From: Sanjay Patel <spatel@rotateright.com>
Date: Tue, 1 Jan 2019 16:08:36 +0000 (+0000)
Subject: [x86] move/rename helper for horizontal op codegen; NFC
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e655b11ced3525d5de295235d253cd7dfe90f9ec;p=llvm

[x86] move/rename helper for horizontal op codegen; NFC

Preliminary commit as suggested in D56011.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350193 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 2ea698d6191..ac072be5ec0 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -18313,6 +18313,16 @@ static SDValue LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) {
                                  In, DAG.getUNDEF(SVT)));
 }
 
+/// Horizontal vector math instructions may be slower than normal math with
+/// shuffles. Limit horizontal op codegen based on size/speed trade-offs, uarch
+/// implementation, and likely shuffle complexity of the alternate sequence.
+static bool shouldUseHorizontalOp(bool IsSingleSource, SelectionDAG &DAG,
+                                  const X86Subtarget &Subtarget) {
+  bool IsOptimizingSize = DAG.getMachineFunction().getFunction().optForSize();
+  bool HasFastHOps = Subtarget.hasFastHorizontalOps();
+  return !IsSingleSource || IsOptimizingSize || HasFastHOps;
+}
+
 /// The only differences between FABS and FNEG are the mask and the logic op.
 /// FNEG also has a folding opportunity for FNEG(FABS(x)).
 static SDValue LowerFABSorFNEG(SDValue Op, SelectionDAG &DAG) {
@@ -37897,16 +37907,6 @@ static bool isHorizontalBinOp(SDValue &LHS, SDValue &RHS, bool IsCommutative) {
   return true;
 }
 
-/// Horizontal vector math instructions may be slower than normal math with
-/// shuffles. Limit horizontal op codegen based on size/speed trade-offs, uarch
-/// implementation, and likely shuffle complexity of the alternate sequence.
-static bool shouldCombineToHorizontalOp(bool IsSingleSource, SelectionDAG &DAG,
-                                        const X86Subtarget &Subtarget) {
-  bool IsOptimizingSize = DAG.getMachineFunction().getFunction().optForSize();
-  bool HasFastHOps = Subtarget.hasFastHorizontalOps();
-  return !IsSingleSource || IsOptimizingSize || HasFastHOps;
-}
-
 /// Do target-specific dag combines on floating-point adds/subs.
 static SDValue combineFaddFsub(SDNode *N, SelectionDAG &DAG,
                                const X86Subtarget &Subtarget) {
@@ -37914,16 +37914,16 @@ static SDValue combineFaddFsub(SDNode *N, SelectionDAG &DAG,
   SDValue LHS = N->getOperand(0);
   SDValue RHS = N->getOperand(1);
   bool IsFadd = N->getOpcode() == ISD::FADD;
+  auto HorizOpcode = IsFadd ? X86ISD::FHADD : X86ISD::FHSUB;
   assert((IsFadd || N->getOpcode() == ISD::FSUB) && "Wrong opcode");
 
   // Try to synthesize horizontal add/sub from adds/subs of shuffles.
   if (((Subtarget.hasSSE3() && (VT == MVT::v4f32 || VT == MVT::v2f64)) ||
        (Subtarget.hasAVX() && (VT == MVT::v8f32 || VT == MVT::v4f64))) &&
       isHorizontalBinOp(LHS, RHS, IsFadd) &&
-      shouldCombineToHorizontalOp(LHS == RHS, DAG, Subtarget)) {
-    auto NewOpcode = IsFadd ? X86ISD::FHADD : X86ISD::FHSUB;
-    return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
-  }
+      shouldUseHorizontalOp(LHS == RHS, DAG, Subtarget))
+    return DAG.getNode(HorizOpcode, SDLoc(N), VT, LHS, RHS);
+
   return SDValue();
 }
 
@@ -40823,7 +40823,7 @@ static SDValue combineAdd(SDNode *N, SelectionDAG &DAG,
   if ((VT == MVT::v8i16 || VT == MVT::v4i32 || VT == MVT::v16i16 ||
        VT == MVT::v8i32) &&
       Subtarget.hasSSSE3() && isHorizontalBinOp(Op0, Op1, true) &&
-      shouldCombineToHorizontalOp(Op0 == Op1, DAG, Subtarget)) {
+      shouldUseHorizontalOp(Op0 == Op1, DAG, Subtarget)) {
     auto HADDBuilder = [](SelectionDAG &DAG, const SDLoc &DL,
                           ArrayRef<SDValue> Ops) {
       return DAG.getNode(X86ISD::HADD, DL, Ops[0].getValueType(), Ops);
@@ -40957,7 +40957,7 @@ static SDValue combineSub(SDNode *N, SelectionDAG &DAG,
   if ((VT == MVT::v8i16 || VT == MVT::v4i32 || VT == MVT::v16i16 ||
        VT == MVT::v8i32) &&
       Subtarget.hasSSSE3() && isHorizontalBinOp(Op0, Op1, false) &&
-      shouldCombineToHorizontalOp(Op0 == Op1, DAG, Subtarget)) {
+      shouldUseHorizontalOp(Op0 == Op1, DAG, Subtarget)) {
     auto HSUBBuilder = [](SelectionDAG &DAG, const SDLoc &DL,
                           ArrayRef<SDValue> Ops) {
       return DAG.getNode(X86ISD::HSUB, DL, Ops[0].getValueType(), Ops);