sjs/compiler
1
0
Fork 0
mirror of https://github.com/samsonjs/compiler.git synced 2026-03-25 08:45:52 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

fix a bug encoding MOV [r/m byte] [immediate byte]

Browse source
This commit is contained in:
Sami Samhuri 2014-02-22 12:10:35 -08:00
parent 7fbee3ae4f
commit 767e97d1c4
1 changed files with 14 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

25
asm/binary.rb
View file

@ -544,9 +544,9 @@ module Assembler
# 3a. mov r/m32, reg32
# 3b. mov memoffset32, eax
# 4. mov r/m32, immediate32
# 5. mov r/m8, reg8
# 5. mov r/m8, imm8
# 6. mov reg8, r/m8
# 7. mov r/m8, imm8
# 7. mov r/m8, reg8
def mov(dest, src)
# These 2 are used in the same way, just the name differs to make the
@ -592,21 +592,24 @@ module Assembler
modrm = [dest, 0]
immediate = src
# version 5: mov r/m8, r8
elsif rm?(dest, :byte) && register?(src, :byte)
opcode = 0x88
modrm = [dest, src.regnum]
# version 5: mov r/m8, imm8
#
# It's important that this check is first because src integers can
# pass the register? check in version 7.
elsif rm?(dest, :byte) && immediate?(src, :byte)
opcode = 0xc6
modrm = [dest, 0]
immediate_byte = src
# version 6: mov r8, r/m8
elsif register?(dest, :byte) && rm?(src, :byte)
opcode = 0x8a
modrm = [src, dest.regnum]
# version 7: mov r/m8, imm8
elsif rm?(dest, :byte) && immediate?(src, :byte)
opcode = 0xc6
modrm = [dest, 0]
immediate_byte = src
# version 7: mov r/m8, r8
elsif rm?(dest, :byte) && register?(src, :byte)
opcode = 0x88
modrm = [dest, src.regnum]
else
# puts "rm?(dest): #{rm?(dest)}\t\trm?(src): #{rm?(src)}"