6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-23 20:29:30 +00:00
Code Issues Projects Releases Wiki Activity

generalize binop reassociation; NFC

Browse Source 
Move the fold introduced in r236031:
http://reviews.llvm.org/rL236031

to its own helper function, so we can use it for other binops.

This is a preliminary step before partially solving:
https://llvm.org/bugs/show_bug.cgi?id=21768
https://llvm.org/bugs/show_bug.cgi?id=23116



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236171 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2015-04-29 22:30:02 +00:00
parent ec4a389039
commit 3c2da524a6
1 changed files with 30 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
View File

@ -7647,6 +7647,33 @@ SDValue DAGCombiner::visitFSUBForFMACombine(SDNode *N) {
return SDValue();
}
static SDValue ReassociateBinops(SDNode *N, SelectionDAG &DAG) {
assert(N->getNumOperands() == 2 && "Invalid node for binop reassociation");
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
unsigned Opcode = N->getOpcode();
// Canonicalize chains of this operation to LHS to allow the following fold.
if (N0.getOpcode() != Opcode && N1.getOpcode() == Opcode)
return DAG.getNode(Opcode, DL, VT, N1, N0);
// Convert a chain of 3 dependent operations into 2 independent operations
// and 1 dependent operation:
// (op N0: (op N00: (op z, w), N01: y), N1: x) ->
// (op N00: (op z, w), (op N1: x, N01: y))
if (N0.getOpcode() == Opcode && N0.hasOneUse() && N1.getOpcode() != Opcode) {
SDValue N00 = N0.getOperand(0);
if (N00.getOpcode() == Opcode) {
SDValue N01 = N0.getOperand(1);
SDValue NewOp = DAG.getNode(Opcode, DL, VT, N1, N01);
return DAG.getNode(Opcode, DL, VT, N00, NewOp);
}
}
return SDValue();
}
SDValue DAGCombiner::visitFADD(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
@ -7781,24 +7808,10 @@ SDValue DAGCombiner::visitFADD(SDNode *N) {
N0.getOperand(0), DAG.getConstantFP(4.0, DL, VT));
}
}
// Canonicalize chains of adds to LHS to simplify the following transform.
if (N0.getOpcode() != ISD::FADD && N1.getOpcode() == ISD::FADD)
return DAG.getNode(ISD::FADD, DL, VT, N1, N0);
// Convert a chain of 3 dependent operations into 2 independent operations
// and 1 dependent operation:
// (fadd N0: (fadd N00: (fadd z, w), N01: y), N1: x) ->
// (fadd N00: (fadd z, w), (fadd N1: x, N01: y))
if (N0.getOpcode() == ISD::FADD && N0.hasOneUse() &&
N1.getOpcode() != ISD::FADD) {
SDValue N00 = N0.getOperand(0);
if (N00.getOpcode() == ISD::FADD) {
SDValue N01 = N0.getOperand(1);
SDValue NewAdd = DAG.getNode(ISD::FADD, DL, VT, N1, N01);
return DAG.getNode(ISD::FADD, DL, VT, N00, NewAdd);
}
}
if (SDValue Reassociated = ReassociateBinops(N, DAG))
return Reassociated;
} // enable-unsafe-fp-math
// FADD -> FMA combines: