FPCALL

Operation

Installs an authenticated resident continuation without return-record memory traffic.

Assembler Syntax

FPCALL <imm16s>

FPCALL <imm32s>

FPCALL <ea>(e)

FPCALL Rn(r)

Privilege

Unprivileged

Required CPUID flags

CFI

FPCALL requires a configured CFI key and reserves the 16-byte protected near-call footprint without accessing that memory range. It installs the continuation PC and a nonzero PA in LPC:LPA. The PA uses the same near-return domain and post-allocation SS:SP binding as PCALL.

2.75in

Encodings

FPCALL <imm16s>

Format: Instruction format for FPCALL <imm16s>

2.75in FPCALL <imm32s>

Format: Instruction format for FPCALL <imm32s>

2.75in FPCALL <ea>(e)

Format: Instruction format for FPCALL <ea>(e)

target — excluded: immediate [canonical_form_reclaim]

2.75in FPCALL Rn(r)

Format: Instruction format for FPCALL Rn(r)