType(0);
+    Type *TyScalar = Ty->getScalarType();
+
+    auto ConstantFoldScalarSincosCall =
+        [&](Constant *Op) -> std::pair<Constant *, Constant *> {
+      Constant *SinResult =
+          ConstantFoldScalarCall(Name, Intrinsic::sin, TyScalar, Op, TLI, Call);
+      Constant *CosResult =
+          ConstantFoldScalarCall(Name, Intrinsic::cos, TyScalar, Op, TLI, Call);
+      return std::make_pair(SinResult, CosResult);
+    };
+
+    if (auto *FVTy = dyn_cast<FixedVectorType>(Ty)) {
+      SmallVector<Constant *> SinResults(FVTy->getNumElements());
+      SmallVector<Constant *> CosResults(FVTy->getNumElements());
+
+      for (unsigned I = 0, E = FVTy->getNumElements(); I != E; ++I) {
+        Constant *Lane = Operands[0]->getAggregateElement(I);
+        std::tie(SinResults[I], CosResults[I]) =
+            ConstantFoldScalarSincosCall(Lane);
+        if (!SinResults[I] || !CosResults[I])
+          return nullptr;
+      }
+
+      return ConstantStruct::get(StTy, ConstantVector::get(SinResults),
+                                 ConstantVector::get(CosResults));
+    }
+
+    auto [SinResult, CosResult] = ConstantFoldScalarSincosCall(Operands[0]);
+    if (!SinResult || !CosResult)
+      return nullptr;
+    return ConstantStruct::get(StTy, SinResult, CosResult);
+  }
   default:
     // TODO: Constant folding of vector intrinsics that fall through here does
     // not work (e.g. overflow intrinsics)