Refactor the constant folding code into it's own function. And call it from both

the SelectionDAG and DAGCombiner code. The only functionality change is that now
the DAG combiner is performing the constant folding for these operations instead
of being a no-op.

This is *not* in response to a bug, so there isn't a testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56550 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 20 insertions, 14 deletions

diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 95c30c6219..6ca8a8c861 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -697,9 +697,15 @@ public:
   /// at least that alignment.
   SDValue CreateStackTemporary(MVT VT, unsigned minAlign = 1);
   
+  /// FoldConstantArithmetic - 
+  SDValue FoldConstantArithmetic(unsigned Opcode,
+                                 MVT VT,
+                                 ConstantSDNode *Cst1,
+                                 ConstantSDNode *Cst2);
+
   /// FoldSetCC - Constant fold a setcc to true or false.
   SDValue FoldSetCC(MVT VT, SDValue N1,
-                      SDValue N2, ISD::CondCode Cond);
+                    SDValue N2, ISD::CondCode Cond);
   
   /// SignBitIsZero - Return true if the sign bit of Op is known to be zero.  We
   /// use this predicate to simplify operations downstream.
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 6210f0fcbc..ee4c9e639b 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -960,7 +960,7 @@ SDValue DAGCombiner::visitADD(SDNode *N) {
     return N1;
   // fold (add c1, c2) -> c1+c2
   if (N0C && N1C)
-    return DAG.getConstant(N0C->getAPIntValue() + N1C->getAPIntValue(), VT);
+    return DAG.FoldConstantArithmetic(ISD::ADD, VT, N0C, N1C);
   // canonicalize constant to RHS
   if (N0C && !N1C)
     return DAG.getNode(ISD::ADD, VT, N1, N0);
@@ -1111,7 +1111,7 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
     return DAG.getConstant(0, N->getValueType(0));
   // fold (sub c1, c2) -> c1-c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::SUB, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C);
   // fold (sub x, c) -> (add x, -c)
   if (N1C)
     return DAG.getNode(ISD::ADD, VT, N0,
@@ -1154,7 +1154,7 @@ SDValue DAGCombiner::visitMUL(SDNode *N) {
     return DAG.getConstant(0, VT);
   // fold (mul c1, c2) -> c1*c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::MUL, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::MUL, VT, N0C, N1C);
   // canonicalize constant to RHS
   if (N0C && !N1C)
     return DAG.getNode(ISD::MUL, VT, N1, N0);
@@ -1236,7 +1236,7 @@ SDValue DAGCombiner::visitSDIV(SDNode *N) {
   
   // fold (sdiv c1, c2) -> c1/c2
   if (N0C && N1C && !N1C->isNullValue())
-    return DAG.getNode(ISD::SDIV, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SDIV, VT, N0C, N1C);
   // fold (sdiv X, 1) -> X
   if (N1C && N1C->getSignExtended() == 1LL)
     return N0;
@@ -1314,7 +1314,7 @@ SDValue DAGCombiner::visitUDIV(SDNode *N) {
   
   // fold (udiv c1, c2) -> c1/c2
   if (N0C && N1C && !N1C->isNullValue())
-    return DAG.getNode(ISD::UDIV, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::UDIV, VT, N0C, N1C);
   // fold (udiv x, (1 << c)) -> x >>u c
   if (N1C && N1C->getAPIntValue().isPowerOf2())
     return DAG.getNode(ISD::SRL, VT, N0, 
@@ -1359,7 +1359,7 @@ SDValue DAGCombiner::visitSREM(SDNode *N) {
   
   // fold (srem c1, c2) -> c1%c2
   if (N0C && N1C && !N1C->isNullValue())
-    return DAG.getNode(ISD::SREM, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SREM, VT, N0C, N1C);
   // If we know the sign bits of both operands are zero, strength reduce to a
   // urem instead.  Handles (X & 0x0FFFFFFF) %s 16 -> X&15
   if (!VT.isVector()) {
@@ -1400,7 +1400,7 @@ SDValue DAGCombiner::visitUREM(SDNode *N) {
   
   // fold (urem c1, c2) -> c1%c2
   if (N0C && N1C && !N1C->isNullValue())
-    return DAG.getNode(ISD::UREM, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::UREM, VT, N0C, N1C);
   // fold (urem x, pow2) -> (and x, pow2-1)
   if (N1C && !N1C->isNullValue() && N1C->getAPIntValue().isPowerOf2())
     return DAG.getNode(ISD::AND, VT, N0,
@@ -1625,7 +1625,7 @@ SDValue DAGCombiner::visitAND(SDNode *N) {
     return DAG.getConstant(0, VT);
   // fold (and c1, c2) -> c1&c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::AND, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::AND, VT, N0C, N1C);
   // canonicalize constant to RHS
   if (N0C && !N1C)
     return DAG.getNode(ISD::AND, VT, N1, N0);
@@ -1824,7 +1824,7 @@ SDValue DAGCombiner::visitOR(SDNode *N) {
     return DAG.getConstant(~0ULL, VT);
   // fold (or c1, c2) -> c1|c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::OR, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::OR, VT, N0C, N1C);
   // canonicalize constant to RHS
   if (N0C && !N1C)
     return DAG.getNode(ISD::OR, VT, N1, N0);
@@ -2117,7 +2117,7 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
     return N1;
   // fold (xor c1, c2) -> c1^c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::XOR, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::XOR, VT, N0C, N1C);
   // canonicalize constant to RHS
   if (N0C && !N1C)
     return DAG.getNode(ISD::XOR, VT, N1, N0);
@@ -2295,7 +2295,7 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
   
   // fold (shl c1, c2) -> c1<<c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::SHL, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SHL, VT, N0C, N1C);
   // fold (shl 0, x) -> 0
   if (N0C && N0C->isNullValue())
     return N0;
@@ -2370,7 +2370,7 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
   
   // fold (sra c1, c2) -> c1>>c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::SRA, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SRA, VT, N0C, N1C);
   // fold (sra 0, x) -> 0
   if (N0C && N0C->isNullValue())
     return N0;
@@ -2476,7 +2476,7 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
   
   // fold (srl c1, c2) -> c1 >>u c2
   if (N0C && N1C)
-    return DAG.getNode(ISD::SRL, VT, N0, N1);
+    return DAG.FoldConstantArithmetic(ISD::SRL, VT, N0C, N1C);
   // fold (srl 0, x) -> 0
   if (N0C && N0C->isNullValue())
     return N0;