Vesta
English
Source code

ENDBR64

Terminate an Indirect Branch in 64-bit Mode

stableVMJITAOTinstruction

Encodings

OpcodeInstructionOp/En64-bitCompat/LegacyDescription
F3 0F 1E FAENDBR64ZOValidValidTerminate indirect branch in 64-bit mode.

Measured cost

Loading measurements from arch-data...

Description

Terminate an indirect branch in 64 bit mode. This opcode is a NOP when CET indirect branch tracking is not enabled and on processors that do not support CET.

Operation

IF EndbranchEnabled(CPL) & IA32_EFER.LMA = 1 & CS.L = 1
    IF CPL = 3
          THEN
                IA32_U_CET.TRACKER = IDLE
                IA32_U_CET.SUPPRESS = 0
          ELSE
                IA32_S_CET.TRACKER = IDLE
                IA32_S_CET.SUPPRESS = 0
    FI;

FI;

Flags affected

None.

Exceptions If the LOCK prefix is used.

#UD

Sources