From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Sun, 11 Oct 2015 16:02:28 +0000 (+0000)
Subject: [DAGCombiner] Tidyup FMINNUM/FMAXNUM constant folding
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=e85795d5a2c1fcb160f72bb2e09e06d544fcbb7c

[DAGCombiner] Tidyup FMINNUM/FMAXNUM constant folding

Enable constant folding for vector splats as well as scalars.

Enable constant canonicalization for all scalar and vector constants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249978 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 9208b3388d9..3280060316c 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -9023,20 +9023,20 @@ SDValue DAGCombiner::visitFNEG(SDNode *N) {
 SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
-  const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
-  const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+  EVT VT = N->getValueType(0);
+  const ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
+  const ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
 
   if (N0CFP && N1CFP) {
     const APFloat &C0 = N0CFP->getValueAPF();
     const APFloat &C1 = N1CFP->getValueAPF();
-    return DAG.getConstantFP(minnum(C0, C1), SDLoc(N), N->getValueType(0));
+    return DAG.getConstantFP(minnum(C0, C1), SDLoc(N), VT);
   }
 
-  if (N0CFP) {
-    EVT VT = N->getValueType(0);
-    // Canonicalize to constant on RHS.
+  // Canonicalize to constant on RHS.
+  if (isConstantFPBuildVectorOrConstantFP(N0) &&
+     !isConstantFPBuildVectorOrConstantFP(N1))
     return DAG.getNode(ISD::FMINNUM, SDLoc(N), VT, N1, N0);
-  }
 
   return SDValue();
 }
@@ -9044,20 +9044,20 @@ SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
 SDValue DAGCombiner::visitFMAXNUM(SDNode *N) {
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
-  const ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
-  const ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+  EVT VT = N->getValueType(0);
+  const ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
+  const ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
 
   if (N0CFP && N1CFP) {
     const APFloat &C0 = N0CFP->getValueAPF();
     const APFloat &C1 = N1CFP->getValueAPF();
-    return DAG.getConstantFP(maxnum(C0, C1), SDLoc(N), N->getValueType(0));
+    return DAG.getConstantFP(maxnum(C0, C1), SDLoc(N), VT);
   }
 
-  if (N0CFP) {
-    EVT VT = N->getValueType(0);
-    // Canonicalize to constant on RHS.
+  // Canonicalize to constant on RHS.
+  if (isConstantFPBuildVectorOrConstantFP(N0) &&
+     !isConstantFPBuildVectorOrConstantFP(N1))
     return DAG.getNode(ISD::FMAXNUM, SDLoc(N), VT, N1, N0);
-  }
 
   return SDValue();
 }