Fixed DAGCombine optimizations which generate select_cc for targets
that do not support it (X86 does not lower select_cc).
PR: 13428
Together with Michael Kuperstein <michael.m.kuperstein@intel.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 942db7d..747bc44 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -6002,29 +6002,36 @@
return DAG.getNode(ISD::UINT_TO_FP, N->getDebugLoc(), VT, N0);
}
- // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
- if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
- !VT.isVector() &&
- (!LegalOperations ||
- TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
- SDValue Ops[] =
- { N0.getOperand(0), N0.getOperand(1),
- DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
- N0.getOperand(2) };
- return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
- }
+ // The next optimizations are desireable only if SELECT_CC can be lowered.
+ // Check against MVT::Other for SELECT_CC, which is a workaround for targets
+ // having to say they don't support SELECT_CC on every type the DAG knows
+ // about, since there is no way to mark an opcode illegal at all value types
+ // (See also visitSELECT)
+ if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
+ // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
+ if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
+ !VT.isVector() &&
+ (!LegalOperations ||
+ TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
+ SDValue Ops[] =
+ { N0.getOperand(0), N0.getOperand(1),
+ DAG.getConstantFP(-1.0, VT) , DAG.getConstantFP(0.0, VT),
+ N0.getOperand(2) };
+ return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
+ }
- // fold (sint_to_fp (zext (setcc x, y, cc))) ->
- // (select_cc x, y, 1.0, 0.0,, cc)
- if (N0.getOpcode() == ISD::ZERO_EXTEND &&
- N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
- (!LegalOperations ||
- TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
- SDValue Ops[] =
- { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
- DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
- N0.getOperand(0).getOperand(2) };
- return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
+ // fold (sint_to_fp (zext (setcc x, y, cc))) ->
+ // (select_cc x, y, 1.0, 0.0,, cc)
+ if (N0.getOpcode() == ISD::ZERO_EXTEND &&
+ N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
+ (!LegalOperations ||
+ TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
+ SDValue Ops[] =
+ { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
+ DAG.getConstantFP(1.0, VT) , DAG.getConstantFP(0.0, VT),
+ N0.getOperand(0).getOperand(2) };
+ return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
+ }
}
return SDValue();
@@ -6052,17 +6059,24 @@
return DAG.getNode(ISD::SINT_TO_FP, N->getDebugLoc(), VT, N0);
}
- // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
- if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
- (!LegalOperations ||
- TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
- SDValue Ops[] =
- { N0.getOperand(0), N0.getOperand(1),
- DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
- N0.getOperand(2) };
- return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
- }
+ // The next optimizations are desireable only if SELECT_CC can be lowered.
+ // Check against MVT::Other for SELECT_CC, which is a workaround for targets
+ // having to say they don't support SELECT_CC on every type the DAG knows
+ // about, since there is no way to mark an opcode illegal at all value types
+ // (See also visitSELECT)
+ if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, MVT::Other)) {
+ // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
+ if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
+ (!LegalOperations ||
+ TLI.isOperationLegalOrCustom(llvm::ISD::ConstantFP, VT))) {
+ SDValue Ops[] =
+ { N0.getOperand(0), N0.getOperand(1),
+ DAG.getConstantFP(1.0, VT), DAG.getConstantFP(0.0, VT),
+ N0.getOperand(2) };
+ return DAG.getNode(ISD::SELECT_CC, N->getDebugLoc(), VT, Ops, 5);
+ }
+ }
return SDValue();
}