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

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Sami Samhuri 2014-02-22 12:10:35 -08:00
parent 7fbee3ae4f
commit 767e97d1c4
1 changed files with 14 additions and 11 deletions
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25
asm/binary.rb
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@ -544,9 +544,9 @@ module Assembler
# 3a. mov r/m32, reg32 # 3a. mov r/m32, reg32
# 3b. mov memoffset32, eax # 3b. mov memoffset32, eax
# 4. mov r/m32, immediate32 # 4. mov r/m32, immediate32
# 5. mov r/m8, reg8 # 5. mov r/m8, imm8
# 6. mov reg8, r/m8 # 6. mov reg8, r/m8
# 7. mov r/m8, imm8 # 7. mov r/m8, reg8
def mov(dest, src) def mov(dest, src)
# These 2 are used in the same way, just the name differs to make the # These 2 are used in the same way, just the name differs to make the
@ -592,21 +592,24 @@ module Assembler
modrm = [dest, 0] modrm = [dest, 0]
immediate = src immediate = src
# version 5: mov r/m8, r8 # version 5: mov r/m8, imm8
elsif rm?(dest, :byte) && register?(src, :byte) #
opcode = 0x88 # It's important that this check is first because src integers can
modrm = [dest, src.regnum] # 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 # version 6: mov r8, r/m8
elsif register?(dest, :byte) && rm?(src, :byte) elsif register?(dest, :byte) && rm?(src, :byte)
opcode = 0x8a opcode = 0x8a
modrm = [src, dest.regnum] modrm = [src, dest.regnum]
# version 7: mov r/m8, imm8 # version 7: mov r/m8, r8
elsif rm?(dest, :byte) && immediate?(src, :byte) elsif rm?(dest, :byte) && register?(src, :byte)
opcode = 0xc6 opcode = 0x88
modrm = [dest, 0] modrm = [dest, src.regnum]
immediate_byte = src
else else
# puts "rm?(dest): #{rm?(dest)}\t\trm?(src): #{rm?(src)}" # puts "rm?(dest): #{rm?(dest)}\t\trm?(src): #{rm?(src)}"