+/// CalculateStackSlotUsed - Return whether this argument will use its
+/// stack slot (instead of being passed in registers). ArgOffset,
+/// AvailableFPRs, and AvailableVRs must hold the current argument
+/// position, and will be updated to account for this argument.
+static bool CalculateStackSlotUsed(EVT ArgVT, ISD::ArgFlagsTy Flags,
+ unsigned PtrByteSize,
+ unsigned LinkageSize,
+ unsigned ParamAreaSize,
+ unsigned &ArgOffset,
+ unsigned &AvailableFPRs,
+ unsigned &AvailableVRs) {
+ bool UseMemory = false;
+
+ // Respect alignment of argument on the stack.
+ unsigned Align = CalculateStackSlotAlignment(ArgVT, Flags, PtrByteSize);
+ ArgOffset = ((ArgOffset + Align - 1) / Align) * Align;
+ // If there's no space left in the argument save area, we must
+ // use memory (this check also catches zero-sized arguments).
+ if (ArgOffset >= LinkageSize + ParamAreaSize)
+ UseMemory = true;
+
+ // Allocate argument on the stack.
+ ArgOffset += CalculateStackSlotSize(ArgVT, Flags, PtrByteSize);
+ // If we overran the argument save area, we must use memory
+ // (this check catches arguments passed partially in memory)
+ if (ArgOffset > LinkageSize + ParamAreaSize)
+ UseMemory = true;
+
+ // However, if the argument is actually passed in an FPR or a VR,
+ // we don't use memory after all.
+ if (!Flags.isByVal()) {
+ if (ArgVT == MVT::f32 || ArgVT == MVT::f64)
+ if (AvailableFPRs > 0) {
+ --AvailableFPRs;
+ return false;
+ }
+ if (ArgVT == MVT::v4f32 || ArgVT == MVT::v4i32 ||
+ ArgVT == MVT::v8i16 || ArgVT == MVT::v16i8 ||
+ ArgVT == MVT::v2f64 || ArgVT == MVT::v2i64)
+ if (AvailableVRs > 0) {
+ --AvailableVRs;
+ return false;
+ }
+ }
+
+ return UseMemory;
+}
+