Specifications

Intel
®
64 and IA-32 Architectures Software Developer’s Manual Documentation Changes 192
Documentation Changes
SUB—Subtract
Opcode Instruction Op/
En
64-Bit
Mode
Compat/
Leg Mode
Description
2C ib SUB AL, imm8 A Valid Valid Subtract imm8 from AL.
2D iw SUB AX, imm16 A Valid Valid Subtract imm16 from AX.
2D id SUB EAX, imm32 A Valid Valid Subtract imm32 from EAX.
REX.W + 2D id SUB RAX, imm32 AValid N.E. Subtract imm32 sign-
extended to 64-bits from
RAX.
80 /5 ib SUB r/m8, imm8 B Valid Valid Subtract imm8 from r/m8.
REX + 80 /5 ib SUB r/m8*, imm8 BValid N.E. Subtract imm8 from r/m8.
81 /5 iw SUB r/m16,
imm16
B Valid Valid Subtract imm16 from
r/m16.
81 /5 id SUB r/m32,
imm32
B Valid Valid Subtract imm32 from
r/m32.
REX.W + 81 /5
id
SUB r/m64,
imm32
BValid N.E. Subtract imm32 sign-
extended to 64-bits from
r/m64.
83 /5 ib SUB r/m16, imm8 B Valid Valid Subtract sign-extended
imm8 from r/m16.
83 /5 ib SUB r/m32, imm8 B Valid Valid Subtract sign-extended
imm8 from r/m32.
REX.W + 83 /5
ib
SUB r/m64, imm8
B Valid N.E. Subtract sign-extended
imm8 from r/m64.
28 /r SUB r/m8, r8 C Valid Valid Subtract r8 from r/m8.
REX + 28 /r SUB r/m8*, r8* CValid N.E. Subtract r8 from r/m8.
29 /r SUB r/m16, r16 C Valid Valid Subtract r16 from r/m16.
29 /r SUB r/m32, r32 C Valid Valid Subtract r32 from r/m32.
REX.W + 29 /r SUB r/m64, r32 CValid N.E. Subtract r64 from r/m64.
2A /r SUB r8, r/m8 D Valid Valid Subtract r/m8 from r8.
REX + 2A /r SUB r8*, r/m8* DValid N.E. Subtract r/m8 from r8.
2B /r SUB r16, r/m16 D Valid Valid Subtract r/m16 from r16.
2B /r SUB r32, r/m32 D Valid Valid Subtract r/m32 from r32.
REX.W + 2B /r SUB r64, r/m64 DValid N.E. Subtract r/m64 from r64.
NOTES:
* In 64-bit mode, r/m8 can not be encoded to access the following byte registers if a REX prefix is
used: AH, BH, CH, DH.