Revert "[optimizing] Improve x86 parallel moves/swaps"
This reverts commit a5c19ce8d200d68a528f2ce0ebff989106c4a933.
This commit introduces a performance regression on CaffeineLogic of 30%.
Change-Id: I917e206e249d44e1748537bc1b2d31054ea4959d
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 183453d..4d74683 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -3958,43 +3958,23 @@
}
void ParallelMoveResolverX86::MoveMemoryToMemory32(int dst, int src) {
- ScratchRegisterScope possible_scratch(
- this, kNoRegister, codegen_->GetNumberOfCoreRegisters());
- int temp = possible_scratch.GetRegister();
- if (temp == kNoRegister) {
- // Use the stack.
- __ pushl(Address(ESP, src));
- __ popl(Address(ESP, dst));
- } else {
- Register temp_reg = static_cast<Register>(temp);
- __ movl(temp_reg, Address(ESP, src));
- __ movl(Address(ESP, dst), temp_reg);
- }
+ ScratchRegisterScope ensure_scratch(
+ this, kNoRegister, EAX, codegen_->GetNumberOfCoreRegisters());
+ Register temp_reg = static_cast<Register>(ensure_scratch.GetRegister());
+ int stack_offset = ensure_scratch.IsSpilled() ? kX86WordSize : 0;
+ __ movl(temp_reg, Address(ESP, src + stack_offset));
+ __ movl(Address(ESP, dst + stack_offset), temp_reg);
}
void ParallelMoveResolverX86::MoveMemoryToMemory64(int dst, int src) {
- ScratchRegisterScope possible_scratch(
- this, kNoRegister, codegen_->GetNumberOfCoreRegisters());
- int temp = possible_scratch.GetRegister();
- if (temp == kNoRegister) {
- // Use the stack instead.
- // Push src low word.
- __ pushl(Address(ESP, src));
- // Push src high word. Stack offset = 4.
- __ pushl(Address(ESP, src + 4 /* offset */ + kX86WordSize /* high */));
-
- // Pop into dst high word. Stack offset = 8.
- // Pop with ESP address uses the 'after increment' value of ESP.
- __ popl(Address(ESP, dst + 4 /* offset */ + kX86WordSize /* high */));
- // Finally dst low word. Stack offset = 4.
- __ popl(Address(ESP, dst));
- } else {
- Register temp_reg = static_cast<Register>(temp);
- __ movl(temp_reg, Address(ESP, src));
- __ movl(Address(ESP, dst), temp_reg);
- __ movl(temp_reg, Address(ESP, src + kX86WordSize));
- __ movl(Address(ESP, dst + kX86WordSize), temp_reg);
- }
+ ScratchRegisterScope ensure_scratch(
+ this, kNoRegister, EAX, codegen_->GetNumberOfCoreRegisters());
+ Register temp_reg = static_cast<Register>(ensure_scratch.GetRegister());
+ int stack_offset = ensure_scratch.IsSpilled() ? kX86WordSize : 0;
+ __ movl(temp_reg, Address(ESP, src + stack_offset));
+ __ movl(Address(ESP, dst + stack_offset), temp_reg);
+ __ movl(temp_reg, Address(ESP, src + stack_offset + kX86WordSize));
+ __ movl(Address(ESP, dst + stack_offset + kX86WordSize), temp_reg);
}
void ParallelMoveResolverX86::EmitMove(size_t index) {
@@ -4059,18 +4039,10 @@
__ xorps(dest, dest);
} else {
ScratchRegisterScope ensure_scratch(
- this, kNoRegister, codegen_->GetNumberOfCoreRegisters());
- int temp_reg = ensure_scratch.GetRegister();
- if (temp_reg == kNoRegister) {
- // Avoid spilling/restoring a scratch register by using the stack.
- __ pushl(Immediate(value));
- __ movss(dest, Address(ESP, 0));
- __ addl(ESP, Immediate(4));
- } else {
- Register temp = static_cast<Register>(temp_reg);
- __ movl(temp, Immediate(value));
- __ movd(dest, temp);
- }
+ this, kNoRegister, EAX, codegen_->GetNumberOfCoreRegisters());
+ Register temp = static_cast<Register>(ensure_scratch.GetRegister());
+ __ movl(temp, Immediate(value));
+ __ movd(dest, temp);
}
} else {
DCHECK(destination.IsStackSlot()) << destination;
@@ -4119,96 +4091,42 @@
}
}
-void ParallelMoveResolverX86::Exchange(Register reg1, Register reg2) {
- // Prefer to avoid xchg as it isn't speedy on smaller processors.
