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LibJS/JIT: Add fast path for Add Int32, Int32

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This uses the 32-bit registers to perform the addition and bail if the
overflow flag (OF) is set.
This commit is contained in:
iliadsh 2023-10-29 01:07:14 +00:00 • committed by Andreas Kling
parent 4b23a7dfb4
commit 4f3945024a
3 changed files with 74 additions and 1 deletions
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27
Userland/Libraries/LibJIT/Assembler.h
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@ -398,6 +398,15 @@ struct Assembler {
label.add_jump(*this, m_output.size());
}
void jump_if_overflow(Label& label)
{
// jo label (RIP-relative 32-bit offset)
emit8(0x0f);
emit8(0x80);
emit32(0xdeadbeef);
label.add_jump(*this, m_output.size());
}
void sign_extend_32_to_64_bits(Reg reg)
{
// movsxd (reg as 64-bit), (reg as 32-bit)
@ -551,6 +560,24 @@ struct Assembler {
}
}
void add32(Operand dst, Operand src)
{
if (dst.type == Operand::Type::Reg && to_underlying(dst.reg) < 8 && src.type == Operand::Type::Reg && to_underlying(src.reg) < 8) {
emit8(0x01);
emit8(0xc0 | (encode_reg(src.reg) << 3) | encode_reg(dst.reg));
} else if (dst.type == Operand::Type::Reg && to_underlying(dst.reg) < 8 && src.type == Operand::Type::Imm && src.fits_in_i8()) {
emit8(0x83);
emit8(0xc0 | encode_reg(dst.reg));
emit8(src.offset_or_immediate);
} else if (dst.type == Operand::Type::Reg && to_underlying(dst.reg) < 8 && src.type == Operand::Type::Imm && src.fits_in_i32()) {
emit8(0x81);
emit8(0xc0 | encode_reg(dst.reg));
emit32(src.offset_or_immediate);
} else {
VERIFY_NOT_REACHED();
}
}
void sub(Operand dst, Operand src)
{
if (dst.type == Operand::Type::Reg && src.type == Operand::Type::Reg) {