Revert "Revert "Implement long negate instruction in the optimizing compiler.""
This reverts commit 30ca3d847fe72cfa33e1b2473100ea2d8bea4517.
Change-Id: I188ca8d460d55d3a9966bcf31e0588575afa77d2
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 7b00d2f..a3b31d8 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -1043,11 +1043,13 @@
new (GetGraph()->GetArena()) LocationSummary(neg, LocationSummary::kNoCall);
switch (neg->GetResultType()) {
case Primitive::kPrimInt:
+ case Primitive::kPrimLong: {
+ bool output_overlaps = (neg->GetResultType() == Primitive::kPrimLong);
locations->SetInAt(0, Location::RequiresRegister());
- locations->SetOut(Location::RequiresRegister());
+ locations->SetOut(Location::RequiresRegister(), output_overlaps);
break;
+ }
- case Primitive::kPrimLong:
case Primitive::kPrimFloat:
case Primitive::kPrimDouble:
LOG(FATAL) << "Not yet implemented neg type " << neg->GetResultType();
@@ -1069,6 +1071,26 @@
break;
case Primitive::kPrimLong:
+ DCHECK(in.IsRegisterPair());
+ // out.lo = 0 - in.lo (and update the carry/borrow (C) flag)
+ __ rsbs(out.AsRegisterPairLow<Register>(),
+ in.AsRegisterPairLow<Register>(),
+ ShifterOperand(0));
+ // We cannot emit an RSC (Reverse Subtract with Carry)
+ // instruction here, as it does not exist in the Thumb-2
+ // instruction set. We use the following approach
+ // using SBC and SUB instead.
+ //
+ // out.hi = -C
+ __ sbc(out.AsRegisterPairHigh<Register>(),
+ out.AsRegisterPairHigh<Register>(),
+ ShifterOperand(out.AsRegisterPairHigh<Register>()));
+ // out.hi = out.hi - in.hi
+ __ sub(out.AsRegisterPairHigh<Register>(),
+ out.AsRegisterPairHigh<Register>(),
+ ShifterOperand(in.AsRegisterPairHigh<Register>()));
+ break;
+
case Primitive::kPrimFloat:
case Primitive::kPrimDouble:
LOG(FATAL) << "Not yet implemented neg type " << neg->GetResultType();