- ScratchRegisterScope possible_scratch(
- this, reg1, codegen_->GetNumberOfCoreRegisters());
- int temp_reg = possible_scratch.GetRegister();
- if (temp_reg == kNoRegister || temp_reg == reg2) {
- __ pushl(reg1);
- __ movl(reg1, reg2);
- __ popl(reg2);
- } else {
- Register temp = static_cast<Register>(temp_reg);
- __ movl(temp, reg1);
- __ movl(reg1, reg2);
- __ movl(reg2, temp);
- }
-}
-
void ParallelMoveResolverX86::Exchange(Register reg, int mem) {
- ScratchRegisterScope possible_scratch(
- this, reg, codegen_->GetNumberOfCoreRegisters());
- int temp_reg = possible_scratch.GetRegister();
- if (temp_reg == kNoRegister) {
- __ pushl(Address(ESP, mem));
- __ movl(Address(ESP, mem + kX86WordSize), reg);
- __ popl(reg);
- } else {
- Register temp = static_cast<Register>(temp_reg);
- __ movl(temp, Address(ESP, mem));
- __ movl(Address(ESP, mem), reg);
- __ movl(reg, temp);
- }
+ Register suggested_scratch = reg == EAX ? EBX : EAX;
+ ScratchRegisterScope ensure_scratch(
+ this, reg, suggested_scratch, codegen_->GetNumberOfCoreRegisters());
+
+ int stack_offset = ensure_scratch.IsSpilled() ? kX86WordSize : 0;
+ __ movl(static_cast<Register>(ensure_scratch.GetRegister()), Address(ESP, mem + stack_offset));
+ __ movl(Address(ESP, mem + stack_offset), reg);
+ __ movl(reg, static_cast<Register>(ensure_scratch.GetRegister()));
}
void ParallelMoveResolverX86::Exchange32(XmmRegister reg, int mem) {
- ScratchRegisterScope possible_scratch(
- this, kNoRegister, codegen_->GetNumberOfCoreRegisters());
- int temp_reg = possible_scratch.GetRegister();
- if (temp_reg == kNoRegister) {
- __ pushl(Address(ESP, mem));
- __ movss(Address(ESP, mem + kX86WordSize), reg);
- __ movss(reg, Address(ESP, 0));
- __ addl(ESP, Immediate(kX86WordSize));
- } else {
- Register temp = static_cast<Register>(temp_reg);
- __ movl(temp, Address(ESP, mem));
- __ movss(Address(ESP, mem), reg);
- __ movd(reg, temp);
- }
+ ScratchRegisterScope ensure_scratch(
+ this, kNoRegister, EAX, codegen_->GetNumberOfCoreRegisters());
+
+ Register temp_reg = static_cast<Register>(ensure_scratch.GetRegister());
+ int stack_offset = ensure_scratch.IsSpilled() ? kX86WordSize : 0;
+ __ movl(temp_reg, Address(ESP, mem + stack_offset));
+ __ movss(Address(ESP, mem + stack_offset), reg);
+ __ movd(reg, temp_reg);
}
void ParallelMoveResolverX86::Exchange(int mem1, int mem2) {
- ScratchRegisterScope possible_scratch1(
- this, kNoRegister, codegen_->GetNumberOfCoreRegisters());
- int temp_reg1 = possible_scratch1.GetRegister();
- if (temp_reg1 == kNoRegister) {
- // No free registers. Use the stack.
- __ pushl(Address(ESP, mem1));
- __ pushl(Address(ESP, mem2 + kX86WordSize));
- // Pop with ESP address uses the 'after increment' value of ESP.
- __ popl(Address(ESP, mem1 + kX86WordSize));
- __ popl(Address(ESP, mem2));
- } else {
- // Got the first one. Try for a second.
- ScratchRegisterScope possible_scratch2(
- this, temp_reg1, codegen_->GetNumberOfCoreRegisters());
- int temp_reg2 = possible_scratch2.GetRegister();
- if (temp_reg2 == kNoRegister) {
- Register temp = static_cast<Register>(temp_reg1);
- // Bummer. Only have one free register to use.
- // Save mem1 on the stack.
- __ pushl(Address(ESP, mem1));
+ ScratchRegisterScope ensure_scratch1(
+ this, kNoRegister, EAX, codegen_->GetNumberOfCoreRegisters());
- // Copy mem2 into mem1.
- __ movl(temp, Address(ESP, mem2 + kX86WordSize));
- __ movl(Address(ESP, mem1 + kX86WordSize), temp);
+ Register suggested_scratch = ensure_scratch1.GetRegister() == EAX ? EBX : EAX;
+ ScratchRegisterScope ensure_scratch2(
+ this, ensure_scratch1.GetRegister(), suggested_scratch, codegen_->GetNumberOfCoreRegisters());
- // Now pop mem1 into mem2.
- // Pop with ESP address uses the 'after increment' value of ESP.
- __ popl(Address(ESP, mem2));
- } else {
- // Great. We have 2 registers to play with.
- Register temp1 = static_cast<Register>(temp_reg1);
- Register temp2 = static_cast<Register>(temp_reg2);
- DCHECK_NE(temp1, temp2);
- __ movl(temp1, Address(ESP, mem1));
- __ movl(temp2, Address(ESP, mem2));
- __ movl(Address(ESP, mem2), temp1);
- __ movl(Address(ESP, mem1), temp2);
- }
- }
+ int stack_offset = ensure_scratch1.IsSpilled() ? kX86WordSize : 0;
+ stack_offset += ensure_scratch2.IsSpilled() ? kX86WordSize : 0;
+ __ movl(static_cast<Register>(ensure_scratch1.GetRegister()), Address(ESP, mem1 + stack_offset));
+ __ movl(static_cast<Register>(ensure_scratch2.GetRegister()), Address(ESP, mem2 + stack_offset));
+ __ movl(Address(ESP, mem2 + stack_offset), static_cast<Register>(ensure_scratch1.GetRegister()));
+ __ movl(Address(ESP, mem1 + stack_offset), static_cast<Register>(ensure_scratch2.GetRegister()));
}
void ParallelMoveResolverX86::EmitSwap(size_t index) {
@@ -4217,7 +4135,7 @@
Location destination = move->GetDestination();
if (source.IsRegister() && destination.IsRegister()) {
- Exchange(destination.AsRegister<Register>(), source.AsRegister<Register>());
+ __ xchgl(destination.AsRegister<Register>(), source.AsRegister<Register>());
} else if (source.IsRegister() && destination.IsStackSlot()) {
Exchange(source.AsRegister<Register>(), destination.GetStackIndex());
} else if (source.IsStackSlot() && destination.IsRegister()) {