diff --git a/crates/core_arch/src/x86/avx2.rs b/crates/core_arch/src/x86/avx2.rs
index 21f20f9c75..2e83400633 100644
--- a/crates/core_arch/src/x86/avx2.rs
+++ b/crates/core_arch/src/x86/avx2.rs
@@ -2961,140 +2961,54 @@ pub fn _mm256_srli_si256<const IMM8: i32>(a: __m256i) -> __m256i {
 #[stable(feature = "simd_x86", since = "1.27.0")]
 pub fn _mm256_bsrli_epi128<const IMM8: i32>(a: __m256i) -> __m256i {
     static_assert_uimm_bits!(IMM8, 8);
+    const fn mask(shift: i32, i: u32) -> u32 {
+        let shift = shift as u32 & 0xff;
+        if shift > 15 || (15 - (i % 16)) < shift {
+            0
+        } else {
+            32 + (i + shift)
+        }
+    }
     unsafe {
         let a = a.as_i8x32();
-        let zero = i8x32::ZERO;
-        let r: i8x32 = match IMM8 % 16 {
-            0 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
-                    22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
-                ],
-            ),
-            1 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 17, 18, 19, 20, 21, 22,
-                    23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
-                ],
-            ),
-            2 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 18, 19, 20, 21, 22, 23,
-                    24, 25, 26, 27, 28, 29, 30, 31, 32, 32,
-                ],
-            ),
-            3 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 19, 20, 21, 22, 23,
-                    24, 25, 26, 27, 28, 29, 30, 31, 32, 32, 32,
-                ],
-            ),
-            4 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 20, 21, 22, 23, 24,
-                    25, 26, 27, 28, 29, 30, 31, 32, 32, 32, 32,
-                ],
-            ),
-            5 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 21, 22, 23, 24, 25,
-                    26, 27, 28, 29, 30, 31, 32, 32, 32, 32, 32,
-                ],
-            ),
-            6 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 22, 23, 24, 25, 26,
-                    27, 28, 29, 30, 31, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            7 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 23, 24, 25, 26,
-                    27, 28, 29, 30, 31, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            8 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    8, 9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 24, 25, 26, 27,
-                    28, 29, 30, 31, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            9 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    9, 10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 25, 26, 27, 28,
-                    29, 30, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            10 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    10, 11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 26, 27, 28, 29,
-                    30, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            11 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    11, 12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 27, 28, 29, 30,
-                    31, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            12 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    12, 13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 28, 29, 30, 31,
-                    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            13 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    13, 14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 29, 30, 31, 32,
-                    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            14 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    14, 15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 30, 31, 32, 32,
-                    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            15 => simd_shuffle!(
-                a,
-                zero,
-                [
-                    15, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 31, 32, 32, 32,
-                    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-                ],
-            ),
-            _ => zero,
-        };
+        let r: i8x32 = simd_shuffle!(
+            i8x32::ZERO,
+            a,
+            [
+                mask(IMM8, 0),
+                mask(IMM8, 1),
+                mask(IMM8, 2),
+                mask(IMM8, 3),
+                mask(IMM8, 4),
+                mask(IMM8, 5),
+                mask(IMM8, 6),
+                mask(IMM8, 7),
+                mask(IMM8, 8),
+                mask(IMM8, 9),
+                mask(IMM8, 10),
+                mask(IMM8, 11),
+                mask(IMM8, 12),
+                mask(IMM8, 13),
+                mask(IMM8, 14),
+                mask(IMM8, 15),
+                mask(IMM8, 16),
+                mask(IMM8, 17),
+                mask(IMM8, 18),
+                mask(IMM8, 19),
+                mask(IMM8, 20),
+                mask(IMM8, 21),
+                mask(IMM8, 22),
+                mask(IMM8, 23),
+                mask(IMM8, 24),
+                mask(IMM8, 25),
+                mask(IMM8, 26),
+                mask(IMM8, 27),
+                mask(IMM8, 28),
