Add VPCLMULQDQ Intrinsics (#943)

crates/core_arch/src/x86/avx512vpclmulqdq.rs

@@ -0,0 +1,266 @@
+//! Vectorized Carry-less Multiplication (VCLMUL)
+//!
+//! The reference is [Intel 64 and IA-32 Architectures Software Developer's
+//! Manual Volume 2: Instruction Set Reference, A-Z][intel64_ref] (p. 4-241).
+//!
+//! [intel64_ref]: http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.pdf
+
+use crate::core_arch::x86::__m256i;
+use crate::core_arch::x86::__m512i;
+
+#[cfg(test)]
+use crate::stdarch_test::assert_instr;
+
+#[allow(improper_ctypes)]
+extern "C" {
+    #[link_name = "llvm.x86.pclmulqdq.256"]
+    fn pclmulqdq_256(a: __m256i, round_key: __m256i, imm8: u8) -> __m256i;
+    #[link_name = "llvm.x86.pclmulqdq.512"]
+    fn pclmulqdq_512(a: __m512i, round_key: __m512i, imm8: u8) -> __m512i;
+}
+
+// for some odd reason on x86_64 we generate the correct long name instructions
+// but on i686 we generate the short name + imm8
+// so we need to special-case on that...
+
+/// Performs a carry-less multiplication of two 64-bit polynomials over the
+/// finite field GF(2^k) - in each of the 4 128-bit lanes.
+///
+/// The immediate byte is used for determining which halves of each lane `a` and `b`
+/// should be used. Immediate bits other than 0 and 4 are ignored.
+/// All lanes share immediate byte.
+///
+/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_mm512_clmulepi64_epi128)
+#[inline]
+#[target_feature(enable = "avx512vpclmulqdq,avx512f")]
+// technically according to Intel's documentation we don't need avx512f here, however LLVM gets confused otherwise
+#[cfg_attr(test, assert_instr(vpclmul, imm8 = 0))]
+#[rustc_args_required_const(2)]
+pub unsafe fn _mm512_clmulepi64_epi128(a: __m512i, b: __m512i, imm8: i32) -> __m512i {
+    macro_rules! call {
+        ($imm8:expr) => {
+            pclmulqdq_512(a, b, $imm8)
+        };
+    }
+    constify_imm8!(imm8, call)
+}
+
+/// Performs a carry-less multiplication of two 64-bit polynomials over the
+/// finite field GF(2^k) - in each of the 2 128-bit lanes.
+///
+/// The immediate byte is used for determining which halves of each lane `a` and `b`
+/// should be used. Immediate bits other than 0 and 4 are ignored.
+/// All lanes share immediate byte.
+///
+/// [Intel's documentation](https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_mm256_clmulepi64_epi128)
+#[inline]
+#[target_feature(enable = "avx512vpclmulqdq,avx512vl")]
+#[cfg_attr(test, assert_instr(vpclmul, imm8 = 0))]
+#[rustc_args_required_const(2)]
+pub unsafe fn _mm256_clmulepi64_epi128(a: __m256i, b: __m256i, imm8: i32) -> __m256i {
+    macro_rules! call {
+        ($imm8:expr) => {
+            pclmulqdq_256(a, b, $imm8)
+        };
+    }
+    constify_imm8!(imm8, call)
+}
+
+#[cfg(test)]
+mod tests {
+    // The constants in the tests below are just bit patterns. They should not
+    // be interpreted as integers; signedness does not make sense for them, but
+    // __mXXXi happens to be defined in terms of signed integers.
+    #![allow(overflowing_literals)]
+
+    use stdarch_test::simd_test;
+
+    use crate::core_arch::x86::*;
+
+    macro_rules! verify_kat_pclmul {
+        ($broadcast:ident, $clmul:ident, $assert:ident) => {
+            // Constants taken from https://software.intel.com/sites/default/files/managed/72/cc/clmul-wp-rev-2.02-2014-04-20.pdf
+         let a = _mm_set_epi64x(0x7b5b546573745665, 0x63746f725d53475d);
+         let a = $broadcast(a);
