Change the model for FP Stack return to use fp operands on the
RET instruction instead of using FpSET_ST0_32. This also generalizes
the code to handling returning of multiple FP results.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48209 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 179f600..d603e1b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -853,27 +853,41 @@
// Regular return.
SDOperand Flag;
+ SmallVector<SDOperand, 6> RetOps;
+ RetOps.push_back(Chain); // Operand #0 = Chain (updated below)
+ // Operand #1 = Bytes To Pop
+ RetOps.push_back(DAG.getConstant(getBytesToPopOnReturn(), MVT::i16));
+
// Copy the result values into the output registers.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &VA = RVLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
SDOperand ValToCopy = Op.getOperand(i*2+1);
- // If this is a copy from an xmm register to ST(0), use an FPExtend to
- // change the value to the FP stack register class.
- if (RVLocs[i].getLocReg() == X86::ST0 &&
- isScalarFPTypeInSSEReg(RVLocs[i].getValVT()))
- ValToCopy = DAG.getNode(ISD::FP_EXTEND, MVT::f80, ValToCopy);
+ // Returns in ST0/ST1 are handled specially: these are pushed as operands to
+ // the RET instruction and handled by the FP Stackifier.
+ if (RVLocs[i].getLocReg() == X86::ST0 ||
+ RVLocs[i].getLocReg() == X86::ST1) {
+ // If this is a copy from an xmm register to ST(0), use an FPExtend to
+ // change the value to the FP stack register class.
+ if (isScalarFPTypeInSSEReg(RVLocs[i].getValVT()))
+ ValToCopy = DAG.getNode(ISD::FP_EXTEND, MVT::f80, ValToCopy);
+ RetOps.push_back(ValToCopy);
+ // Don't emit a copytoreg.
+ continue;
+ }
Chain = DAG.getCopyToReg(Chain, VA.getLocReg(), ValToCopy, Flag);
Flag = Chain.getValue(1);
}
- SDOperand BytesToPop = DAG.getConstant(getBytesToPopOnReturn(), MVT::i16);
+ RetOps[0] = Chain; // Update chain.
+
+ // Add the flag if we have it.
if (Flag.Val)
- return DAG.getNode(X86ISD::RET_FLAG, MVT::Other, Chain, BytesToPop, Flag);
- else
- return DAG.getNode(X86ISD::RET_FLAG, MVT::Other, Chain, BytesToPop);
+ RetOps.push_back(Flag);
+
+ return DAG.getNode(X86ISD::RET_FLAG, MVT::Other, &RetOps[0], RetOps.size());
}