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[baseline] Advance the jump in JumpLoop to reduce loop size

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Baseline compiler generates instructions for bytecode JumpLoop with
the below layout:

  [OSR Check Armed]
  [OSR Handle Armed]
  [Jump Loop Header]

This CL advances [Jump Loop Header] and the layout will be:

  [OSR Check Armed]
  [Jump Loop Header]
  [OSR Handle Armed]

This can reduce the sizes of loops in baseline code.

Change-Id: I0a3996fddffd33caaef965c05f5c2593ad8951bc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3759947
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
Cr-Commit-Position: refs/heads/main@{#81762}
This commit is contained in:
Hao Xu 2022-07-18 16:48:34 +08:00 committed by V8 LUCI CQ
parent 871ebe71e5
commit de831b3db7
1 changed files with 32 additions and 20 deletions
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52
src/baseline/baseline-compiler.cc
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@ -1921,34 +1921,23 @@ void BaselineCompiler::VisitCreateRestParameter() {
}
void BaselineCompiler::VisitJumpLoop() {
Label osr_not_armed;
Label osr_armed, osr_not_armed;
using D = BaselineOnStackReplacementDescriptor;
Register feedback_vector = Register::no_reg();
Register osr_state = Register::no_reg();
const int loop_depth = iterator().GetImmediateOperand(1);
{
ASM_CODE_COMMENT_STRING(&masm_, "OSR Check Armed");
using D = BaselineOnStackReplacementDescriptor;
BaselineAssembler::ScratchRegisterScope temps(&basm_);
Register feedback_vector = temps.AcquireScratch();
Register osr_state = temps.AcquireScratch();
feedback_vector = temps.AcquireScratch();
osr_state = temps.AcquireScratch();
LoadFeedbackVector(feedback_vector);
__ LoadWord8Field(osr_state, feedback_vector,
FeedbackVector::kOsrStateOffset);
const int loop_depth = iterator().GetImmediateOperand(1);
static_assert(FeedbackVector::MaybeHasOptimizedOsrCodeBit::encode(true) >
FeedbackVector::kMaxOsrUrgency);
__ JumpIfByte(Condition::kUnsignedLessThanEqual, osr_state, loop_depth,
&osr_not_armed, Label::kNear);
Label osr;
Register maybe_target_code = D::MaybeTargetCodeRegister();
DCHECK(!AreAliased(maybe_target_code, feedback_vector, osr_state));
__ TryLoadOptimizedOsrCode(maybe_target_code, feedback_vector,
iterator().GetSlotOperand(2), &osr,
Label::kNear);
__ DecodeField<FeedbackVector::OsrUrgencyBits>(osr_state);
__ JumpIfByte(Condition::kUnsignedLessThanEqual, osr_state, loop_depth,
&osr_not_armed, Label::kNear);
__ Bind(&osr);
CallBuiltin<Builtin::kBaselineOnStackReplacement>(maybe_target_code);
__ JumpIfByte(Condition::kUnsignedGreaterThan, osr_state, loop_depth,
&osr_armed, Label::kNear);
}
__ Bind(&osr_not_armed);
@ -1959,6 +1948,29 @@ void BaselineCompiler::VisitJumpLoop() {
// bound.
DCHECK(label->is_bound());
UpdateInterruptBudgetAndJumpToLabel(weight, label, label);
{
ASM_CODE_COMMENT_STRING(&masm_, "OSR Handle Armed");
__ Bind(&osr_armed);
Label osr;
BaselineAssembler::ScratchRegisterScope temps(&basm_);
Register scratch0 = temps.AcquireScratch();
Register scratch1 = temps.AcquireScratch();
DCHECK_EQ(scratch0, feedback_vector);
DCHECK_EQ(scratch1, osr_state);
Register maybe_target_code = D::MaybeTargetCodeRegister();
DCHECK(!AreAliased(maybe_target_code, scratch0, scratch1));
__ TryLoadOptimizedOsrCode(maybe_target_code, scratch0,
iterator().GetSlotOperand(2), &osr,
Label::kNear);
__ DecodeField<FeedbackVector::OsrUrgencyBits>(scratch1);
__ JumpIfByte(Condition::kUnsignedLessThanEqual, scratch1, loop_depth,
&osr_not_armed, Label::kNear);
__ Bind(&osr);
CallBuiltin<Builtin::kBaselineOnStackReplacement>(maybe_target_code);
__ Jump(&osr_not_armed, Label::kNear);
}
}
void BaselineCompiler::VisitJump() {