+                mask(IMM8, 29),
+                mask(IMM8, 30),
+                mask(IMM8, 31),
+            ],
+        );
         transmute(r)
     }
 }
diff --git a/crates/core_arch/src/x86/avx512bw.rs b/crates/core_arch/src/x86/avx512bw.rs
index b60b0b7079..ba3c28cd5f 100644
--- a/crates/core_arch/src/x86/avx512bw.rs
+++ b/crates/core_arch/src/x86/avx512bw.rs
@@ -11208,203 +11208,86 @@ pub fn _mm512_bslli_epi128<const IMM8: i32>(a: __m512i) -> __m512i {
 pub fn _mm512_bsrli_epi128<const IMM8: i32>(a: __m512i) -> __m512i {
     unsafe {
         static_assert_uimm_bits!(IMM8, 8);
+        const fn mask(shift: i32, i: u32) -> u32 {
+            let shift = shift as u32 & 0xff;
+            if shift > 15 || (15 - (i % 16)) < shift {
+                0
+            } else {
+                64 + (i + shift)
+            }
+        }
         let a = a.as_i8x64();
         let zero = i8x64::ZERO;
-        let r: i8x64 = match IMM8 % 16 {
-            0 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
-                        21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
-                        40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
-                        59, 60, 61, 62, 63,
-                    ],
-                )
-            }
-            1 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 17, 18, 19, 20, 21,
-                        22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 80, 33, 34, 35, 36, 37, 38, 39, 40,
-                        41, 42, 43, 44, 45, 46, 47, 96, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
-                        60, 61, 62, 63, 112,
-                    ],
-                )
-            }
-            2 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 18, 19, 20, 21, 22,
-                        23, 24, 25, 26, 27, 28, 29, 30, 31, 80, 81, 34, 35, 36, 37, 38, 39, 40, 41,
-                        42, 43, 44, 45, 46, 47, 96, 97, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
-                        61, 62, 63, 112, 113,
-                    ],
-                )
-            }
-            3 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 19, 20, 21, 22,
-                        23, 24, 25, 26, 27, 28, 29, 30, 31, 80, 81, 82, 35, 36, 37, 38, 39, 40, 41,
-                        42, 43, 44, 45, 46, 47, 96, 97, 98, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
-                        61, 62, 63, 112, 113, 114,
-                    ],
-                )
-            }
-            4 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 20, 21, 22, 23,
-                        24, 25, 26, 27, 28, 29, 30, 31, 80, 81, 82, 83, 36, 37, 38, 39, 40, 41, 42,
-                        43, 44, 45, 46, 47, 96, 97, 98, 99, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
-                        62, 63, 112, 113, 114, 115,
-                    ],
-                )
-            }
-            5 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 21, 22, 23, 24,
-                        25, 26, 27, 28, 29, 30, 31, 80, 81, 82, 83, 84, 37, 38, 39, 40, 41, 42, 43,
-                        44, 45, 46, 47, 96, 97, 98, 99, 100, 53, 54, 55, 56, 57, 58, 59, 60, 61,
-                        62, 63, 112, 113, 114, 115, 116,
-                    ],
-                )
-            }
-            6 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 22, 23, 24, 25,
-                        26, 27, 28, 29, 30, 31, 80, 81, 82, 83, 84, 85, 38, 39, 40, 41, 42, 43, 44,
-                        45, 46, 47, 96, 97, 98, 99, 100, 101, 54, 55, 56, 57, 58, 59, 60, 61, 62,
-                        63, 112, 113, 114, 115, 116, 117,
-                    ],
-                )
-            }
-            7 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        7, 8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 23, 24, 25,
-                        26, 27, 28, 29, 30, 31, 80, 81, 82, 83, 84, 85, 86, 39, 40, 41, 42, 43, 44,
-                        45, 46, 47, 96, 97, 98, 99, 100, 101, 102, 55, 56, 57, 58, 59, 60, 61, 62,
-                        63, 112, 113, 114, 115, 116, 117, 118,
-                    ],
-                )
-            }
-            8 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        8, 9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 24, 25, 26,
-                        27, 28, 29, 30, 31, 80, 81, 82, 83, 84, 85, 86, 87, 40, 41, 42, 43, 44, 45,
-                        46, 47, 96, 97, 98, 99, 100, 101, 102, 103, 56, 57, 58, 59, 60, 61, 62, 63,
-                        112, 113, 114, 115, 116, 117, 118, 119,
-                    ],
-                )
-            }
-            9 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        9, 10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 25, 26, 27,
-                        28, 29, 30, 31, 80, 81, 82, 83, 84, 85, 86, 87, 88, 41, 42, 43, 44, 45, 46,
-                        47, 96, 97, 98, 99, 100, 101, 102, 103, 104, 57, 58, 59, 60, 61, 62, 63,
-                        112, 113, 114, 115, 116, 117, 118, 119, 120,
-                    ],
-                )
-            }
-            10 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        10, 11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 26, 27, 28,
