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Commit 6db15ae3 authored by fschneider@chromium.org's avatar fschneider@chromium.org
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Remove peephole optimiziations from IA32 and ARM assembler. 

They are not used with Crankshaft anymore.
Review URL: http://codereview.chromium.org/7003025

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7854 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent 8a0b1f5b
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Showing with 0 additions and 556 deletions
src/arm/assembler-arm.cc
View file @ 6db15ae3
......@@ -289,9 +289,7 @@ static const int kMinimalBufferSize = 4*KB;
Assembler::Assembler(Isolate* arg_isolate, void* buffer, int buffer_size)
: AssemblerBase(arg_isolate),
positions_recorder_(this),
allow_peephole_optimization_(false),
emit_debug_code_(FLAG_debug_code) {
allow_peephole_optimization_ = FLAG_peephole_optimization;
if (buffer == NULL) {
// Do our own buffer management.
if (buffer_size <= kMinimalBufferSize) {
......@@ -1096,20 +1094,6 @@ void Assembler::rsb(Register dst, Register src1, const Operand& src2,
void Assembler::add(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | ADD | s, src1, dst, src2);
// Eliminate pattern: push(r), pop()
// str(src, MemOperand(sp, 4, NegPreIndex), al);
// add(sp, sp, Operand(kPointerSize));
// Both instructions can be eliminated.
if (can_peephole_optimize(2) &&
// Pattern.
instr_at(pc_ - 1 * kInstrSize) == kPopInstruction &&
(instr_at(pc_ - 2 * kInstrSize) & ~kRdMask) == kPushRegPattern) {
pc_ -= 2 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x push(reg)/pop() eliminated\n", pc_offset());
}
}
}
......@@ -1414,195 +1398,11 @@ void Assembler::ldr(Register dst, const MemOperand& src, Condition cond) {
positions_recorder()->WriteRecordedPositions();
}
addrmod2(cond | B26 | L, dst, src);
// Eliminate pattern: push(ry), pop(rx)
// str(ry, MemOperand(sp, 4, NegPreIndex), al)
// ldr(rx, MemOperand(sp, 4, PostIndex), al)
// Both instructions can be eliminated if ry = rx.
// If ry != rx, a register copy from ry to rx is inserted
// after eliminating the push and the pop instructions.
if (can_peephole_optimize(2)) {
Instr push_instr = instr_at(pc_ - 2 * kInstrSize);
Instr pop_instr = instr_at(pc_ - 1 * kInstrSize);
if (IsPush(push_instr) && IsPop(pop_instr)) {
if (Instruction::RdValue(pop_instr) != Instruction::RdValue(push_instr)) {
// For consecutive push and pop on different registers,
// we delete both the push & pop and insert a register move.
// push ry, pop rx --> mov rx, ry
Register reg_pushed, reg_popped;
reg_pushed = GetRd(push_instr);
reg_popped = GetRd(pop_instr);
pc_ -= 2 * kInstrSize;
// Insert a mov instruction, which is better than a pair of push & pop
mov(reg_popped, reg_pushed);
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (diff reg) replaced by a reg move\n",
pc_offset());
}
} else {
// For consecutive push and pop on the same register,
// both the push and the pop can be deleted.
pc_ -= 2 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (same reg) eliminated\n", pc_offset());
}
}
}
}
if (can_peephole_optimize(2)) {
Instr str_instr = instr_at(pc_ - 2 * kInstrSize);
Instr ldr_instr = instr_at(pc_ - 1 * kInstrSize);
if ((IsStrRegFpOffset(str_instr) &&
IsLdrRegFpOffset(ldr_instr)) ||
(IsStrRegFpNegOffset(str_instr) &&
IsLdrRegFpNegOffset(ldr_instr))) {
if ((ldr_instr & kLdrStrInstrArgumentMask) ==
(str_instr & kLdrStrInstrArgumentMask)) {
// Pattern: Ldr/str same fp+offset, same register.
//
// The following:
// str rx, [fp, #-12]
// ldr rx, [fp, #-12]
//
// Becomes:
// str rx, [fp, #-12]
pc_ -= 1 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x str/ldr (fp + same offset), same reg\n", pc_offset());
}
} else if ((ldr_instr & kLdrStrOffsetMask) ==
(str_instr & kLdrStrOffsetMask)) {
// Pattern: Ldr/str same fp+offset, different register.
