Auto merge of #3072 - eduardosm:llvm.ctpop, r=saethlin

Implement `llvm.ctpop.v*` intrinsics

Tested through x86 avx512vpopcntdq and avx512bitalg functions.

I picked them from https://github.com/rust-lang/miri/issues/2057#issuecomment-1716309674, which looked easy.

3 files changed, 280 insertions, 0 deletions

diff --git a/src/tools/miri/src/shims/foreign_items.rs b/src/tools/miri/src/shims/foreign_items.rs
index 0e8eaf450e4..f596df1f7a1 100644
--- a/src/tools/miri/src/shims/foreign_items.rs
+++ b/src/tools/miri/src/shims/foreign_items.rs
@@ -1032,6 +1032,29 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 }
             }
 
+            // Used to implement the x86 `_mm{,256,512}_popcnt_epi{8,16,32,64}` and wasm
+            // `{i,u}8x16_popcnt` functions.
+            name if name.starts_with("llvm.ctpop.v") => {
+                let [op] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+
+                let (op, op_len) = this.operand_to_simd(op)?;
+                let (dest, dest_len) = this.place_to_simd(dest)?;
+
+                assert_eq!(dest_len, op_len);
+
+                for i in 0..dest_len {
+                    let op = this.read_immediate(&this.project_index(&op, i)?)?;
+                    // Use `to_uint` to get a zero-extended `u128`. Those
+                    // extra zeros will not affect `count_ones`.
+                    let res = op.to_scalar().to_uint(op.layout.size)?.count_ones();
+
+                    this.write_scalar(
+                        Scalar::from_uint(res, op.layout.size),
+                        &this.project_index(&dest, i)?,
+                    )?;
+                }
+            }
+
             name if name.starts_with("llvm.x86.sse.") => {
                 return shims::x86::sse::EvalContextExt::emulate_x86_sse_intrinsic(
                     this, link_name, abi, args, dest,
diff --git a/src/tools/miri/tests/pass/intrinsics-x86-avx512bitalg.rs b/src/tools/miri/tests/pass/intrinsics-x86-avx512bitalg.rs
new file mode 100644
index 00000000000..19f9b94ff08
--- /dev/null
+++ b/src/tools/miri/tests/pass/intrinsics-x86-avx512bitalg.rs
@@ -0,0 +1,133 @@
+// Ignore everything except x86 and x86_64
+// Any additional target are added to CI should be ignored here
+//@ignore-target-aarch64
+//@ignore-target-arm
+//@ignore-target-avr
+//@ignore-target-s390x
+//@ignore-target-thumbv7em
+//@ignore-target-wasm32
+//@compile-flags: -C target-feature=+avx512bitalg,+avx512f,+avx512vl
+
+#![feature(avx512_target_feature)]
+#![feature(stdsimd)]
+
+#[cfg(target_arch = "x86")]
+use std::arch::x86::*;
+#[cfg(target_arch = "x86_64")]
+use std::arch::x86_64::*;
+use std::mem::transmute;
+
+fn main() {
+    assert!(is_x86_feature_detected!("avx512bitalg"));
+    assert!(is_x86_feature_detected!("avx512f"));
+    assert!(is_x86_feature_detected!("avx512vl"));
+
+    unsafe {
+        test_avx512bitalg();
+    }
+}
+
+// Some of 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)]
+#[target_feature(enable = "avx512bitalg,avx512f,avx512vl")]
+unsafe fn test_avx512bitalg() {
+    // Mostly copied from library/stdarch/crates/core_arch/src/x86/avx512bitalg.rs
+
+    #[target_feature(enable = "avx512bitalg,avx512f")]
+    unsafe fn test_mm512_popcnt_epi16() {
+        let test_data = _mm512_set_epi16(
+            0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1_FF, 0x3_FF, 0x7_FF, 0xF_FF, 0x1F_FF,
+            0x3F_FF, 0x7F_FF, 0xFF_FF, -1, -100, 255, 256, 2, 4, 8, 16, 32, 64, 128, 256, 512,
+            1024, 2048,
+        );
+        let actual_result = _mm512_popcnt_epi16(test_data);
+        let reference_result = _mm512_set_epi16(
+            0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 16, 12, 8, 1, 1, 1, 1, 1, 1,
+            1, 1, 1, 1, 1, 1,
+        );
+        assert_eq_m512i(actual_result, reference_result);
+    }
+    test_mm512_popcnt_epi16();
+
+    #[target_feature(enable = "avx512bitalg,avx512f,avx512vl")]
+    unsafe fn test_mm256_popcnt_epi16() {
+        let test_data = _mm256_set_epi16(
