WebAssembly#372 Integer Sign/Zero Extension

Author: omnisip

proposals/simd/BinarySIMD.md

@@ -225,3 +225,9 @@ For example, `ImmLaneIdx16` is a byte with values in the range 0-15 (inclusive).
 | `f32x4.convert_i32x4_u`    |    `0xfb`| -                  |
 | `v128.load32_zero`         |    `0xfc`| -                  |
 | `v128.load64_zero`         |    `0xfd`| -                  |
+| `i32x4.widen_i8x16_u`      |          | -                  |
+| `i32x4.widen_i8x16_s`      |          | -                  |
+| `i64x2.widen_i8x16_u`      |          | -                  |
+| `i64x2.widen_i8x16_s`      |          | -                  |
+| `i64x2.widen_i16x8_u`      |          | -                  |
+| `i64x2.widen_i16x8_s`      |          | -                  |

proposals/simd/ImplementationStatus.md

@@ -193,6 +193,12 @@
 | `f32x4.convert_i32x4_u`    |               `-msimd128` | :heavy_check_mark: |                    |                    | :heavy_check_mark: |
 | `v128.load32_zero`         |                           | :heavy_check_mark: |                    |                    | :heavy_check_mark: |
 | `v128.load64_zero`         |                           | :heavy_check_mark: |                    |                    | :heavy_check_mark: |
+| `i32x4.widen_i8x16_u`      |                           | -                  |                    |                    |                    |
+| `i32x4.widen_i8x16_s`      |                           | -                  |                    |                    |                    |
+| `i64x2.widen_i8x16_u`      |                           | -                  |                    |                    |                    |
+| `i64x2.widen_i8x16_s`      |                           | -                  |                    |                    |                    |
+| `i64x2.widen_i16x8_u`      |                           | -                  |                    |                    |                    |
+| `i64x2.widen_i16x8_s`      |                           | -                  |                    |                    |                    |
 
 [1] Tip of tree LLVM as of May 20, 2020
 

proposals/simd/SIMD.md

@@ -1046,3 +1046,25 @@ def S.widen_low_T_u(a):
 def S.widen_high_T_u(a):
     return S.widen_high_T(Zext, a)
 ```
+### Integer to integer Widening (Constant Immediate)
+* `i32x4.widen_i8x16_u(v128: a, ImmLaneIdx4: c) -> v128`
+* `i32x4.widen_i8x16_s(v128: a, ImmLaneIdx4: c) -> v128`
+* `i64x2.widen_i8x16_u(v128: a, ImmLaneIdx8: c) -> v128`
+* `i64x2.widen_i8x16_s(v128: a, ImmLaneIdx8: c) -> v128`
+* `i64x2.widen_i16x8_u(v128: a, ImmLaneIdx4: c) -> v128`
+* `i64x2.widen_i16x8_s(v128: a, ImmLaneIdx4: c) -> v128`
+
+Using the constant immediate, widens selected integers with zero or sign extension.
+```python
+def S.widen_T_u(a,c):
+    result = S.New()
+    for i in range(S.Lanes):
+            result[i] = Zext(a[S.Lanes + i + c])
+    return result
+
+def S.widen_T_s(a,c):
+    result = S.New()
+    for i in range(S.Lanes):
+            result[i] = Sext(a[S.Lanes + i + c])
+    return result
+```