benefitFromCodePlacementOpt = true;
}
+// FIXME: It might make sense to define the representative register class as the
+// nearest super-register that has a non-null superset. For example, DPR_VFP2 is
+// a super-register of SPR, and DPR is a superset if DPR_VFP2. Consequently,
+// SPR's representative would be DPR_VFP2. This should work well if register
+// pressure tracking were modified such that a register use would increment the
+// pressure of the register class's representative and all of it's super
+// classes' representatives transitively. We have not implemented this because
+// of the difficulty prior to coalescing of modeling operand register classes
+// due to the common occurence of cross class copies and subregister insertions
+// and extractions.
std::pair<const TargetRegisterClass*, uint8_t>
ARMTargetLowering::findRepresentativeClass(EVT VT) const{
const TargetRegisterClass *RRC = 0;
case MVT::f32: case MVT::f64: case MVT::v8i8: case MVT::v4i16:
case MVT::v2i32: case MVT::v1i64: case MVT::v2f32:
RRC = ARM::DPRRegisterClass;
+ // When NEON is used for SP, only half of the register file is available
+ // because operations that define both SP and DP results will be constrained
+ // to the VFP2 class (D0-D15). We currently model this constraint prior to
+ // coalescing by double-counting the SP regs. See the FIXME above.
+ if (Subtarget->useNEONForSinglePrecisionFP())
+ Cost = 2;
break;
case MVT::v16i8: case MVT::v8i16: case MVT::v4i32: case MVT::v2i64:
case MVT::v4f32: case MVT::v2f64: