Class: Memory

Inherits:
Object show all
Defined in:
lib/rlang/lib/memory.rb,
lib/simul/classes/memory.rb

Overview

Rubinius WebAssembly VM Copyright © 2019-2020, Laurent Julliard and contributors All rights reserved.

Web Assembly memory access methods

Constant Summary collapse

MAX_SIZE =

Initial memory size (8 pages of WASM memory - 64 KB each)

8
WASM_PAGE_SIZE = 
64 * 1024
MAX_I32 = 
2**32 - 1
@@mem = 
nil

Class Method Summary collapse

Class Method Details

.copy(src, dest, size) ⇒ Object

Copy memory from source to destination address TODO: optimize this method using 64 bits copy first then 32 bits, then 16, then 8 bits



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# File 'lib/rlang/lib/memory.rb', line 21

def self.copy(src, dest, size)
  arg src: :I32, dest: :I32
  result :none
  idx = 0
  while idx < size
    inline wat: '(i32.store8 
    (i32.add (local.get $dest) (local.get $idx))
    (i32.load8_u (i32.add (local.get $src) (local.get $idx)))
    )', wtype: :none
    idx += 1
  end
end

.dump ⇒ Object 



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# File 'lib/simul/classes/memory.rb', line 26

def self.dump
  @@mem
end

.grow(delta) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 14

def self.grow(delta)
  inline wat: '(memory.grow (local.get $delta))'
end

.init(max_size) ⇒ Object

size unit in WASM pages (64 KB)



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# File 'lib/simul/classes/memory.rb', line 12

def self.init(max_size)
  @@max_size = max_size || MAX_SIZE
  @@mem_size = @@max_size * WASM_PAGE_SIZE
  @@mem = String.new("\00"*@@mem_size, encoding:'ASCII-8BIT', capacity: @@mem_size)
end

.load(address, type = Type::I32, nbits = nil, signed = false) ⇒ Object 



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# File 'lib/simul/classes/memory.rb', line 30

def self.load(address, type=Type::I32 , nbits=nil, signed=false)
  if type == Type::I32
    if nbits.nil? || nbits == 32
      # i32.load: load 4 bytes as i32
      value = @@mem.byteslice(address,4).unpack('L').first
    elsif nbits == 16
      if signed
        # i32.load16_s: load 2 bytes and sign-extend i16 to i32
        value = @@mem.byteslice(address,2).unpack('s').first
      else
        # i32.load16_u: load 2 bytes and zero-extend i16 to i32
        value = @@mem.byteslice(address,2).unpack('S').first
      end
    elsif nbits == 8
      if signed
        # i32.load8_s: load 1 byte and sign-extend i8 to i32
        value = @@mem.byteslice(address).unpack('c').first
      else
        # i32.load16_u: load 1 byte and zero-extend i8 to i32
        value = @@mem.byteslice(address).unpack('C').first
      end
    else
      raise "Unknown number of bits #{nbits}"
    end
    return Type::I32.new(value)
  elsif type == Type::I64
    if nbits.nil? || nbits == 64
      # i64.load: load 8 bytes as i64
      value = @@mem.byteslice(address,8).unpack('Q').first
    elsif nbits == 32
      if signed
        # i64.load32_s: load 4 bytes and sign-extend i32 to i64
        value = @@mem.byteslice(address,4).unpack('l').first
      else
        # i64.load32_u: load 4 bytes and zero-extend i32 to i64
        value = @@mem.byteslice(address,4).unpack('L').first
      end
    elsif nbits == 16
      if signed
        # i64.load16_s: load 2 bytes and sign-extend i16 to i64
        value = @@mem.byteslice(address,2).unpack('s').first
      else
        # i64.load16_u: load 2 bytes and zero-extend i16 to i64
        value = @@mem.byteslice(address,2).unpack('S').first
      end
    elsif nbits == 8
      if signed
        # i64.load8_s: load 1 byte and sign-extend i8 to i64
        value = @@mem.byteslice(address).unpack('c').first
      else
        # i64.load8_u: load 1 byte and zero-extend i8 to i64
        value = @@mem.byteslice(address).unpack('C').first
      end
    else
      raise "Unknown number of bits #{nbits}"
    end
    return Type::I64.new(value)
  else
    raise "Unknown target type #{type}"
  end

end

.load32(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 48

def self.load32(addr)
  arg addr: :I32
  result :I32
  inline wat: '(i32.load (local.get $addr))',
         wtype: :I32
end

