From 9c2ba72bc3be2dbb7ac2ff5751f4b37b70c3fbd0 Mon Sep 17 00:00:00 2001
From: Yury Delendik <ydelendik@mozilla.com>
Date: Wed, 14 Jun 2023 16:40:51 -0500
Subject: [PATCH] feat: extend 0xfd prefix codespace; add relaxed_simd ops.

---
 src/WasmParser.ts                             | 539 ++++++++++--------
 test/__fixtures__/relaxed_simd.wasm           | Bin 0 -> 614 bytes
 .../parse-and-disassemble.test.ts.snap        | 111 ++++
 test/wabt-compatibility.test.ts               |   1 +
 4 files changed, 413 insertions(+), 238 deletions(-)
 create mode 100644 test/__fixtures__/relaxed_simd.wasm

diff --git a/src/WasmParser.ts b/src/WasmParser.ts
index 83c432c..ce22b70 100644
--- a/src/WasmParser.ts
+++ b/src/WasmParser.ts
@@ -332,242 +332,264 @@ export const enum OperatorCode {
   i64_atomic_rmw16_cmpxchg_u = 0xfe4d,
   i64_atomic_rmw32_cmpxchg_u = 0xfe4e,
 
-  v128_load = 0xfd00,
-  i16x8_load8x8_s = 0xfd01,
-  i16x8_load8x8_u = 0xfd02,
-  i32x4_load16x4_s = 0xfd03,
-  i32x4_load16x4_u = 0xfd04,
-  i64x2_load32x2_s = 0xfd05,
-  i64x2_load32x2_u = 0xfd06,
-  v8x16_load_splat = 0xfd07,
-  v16x8_load_splat = 0xfd08,
-  v32x4_load_splat = 0xfd09,
-  v64x2_load_splat = 0xfd0a,
-  v128_store = 0xfd0b,
-  v128_const = 0xfd0c,
-  i8x16_shuffle = 0xfd0d,
-  i8x16_swizzle = 0xfd0e,
-  i8x16_splat = 0xfd0f,
-  i16x8_splat = 0xfd10,
-  i32x4_splat = 0xfd11,
-  i64x2_splat = 0xfd12,
-  f32x4_splat = 0xfd13,
-  f64x2_splat = 0xfd14,
-  i8x16_extract_lane_s = 0xfd15,
-  i8x16_extract_lane_u = 0xfd16,
-  i8x16_replace_lane = 0xfd17,
-  i16x8_extract_lane_s = 0xfd18,
-  i16x8_extract_lane_u = 0xfd19,
-  i16x8_replace_lane = 0xfd1a,
-  i32x4_extract_lane = 0xfd1b,
-  i32x4_replace_lane = 0xfd1c,
-  i64x2_extract_lane = 0xfd1d,
-  i64x2_replace_lane = 0xfd1e,
-  f32x4_extract_lane = 0xfd1f,
-  f32x4_replace_lane = 0xfd20,
-  f64x2_extract_lane = 0xfd21,
-  f64x2_replace_lane = 0xfd22,
-  i8x16_eq = 0xfd23,
-  i8x16_ne = 0xfd24,
-  i8x16_lt_s = 0xfd25,
-  i8x16_lt_u = 0xfd26,
-  i8x16_gt_s = 0xfd27,
-  i8x16_gt_u = 0xfd28,
-  i8x16_le_s = 0xfd29,
-  i8x16_le_u = 0xfd2a,
-  i8x16_ge_s = 0xfd2b,
-  i8x16_ge_u = 0xfd2c,
-  i16x8_eq = 0xfd2d,
