v128.const text (#65)

Author: tlively

proposals/simd/TextSIMD.md

@@ -0,0 +1,21 @@
+# Text format for SIMD
+
+### v128.const
+
+The `v128.const` instruction has multiple valid text formats corresponding to
+different lane interpretations. The valid text formats are
+
+```
+v128.const i8x16 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8 i8
+v128.const i16x8 i16 i16 i16 i16 i16 i16 i16 i16
+v128.const i32x4 i32 i32 i32 i32
+v128.const i64x2 i64 i64
+v128.const f32x4 f32 f32 f32 f32
+v128.const f64x2 f64 f64
+```
+
+The canonical text format used for printing `v128.const` instructions is
+
+```
+v128.const i32x4 0xNNNNNNNN 0xNNNNNNNN 0xNNNNNNNN 0xNNNNNNNN
+```