SelectionDAG: Fix incorrect condition checks in some cases of folding FADD/FMUL combinations; also improve accuracy of comments

llvm-svn: 183993

1 files changed, 16 insertions, 16 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 046dd416f31..570ea4c0cbf 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5919,7 +5919,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
       ConstantFPSDNode *CFP00 = dyn_cast<ConstantFPSDNode>(N0.getOperand(0));
       ConstantFPSDNode *CFP01 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
 
-      // (fadd (fmul c, x), x) -> (fmul c+1, x)
+      // (fadd (fmul c, x), x) -> (fmul x, c+1)
       if (CFP00 && !CFP01 && N0.getOperand(1) == N1) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP00, 0),
@@ -5928,7 +5928,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
                            N1, NewCFP);
       }
 
-      // (fadd (fmul x, c), x) -> (fmul c+1, x)
+      // (fadd (fmul x, c), x) -> (fmul x, c+1)
       if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP01, 0),
@@ -5937,7 +5937,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
                            N1, NewCFP);
       }
 
-      // (fadd (fmul c, x), (fadd x, x)) -> (fmul c+2, x)
+      // (fadd (fmul c, x), (fadd x, x)) -> (fmul x, c+2)
       if (CFP00 && !CFP01 && N1.getOpcode() == ISD::FADD &&
           N1.getOperand(0) == N1.getOperand(1) &&
           N0.getOperand(1) == N1.getOperand(0)) {
@@ -5948,7 +5948,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
                            N0.getOperand(1), NewCFP);
       }
 
-      // (fadd (fmul x, c), (fadd x, x)) -> (fmul c+2, x)
+      // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
       if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
           N1.getOperand(0) == N1.getOperand(1) &&
           N0.getOperand(0) == N1.getOperand(0)) {
@@ -5964,7 +5964,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
       ConstantFPSDNode *CFP10 = dyn_cast<ConstantFPSDNode>(N1.getOperand(0));
       ConstantFPSDNode *CFP11 = dyn_cast<ConstantFPSDNode>(N1.getOperand(1));
 
-      // (fadd x, (fmul c, x)) -> (fmul c+1, x)
+      // (fadd x, (fmul c, x)) -> (fmul x, c+1)
       if (CFP10 && !CFP11 && N1.getOperand(1) == N0) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP10, 0),
@@ -5973,7 +5973,7 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
                            N0, NewCFP);
       }
 
-      // (fadd x, (fmul x, c)) -> (fmul c+1, x)
+      // (fadd x, (fmul x, c)) -> (fmul x, c+1)
       if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP11, 0),
@@ -5983,26 +5983,26 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
       }
 
 
-      // (fadd (fadd x, x), (fmul c, x)) -> (fmul c+2, x)
-      if (CFP10 && !CFP11 && N1.getOpcode() == ISD::FADD &&
-          N1.getOperand(0) == N1.getOperand(1) &&
-          N0.getOperand(1) == N1.getOperand(0)) {
+      // (fadd (fadd x, x), (fmul c, x)) -> (fmul x, c+2)
+      if (CFP10 && !CFP11 && N0.getOpcode() == ISD::FADD &&
+          N0.getOperand(0) == N0.getOperand(1) &&
+          N1.getOperand(1) == N0.getOperand(0)) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP10, 0),
                                      DAG.getConstantFP(2.0, VT));
         return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
-                           N0.getOperand(1), NewCFP);
+                           N1.getOperand(1), NewCFP);
       }
 
-      // (fadd (fadd x, x), (fmul x, c)) -> (fmul c+2, x)
-      if (CFP11 && !CFP10 && N1.getOpcode() == ISD::FADD &&
-          N1.getOperand(0) == N1.getOperand(1) &&
-          N0.getOperand(0) == N1.getOperand(0)) {
+      // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
+      if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
+          N0.getOperand(0) == N0.getOperand(1) &&
+          N1.getOperand(0) == N0.getOperand(0)) {
         SDValue NewCFP = DAG.getNode(ISD::FADD, SDLoc(N), VT,
                                      SDValue(CFP11, 0),
                                      DAG.getConstantFP(2.0, VT));
         return DAG.getNode(ISD::FMUL, SDLoc(N), VT,
-                           N0.getOperand(0), NewCFP);
+                           N1.getOperand(0), NewCFP);
       }
     }