-  i16x8_ne = 0xfd2e,
-  i16x8_lt_s = 0xfd2f,
-  i16x8_lt_u = 0xfd30,
-  i16x8_gt_s = 0xfd31,
-  i16x8_gt_u = 0xfd32,
-  i16x8_le_s = 0xfd33,
-  i16x8_le_u = 0xfd34,
-  i16x8_ge_s = 0xfd35,
-  i16x8_ge_u = 0xfd36,
-  i32x4_eq = 0xfd37,
-  i32x4_ne = 0xfd38,
-  i32x4_lt_s = 0xfd39,
-  i32x4_lt_u = 0xfd3a,
-  i32x4_gt_s = 0xfd3b,
-  i32x4_gt_u = 0xfd3c,
-  i32x4_le_s = 0xfd3d,
-  i32x4_le_u = 0xfd3e,
-  i32x4_ge_s = 0xfd3f,
-  i32x4_ge_u = 0xfd40,
-  f32x4_eq = 0xfd41,
-  f32x4_ne = 0xfd42,
-  f32x4_lt = 0xfd43,
-  f32x4_gt = 0xfd44,
-  f32x4_le = 0xfd45,
-  f32x4_ge = 0xfd46,
-  f64x2_eq = 0xfd47,
-  f64x2_ne = 0xfd48,
-  f64x2_lt = 0xfd49,
-  f64x2_gt = 0xfd4a,
-  f64x2_le = 0xfd4b,
-  f64x2_ge = 0xfd4c,
-  v128_not = 0xfd4d,
-  v128_and = 0xfd4e,
-  v128_andnot = 0xfd4f,
-  v128_or = 0xfd50,
-  v128_xor = 0xfd51,
-  v128_bitselect = 0xfd52,
-  v128_any_true = 0xfd53,
-  v128_load8_lane = 0xfd54,
-  v128_load16_lane = 0xfd55,
-  v128_load32_lane = 0xfd56,
-  v128_load64_lane = 0xfd57,
-  v128_store8_lane = 0xfd58,
-  v128_store16_lane = 0xfd59,
-  v128_store32_lane = 0xfd5a,
-  v128_store64_lane = 0xfd5b,
-  v128_load32_zero = 0xfd5c,
-  v128_load64_zero = 0xfd5d,
-  f32x4_demote_f64x2_zero = 0xfd5e,
-  f64x2_promote_low_f32x4 = 0xfd5f,
-  i8x16_abs = 0xfd60,
-  i8x16_neg = 0xfd61,
-  i8x16_popcnt = 0xfd62,
-  i8x16_all_true = 0xfd63,
-  i8x16_bitmask = 0xfd64,
-  i8x16_narrow_i16x8_s = 0xfd65,
-  i8x16_narrow_i16x8_u = 0xfd66,
-  f32x4_ceil = 0xfd67,
-  f32x4_floor = 0xfd68,
-  f32x4_trunc = 0xfd69,
-  f32x4_nearest = 0xfd6a,
-  i8x16_shl = 0xfd6b,
-  i8x16_shr_s = 0xfd6c,
-  i8x16_shr_u = 0xfd6d,
-  i8x16_add = 0xfd6e,
-  i8x16_add_sat_s = 0xfd6f,
-  i8x16_add_sat_u = 0xfd70,
-  i8x16_sub = 0xfd71,
-  i8x16_sub_sat_s = 0xfd72,
-  i8x16_sub_sat_u = 0xfd73,
-  f64x2_ceil = 0xfd74,
-  f64x2_floor = 0xfd75,
-  i8x16_min_s = 0xfd76,
-  i8x16_min_u = 0xfd77,
-  i8x16_max_s = 0xfd78,
-  i8x16_max_u = 0xfd79,
-  f64x2_trunc = 0xfd7a,
-  i8x16_avgr_u = 0xfd7b,
-  i16x8_extadd_pairwise_i8x16_s = 0xfd7c,
-  i16x8_extadd_pairwise_i8x16_u = 0xfd7d,
-  i32x4_extadd_pairwise_i16x8_s = 0xfd7e,
-  i32x4_extadd_pairwise_i16x8_u = 0xfd7f,
-  i16x8_abs = 0xfd80,
-  i16x8_neg = 0xfd81,
-  i16x8_q15mulr_sat_s = 0xfd82,
-  i16x8_all_true = 0xfd83,
-  i16x8_bitmask = 0xfd84,
-  i16x8_narrow_i32x4_s = 0xfd85,
-  i16x8_narrow_i32x4_u = 0xfd86,
-  i16x8_extend_low_i8x16_s = 0xfd87,
-  i16x8_extend_high_i8x16_s = 0xfd88,
-  i16x8_extend_low_i8x16_u = 0xfd89,
-  i16x8_extend_high_i8x16_u = 0xfd8a,
-  i16x8_shl = 0xfd8b,
-  i16x8_shr_s = 0xfd8c,
-  i16x8_shr_u = 0xfd8d,
-  i16x8_add = 0xfd8e,
-  i16x8_add_sat_s = 0xfd8f,
-  i16x8_add_sat_u = 0xfd90,
-  i16x8_sub = 0xfd91,
-  i16x8_sub_sat_s = 0xfd92,
-  i16x8_sub_sat_u = 0xfd93,
-  f64x2_nearest = 0xfd94,
-  i16x8_mul = 0xfd95,
-  i16x8_min_s = 0xfd96,
-  i16x8_min_u = 0xfd97,
-  i16x8_max_s = 0xfd98,
-  i16x8_max_u = 0xfd99,
-  i16x8_avgr_u = 0xfd9b,
-  i16x8_extmul_low_i8x16_s = 0xfd9c,
-  i16x8_extmul_high_i8x16_s = 0xfd9d,
-  i16x8_extmul_low_i8x16_u = 0xfd9e,
-  i16x8_extmul_high_i8x16_u = 0xfd9f,
-  i32x4_abs = 0xfda0,
-  i32x4_neg = 0xfda1,
-  i32x4_all_true = 0xfda3,
-  i32x4_bitmask = 0xfda4,
-  i32x4_extend_low_i16x8_s = 0xfda7,
-  i32x4_extend_high_i16x8_s = 0xfda8,
-  i32x4_extend_low_i16x8_u = 0xfda9,
-  i32x4_extend_high_i16x8_u = 0xfdaa,
-  i32x4_shl = 0xfdab,
-  i32x4_shr_s = 0xfdac,
-  i32x4_shr_u = 0xfdad,
-  i32x4_add = 0xfdae,
-  i32x4_sub = 0xfdb1,
-  i32x4_mul = 0xfdb5,
-  i32x4_min_s = 0xfdb6,
-  i32x4_min_u = 0xfdb7,
-  i32x4_max_s = 0xfdb8,
-  i32x4_max_u = 0xfdb9,
-  i32x4_dot_i16x8_s = 0xfdba,
-  i32x4_extmul_low_i16x8_s = 0xfdbc,
-  i32x4_extmul_high_i16x8_s = 0xfdbd,
-  i32x4_extmul_low_i16x8_u = 0xfdbe,
-  i32x4_extmul_high_i16x8_u = 0xfdbf,
-  i64x2_abs = 0xfdc0,
-  i64x2_neg = 0xfdc1,
-  i64x2_all_true = 0xfdc3,
-  i64x2_bitmask = 0xfdc4,
-  i64x2_extend_low_i32x4_s = 0xfdc7,
-  i64x2_extend_high_i32x4_s = 0xfdc8,
-  i64x2_extend_low_i32x4_u = 0xfdc9,
-  i64x2_extend_high_i32x4_u = 0xfdca,
-  i64x2_shl = 0xfdcb,
-  i64x2_shr_s = 0xfdcc,
-  i64x2_shr_u = 0xfdcd,
-  i64x2_add = 0xfdce,
-  i64x2_sub = 0xfdd1,
-  i64x2_mul = 0xfdd5,
-  i64x2_eq = 0xfdd6,
-  i64x2_ne = 0xfdd7,
-  i64x2_lt_s = 0xfdd8,
-  i64x2_gt_s = 0xfdd9,
-  i64x2_le_s = 0xfdda,
-  i64x2_ge_s = 0xfddb,
-  i64x2_extmul_low_i32x4_s = 0xfddc,
-  i64x2_extmul_high_i32x4_s = 0xfddd,
-  i64x2_extmul_low_i32x4_u = 0xfdde,
-  i64x2_extmul_high_i32x4_u = 0xfddf,
-  f32x4_abs = 0xfde0,
-  f32x4_neg = 0xfde1,
-  f32x4_sqrt = 0xfde3,
-  f32x4_add = 0xfde4,
-  f32x4_sub = 0xfde5,
-  f32x4_mul = 0xfde6,
-  f32x4_div = 0xfde7,
-  f32x4_min = 0xfde8,
-  f32x4_max = 0xfde9,
-  f32x4_pmin = 0xfdea,
-  f32x4_pmax = 0xfdeb,
-  f64x2_abs = 0xfdec,
-  f64x2_neg = 0xfded,
-  f64x2_sqrt = 0xfdef,
-  f64x2_add = 0xfdf0,
-  f64x2_sub = 0xfdf1,
-  f64x2_mul = 0xfdf2,
-  f64x2_div = 0xfdf3,
-  f64x2_min = 0xfdf4,
-  f64x2_max = 0xfdf5,
-  f64x2_pmin = 0xfdf6,
-  f64x2_pmax = 0xfdf7,
-  i32x4_trunc_sat_f32x4_s = 0xfdf8,
-  i32x4_trunc_sat_f32x4_u = 0xfdf9,
-  f32x4_convert_i32x4_s = 0xfdfa,
-  f32x4_convert_i32x4_u = 0xfdfb,
-  i32x4_trunc_sat_f64x2_s_zero = 0xfdfc,
-  i32x4_trunc_sat_f64x2_u_zero = 0xfdfd,
-  f64x2_convert_low_i32x4_s = 0xfdfe,
-  f64x2_convert_low_i32x4_u = 0xfdff,
+  v128_load = 0xfd000,
+  i16x8_load8x8_s = 0xfd001,
+  i16x8_load8x8_u = 0xfd002,
+  i32x4_load16x4_s = 0xfd003,
+  i32x4_load16x4_u = 0xfd004,
+  i64x2_load32x2_s = 0xfd005,
+  i64x2_load32x2_u = 0xfd006,
+  v8x16_load_splat = 0xfd007,
+  v16x8_load_splat = 0xfd008,
+  v32x4_load_splat = 0xfd009,
+  v64x2_load_splat = 0xfd00a,
+  v128_store = 0xfd00b,
+  v128_const = 0xfd00c,
+  i8x16_shuffle = 0xfd00d,
+  i8x16_swizzle = 0xfd00e,
+  i8x16_splat = 0xfd00f,
+  i16x8_splat = 0xfd010,
+  i32x4_splat = 0xfd011,
+  i64x2_splat = 0xfd012,
+  f32x4_splat = 0xfd013,
+  f64x2_splat = 0xfd014,
+  i8x16_extract_lane_s = 0xfd015,
+  i8x16_extract_lane_u = 0xfd016,
+  i8x16_replace_lane = 0xfd017,
+  i16x8_extract_lane_s = 0xfd018,
+  i16x8_extract_lane_u = 0xfd019,
+  i16x8_replace_lane = 0xfd01a,
+  i32x4_extract_lane = 0xfd01b,
+  i32x4_replace_lane = 0xfd01c,
+  i64x2_extract_lane = 0xfd01d,
+  i64x2_replace_lane = 0xfd01e,
+  f32x4_extract_lane = 0xfd01f,
+  f32x4_replace_lane = 0xfd020,
+  f64x2_extract_lane = 0xfd021,
+  f64x2_replace_lane = 0xfd022,
+  i8x16_eq = 0xfd023,
+  i8x16_ne = 0xfd024,
+  i8x16_lt_s = 0xfd025,
+  i8x16_lt_u = 0xfd026,
+  i8x16_gt_s = 0xfd027,
+  i8x16_gt_u = 0xfd028,
+  i8x16_le_s = 0xfd029,
+  i8x16_le_u = 0xfd02a,
+  i8x16_ge_s = 0xfd02b,
+  i8x16_ge_u = 0xfd02c,
+  i16x8_eq = 0xfd02d,
+  i16x8_ne = 0xfd02e,
+  i16x8_lt_s = 0xfd02f,
+  i16x8_lt_u = 0xfd030,
+  i16x8_gt_s = 0xfd031,
+  i16x8_gt_u = 0xfd032,
+  i16x8_le_s = 0xfd033,
+  i16x8_le_u = 0xfd034,
+  i16x8_ge_s = 0xfd035,
+  i16x8_ge_u = 0xfd036,
+  i32x4_eq = 0xfd037,
+  i32x4_ne = 0xfd038,
+  i32x4_lt_s = 0xfd039,
+  i32x4_lt_u = 0xfd03a,
+  i32x4_gt_s = 0xfd03b,
+  i32x4_gt_u = 0xfd03c,
+  i32x4_le_s = 0xfd03d,
+  i32x4_le_u = 0xfd03e,
+  i32x4_ge_s = 0xfd03f,
+  i32x4_ge_u = 0xfd040,
+  f32x4_eq = 0xfd041,
+  f32x4_ne = 0xfd042,
+  f32x4_lt = 0xfd043,
+  f32x4_gt = 0xfd044,
+  f32x4_le = 0xfd045,
+  f32x4_ge = 0xfd046,
+  f64x2_eq = 0xfd047,
+  f64x2_ne = 0xfd048,
+  f64x2_lt = 0xfd049,
+  f64x2_gt = 0xfd04a,
+  f64x2_le = 0xfd04b,
+  f64x2_ge = 0xfd04c,
+  v128_not = 0xfd04d,
+  v128_and = 0xfd04e,
+  v128_andnot = 0xfd04f,
+  v128_or = 0xfd050,
+  v128_xor = 0xfd051,
+  v128_bitselect = 0xfd052,
+  v128_any_true = 0xfd053,
+  v128_load8_lane = 0xfd054,
+  v128_load16_lane = 0xfd055,
+  v128_load32_lane = 0xfd056,
+  v128_load64_lane = 0xfd057,
+  v128_store8_lane = 0xfd058,
+  v128_store16_lane = 0xfd059,
+  v128_store32_lane = 0xfd05a,
+  v128_store64_lane = 0xfd05b,
+  v128_load32_zero = 0xfd05c,
+  v128_load64_zero = 0xfd05d,
+  f32x4_demote_f64x2_zero = 0xfd05e,
+  f64x2_promote_low_f32x4 = 0xfd05f,
+  i8x16_abs = 0xfd060,
+  i8x16_neg = 0xfd061,
+  i8x16_popcnt = 0xfd062,
+  i8x16_all_true = 0xfd063,
+  i8x16_bitmask = 0xfd064,
+  i8x16_narrow_i16x8_s = 0xfd065,
+  i8x16_narrow_i16x8_u = 0xfd066,
+  f32x4_ceil = 0xfd067,
+  f32x4_floor = 0xfd068,
+  f32x4_trunc = 0xfd069,
+  f32x4_nearest = 0xfd06a,
+  i8x16_shl = 0xfd06b,
+  i8x16_shr_s = 0xfd06c,
+  i8x16_shr_u = 0xfd06d,
+  i8x16_add = 0xfd06e,
+  i8x16_add_sat_s = 0xfd06f,
+  i8x16_add_sat_u = 0xfd070,
+  i8x16_sub = 0xfd071,
+  i8x16_sub_sat_s = 0xfd072,
+  i8x16_sub_sat_u = 0xfd073,
+  f64x2_ceil = 0xfd074,
+  f64x2_floor = 0xfd075,
+  i8x16_min_s = 0xfd076,
+  i8x16_min_u = 0xfd077,
+  i8x16_max_s = 0xfd078,
+  i8x16_max_u = 0xfd079,
+  f64x2_trunc = 0xfd07a,
+  i8x16_avgr_u = 0xfd07b,
+  i16x8_extadd_pairwise_i8x16_s = 0xfd07c,
+  i16x8_extadd_pairwise_i8x16_u = 0xfd07d,
+  i32x4_extadd_pairwise_i16x8_s = 0xfd07e,
+  i32x4_extadd_pairwise_i16x8_u = 0xfd07f,
+  i16x8_abs = 0xfd080,
+  i16x8_neg = 0xfd081,
+  i16x8_q15mulr_sat_s = 0xfd082,
+  i16x8_all_true = 0xfd083,
+  i16x8_bitmask = 0xfd084,
+  i16x8_narrow_i32x4_s = 0xfd085,
+  i16x8_narrow_i32x4_u = 0xfd086,
+  i16x8_extend_low_i8x16_s = 0xfd087,
+  i16x8_extend_high_i8x16_s = 0xfd088,
+  i16x8_extend_low_i8x16_u = 0xfd089,
+  i16x8_extend_high_i8x16_u = 0xfd08a,
+  i16x8_shl = 0xfd08b,
+  i16x8_shr_s = 0xfd08c,
+  i16x8_shr_u = 0xfd08d,
+  i16x8_add = 0xfd08e,
+  i16x8_add_sat_s = 0xfd08f,
+  i16x8_add_sat_u = 0xfd090,
+  i16x8_sub = 0xfd091,
+  i16x8_sub_sat_s = 0xfd092,
+  i16x8_sub_sat_u = 0xfd093,
+  f64x2_nearest = 0xfd094,
+  i16x8_mul = 0xfd095,
+  i16x8_min_s = 0xfd096,
+  i16x8_min_u = 0xfd097,
+  i16x8_max_s = 0xfd098,
+  i16x8_max_u = 0xfd099,
+  i16x8_avgr_u = 0xfd09b,
+  i16x8_extmul_low_i8x16_s = 0xfd09c,
+  i16x8_extmul_high_i8x16_s = 0xfd09d,
+  i16x8_extmul_low_i8x16_u = 0xfd09e,
+  i16x8_extmul_high_i8x16_u = 0xfd09f,
+  i32x4_abs = 0xfd0a0,
+  i32x4_neg = 0xfd0a1,
+  i32x4_all_true = 0xfd0a3,
+  i32x4_bitmask = 0xfd0a4,
+  i32x4_extend_low_i16x8_s = 0xfd0a7,
+  i32x4_extend_high_i16x8_s = 0xfd0a8,
+  i32x4_extend_low_i16x8_u = 0xfd0a9,
+  i32x4_extend_high_i16x8_u = 0xfd0aa,
+  i32x4_shl = 0xfd0ab,
+  i32x4_shr_s = 0xfd0ac,
+  i32x4_shr_u = 0xfd0ad,
+  i32x4_add = 0xfd0ae,
+  i32x4_sub = 0xfd0b1,
+  i32x4_mul = 0xfd0b5,
+  i32x4_min_s = 0xfd0b6,
+  i32x4_min_u = 0xfd0b7,
+  i32x4_max_s = 0xfd0b8,
+  i32x4_max_u = 0xfd0b9,
+  i32x4_dot_i16x8_s = 0xfd0ba,
+  i32x4_extmul_low_i16x8_s = 0xfd0bc,
+  i32x4_extmul_high_i16x8_s = 0xfd0bd,
+  i32x4_extmul_low_i16x8_u = 0xfd0be,
+  i32x4_extmul_high_i16x8_u = 0xfd0bf,
+  i64x2_abs = 0xfd0c0,
+  i64x2_neg = 0xfd0c1,
+  i64x2_all_true = 0xfd0c3,
+  i64x2_bitmask = 0xfd0c4,
+  i64x2_extend_low_i32x4_s = 0xfd0c7,
+  i64x2_extend_high_i32x4_s = 0xfd0c8,
+  i64x2_extend_low_i32x4_u = 0xfd0c9,
+  i64x2_extend_high_i32x4_u = 0xfd0ca,
+  i64x2_shl = 0xfd0cb,
+  i64x2_shr_s = 0xfd0cc,
+  i64x2_shr_u = 0xfd0cd,
+  i64x2_add = 0xfd0ce,
+  i64x2_sub = 0xfd0d1,
+  i64x2_mul = 0xfd0d5,
+  i64x2_eq = 0xfd0d6,
+  i64x2_ne = 0xfd0d7,
+  i64x2_lt_s = 0xfd0d8,
+  i64x2_gt_s = 0xfd0d9,
+  i64x2_le_s = 0xfd0da,
+  i64x2_ge_s = 0xfd0db,
+  i64x2_extmul_low_i32x4_s = 0xfd0dc,
+  i64x2_extmul_high_i32x4_s = 0xfd0dd,
+  i64x2_extmul_low_i32x4_u = 0xfd0de,
+  i64x2_extmul_high_i32x4_u = 0xfd0df,
+  f32x4_abs = 0xfd0e0,
+  f32x4_neg = 0xfd0e1,
+  f32x4_sqrt = 0xfd0e3,
+  f32x4_add = 0xfd0e4,
+  f32x4_sub = 0xfd0e5,
+  f32x4_mul = 0xfd0e6,
+  f32x4_div = 0xfd0e7,
+  f32x4_min = 0xfd0e8,
+  f32x4_max = 0xfd0e9,
+  f32x4_pmin = 0xfd0ea,
+  f32x4_pmax = 0xfd0eb,
+  f64x2_abs = 0xfd0ec,
+  f64x2_neg = 0xfd0ed,
+  f64x2_sqrt = 0xfd0ef,
+  f64x2_add = 0xfd0f0,
+  f64x2_sub = 0xfd0f1,
+  f64x2_mul = 0xfd0f2,
+  f64x2_div = 0xfd0f3,
+  f64x2_min = 0xfd0f4,
+  f64x2_max = 0xfd0f5,
+  f64x2_pmin = 0xfd0f6,
+  f64x2_pmax = 0xfd0f7,
+  i32x4_trunc_sat_f32x4_s = 0xfd0f8,
+  i32x4_trunc_sat_f32x4_u = 0xfd0f9,
+  f32x4_convert_i32x4_s = 0xfd0fa,
+  f32x4_convert_i32x4_u = 0xfd0fb,
+  i32x4_trunc_sat_f64x2_s_zero = 0xfd0fc,
+  i32x4_trunc_sat_f64x2_u_zero = 0xfd0fd,
+  f64x2_convert_low_i32x4_s = 0xfd0fe,
+  f64x2_convert_low_i32x4_u = 0xfd0ff,
+
+  // Relaxed SIMD
+  i8x16_relaxed_swizzle = 0xfd100,
+  i32x4_relaxed_trunc_f32x4_s = 0xfd101,
+  i32x4_relaxed_trunc_f32x4_u = 0xfd102,
+  i32x4_relaxed_trunc_f64x2_s_zero = 0xfd103,
+  i32x4_relaxed_trunc_f64x2_u_zero = 0xfd104,
+  f32x4_relaxed_madd = 0xfd105,
+  f32x4_relaxed_nmadd = 0xfd106,
+  f64x2_relaxed_madd = 0xfd107,
+  f64x2_relaxed_nmadd = 0xfd108,
+  i8x16_relaxed_laneselect = 0xfd109,
+  i16x8_relaxed_laneselect = 0xfd10a,
+  i32x4_relaxed_laneselect = 0xfd10b,
+  i64x2_relaxed_laneselect = 0xfd10c,
+  f32x4_relaxed_min = 0xfd10d,
+  f32x4_relaxed_max = 0xfd10e,
+  f64x2_relaxed_min = 0xfd10f,
+  f64x2_relaxed_max = 0xfd110,
+  i16x8_relaxed_q15mulr_s = 0xfd111,
+  i16x8_dot_i8x16_i7x16_s = 0xfd112,
+  i32x4_dot_i8x16_i7x16_add_s = 0xfd113,
 
   // GC proposal (milestone 6).
