[X86] Sink complex MCU CC helper to .cpp file from .h file, NFC
llvm-svn: 351384
diff --git a/llvm/lib/Target/X86/X86CallingConv.cpp b/llvm/lib/Target/X86/X86CallingConv.cpp
index 59dde98..81f13f9 100644
--- a/llvm/lib/Target/X86/X86CallingConv.cpp
+++ b/llvm/lib/Target/X86/X86CallingConv.cpp
@@ -205,4 +205,60 @@
return false; // No register was assigned - Continue the search.
}
+bool CC_X86_32_MCUInReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
+ CCValAssign::LocInfo &LocInfo,
+ ISD::ArgFlagsTy &ArgFlags, CCState &State) {
+ // This is similar to CCAssignToReg<[EAX, EDX, ECX]>, but makes sure
+ // not to split i64 and double between a register and stack
+ static const MCPhysReg RegList[] = {X86::EAX, X86::EDX, X86::ECX};
+ static const unsigned NumRegs = sizeof(RegList) / sizeof(RegList[0]);
+
+ SmallVectorImpl<CCValAssign> &PendingMembers = State.getPendingLocs();
+
+ // If this is the first part of an double/i64/i128, or if we're already
+ // in the middle of a split, add to the pending list. If this is not
+ // the end of the split, return, otherwise go on to process the pending
+ // list
+ if (ArgFlags.isSplit() || !PendingMembers.empty()) {
+ PendingMembers.push_back(
+ CCValAssign::getPending(ValNo, ValVT, LocVT, LocInfo));
+ if (!ArgFlags.isSplitEnd())
+ return true;
+ }
+
+ // If there are no pending members, we are not in the middle of a split,
+ // so do the usual inreg stuff.
+ if (PendingMembers.empty()) {
+ if (unsigned Reg = State.AllocateReg(RegList)) {
+ State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
+ return true;
+ }
+ return false;
+ }
+
+ assert(ArgFlags.isSplitEnd());
+
+ // We now have the entire original argument in PendingMembers, so decide
+ // whether to use registers or the stack.
+ // Per the MCU ABI:
+ // a) To use registers, we need to have enough of them free to contain
+ // the entire argument.
+ // b) We never want to use more than 2 registers for a single argument.
+
+ unsigned FirstFree = State.getFirstUnallocated(RegList);
+ bool UseRegs = PendingMembers.size() <= std::min(2U, NumRegs - FirstFree);
+
+ for (auto &It : PendingMembers) {
+ if (UseRegs)
+ It.convertToReg(State.AllocateReg(RegList[FirstFree++]));
+ else
+ It.convertToMem(State.AllocateStack(4, 4));
+ State.addLoc(It);
+ }
+
+ PendingMembers.clear();
+
+ return true;
+}
+
} // End llvm namespace