+            0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, 0x1_FF, 0x3_FF, 0x7_FF, 0xF_FF, 0x1F_FF,
+            0x3F_FF, 0x7F_FF,
+        );
+        let actual_result = _mm256_popcnt_epi16(test_data);
+        let reference_result =
+            _mm256_set_epi16(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
+        assert_eq_m256i(actual_result, reference_result);
+    }
+    test_mm256_popcnt_epi16();
+
+    #[target_feature(enable = "avx512bitalg,avx512f,avx512vl")]
+    unsafe fn test_mm_popcnt_epi16() {
+        let test_data = _mm_set_epi16(0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F);
+        let actual_result = _mm_popcnt_epi16(test_data);
+        let reference_result = _mm_set_epi16(0, 1, 2, 3, 4, 5, 6, 7);
+        assert_eq_m128i(actual_result, reference_result);
+    }
+    test_mm_popcnt_epi16();
+
+    #[target_feature(enable = "avx512bitalg,avx512f")]
+    unsafe fn test_mm512_popcnt_epi8() {
+        let test_data = _mm512_set_epi8(
+            0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, -1, 2, 4, 8, 16, 32, 64, 128, 171, 206, 100,
+            217, 109, 253, 190, 177, 254, 179, 215, 230, 68, 201, 172, 183, 154, 84, 56, 227, 189,
+            140, 35, 117, 219, 169, 226, 170, 13, 22, 159, 251, 73, 121, 143, 145, 85, 91, 137, 90,
+            225, 21, 249, 211, 155, 228, 70,
+        );
+        let actual_result = _mm512_popcnt_epi8(test_data);
+        let reference_result = _mm512_set_epi8(
+            0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 1, 1, 1, 1, 1, 1, 1, 5, 5, 3, 5, 5, 7, 6, 4, 7, 5, 6, 5,
+            2, 4, 4, 6, 4, 3, 3, 5, 6, 3, 3, 5, 6, 4, 4, 4, 3, 3, 6, 7, 3, 5, 5, 3, 4, 5, 3, 4, 4,
+            3, 6, 5, 5, 4, 3,
+        );
+        assert_eq_m512i(actual_result, reference_result);
+    }
+    test_mm512_popcnt_epi8();
+
+    #[target_feature(enable = "avx512bitalg,avx512f,avx512vl")]
+    unsafe fn test_mm256_popcnt_epi8() {
+        let test_data = _mm256_set_epi8(
+            0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, -1, 2, 4, 8, 16, 32, 64, 128, 171, 206, 100,
+            217, 109, 253, 190, 177, 254, 179, 215, 230, 68, 201, 172,
+        );
+        let actual_result = _mm256_popcnt_epi8(test_data);
+        let reference_result = _mm256_set_epi8(
+            0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 1, 1, 1, 1, 1, 1, 1, 5, 5, 3, 5, 5, 7, 6, 4, 7, 5, 6, 5,
+            2, 4, 4,
+        );
+        assert_eq_m256i(actual_result, reference_result);
+    }
+    test_mm256_popcnt_epi8();
+
+    #[target_feature(enable = "avx512bitalg,avx512f,avx512vl")]
+    unsafe fn test_mm_popcnt_epi8() {
+        let test_data =
+            _mm_set_epi8(0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, -1, 2, 4, 8, 16, 32, 64);
+        let actual_result = _mm_popcnt_epi8(test_data);
+        let reference_result = _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 1, 1, 1, 1, 1, 1);
+        assert_eq_m128i(actual_result, reference_result);
+    }
+    test_mm_popcnt_epi8();
+}
+
+#[track_caller]
+unsafe fn assert_eq_m512i(a: __m512i, b: __m512i) {
+    assert_eq!(transmute::<_, [i32; 16]>(a), transmute::<_, [i32; 16]>(b))
+}
+
+#[track_caller]
+unsafe fn assert_eq_m256i(a: __m256i, b: __m256i) {
+    assert_eq!(transmute::<_, [u64; 4]>(a), transmute::<_, [u64; 4]>(b))
+}
+
+#[track_caller]
+unsafe fn assert_eq_m128i(a: __m128i, b: __m128i) {
+    assert_eq!(transmute::<_, [u64; 2]>(a), transmute::<_, [u64; 2]>(b))
+}
diff --git a/src/tools/miri/tests/pass/intrinsics-x86-avx512vpopcntdq.rs b/src/tools/miri/tests/pass/intrinsics-x86-avx512vpopcntdq.rs
new file mode 100644
index 00000000000..5c8821305e6
--- /dev/null
+++ b/src/tools/miri/tests/pass/intrinsics-x86-avx512vpopcntdq.rs
@@ -0,0 +1,124 @@
+// Ignore everything except x86 and x86_64
+// Any additional target are added to CI should be ignored here
+//@ignore-target-aarch64
+//@ignore-target-arm
+//@ignore-target-avr
+//@ignore-target-s390x
+//@ignore-target-thumbv7em
+//@ignore-target-wasm32
+//@compile-flags: -C target-feature=+avx512vpopcntdq,+avx512f,+avx512vl
