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[turbofan] make live ranges stateless

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this is necessary for the greedy allocator to use the relevant functions, as well as the sanity of someone looking at the code

BUG=

Review URL: https://codereview.chromium.org/1056063004

Cr-Commit-Position: refs/heads/master@{#28006}
This commit is contained in:
dcarney 2015-04-22 05:44:58 -07:00 committed by Commit bot
parent f3ee83b631
commit 157c64f560
2 changed files with 22 additions and 20 deletions
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18
src/compiler/register-allocator.cc
View File

@ -251,9 +251,11 @@ void LiveRange::CommitSpillOperand(AllocatedOperand* operand) {
}
UsePosition* LiveRange::NextUsePosition(LifetimePosition start) {
UsePosition* LiveRange::NextUsePosition(LifetimePosition start) const {
UsePosition* use_pos = last_processed_use_;
if (use_pos == nullptr) use_pos = first_pos();
if (use_pos == nullptr || use_pos->pos().Value() > start.Value()) {
use_pos = first_pos();
}
while (use_pos != nullptr && use_pos->pos().Value() < start.Value()) {
use_pos = use_pos->next();
}
@ -263,7 +265,7 @@ UsePosition* LiveRange::NextUsePosition(LifetimePosition start) {
UsePosition* LiveRange::NextUsePositionRegisterIsBeneficial(
LifetimePosition start) {
LifetimePosition start) const {
UsePosition* pos = NextUsePosition(start);
while (pos != nullptr && !pos->RegisterIsBeneficial()) {
pos = pos->next();
@ -273,7 +275,7 @@ UsePosition* LiveRange::NextUsePositionRegisterIsBeneficial(
UsePosition* LiveRange::PreviousUsePositionRegisterIsBeneficial(
LifetimePosition start) {
LifetimePosition start) const {
auto pos = first_pos();
UsePosition* prev = nullptr;
while (pos != nullptr && pos->pos().Value() < start.Value()) {
@ -284,7 +286,7 @@ UsePosition* LiveRange::PreviousUsePositionRegisterIsBeneficial(
}
UsePosition* LiveRange::NextRegisterPosition(LifetimePosition start) {
UsePosition* LiveRange::NextRegisterPosition(LifetimePosition start) const {
UsePosition* pos = NextUsePosition(start);
while (pos != nullptr && pos->type() != UsePositionType::kRequiresRegister) {
pos = pos->next();
@ -293,7 +295,7 @@ UsePosition* LiveRange::NextRegisterPosition(LifetimePosition start) {
}
bool LiveRange::CanBeSpilled(LifetimePosition pos) {
bool LiveRange::CanBeSpilled(LifetimePosition pos) const {
// We cannot spill a live range that has a use requiring a register
// at the current or the immediate next position.
auto use_pos = NextRegisterPosition(pos);
@ -571,7 +573,7 @@ bool LiveRange::CanCover(LifetimePosition position) const {
}
bool LiveRange::Covers(LifetimePosition position) {
bool LiveRange::Covers(LifetimePosition position) const {
if (!CanCover(position)) return false;
auto start_search = FirstSearchIntervalForPosition(position);
for (auto interval = start_search; interval != nullptr;
@ -586,7 +588,7 @@ bool LiveRange::Covers(LifetimePosition position) {
}
LifetimePosition LiveRange::FirstIntersection(LiveRange* other) {
LifetimePosition LiveRange::FirstIntersection(LiveRange* other) const {
auto b = other->first_interval();
if (b == nullptr) return LifetimePosition::Invalid();
auto advance_last_processed_up_to = b->start();

24
src/compiler/register-allocator.h
View File

@ -246,25 +246,24 @@ class LiveRange final : public ZoneObject {
// Returns use position in this live range that follows both start
// and last processed use position.
// Modifies internal state of live range!
UsePosition* NextUsePosition(LifetimePosition start);
UsePosition* NextUsePosition(LifetimePosition start) const;
// Returns use position for which register is required in this live
// range and which follows both start and last processed use position
// Modifies internal state of live range!
UsePosition* NextRegisterPosition(LifetimePosition start);
UsePosition* NextRegisterPosition(LifetimePosition start) const;
// Returns use position for which register is beneficial in this live
// range and which follows both start and last processed use position
// Modifies internal state of live range!
UsePosition* NextUsePositionRegisterIsBeneficial(LifetimePosition start);
UsePosition* NextUsePositionRegisterIsBeneficial(
LifetimePosition start) const;
// Returns use position for which register is beneficial in this live
// range and which precedes start.
UsePosition* PreviousUsePositionRegisterIsBeneficial(LifetimePosition start);
UsePosition* PreviousUsePositionRegisterIsBeneficial(
LifetimePosition start) const;
// Can this live range be spilled at this position.
bool CanBeSpilled(LifetimePosition pos);
bool CanBeSpilled(LifetimePosition pos) const;
// Split this live range at the given position which must follow the start of
// the range.
@ -330,8 +329,8 @@ class LiveRange final : public ZoneObject {
bool ShouldBeAllocatedBefore(const LiveRange* other) const;
bool CanCover(LifetimePosition position) const;
bool Covers(LifetimePosition position);
LifetimePosition FirstIntersection(LiveRange* other);
bool Covers(LifetimePosition position) const;
LifetimePosition FirstIntersection(LiveRange* other) const;
// Add a new interval or a new use position to this live range.
void EnsureInterval(LifetimePosition start, LifetimePosition end, Zone* zone);
@ -373,9 +372,10 @@ class LiveRange final : public ZoneObject {
LiveRange* next_;
// This is used as a cache, it doesn't affect correctness.
mutable UseInterval* current_interval_;
UsePosition* last_processed_use_;
// This is used as a cache, it doesn't affect correctness.
mutable UsePosition* last_processed_use_;
// This is used as a cache, it's invalid outside of BuildLiveRanges.
InstructionOperand* current_hint_operand_;
mutable InstructionOperand* current_hint_operand_;
int spill_start_index_;
SpillType spill_type_;
union {