Convert some SSE2 intrinsics to const generics (#1021)

Author: lqd

crates/core_arch/src/macros.rs

@@ -1,5 +1,21 @@
 //! Utility macros.
 
+// Helper struct used to trigger const eval errors when a const generic immediate value is
+// out of range.
+pub(crate) struct ValidateConstImm8<const imm8: i32>();
+impl<const imm8: i32> ValidateConstImm8<imm8> {
+    pub(crate) const VALID: () = {
+        let _ = 1 / ((imm8 >= 0 && imm8 <= 255) as usize);
+    };
+}
+
+#[allow(unused)]
+macro_rules! static_assert_imm8 {
+    ($imm:ident) => {
+        let _ = $crate::core_arch::macros::ValidateConstImm8::<$imm>::VALID;
+    };
+}
+
 #[allow(unused)]
 macro_rules! static_assert {
     ($imm:ident : $ty:ty where $e:expr) => {
@@ -320,48 +336,6 @@ macro_rules! constify_imm5 {
     };
 }
 
-//immediate value: -16:15
-#[allow(unused)]
-macro_rules! constify_imm5 {
-    ($imm8:expr, $expand:ident) => {
-        #[allow(overflowing_literals)]
-        match ($imm8) & 0b1_1111 {
-            0 => $expand!(0),
-            1 => $expand!(1),
-            2 => $expand!(2),
-            3 => $expand!(3),
-            4 => $expand!(4),
-            5 => $expand!(5),
-            6 => $expand!(6),
-            7 => $expand!(7),
-            8 => $expand!(8),
-            9 => $expand!(9),
-            10 => $expand!(10),
-            11 => $expand!(11),
-            12 => $expand!(12),
-            13 => $expand!(13),
-            14 => $expand!(14),
-            15 => $expand!(15),
-            16 => $expand!(16),
-            17 => $expand!(17),
-            18 => $expand!(18),
-            19 => $expand!(19),
-            20 => $expand!(20),
-            21 => $expand!(21),
-            22 => $expand!(22),
-            23 => $expand!(23),
-            24 => $expand!(24),
-            25 => $expand!(25),
-            26 => $expand!(26),
-            27 => $expand!(27),
-            28 => $expand!(28),
-            29 => $expand!(29),
-            30 => $expand!(30),
-            _ => $expand!(31),
-        }
-    };
-}
-
 //immediate value: 0:16
 #[allow(unused)]
 macro_rules! constify_imm4 {

crates/core_arch/src/x86/avx512bw.rs

@@ -5858,7 +5858,7 @@ pub unsafe fn _mm256_maskz_srai_epi16(k: __mmask16, a: __m256i, imm8: u32) -> __
 pub unsafe fn _mm_mask_srai_epi16(src: __m128i, k: __mmask8, a: __m128i, imm8: u32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_srai_epi16(a, $imm8)
+            _mm_srai_epi16::<$imm8>(a)
         };
     }
     let shf = constify_imm8_sae!(imm8, call);
@@ -5875,7 +5875,7 @@ pub unsafe fn _mm_mask_srai_epi16(src: __m128i, k: __mmask8, a: __m128i, imm8: u
 pub unsafe fn _mm_maskz_srai_epi16(k: __mmask8, a: __m128i, imm8: u32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_srai_epi16(a, $imm8)
+            _mm_srai_epi16::<$imm8>(a)
         };
     }
     let shf = constify_imm8_sae!(imm8, call);
@@ -7414,7 +7414,7 @@ pub unsafe fn _mm_mask_shufflelo_epi16(
 ) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shufflelo_epi16(a, $imm8)
+            _mm_shufflelo_epi16::<$imm8>(a)
         };
     }
     let shuffle = constify_imm8_sae!(imm8, call);
@@ -7431,7 +7431,7 @@ pub unsafe fn _mm_mask_shufflelo_epi16(
 pub unsafe fn _mm_maskz_shufflelo_epi16(k: __mmask8, a: __m128i, imm8: i32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shufflelo_epi16(a, $imm8)
+            _mm_shufflelo_epi16::<$imm8>(a)
         };
     }
     let shuffle = constify_imm8_sae!(imm8, call);
@@ -7592,7 +7592,7 @@ pub unsafe fn _mm_mask_shufflehi_epi16(
 ) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shufflehi_epi16(a, $imm8)
+            _mm_shufflehi_epi16::<$imm8>(a)
         };
     }
     let shuffle = constify_imm8_sae!(imm8, call);
@@ -7609,7 +7609,7 @@ pub unsafe fn _mm_mask_shufflehi_epi16(
 pub unsafe fn _mm_maskz_shufflehi_epi16(k: __mmask8, a: __m128i, imm8: i32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shufflehi_epi16(a, $imm8)
+            _mm_shufflehi_epi16::<$imm8>(a)
         };
     }
     let shuffle = constify_imm8_sae!(imm8, call);

crates/core_arch/src/x86/avx512f.rs

@@ -19238,7 +19238,7 @@ pub unsafe fn _mm256_maskz_srai_epi32(k: __mmask8, a: __m256i, imm8: u32) -> __m
 pub unsafe fn _mm_mask_srai_epi32(src: __m128i, k: __mmask8, a: __m128i, imm8: u32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_srai_epi32(a, $imm8)
+            _mm_srai_epi32::<$imm8>(a)
         };
     }
     let shf = constify_imm8_sae!(imm8, call);
@@ -19255,7 +19255,7 @@ pub unsafe fn _mm_mask_srai_epi32(src: __m128i, k: __mmask8, a: __m128i, imm8: u
 pub unsafe fn _mm_maskz_srai_epi32(k: __mmask8, a: __m128i, imm8: u32) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_srai_epi32(a, $imm8)
+            _mm_srai_epi32::<$imm8>(a)
         };
     }
     let shf = constify_imm8_sae!(imm8, call);
@@ -22495,7 +22495,7 @@ pub unsafe fn _mm_mask_shuffle_epi32(
 ) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shuffle_epi32(a, $imm8)
+            _mm_shuffle_epi32::<$imm8>(a)
         };
     }
     let r = constify_imm8_sae!(imm8, call);
@@ -22512,7 +22512,7 @@ pub unsafe fn _mm_mask_shuffle_epi32(
 pub unsafe fn _mm_maskz_shuffle_epi32(k: __mmask8, a: __m128i, imm8: _MM_PERM_ENUM) -> __m128i {
     macro_rules! call {
         ($imm8:expr) => {
-            _mm_shuffle_epi32(a, $imm8)
+            _mm_shuffle_epi32::<$imm8>(a)
         };
     }
     let r = constify_imm8_sae!(imm8, call);

crates/core_arch/src/x86/sse.rs

@@ -1010,7 +1010,7 @@ pub const fn _MM_SHUFFLE(z: u32, y: u32, x: u32, w: u32) -> i32 {
 #[rustc_legacy_const_generics(2)]
 #[stable(feature = "simd_x86", since = "1.27.0")]
 pub unsafe fn _mm_shuffle_ps<const mask: i32>(a: __m128, b: __m128) -> __m128 {
-    static_assert!(mask: i32 where mask >= 0 && mask <= 255);
+    static_assert_imm8!(mask);
     simd_shuffle4(
         a,
         b,