• Top
  • Documentation
  • Books
  • Recursion-and-induction
  • Boolean-reasoning
  • Projects
  • Debugging
  • Std
  • Proof-automation
  • Macro-libraries
  • ACL2
  • Interfacing-tools
  • Hardware-verification
  • Software-verification
    • Kestrel-books
    • X86isa
      • Program-execution
      • Introduction
      • X86isa-build-instructions
      • Publications
      • Contributors
      • Machine
        • Syscalls
        • Cpuid
        • X86isa-state
        • Linear-memory
        • Rflag-specifications
        • Characterizing-undefined-behavior
        • Top-level-memory
        • App-view
        • X86-decoder
          • Get-prefixes
          • Vex-0f3a-execute
          • Vex-0f38-execute
          • Vex-0f-execute
          • Two-byte-opcode-execute
          • Second-three-byte-opcode-execute
          • One-byte-opcode-execute
          • First-three-byte-opcode-execute
          • Evex-0f3a-execute
          • Evex-0f38-execute
          • Evex-0f-execute
          • X86-fetch-decode-execute
          • Vex-decode-and-execute
          • Evex-decode-and-execute
          • Opcode-maps
          • X86-run
          • Implemented-opcodes
          • Three-byte-opcode-decode-and-execute
          • X86-run-halt-count
          • Two-byte-opcode-decode-and-execute
          • X86-run-steps
          • X86-fetch-decode-execute-halt
          • X86-run-halt
          • X86-run-steps1
        • Physical-memory
        • Decoding-and-spec-utils
        • Instructions
        • X86-modes
        • Segmentation
        • Register-readers-and-writers
        • Other-non-deterministic-computations
        • Environment
        • Paging
      • Implemented-opcodes
      • Proof-utilities
      • To-do
      • Concrete-simulation-examples
      • Model-validation
      • Utils
      • Debugging-code-proofs
    • Execloader
    • Axe
  • Testing-utilities
  • Math

• X86-decoder

Evex-decode-and-execute

Signature

(evex-decode-and-execute proc-mode start-rip temp-rip 
                         prefixes rex-byte evex-prefixes x86) 
 
  → 
x86

Arguments

temp-rip — temp-rip points to the byte following the first two EVEX prefixes that were already read and placed in the evex-prefixes structure in x86-fetch-decode-execute.

evex-prefixes — Only byte0 and byte1 fields are populated when this function is called.

evex-decode-and-execute dispatches control to EVEX-encoded instructions.

