Address nits

Author: dheaton-arm

llvm/docs/LangRef.rst

@@ -20318,18 +20318,19 @@ The argument to this intrinsic must be a vector of floating-point values.
 Vector Partial Reduction Intrinsics
 -----------------------------------
 
-Partial reductions of vectors can be expressed using the following intrinsics.
-Each one reduces the concatenation of the two vector arguments down to the
-number of elements of the result vector type.
+Partial reductions of vectors can be expressed using the intrinsics described in
+this section. Each one reduces the concatenation of the two vector arguments
+down to the number of elements of the result vector type.
 
-Other than the reduction operator (e.g. add, fadd) the way in which the
+Other than the reduction operator (e.g. add, fadd), the way in which the
 concatenated arguments is reduced is entirely unspecified. By their nature these
-intrinsics are not expected to be useful in isolation but instead implement the
-first phase of an overall reduction operation.
+intrinsics are not expected to be useful in isolation but can instead be used to
+implement the first phase of an overall reduction operation.
 
 The typical use case is loop vectorization where reductions are split into an
 in-loop phase, where maintaining an unordered vector result is important for
-performance, and an out-of-loop phase to calculate the final scalar result.
+performance, and an out-of-loop phase is required to calculate the final scalar
+result.
 
 By avoiding the introduction of new ordering constraints, these intrinsics
 enhance the ability to leverage a target's accumulation instructions.
@@ -20381,9 +20382,7 @@ Semantics:
 
 As the way in which the arguments to this floating-point intrinsic are reduced
 is unspecified, this intrinsic will assume floating-point reassociation and
-contraction, which may result in variations to the results due to reordering or
-by lowering to different instructions (including combining multiple instructions
-into a single one).
+contraction, which may result in variations to the results.
 
 '``llvm.vector.insert``' Intrinsic
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -12077,20 +12077,14 @@ SDValue TargetLowering::expandPartialReduceMLA(SDNode *N,
   }
   SDValue Input = MulLHS;
   APInt ConstantOne;
-  ConstantFPSDNode *C;
-  if (!(N->getOpcode() == ISD::PARTIAL_REDUCE_FMLA &&
-        (C = llvm::isConstOrConstSplatFP(MulRHS, false)) &&
-        C->isExactlyValue(1.0)) &&
-      !(ISD::isConstantSplatVector(MulRHS.getNode(), ConstantOne) &&
-        ConstantOne.isOne()))
-    switch (N->getOpcode()) {
-    case ISD::PARTIAL_REDUCE_FMLA:
+  if (N->getOpcode() == ISD::PARTIAL_REDUCE_FMLA) {
+    ConstantFPSDNode *C = llvm::isConstOrConstSplatFP(MulRHS, false);
+    if (!(C && C->isExactlyValue(1.0)))
       Input = DAG.getNode(ISD::FMUL, DL, ExtMulOpVT, MulLHS, MulRHS);
-      break;
-    default:
-      Input = DAG.getNode(ISD::MUL, DL, ExtMulOpVT, MulLHS, MulRHS);
-      break;
-    };
+  } else if (!(ISD::isConstantSplatVector(MulRHS.getNode(), ConstantOne) &&
+               ConstantOne.isOne())) {
+    Input = DAG.getNode(ISD::MUL, DL, ExtMulOpVT, MulLHS, MulRHS);
+  }
 
   unsigned Stride = AccVT.getVectorMinNumElements();
   unsigned ScaleFactor = MulOpVT.getVectorMinNumElements() / Stride;

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -2290,11 +2290,9 @@ void AArch64TargetLowering::addTypeForFixedLengthSVE(MVT VT) {
                                 MVT::getVectorVT(MVT::i8, NumElts * 8), Custom);
   }
 
-  if (Subtarget->hasSVE2p1()) {
-    if (VT.getVectorElementType() == MVT::f32)
-      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, VT,
-                                MVT::getVectorVT(MVT::f16, NumElts * 2),
-                                Custom);
+  if (Subtarget->hasSVE2p1() && VT.getVectorElementType() == MVT::f32) {
+    setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, VT,
+                              MVT::getVectorVT(MVT::f16, NumElts * 2), Custom);
   }
 
   // Lower fixed length vector operations to scalable equivalents.