+         let b = _mm_set_epi64x(0x4869285368617929, 0x5b477565726f6e5d);
+         let b = $broadcast(b);
+         let r00 = _mm_set_epi64x(0x1d4d84c85c3440c0, 0x929633d5d36f0451);
+         let r00 = $broadcast(r00);
+         let r01 = _mm_set_epi64x(0x1bd17c8d556ab5a1, 0x7fa540ac2a281315);
+         let r01 = $broadcast(r01);
+         let r10 = _mm_set_epi64x(0x1a2bf6db3a30862f, 0xbabf262df4b7d5c9);
+         let r10 = $broadcast(r10);
+         let r11 = _mm_set_epi64x(0x1d1e1f2c592e7c45, 0xd66ee03e410fd4ed);
+         let r11 = $broadcast(r11);
+
+         $assert($clmul(a, b, 0x00), r00);
+         $assert($clmul(a, b, 0x10), r01);
+         $assert($clmul(a, b, 0x01), r10);
+         $assert($clmul(a, b, 0x11), r11);
+
+         let a0 = _mm_set_epi64x(0x0000000000000000, 0x8000000000000000);
+         let a0 = $broadcast(a0);
+         let r = _mm_set_epi64x(0x4000000000000000, 0x0000000000000000);
+         let r = $broadcast(r);
+         $assert($clmul(a0, a0, 0x00), r);
+        }
+    }
+
+    macro_rules! unroll {
+        ($target:ident[4] = $op:ident($source:ident,4);) => {
+            $target[3] = $op($source, 3);
+            $target[2] = $op($source, 2);
+            unroll! {$target[2] = $op($source,2);}
+        };
+        ($target:ident[2] = $op:ident($source:ident,2);) => {
+            $target[1] = $op($source, 1);
+            $target[0] = $op($source, 0);
+        };
+        (assert_eq_m128i($op:ident($vec_res:ident,4),$lin_res:ident[4]);) => {
+            assert_eq_m128i($op($vec_res, 3), $lin_res[3]);
+            assert_eq_m128i($op($vec_res, 2), $lin_res[2]);
+            unroll! {assert_eq_m128i($op($vec_res,2),$lin_res[2]);}
+        };
+        (assert_eq_m128i($op:ident($vec_res:ident,2),$lin_res:ident[2]);) => {
+            assert_eq_m128i($op($vec_res, 1), $lin_res[1]);
+            assert_eq_m128i($op($vec_res, 0), $lin_res[0]);
+        };
+    }
+
+    // this function tests one of the possible 4 instances
+    // with different inputs across lanes
+    #[target_feature(enable = "avx512vpclmulqdq,avx512f")]
+    unsafe fn verify_512_helper(
+        linear: unsafe fn(__m128i, __m128i) -> __m128i,
+        vectorized: unsafe fn(__m512i, __m512i) -> __m512i,
+    ) {
+        let a = _mm512_set_epi64(
+            0xDCB4DB3657BF0B7D,
+            0x18DB0601068EDD9F,
+            0xB76B908233200DC5,
+            0xE478235FA8E22D5E,
+            0xAB05CFFA2621154C,
+            0x1171B47A186174C9,
+            0x8C6B6C0E7595CEC9,
+            0xBE3E7D4934E961BD,
+        );
+        let b = _mm512_set_epi64(
+            0x672F6F105A94CEA7,
+            0x8298B8FFCA5F829C,
+            0xA3927047B3FB61D8,
+            0x978093862CDE7187,
+            0xB1927AB22F31D0EC,
+            0xA9A5DA619BE4D7AF,
+            0xCA2590F56884FDC6,
+            0x19BE9F660038BDB5,
+        );
+
+        let mut a_decomp = [_mm_setzero_si128(); 4];
+        unroll! {a_decomp[4] = _mm512_extracti32x4_epi32(a,4);}
+        let mut b_decomp = [_mm_setzero_si128(); 4];
+        unroll! {b_decomp[4] = _mm512_extracti32x4_epi32(b,4);}
+
+        let r = vectorized(a, b);
+        let mut e_decomp = [_mm_setzero_si128(); 4];
+        for i in 0..4 {
+            e_decomp[i] = linear(a_decomp[i], b_decomp[i]);
+        }
+        unroll! {assert_eq_m128i(_mm512_extracti32x4_epi32(r,4),e_decomp[4]);}
+    }
+
+    // this function tests one of the possible 4 instances
