[bmi2] implement all bmi2 instructions

library/stdarch/src/lib.rs

@@ -1,7 +1,7 @@
 #![allow(dead_code)]
 #![feature(
     const_fn, link_llvm_intrinsics, platform_intrinsics, repr_simd, simd_ffi,
-    target_feature, cfg_target_feature
+    target_feature, cfg_target_feature, i128_type
 )]
 
 /// Platform independent SIMD vector types and operations.

library/stdarch/src/x86/bmi2.rs

@@ -0,0 +1,193 @@
+/// Unsigned multiply without affecting flags.
+///
+/// Unsigned multiplication of `a` with `b` returning a pair `(lo, hi)` with
+/// the low half and the high half of the result.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _mulx_u32(a: u32, b: u32) -> (u32, u32) {
+    let result: u64 = (a as u64) * (b as u64);
+    let hi = (result >> 32) as u32;
+    (result as u32, hi)
+}
+
+/// Unsigned multiply without affecting flags.
+///
+/// Unsigned multiplication of `a` with `b` returning a pair `(lo, hi)` with
+/// the low half and the high half of the result.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _mulx_u64(a: u64, b: u64) -> (u64, u64) {
+    let result: u128 = (a as u128) * (b as u128);
+    let hi = (result >> 64) as u64;
+    (result as u64, hi)
+}
+
+#[allow(dead_code)]
+extern "platform-intrinsic" {
+    fn x86_bmi2_bzhi_32(x: u32, y: u32) -> u32;
+    fn x86_bmi2_bzhi_64(x: u64, y: u64) -> u64;
+    fn x86_bmi2_pdep_32(x: u32, y: u32) -> u32;
+    fn x86_bmi2_pdep_64(x: u64, y: u64) -> u64;
+    fn x86_bmi2_pext_32(x: u32, y: u32) -> u32;
+    fn x86_bmi2_pext_64(x: u64, y: u64) -> u64;
+}
+
+
+/// Zero higher bits of `a` >= `index`.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _bzhi_u32(a: u32, index: u32) -> u32 {
+    unsafe { x86_bmi2_bzhi_32(a, index) }
+}
+
+/// Zero higher bits of `a` >= `index`.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _bzhi_u64(a: u64, index: u64) -> u64 {
+    unsafe { x86_bmi2_bzhi_64(a, index) }
+}
+
+
+/// Scatter contiguous low order bits of `a` to the result at the positions
+/// specified by the `mask`.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _pdep_u32(a: u32, mask: u32) -> u32 {
+    unsafe { x86_bmi2_pdep_32(a, mask) }
+}
+
+/// Scatter contiguous low order bits of `a` to the result at the positions
+/// specified by the `mask`.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _pdep_u64(a: u64, mask: u64) -> u64 {
+    unsafe { x86_bmi2_pdep_64(a, mask) }
+}
+
+/// Gathers the bits of `x` specified by the `mask` into the contiguous low
+/// order bit positions of the result.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _pext_u32(a: u32, mask: u32) -> u32 {
+    unsafe { x86_bmi2_pext_32(a, mask) }
+}
+
+/// Gathers the bits of `x` specified by the `mask` into the contiguous low
+/// order bit positions of the result.
+#[inline(always)]
+#[target_feature = "+bmi2"]
+pub fn _pext_u64(a: u64, mask: u64) -> u64 {
+    unsafe { x86_bmi2_pext_64(a, mask) }
+}
+
+
+#[cfg(all(test, target_feature = "bmi2", any(target_arch = "x86", target_arch = "x86_64")))]
+mod tests {
+    use x86::bmi2;
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _pext_u32() {
+        let n  = 0b1011_1110_1001_0011u32;
+
+        let m0 = 0b0110_0011_1000_0101u32;
+        let s0 = 0b0000_0000_0011_0101u32;
+
+        let m1 = 0b1110_1011_1110_1111u32;
+        let s1 = 0b0001_0111_0100_0011u32;
+
+        assert_eq!(bmi2::_pext_u32(n, m0), s0);
+        assert_eq!(bmi2::_pext_u32(n, m1), s1);
+    }
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _pext_u64() {
+        let n  = 0b1011_1110_1001_0011u64;
+
+        let m0 = 0b0110_0011_1000_0101u64;
+        let s0 = 0b0000_0000_0011_0101u64;
+
+        let m1 = 0b1110_1011_1110_1111u64;
+        let s1 = 0b0001_0111_0100_0011u64;
+
+        assert_eq!(bmi2::_pext_u64(n, m0), s0);
+        assert_eq!(bmi2::_pext_u64(n, m1), s1);
+    }
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _pdep_u32() {
+        let n  = 0b1011_1110_1001_0011u32;
+
+        let m0 = 0b0110_0011_1000_0101u32;
+        let s0 = 0b0000_0010_0000_0101u32;
+
+        let m1 = 0b1110_1011_1110_1111u32;
+        let s1 = 0b1110_1001_0010_0011u32;
+
+        assert_eq!(bmi2::_pdep_u32(n, m0), s0);
+        assert_eq!(bmi2::_pdep_u32(n, m1), s1);
+    }
+
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _pdep_u64() {
+        let n  = 0b1011_1110_1001_0011u64;
+
+        let m0 = 0b0110_0011_1000_0101u64;
+        let s0 = 0b0000_0010_0000_0101u64;
+
+        let m1 = 0b1110_1011_1110_1111u64;
+        let s1 = 0b1110_1001_0010_0011u64;
+
+        assert_eq!(bmi2::_pdep_u64(n, m0), s0);
+        assert_eq!(bmi2::_pdep_u64(n, m1), s1);
+    }
+
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _bzhi_u32() {
+        let n = 0b1111_0010u32;
+        let s = 0b0001_0010u32;
+        assert_eq!(bmi2::_bzhi_u32(n, 5), s);
+    }
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _bzhi_u64() {
+        let n = 0b1111_0010u64;
+        let s = 0b0001_0010u64;
+        assert_eq!(bmi2::_bzhi_u64(n, 5), s);
+    }
+
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _mulx_u32() {
+        let a: u32 = 4_294_967_200;
+        let b: u32 = 2;
+        let (lo, hi): (u32, u32)  = bmi2::_mulx_u32(a, b);
+        // result = 8589934400
+        //        = 0b0001_1111_1111_1111_1111_1111_1111_0100_0000u64
+        //            ^~hi ^~lo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        assert_eq!(lo, 0b1111_1111_1111_1111_1111_1111_0100_0000u32);
+        assert_eq!(hi, 0b0001u32);
+    }
+
+    #[test]
+    #[target_feature = "+bmi2"]
+    fn _mulx_u64() {
+        let a: u64 = 9_223_372_036_854_775_800;
+        let b: u64 = 100;
+        let (lo, hi): (u64, u64)  = bmi2::_mulx_u64(a, b);
+        // result = 922337203685477580000
+        //        = 0b00110001_11111111_11111111_11111111_11111111_11111111_11111111_11111100_11100000u128
+        //            ^~hi~~~~ ^~lo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+        assert_eq!(lo, 0b11111111_11111111_11111111_11111111_11111111_11111111_11111100_11100000u64);
+        assert_eq!(hi, 0b00110001u64);
+    }
+
+}

library/stdarch/src/x86/mod.rs

@@ -21,3 +21,4 @@ mod avx;
 mod avx2;
 
 mod bmi;
+mod bmi2;