[Analysis] atan2: isTriviallyVectorizable; add to massv and accelerate veclibs (#113637)

This change is part of this proposal:
https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294

- Return true for atan2 from isTriviallyVectorizable
- Add atan2 to VecFuncs.def for massv and accelerate libraries.
- Add atan2 to hasOptimizedCodeGen
- Add atan2 support in llvm/lib/Analysis/ValueTracking.cpp
llvm::getIntrinsicForCallSite and update vectorization tests
- Add atan2 name check to isLoweredToCall in
llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
- Note: there's no test coverage for these names in isLoweredToCall, except that Transforms/TailCallElim/inf-recursion.ll is impacted by the "fabs" case

Thanks to @jroelofs for the atan2 accelerate veclib and associated test
additions, plus the hasOptimizedCodeGen addition.

Part of: Implement the atan2 HLSL Function #70096.

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/VectorUtils.cpp b/llvm/lib/Analysis/VectorUtils.cpp
index cd5cf04..15e325a 100644
--- a/llvm/lib/Analysis/VectorUtils.cpp
+++ b/llvm/lib/Analysis/VectorUtils.cpp
@@ -69,6 +69,7 @@ bool llvm::isTriviallyVectorizable(Intrinsic::ID ID) {
   case Intrinsic::asin:
   case Intrinsic::acos:
   case Intrinsic::atan:
+  case Intrinsic::atan2:
   case Intrinsic::sin:
   case Intrinsic::cos:
   case Intrinsic::tan: