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authorDimitry Andric <dim@FreeBSD.org>2021-04-26 11:23:24 +0000
committerDimitry Andric <dim@FreeBSD.org>2021-06-13 20:01:15 +0000
commitd409305fa3838fb39b38c26fc085fb729b8766d5 (patch)
treefd234b27775fb59a57266cf36a05ec916e79a85f /contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
parente8d8bef961a50d4dc22501cde4fb9fb0be1b2532 (diff)
parentb4125f7d51da2bb55d3b850dba9a69c201c3422c (diff)
Diffstat (limited to 'contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r--contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp17
1 files changed, 12 insertions, 5 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 615bea2a4905..6a6f83827f72 100644
--- a/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -6517,8 +6517,11 @@ static SDValue extractShiftForRotate(SelectionDAG &DAG, SDValue OppShift,
// reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate
// in direction shift1 by Neg. The range [0, EltSize) means that we only need
// to consider shift amounts with defined behavior.
+//
+// The IsRotate flag should be set when the LHS of both shifts is the same.
+// Otherwise if matching a general funnel shift, it should be clear.
static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned EltSize,
- SelectionDAG &DAG) {
+ SelectionDAG &DAG, bool IsRotate) {
// If EltSize is a power of 2 then:
//
// (a) (Pos == 0 ? 0 : EltSize - Pos) == (EltSize - Pos) & (EltSize - 1)
@@ -6550,8 +6553,11 @@ static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned EltSize,
// always invokes undefined behavior for 32-bit X.
//
// Below, Mask == EltSize - 1 when using [A] and is all-ones otherwise.
+ //
+ // NOTE: We can only do this when matching an AND and not a general
+ // funnel shift.
unsigned MaskLoBits = 0;
- if (Neg.getOpcode() == ISD::AND && isPowerOf2_64(EltSize)) {
+ if (IsRotate && Neg.getOpcode() == ISD::AND && isPowerOf2_64(EltSize)) {
if (ConstantSDNode *NegC = isConstOrConstSplat(Neg.getOperand(1))) {
KnownBits Known = DAG.computeKnownBits(Neg.getOperand(0));
unsigned Bits = Log2_64(EltSize);
@@ -6641,7 +6647,8 @@ SDValue DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
// (srl x, (*ext y))) ->
// (rotr x, y) or (rotl x, (sub 32, y))
EVT VT = Shifted.getValueType();
- if (matchRotateSub(InnerPos, InnerNeg, VT.getScalarSizeInBits(), DAG)) {
+ if (matchRotateSub(InnerPos, InnerNeg, VT.getScalarSizeInBits(), DAG,
+ /*IsRotate*/ true)) {
bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
HasPos ? Pos : Neg);
@@ -6670,7 +6677,7 @@ SDValue DAGCombiner::MatchFunnelPosNeg(SDValue N0, SDValue N1, SDValue Pos,
// fold (or (shl x0, (*ext (sub 32, y))),
// (srl x1, (*ext y))) ->
// (fshr x0, x1, y) or (fshl x0, x1, (sub 32, y))
- if (matchRotateSub(InnerPos, InnerNeg, EltBits, DAG)) {
+ if (matchRotateSub(InnerPos, InnerNeg, EltBits, DAG, /*IsRotate*/ N0 == N1)) {
bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, N0, N1,
HasPos ? Pos : Neg);
@@ -21174,7 +21181,7 @@ SDValue DAGCombiner::visitFP16_TO_FP(SDNode *N) {
SDValue N0 = N->getOperand(0);
// fold fp16_to_fp(op & 0xffff) -> fp16_to_fp(op)
- if (N0->getOpcode() == ISD::AND) {
+ if (!TLI.shouldKeepZExtForFP16Conv() && N0->getOpcode() == ISD::AND) {
ConstantSDNode *AndConst = getAsNonOpaqueConstant(N0.getOperand(1));
if (AndConst && AndConst->getAPIntValue() == 0xffff) {
return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), N->getValueType(0),