+
+#![feature(avx512_target_feature)]
+#![feature(stdsimd)]
+
+#[cfg(target_arch = "x86")]
+use std::arch::x86::*;
+#[cfg(target_arch = "x86_64")]
+use std::arch::x86_64::*;
+use std::mem::transmute;
+
+fn main() {
+    assert!(is_x86_feature_detected!("avx512vpopcntdq"));
+    assert!(is_x86_feature_detected!("avx512f"));
+    assert!(is_x86_feature_detected!("avx512vl"));
+
+    unsafe {
+        test_avx512vpopcntdq();
+    }
+}
+
+#[target_feature(enable = "avx512vpopcntdq,avx512f,avx512vl")]
+unsafe fn test_avx512vpopcntdq() {
+    // Mostly copied from library/stdarch/crates/core_arch/src/x86/avx512vpopcntdq.rs
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512f")]
+    unsafe fn test_mm512_popcnt_epi32() {
+        let test_data = _mm512_set_epi32(
+            0,
+            1,
+            -1,
+            2,
+            7,
+            0xFF_FE,
+            0x7F_FF_FF_FF,
+            -100,
+            0x40_00_00_00,
+            103,
+            371,
+            552,
+            432_948,
+            818_826_998,
+            255,
+            256,
+        );
+        let actual_result = _mm512_popcnt_epi32(test_data);
+        let reference_result =
+            _mm512_set_epi32(0, 1, 32, 1, 3, 15, 31, 28, 1, 5, 6, 3, 10, 17, 8, 1);
+        assert_eq_m512i(actual_result, reference_result);
+    }
+    test_mm512_popcnt_epi32();
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512f,avx512vl")]
+    unsafe fn test_mm256_popcnt_epi32() {
+        let test_data = _mm256_set_epi32(0, 1, -1, 2, 7, 0xFF_FE, 0x7F_FF_FF_FF, -100);
+        let actual_result = _mm256_popcnt_epi32(test_data);
+        let reference_result = _mm256_set_epi32(0, 1, 32, 1, 3, 15, 31, 28);
+        assert_eq_m256i(actual_result, reference_result);
+    }
+    test_mm256_popcnt_epi32();
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512f,avx512vl")]
+    unsafe fn test_mm_popcnt_epi32() {
+        let test_data = _mm_set_epi32(0, 1, -1, -100);
+        let actual_result = _mm_popcnt_epi32(test_data);
+        let reference_result = _mm_set_epi32(0, 1, 32, 28);
+        assert_eq_m128i(actual_result, reference_result);
+    }
+    test_mm_popcnt_epi32();
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512f")]
+    unsafe fn test_mm512_popcnt_epi64() {
+        let test_data = _mm512_set_epi64(0, 1, -1, 2, 7, 0xFF_FE, 0x7F_FF_FF_FF_FF_FF_FF_FF, -100);
+        let actual_result = _mm512_popcnt_epi64(test_data);
+        let reference_result = _mm512_set_epi64(0, 1, 64, 1, 3, 15, 63, 60);
+        assert_eq_m512i(actual_result, reference_result);
+    }
+    test_mm512_popcnt_epi64();
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512vl")]
+    unsafe fn test_mm256_popcnt_epi64() {
+        let test_data = _mm256_set_epi64x(0, 1, -1, -100);
+        let actual_result = _mm256_popcnt_epi64(test_data);
+        let reference_result = _mm256_set_epi64x(0, 1, 64, 60);
+        assert_eq_m256i(actual_result, reference_result);
+    }
+    test_mm256_popcnt_epi64();
+
+    #[target_feature(enable = "avx512vpopcntdq,avx512vl")]
+    unsafe fn test_mm_popcnt_epi64() {
+        let test_data = _mm_set_epi64x(0, 1);
+        let actual_result = _mm_popcnt_epi64(test_data);
+        let reference_result = _mm_set_epi64x(0, 1);
+        assert_eq_m128i(actual_result, reference_result);
+        let test_data = _mm_set_epi64x(-1, -100);
+        let actual_result = _mm_popcnt_epi64(test_data);
+        let reference_result = _mm_set_epi64x(64, 60);
+        assert_eq_m128i(actual_result, reference_result);
+    }
+    test_mm_popcnt_epi64();
+}
+
+#[track_caller]
+unsafe fn assert_eq_m512i(a: __m512i, b: __m512i) {
+    assert_eq!(transmute::<_, [i32; 16]>(a), transmute::<_, [i32; 16]>(b))
+}
+
+#[track_caller]
+unsafe fn assert_eq_m256i(a: __m256i, b: __m256i) {
+    assert_eq!(transmute::<_, [u64; 4]>(a), transmute::<_, [u64; 4]>(b))
+}
+
+#[track_caller]
+unsafe fn assert_eq_m128i(a: __m128i, b: __m128i) {
+    assert_eq!(transmute::<_, [u64; 2]>(a), transmute::<_, [u64; 2]>(b))
+}