.load32_16(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 41

def self.load32_16(addr)
  arg addr: :I32
  result :I32
  inline wat: '(i32.load16_u (local.get $addr))',
         wtype: :I32
end

.load32_8(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 34

def self.load32_8(addr)
  arg addr: :I32
  result :I32
  inline wat: '(i32.load8_u (local.get $addr))',
         wtype: :I32
end

.load64(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 74

def self.load64(addr)
  arg addr: :I32
  result :I64
  inline wat: '(i64.load (local.get $addr))',
         wtype: :I64
end

.load64_16(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 62

def self.load64_16(addr)
  arg addr: :I32
  result :I64
  inline wat: '(i64.load16_u (local.get $addr))',
         wtype: :I64
end

.load64_32(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 68

def self.load64_32(addr)
  arg addr: :I32
  result :I64
  inline wat: '(i64.load32_u (local.get $addr))',
         wtype: :I64
end

.load64_8(addr) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 55

def self.load64_8(addr)
  arg addr: :I32
  result :I64
  inline wat: '(i64.load8_u (local.get $addr))',
         wtype: :I64
end

.size ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 10

def self.size
  inline wat: '(memory.size)'
end

.size_in_bytes ⇒ Object 



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# File 'lib/simul/classes/memory.rb', line 22

def self.size_in_bytes
  @@mem_size
end

.store(address, value, nbits = 32) ⇒ Object 



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# File 'lib/simul/classes/memory.rb', line 93

def self.store(address, value, nbits=32)
  #puts '***', address, value, nbits
  if value.is_a? Integer || (value.is_a? Type::I32)
    raise "Value #{value} too large to fit in 32 bits at address #{}" if value > MAX_I32
    case nbits
    when 64
      raise "Cannot store i64 in i32 memory location (wrap/truncate first)"
    when nil, 32
      # i32.store: (no conversion) store 4 bytes
      @@mem[address,4] = [value].pack('L<')
    when 16
      # i32.store16: wrap i32 to i16 and store 2 bytes
      @@mem[address,2] = [value].pack('S<')
    when 8
      # i32.store8: wrap i32 to i8 and store 1 byte
      @@mem[address] = [value].pack('C')
    end
  elsif value.is_a? Type::I64
    case nbits
    when nil, 64
      # i64.store: (no conversion) store 8 bytes
      @@mem[address,8] = [value].pack('Q<')        
    when 32
      # i64.store32: (no conversion) store 4 bytes
      @@mem[address,4] = [value].pack('L<')
    when 16
      # i64.store16: wrap i32 to i16 and store 2 bytes
      @@mem[address,2] = [value].pack('S<')
    when 8
      # i64.store8: wrap i32 to i8 and store 1 byte
      @@mem[address] = [value].pack('C')
    end
  else
    raise "Unknow data type #{value.class} for #{value}"
  end

end

.store32(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 95

def self.store32(addr, value)
  arg addr: :I32, value: :I32
  result :none
  inline wat: '(i32.store (local.get $addr) (local.get $value))',
         wtype: :none
end

.store32_16(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 88

def self.store32_16(addr, value)
  arg addr: :I32, value: :I32
  result :none
  inline wat: '(i32.store16 (local.get $addr) (local.get $value))',
         wtype: :none
end

.store32_8(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 81

def self.store32_8(addr, value)
  arg addr: :I32, value: :I32
  result :none
  inline wat: '(i32.store8 (local.get $addr) (local.get $value))',
         wtype: :none
end

.store64(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 123

def self.store64(addr, value)
  arg addr: :I32, value: :I64
  result :none
  inline wat: '(i64.store (local.get $addr) (local.get $value))',
         wtype: :none
end

.store64_16(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 109

def self.store64_16(addr, value)
  arg addr: :I32, value: :I64
  result :none
  inline wat: '(i64.store16 (local.get $addr) (local.get $value))',
         wtype: :none
end

.store64_32(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 116

def self.store64_32(addr, value)
  arg addr: :I32, value: :I64
  result :none
  inline wat: '(i64.store32 (local.get $addr) (local.get $value))',
         wtype: :none
end

.store64_8(addr, value) ⇒ Object 



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# File 'lib/rlang/lib/memory.rb', line 102

def self.store64_8(addr, value)
  arg addr: :I32, value: :I64
  result :none
  inline wat: '(i64.store8 (local.get $addr) (local.get $value))',
         wtype: :none
end