-                        29, 30, 31, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 42, 43, 44, 45, 46, 47,
-                        96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 58, 59, 60, 61, 62, 63, 112,
-                        113, 114, 115, 116, 117, 118, 119, 120, 121,
-                    ],
-                )
-            }
-            11 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        11, 12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 27, 28, 29,
-                        30, 31, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 43, 44, 45, 46, 47, 96,
-                        97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 59, 60, 61, 62, 63, 112,
-                        113, 114, 115, 116, 117, 118, 119, 120, 121, 122,
-                    ],
-                )
-            }
-            12 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        12, 13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 28, 29, 30,
-                        31, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 44, 45, 46, 47, 96, 97,
-                        98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 60, 61, 62, 63, 112, 113,
-                        114, 115, 116, 117, 118, 119, 120, 121, 122, 123,
-                    ],
-                )
-            }
-            13 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        13, 14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 29, 30, 31,
-                        80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 45, 46, 47, 96, 97, 98,
-                        99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 61, 62, 63, 112, 113, 114,
-                        115, 116, 117, 118, 119, 120, 121, 122, 123, 124,
-                    ],
-                )
-            }
-            14 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        14, 15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 30, 31, 80,
-                        81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 46, 47, 96, 97, 98, 99,
-                        100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 62, 63, 112, 113, 114,
-                        115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125,
-                    ],
-                )
-            }
-            15 => {
-                simd_shuffle!(
-                    a,
-                    zero,
-                    [
-                        15, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 31, 80, 81,
-                        82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 47, 96, 97, 98, 99,
-                        100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 63, 112, 113, 114,
-                        115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
-                    ],
-                )
-            }
-            _ => zero,
-        };
+        let r: i8x64 = simd_shuffle!(
+            zero,
+            a,
+            [
+                mask(IMM8, 0),
+                mask(IMM8, 1),
+                mask(IMM8, 2),
+                mask(IMM8, 3),
+                mask(IMM8, 4),
+                mask(IMM8, 5),
+                mask(IMM8, 6),
+                mask(IMM8, 7),
+                mask(IMM8, 8),
+                mask(IMM8, 9),
+                mask(IMM8, 10),
+                mask(IMM8, 11),
+                mask(IMM8, 12),
+                mask(IMM8, 13),
+                mask(IMM8, 14),
+                mask(IMM8, 15),
+                mask(IMM8, 16),
+                mask(IMM8, 17),
+                mask(IMM8, 18),
+                mask(IMM8, 19),
+                mask(IMM8, 20),
+                mask(IMM8, 21),
+                mask(IMM8, 22),
+                mask(IMM8, 23),
+                mask(IMM8, 24),
+                mask(IMM8, 25),
+                mask(IMM8, 26),
+                mask(IMM8, 27),
+                mask(IMM8, 28),
+                mask(IMM8, 29),
+                mask(IMM8, 30),
+                mask(IMM8, 31),
+                mask(IMM8, 32),
+                mask(IMM8, 33),
+                mask(IMM8, 34),
+                mask(IMM8, 35),
+                mask(IMM8, 36),
+                mask(IMM8, 37),
+                mask(IMM8, 38),
+                mask(IMM8, 39),
+                mask(IMM8, 40),
+                mask(IMM8, 41),
+                mask(IMM8, 42),
+                mask(IMM8, 43),
+                mask(IMM8, 44),
+                mask(IMM8, 45),
+                mask(IMM8, 46),
+                mask(IMM8, 47),
+                mask(IMM8, 48),
+                mask(IMM8, 49),
+                mask(IMM8, 50),
+                mask(IMM8, 51),
+                mask(IMM8, 52),
+                mask(IMM8, 53),
+                mask(IMM8, 54),
+                mask(IMM8, 55),
+                mask(IMM8, 56),
+                mask(IMM8, 57),
+                mask(IMM8, 58),
+                mask(IMM8, 59),
+                mask(IMM8, 60),
+                mask(IMM8, 61),
+                mask(IMM8, 62),
+                mask(IMM8, 63),
+            ],
+        );
         transmute(r)
     }
 }