+    // with different inputs across lanes for the VL version
+    #[target_feature(enable = "avx512vpclmulqdq,avx512vl")]
+    unsafe fn verify_256_helper(
+        linear: unsafe fn(__m128i, __m128i) -> __m128i,
+        vectorized: unsafe fn(__m256i, __m256i) -> __m256i,
+    ) {
+        let a = _mm512_set_epi64(
+            0xDCB4DB3657BF0B7D,
+            0x18DB0601068EDD9F,
+            0xB76B908233200DC5,
+            0xE478235FA8E22D5E,
+            0xAB05CFFA2621154C,
+            0x1171B47A186174C9,
+            0x8C6B6C0E7595CEC9,
+            0xBE3E7D4934E961BD,
+        );
+        let b = _mm512_set_epi64(
+            0x672F6F105A94CEA7,
+            0x8298B8FFCA5F829C,
+            0xA3927047B3FB61D8,
+            0x978093862CDE7187,
+            0xB1927AB22F31D0EC,
+            0xA9A5DA619BE4D7AF,
+            0xCA2590F56884FDC6,
+            0x19BE9F660038BDB5,
+        );
+
+        let mut a_decomp = [_mm_setzero_si128(); 2];
+        unroll! {a_decomp[2] = _mm512_extracti32x4_epi32(a,2);}
+        let mut b_decomp = [_mm_setzero_si128(); 2];
+        unroll! {b_decomp[2] = _mm512_extracti32x4_epi32(b,2);}
+
+        let r = vectorized(
+            _mm512_extracti64x4_epi64(a, 0),
+            _mm512_extracti64x4_epi64(b, 0),
+        );
+        let mut e_decomp = [_mm_setzero_si128(); 2];
+        for i in 0..2 {
+            e_decomp[i] = linear(a_decomp[i], b_decomp[i]);
+        }
+        unroll! {assert_eq_m128i(_mm256_extracti128_si256(r,2),e_decomp[2]);}
+    }
+
+    #[simd_test(enable = "avx512vpclmulqdq,avx512f")]
+    unsafe fn test_mm512_clmulepi64_epi128() {
+        verify_kat_pclmul!(
+            _mm512_broadcast_i32x4,
+            _mm512_clmulepi64_epi128,
+            assert_eq_m512i
+        );
+
+        verify_512_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x00),
+            |a, b| _mm512_clmulepi64_epi128(a, b, 0x00),
+        );
+        verify_512_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x01),
+            |a, b| _mm512_clmulepi64_epi128(a, b, 0x01),
+        );
+        verify_512_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x10),
+            |a, b| _mm512_clmulepi64_epi128(a, b, 0x10),
+        );
+        verify_512_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x11),
+            |a, b| _mm512_clmulepi64_epi128(a, b, 0x11),
+        );
+    }
+
+    #[simd_test(enable = "avx512vpclmulqdq,avx512vl")]
+    unsafe fn test_mm256_clmulepi64_epi128() {
+        verify_kat_pclmul!(
+            _mm256_broadcastsi128_si256,
+            _mm256_clmulepi64_epi128,
+            assert_eq_m256i
+        );
+
+        verify_256_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x00),
+            |a, b| _mm256_clmulepi64_epi128(a, b, 0x00),
+        );
+        verify_256_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x01),
+            |a, b| _mm256_clmulepi64_epi128(a, b, 0x01),
+        );
+        verify_256_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x10),
+            |a, b| _mm256_clmulepi64_epi128(a, b, 0x10),
+        );
+        verify_256_helper(
+            |a, b| _mm_clmulepi64_si128(a, b, 0x11),
+            |a, b| _mm256_clmulepi64_epi128(a, b, 0x11),
+        );
+    }
+}

crates/core_arch/src/x86/mod.rs

@@ -675,6 +675,9 @@ pub use self::avx512ifma::*;
 mod avx512vaes;
 pub use self::avx512vaes::*;
 
+mod avx512vpclmulqdq;
+pub use self::avx512vpclmulqdq::*;
+
 mod bt;
 pub use self::bt::*;