//
// The following:
// str rx, [fp, #-12]
// ldr ry, [fp, #-12]
//
// Becomes:
// str rx, [fp, #-12]
// mov ry, rx
Register reg_stored, reg_loaded;
reg_stored = GetRd(str_instr);
reg_loaded = GetRd(ldr_instr);
pc_ -= 1 * kInstrSize;
// Insert a mov instruction, which is better than ldr.
mov(reg_loaded, reg_stored);
if (FLAG_print_peephole_optimization) {
PrintF("%x str/ldr (fp + same offset), diff reg \n", pc_offset());
}
}
}
}
if (can_peephole_optimize(3)) {
Instr mem_write_instr = instr_at(pc_ - 3 * kInstrSize);
Instr ldr_instr = instr_at(pc_ - 2 * kInstrSize);
Instr mem_read_instr = instr_at(pc_ - 1 * kInstrSize);
if (IsPush(mem_write_instr) &&
IsPop(mem_read_instr)) {
if ((IsLdrRegFpOffset(ldr_instr) ||
IsLdrRegFpNegOffset(ldr_instr))) {
if (Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(mem_read_instr)) {
// Pattern: push & pop from/to same register,
// with a fp+offset ldr in between
//
// The following:
// str rx, [sp, #-4]!
// ldr rz, [fp, #-24]
// ldr rx, [sp], #+4
//
// Becomes:
// if(rx == rz)
// delete all
// else
// ldr rz, [fp, #-24]
if (Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(ldr_instr)) {
pc_ -= 3 * kInstrSize;
} else {
pc_ -= 3 * kInstrSize;
// Reinsert back the ldr rz.
emit(ldr_instr);
}
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop -dead ldr fp+offset in middle\n", pc_offset());
}
} else {
// Pattern: push & pop from/to different registers
// with a fp+offset ldr in between
//
// The following:
// str rx, [sp, #-4]!
// ldr rz, [fp, #-24]
// ldr ry, [sp], #+4
//
// Becomes:
// if(ry == rz)
// mov ry, rx;
// else if(rx != rz)
// ldr rz, [fp, #-24]
// mov ry, rx
// else if((ry != rz) || (rx == rz)) becomes:
// mov ry, rx
// ldr rz, [fp, #-24]
Register reg_pushed, reg_popped;
if (Instruction::RdValue(mem_read_instr) ==
Instruction::RdValue(ldr_instr)) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
mov(reg_popped, reg_pushed);
} else if (Instruction::RdValue(mem_write_instr) !=
Instruction::RdValue(ldr_instr)) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
emit(ldr_instr);
mov(reg_popped, reg_pushed);
} else if ((Instruction::RdValue(mem_read_instr) !=
Instruction::RdValue(ldr_instr)) ||
(Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(ldr_instr))) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
mov(reg_popped, reg_pushed);
emit(ldr_instr);
}
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (ldr fp+off in middle)\n", pc_offset());
}
}
}
}
}
}
void Assembler::str(Register src, const MemOperand& dst, Condition cond) {
addrmod2(cond | B26, src, dst);
// Eliminate pattern: pop(), push(r)
// add sp, sp, #4 LeaveCC, al; str r, [sp, #-4], al
// -> str r, [sp, 0], al
if (can_peephole_optimize(2) &&
// Pattern.
instr_at(pc_ - 1 * kInstrSize) == (kPushRegPattern | src.code() * B12) &&
instr_at(pc_ - 2 * kInstrSize) == kPopInstruction) {
pc_ -= 2 * kInstrSize;
emit(al | B26 | 0 | Offset | sp.code() * B16 | src.code() * B12);
if (FLAG_print_peephole_optimization) {
PrintF("%x pop()/push(reg) eliminated\n", pc_offset());
}
}
}
......
src/arm/assembler-arm.h
View file @ 6db15ae3
......@@ -1186,12 +1186,6 @@ class Assembler : public AssemblerBase {
PositionsRecorder* positions_recorder() { return &positions_recorder_; }
bool can_peephole_optimize(int instructions) {
if (!allow_peephole_optimization_) return false;
if (last_bound_pos_ > pc_offset() - instructions * kInstrSize) return false;
return reloc_info_writer.last_pc() <= pc_ - instructions * kInstrSize;
}
// Read/patch instructions
static Instr instr_at(byte* pc) { return *reinterpret_cast<Instr*>(pc); }
static void instr_at_put(byte* pc, Instr instr) {
......@@ -1362,7 +1356,6 @@ class Assembler : public AssemblerBase {
friend class BlockConstPoolScope;
PositionsRecorder positions_recorder_;
bool allow_peephole_optimization_;
bool emit_debug_code_;
friend class PositionsRecorder;
friend class EnsureSpace;
......
src/ia32/assembler-ia32.cc
View file @ 6db15ae3
This diff is collapsed.
src/ia32/assembler-ia32.h
View file @ 6db15ae3
......@@ -1124,9 +1124,6 @@ class Assembler : public AssemblerBase {
byte* pc_; // the program counter; moves forward
RelocInfoWriter reloc_info_writer;
// push-pop elimination
byte* last_pc_;
PositionsRecorder positions_recorder_;
bool emit_debug_code_;
......
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