Reference: Intel Vol. 2A, Section 2.6: Intel(R) AVX-512 Encoding

Definitions and Theorems

Function: evex-decode-and-execute

(defun
 evex-decode-and-execute
 (proc-mode start-rip temp-rip
            prefixes rex-byte evex-prefixes x86)
 (declare (xargs :stobjs (x86)))
 (declare (type (integer 0 4) proc-mode)
          (type (signed-byte 48) start-rip)
          (type (signed-byte 48) temp-rip)
          (type (unsigned-byte 52) prefixes)
          (type (unsigned-byte 8) rex-byte)
          (type (unsigned-byte 32) evex-prefixes))
 (declare (xargs :guard (and (evex-prefixes-p evex-prefixes)
                             (prefixes-p prefixes))))
 (let
  ((__function__ 'evex-decode-and-execute))
  (declare (ignorable __function__))
  (b*
   ((ctx 'evex-decode-and-execute)
    ((when (not (equal rex-byte 0)))
     (!!fault-fresh :ud
                    :evex-prefixes evex-prefixes
                    :rex rex-byte))
    ((when (equal (the (unsigned-byte 8)
                       (prefixes->lck prefixes))
                  240))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :lock-prefix))
    ((when (equal (the (unsigned-byte 8)
                       (prefixes->rep prefixes))
                  242))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :f2-prefix))
    ((when (equal (the (unsigned-byte 8)
                       (prefixes->rep prefixes))
                  243))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :f3-prefix))
    ((when (equal (the (unsigned-byte 8)
                       (prefixes->opr prefixes))
                  102))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :66-prefix))
    (evex-byte1 (evex-prefixes->byte1 evex-prefixes))
    ((when (not (equal (evex-byte1->res evex-byte1) 0)))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :byte1-reserved-bits))
    ((mv evex-0f-map?
         evex-0f38-map? evex-0f3a-map?)
     (mv (equal (evex-byte1->mm evex-byte1) 1)
         (equal (evex-byte1->mm evex-byte1) 2)
         (equal (evex-byte1->mm evex-byte1) 3)))
    ((when (not (or evex-0f-map?
                    evex-0f38-map? evex-0f3a-map?)))
     (!!fault-fresh :ud
                    :evex-prefixes evex-prefixes
                    :mm evex-byte1))
    ((mv flg0 (the (unsigned-byte 8) evex-byte2)
         x86)
     (rme08 proc-mode temp-rip 1 :x x86))
    ((when flg0)
     (!!ms-fresh :evex-byte2-read-error flg0))
    ((mv flg1 temp-rip)
     (add-to-*ip proc-mode temp-rip 1 x86))
    ((when flg1)
     (!!ms-fresh :increment-error flg1))
    (evex-prefixes (!evex-prefixes->byte2 evex-byte2 evex-prefixes))
    ((when (not (equal (evex-byte2->res evex-byte2) 1)))
     (!!fault-fresh :ud :evex-prefixes
                    evex-prefixes :byte2-reserved-bit))
    ((mv flg2 (the (unsigned-byte 8) evex-byte3)
         x86)
     (rme08 proc-mode temp-rip 1 :x x86))
    ((when flg2)
     (!!ms-fresh :evex-byte3-read-error flg2))
    ((mv flg3 temp-rip)
     (add-to-*ip proc-mode temp-rip 1 x86))
    ((when flg3)
     (!!ms-fresh :increment-error flg3))
    ((mv flg4 (the (unsigned-byte 8) opcode)
         x86)
     (rme08 proc-mode temp-rip 1 :x x86))
    ((when flg4)
     (!!ms-fresh :opcode-read-error flg4))
    ((mv flg5 temp-rip)
     (add-to-*ip proc-mode temp-rip 1 x86))
    ((when flg5)
     (!!ms-fresh :increment-error flg5))
    ((mv flg6 (the (unsigned-byte 8) modr/m)
         x86)
     (rme08 proc-mode temp-rip 1 :x x86))
    ((when flg6)
     (!!ms-fresh :modr/m-byte-read-error flg6))
    ((mv flg7 temp-rip)
     (add-to-*ip proc-mode temp-rip 1 x86))
    ((when flg7)
     (!!ms-fresh :increment-error flg7))
    (sib? (b* ((p4? (eql 103
                         (the (unsigned-byte 8)
                              (prefixes->adr prefixes))))
               (16-bit-addressp
                    (eql 2
                         (select-address-size proc-mode p4? x86))))
              (x86-decode-sib-p modr/m 16-bit-addressp)))
    ((mv flg8 (the (unsigned-byte 8) sib)
         x86)
     (if sib? (rme08 proc-mode temp-rip 1 :x x86)
         (mv nil 0 x86)))
    ((when flg8)
     (!!ms-fresh :sib-byte-read-error flg8))
    ((mv flg9 temp-rip)
     (if sib?
         (add-to-*ip proc-mode temp-rip 1 x86)
         (mv nil temp-rip)))
    ((when flg9)
     (!!ms-fresh :increment-error flg9)))
   (cond
       (evex-0f-map?
            (evex-0f-execute proc-mode
                             start-rip temp-rip prefixes rex-byte
                             evex-prefixes opcode modr/m sib x86))
       (evex-0f38-map?
            (evex-0f38-execute proc-mode
                               start-rip temp-rip prefixes rex-byte
                               evex-prefixes opcode modr/m sib x86))
       (evex-0f3a-map?
            (evex-0f3a-execute proc-mode
                               start-rip temp-rip prefixes rex-byte
                               evex-prefixes opcode modr/m sib x86))
       (t (!!ms-fresh :illegal-value-of-evex-mm))))))

Theorem: x86p-evex-decode-and-execute

(defthm
 x86p-evex-decode-and-execute
 (implies
  (x86p x86)
  (x86p
    (evex-decode-and-execute proc-mode start-rip temp-rip
                             prefixes rex-byte evex-prefixes x86))))