Don't block quick callee saved registers for optimizing.
This change builds on:
https://android-review.googlesource.com/#/c/118983/
- Also fix x86_64 assembler bug triggered by this change.
- Fix (and improve) x86's backend byte register usage.
- Fix a bug in baseline register allocator: a fixed
out register must prevent inputs from allocating it.
Change-Id: I4883862e29b4e4b6470f1823cf7eab7e7863d8ad
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index 461409d..5334031 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -177,6 +177,31 @@
}
}
+void CodeGenerator::MaybeBlockPhysicalRegisters(Location loc, bool is_output) const {
+ // The DCHECKS below check that a register is not specified twice in
+ // the summary.
+ // Note that fixed output registers are allowed to overlap with fixed input and
+ // temp registers: the writer of the location summary has to make sure they
+ // don't conflict with each other.
+ if (loc.IsRegister()) {
+ DCHECK(is_output || !blocked_core_registers_[loc.reg()]);
+ blocked_core_registers_[loc.reg()] = true;
+ } else if (loc.IsFpuRegister()) {
+ DCHECK(is_output || !blocked_fpu_registers_[loc.reg()]);
+ blocked_fpu_registers_[loc.reg()] = true;
+ } else if (loc.IsFpuRegisterPair()) {
+ DCHECK(is_output || !blocked_fpu_registers_[loc.AsFpuRegisterPairLow<int>()]);
+ blocked_fpu_registers_[loc.AsFpuRegisterPairLow<int>()] = true;
+ DCHECK(is_output || !blocked_fpu_registers_[loc.AsFpuRegisterPairHigh<int>()]);
+ blocked_fpu_registers_[loc.AsFpuRegisterPairHigh<int>()] = true;
+ } else if (loc.IsRegisterPair()) {
+ DCHECK(is_output || !blocked_core_registers_[loc.AsRegisterPairLow<int>()]);
+ blocked_core_registers_[loc.AsRegisterPairLow<int>()] = true;
+ DCHECK(is_output || !blocked_core_registers_[loc.AsRegisterPairHigh<int>()]);
+ blocked_core_registers_[loc.AsRegisterPairHigh<int>()] = true;
+ }
+}
+
void CodeGenerator::AllocateRegistersLocally(HInstruction* instruction) const {
LocationSummary* locations = instruction->GetLocations();
if (locations == nullptr) return;
@@ -196,43 +221,18 @@
// Mark all fixed input, temp and output registers as used.
for (size_t i = 0, e = locations->GetInputCount(); i < e; ++i) {
Location loc = locations->InAt(i);
- // The DCHECKS below check that a register is not specified twice in
- // the summary.
- if (loc.IsRegister()) {
- DCHECK(!blocked_core_registers_[loc.reg()]);
- blocked_core_registers_[loc.reg()] = true;
- } else if (loc.IsFpuRegister()) {
- DCHECK(!blocked_fpu_registers_[loc.reg()]);
- blocked_fpu_registers_[loc.reg()] = true;
- } else if (loc.IsFpuRegisterPair()) {
- DCHECK(!blocked_fpu_registers_[loc.AsFpuRegisterPairLow<int>()]);
- blocked_fpu_registers_[loc.AsFpuRegisterPairLow<int>()] = true;
- DCHECK(!blocked_fpu_registers_[loc.AsFpuRegisterPairHigh<int>()]);
- blocked_fpu_registers_[loc.AsFpuRegisterPairHigh<int>()] = true;
- } else if (loc.IsRegisterPair()) {
- DCHECK(!blocked_core_registers_[loc.AsRegisterPairLow<int>()]);
- blocked_core_registers_[loc.AsRegisterPairLow<int>()] = true;
- DCHECK(!blocked_core_registers_[loc.AsRegisterPairHigh<int>()]);
- blocked_core_registers_[loc.AsRegisterPairHigh<int>()] = true;
- }
+ MaybeBlockPhysicalRegisters(loc, false);
}
for (size_t i = 0, e = locations->GetTempCount(); i < e; ++i) {
Location loc = locations->GetTemp(i);
- // The DCHECKS below check that a register is not specified twice in
- // the summary.
- if (loc.IsRegister()) {
- DCHECK(!blocked_core_registers_[loc.reg()]);
- blocked_core_registers_[loc.reg()] = true;
- } else if (loc.IsFpuRegister()) {
- DCHECK(!blocked_fpu_registers_[loc.reg()]);
- blocked_fpu_registers_[loc.reg()] = true;
- } else {
- DCHECK(loc.GetPolicy() == Location::kRequiresRegister
- || loc.GetPolicy() == Location::kRequiresFpuRegister);
- }
+ MaybeBlockPhysicalRegisters(loc, false);
}
+ // If the output is a fixed register, mark it as used.
+ Location result_location = locations->Out();
+ MaybeBlockPhysicalRegisters(result_location, true);
+
SetupBlockedRegisters();
// Allocate all unallocated input locations.
@@ -276,9 +276,11 @@
<< loc.GetPolicy();
}
locations->SetTempAt(i, loc);
+ } else {
+ DCHECK(loc.IsFpuRegister() || loc.IsRegister());
}
}
- Location result_location = locations->Out();
+
if (result_location.IsUnallocated()) {
switch (result_location.GetPolicy()) {
case Location::kAny: