2018-06-15 14:40:34 +02:00

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//! `i586`'s `xsave` and `xsaveopt` target feature intrinsics
#![cfg_attr(feature = "cargo-clippy", allow(stutter))]
#[cfg(test)]
use stdsimd_test::assert_instr;
#[allow(improper_ctypes)]
extern "C" {
#[link_name = "llvm.x86.xsave"]
fn xsave(p: *mut u8, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xrstor"]
fn xrstor(p: *const u8, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xsetbv"]
fn xsetbv(v: u32, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xsaveopt"]
fn xsaveopt(p: *mut u8, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xsavec"]
fn xsavec(p: *mut u8, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xsaves"]
fn xsaves(p: *mut u8, hi: u32, lo: u32) -> ();
#[link_name = "llvm.x86.xrstors"]
fn xrstors(p: *const u8, hi: u32, lo: u32) -> ();
}
/// Perform a full or partial save of the enabled processor states to memory at
/// `mem_addr`.
///
/// State is saved based on bits `[62:0]` in `save_mask` and XCR0.
/// `mem_addr` must be aligned on a 64-byte boundary.
///
/// The format of the XSAVE area is detailed in Section 13.4, “XSAVE Area,” of
/// Intel® 64 and IA-32 Architectures Software Developers Manual, Volume 1.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xsave)
#[inline]
#[target_feature(enable = "xsave")]
#[cfg_attr(test, assert_instr(xsave))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xsave(mem_addr: *mut u8, save_mask: u64) {
xsave(mem_addr, (save_mask >> 32) as u32, save_mask as u32);
}
/// Perform a full or partial restore of the enabled processor states using
/// the state information stored in memory at `mem_addr`.
///
/// State is restored based on bits `[62:0]` in `rs_mask`, `XCR0`, and
/// `mem_addr.HEADER.XSTATE_BV`. `mem_addr` must be aligned on a 64-byte
/// boundary.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xrstor)
#[inline]
#[target_feature(enable = "xsave")]
#[cfg_attr(test, assert_instr(xrstor))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xrstor(mem_addr: *const u8, rs_mask: u64) {
xrstor(mem_addr, (rs_mask >> 32) as u32, rs_mask as u32);
}
/// `XFEATURE_ENABLED_MASK` for `XCR`
///
/// This intrinsic maps to `XSETBV` instruction.
#[stable(feature = "simd_x86", since = "1.27.0")]
pub const _XCR_XFEATURE_ENABLED_MASK: u32 = 0;
/// Copy 64-bits from `val` to the extended control register (`XCR`) specified
/// by `a`.
///
/// Currently only `XFEATURE_ENABLED_MASK` `XCR` is supported.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xsetbv)
#[inline]
#[target_feature(enable = "xsave")]
#[cfg_attr(test, assert_instr(xsetbv))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xsetbv(a: u32, val: u64) {
xsetbv(a, (val >> 32) as u32, val as u32);
}
/// Reads the contents of the extended control register `XCR`
/// specified in `xcr_no`.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xgetbv)
#[inline]
#[target_feature(enable = "xsave")]
#[cfg_attr(test, assert_instr(xgetbv))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xgetbv(xcr_no: u32) -> u64 {
let eax: u32;
let edx: u32;
asm!("xgetbv" : "={eax}"(eax), "={edx}"(edx) : "{ecx}"(xcr_no));
((edx as u64) << 32) | (eax as u64)
}
/// Perform a full or partial save of the enabled processor states to memory at
/// `mem_addr`.
///
/// State is saved based on bits `[62:0]` in `save_mask` and `XCR0`.
/// `mem_addr` must be aligned on a 64-byte boundary. The hardware may optimize
/// the manner in which data is saved. The performance of this instruction will
/// be equal to or better than using the `XSAVE` instruction.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xsaveopt)
#[inline]
#[target_feature(enable = "xsave,xsaveopt")]
#[cfg_attr(test, assert_instr(xsaveopt))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xsaveopt(mem_addr: *mut u8, save_mask: u64) {
xsaveopt(mem_addr, (save_mask >> 32) as u32, save_mask as u32);
}
/// Perform a full or partial save of the enabled processor states to memory
/// at `mem_addr`.
///
/// `xsavec` differs from `xsave` in that it uses compaction and that it may
/// use init optimization. State is saved based on bits `[62:0]` in `save_mask`
/// and `XCR0`. `mem_addr` must be aligned on a 64-byte boundary.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xsavec)
#[inline]
#[target_feature(enable = "xsave,xsavec")]
#[cfg_attr(test, assert_instr(xsavec))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xsavec(mem_addr: *mut u8, save_mask: u64) {
xsavec(mem_addr, (save_mask >> 32) as u32, save_mask as u32);
}
/// Perform a full or partial save of the enabled processor states to memory at
/// `mem_addr`
///
/// `xsaves` differs from xsave in that it can save state components
/// corresponding to bits set in `IA32_XSS` `MSR` and that it may use the
/// modified optimization. State is saved based on bits `[62:0]` in `save_mask`
/// and `XCR0`. `mem_addr` must be aligned on a 64-byte boundary.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xsaves)
#[inline]
#[target_feature(enable = "xsave,xsaves")]
#[cfg_attr(test, assert_instr(xsaves))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xsaves(mem_addr: *mut u8, save_mask: u64) {
xsaves(mem_addr, (save_mask >> 32) as u32, save_mask as u32);
}
/// Perform a full or partial restore of the enabled processor states using the
/// state information stored in memory at `mem_addr`.
///
/// `xrstors` differs from `xrstor` in that it can restore state components
/// corresponding to bits set in the `IA32_XSS` `MSR`; `xrstors` cannot restore
/// from an `xsave` area in which the extended region is in the standard form.
/// State is restored based on bits `[62:0]` in `rs_mask`, `XCR0`, and
/// `mem_addr.HEADER.XSTATE_BV`. `mem_addr` must be aligned on a 64-byte
/// boundary.
///
/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_xrstors)
#[inline]
#[target_feature(enable = "xsave,xsaves")]
#[cfg_attr(test, assert_instr(xrstors))]
#[stable(feature = "simd_x86", since = "1.27.0")]
pub unsafe fn _xrstors(mem_addr: *const u8, rs_mask: u64) {
xrstors(mem_addr, (rs_mask >> 32) as u32, rs_mask as u32);
}
#[cfg(test)]
mod tests {
use std::fmt;
use std::prelude::v1::*;
use coresimd::x86::*;
use stdsimd_test::simd_test;
#[repr(align(64))]
struct XsaveArea {
// max size for 256-bit registers is 800 bytes:
// see https://software.intel.com/en-us/node/682996
// max size for 512-bit registers is 2560 bytes:
// FIXME: add source
data: [u8; 2560],
}
impl XsaveArea {
fn new() -> XsaveArea {
XsaveArea { data: [0; 2560] }
}
fn ptr(&mut self) -> *mut u8 {
&mut self.data[0] as *mut _ as *mut u8
}
}
impl PartialEq<XsaveArea> for XsaveArea {
fn eq(&self, other: &XsaveArea) -> bool {
for i in 0..self.data.len() {
if self.data[i] != other.data[i] {
return false;
}
}
true
}
}
impl fmt::Debug for XsaveArea {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "[")?;
for i in 0..self.data.len() {
write!(f, "{}", self.data[i])?;
if i != self.data.len() - 1 {
write!(f, ", ")?;
}
}
write!(f, "]")
}
}
// FIXME: https://github.com/rust-lang-nursery/stdsimd/issues/209
/*
#[simd_test(enable = "xsave")]
unsafe fn xsave() {
let m = 0xFFFFFFFFFFFFFFFF_u64; //< all registers
let mut a = XsaveArea::new();
let mut b = XsaveArea::new();
_xsave(a.ptr(), m);
_xrstor(a.ptr(), m);
_xsave(b.ptr(), m);
assert_eq!(a, b);
}
*/
#[simd_test(enable = "xsave")]
unsafe fn xgetbv_xsetbv() {
let xcr_n: u32 = _XCR_XFEATURE_ENABLED_MASK;
let xcr: u64 = _xgetbv(xcr_n);
// FIXME: XSETBV is a privileged instruction we should only test this
// when running in privileged mode:
//
// _xsetbv(xcr_n, xcr);
let xcr_cpy: u64 = _xgetbv(xcr_n);
assert_eq!(xcr, xcr_cpy);
}
// FIXME: https://github.com/rust-lang-nursery/stdsimd/issues/209
/*
#[simd_test(enable = "xsave,xsaveopt")]
unsafe fn xsaveopt() {
let m = 0xFFFFFFFFFFFFFFFF_u64; //< all registers
let mut a = XsaveArea::new();
let mut b = XsaveArea::new();
_xsaveopt(a.ptr(), m);
_xrstor(a.ptr(), m);
_xsaveopt(b.ptr(), m);
assert_eq!(a, b);
}
*/
// FIXME: this looks like a bug in Intel's SDE:
#[cfg(not(stdsimd_intel_sde))]
#[simd_test(enable = "xsave,xsavec")]
unsafe fn xsavec() {
let m = 0xFFFFFFFFFFFFFFFF_u64; //< all registers
let mut a = XsaveArea::new();
let mut b = XsaveArea::new();
_xsavec(a.ptr(), m);
_xrstor(a.ptr(), m);
_xsavec(b.ptr(), m);
assert_eq!(a, b);
}
// FIXME: https://github.com/rust-lang-nursery/stdsimd/issues/209
/*
#[simd_test(enable = "xsave,xsaves")]
unsafe fn xsaves() {
let m = 0xFFFFFFFFFFFFFFFF_u64; //< all registers
let mut a = XsaveArea::new();
let mut b = XsaveArea::new();
_xsaves(a.ptr(), m);
_xrstors(a.ptr(), m);
_xsaves(b.ptr(), m);
assert_eq!(a, b);
}
*/
}