   struct_new_with_rtt = 0xfb01,
@@ -1176,8 +1198,28 @@ export const OperatorCodeNames = [
   "i32x4.trunc_sat_f64x2_u_zero",
   "f64x2.convert_low_i32x4_s",
   "f64x2.convert_low_i32x4_u",
+  "i8x16.relaxed_swizzle",
+  "i32x4.relaxed_trunc_f32x4_s",
+  "i32x4.relaxed_trunc_f32x4_u",
+  "i32x4.relaxed_trunc_f64x2_s_zero",
+  "i32x4.relaxed_trunc_f64x2_u_zero",
+  "f32x4.relaxed_madd",
+  "f32x4.relaxed_nmadd",
+  "f64x2.relaxed_madd",
+  "f64x2.relaxed_nmadd",
+  "i8x16.relaxed_laneselect",
+  "i16x8.relaxed_laneselect",
+  "i32x4.relaxed_laneselect",
+  "i64x2.relaxed_laneselect",
+  "f32x4.relaxed_min",
+  "f32x4.relaxed_max",
+  "f64x2.relaxed_min",
+  "f64x2.relaxed_max",
+  "i16x8.relaxed_q15mulr_s",
+  "i16x8.dot_i8x16_i7x16_s",
+  "i32x4.dot_i8x16_i7x16_add_s",
 ].forEach((s, i) => {
-  OperatorCodeNames[0xfd00 | i] = s;
+  OperatorCodeNames[0xfd000 | i] = s;
 });
 
 [
@@ -2870,7 +2912,7 @@ export class BinaryReader {
     if (!this.hasVarIntBytes()) {
       return false;
     }
-    var code = this.readVarUint32() | 0xfd00;
+    var code = this.readVarUint32() | 0xfd000;
     var memoryAddress;
     var literal;
     var lineIndex;
@@ -3117,6 +3159,27 @@ export class BinaryReader {
       case OperatorCode.f64x2_convert_low_i32x4_s:
       case OperatorCode.f64x2_convert_low_i32x4_u:
         break;
+      case OperatorCode.i8x16_relaxed_swizzle:
+      case OperatorCode.i32x4_relaxed_trunc_f32x4_s:
+      case OperatorCode.i32x4_relaxed_trunc_f32x4_u:
+      case OperatorCode.i32x4_relaxed_trunc_f64x2_s_zero:
+      case OperatorCode.i32x4_relaxed_trunc_f64x2_u_zero:
+      case OperatorCode.f32x4_relaxed_madd:
+      case OperatorCode.f32x4_relaxed_nmadd:
+      case OperatorCode.f64x2_relaxed_madd:
+      case OperatorCode.f64x2_relaxed_nmadd:
+      case OperatorCode.i8x16_relaxed_laneselect:
+      case OperatorCode.i16x8_relaxed_laneselect:
+      case OperatorCode.i32x4_relaxed_laneselect:
+      case OperatorCode.i64x2_relaxed_laneselect:
+      case OperatorCode.f32x4_relaxed_min:
+      case OperatorCode.f32x4_relaxed_max:
+      case OperatorCode.f64x2_relaxed_min:
+      case OperatorCode.f64x2_relaxed_max:
+      case OperatorCode.i16x8_relaxed_q15mulr_s:
+      case OperatorCode.i16x8_dot_i8x16_i7x16_s:
+      case OperatorCode.i32x4_dot_i8x16_i7x16_add_s:
+        break;
       default:
         this.error = new Error(
           `Unknown operator: 0x${code.toString(16).padStart(4, "0")}`
diff --git a/test/__fixtures__/relaxed_simd.wasm b/test/__fixtures__/relaxed_simd.wasm
new file mode 100644
index 0000000000000000000000000000000000000000..b4683d875dd046f8d8754ef4f33c4d21c68862ed
GIT binary patch
literal 614
zcmZvW+fIW(5QcY`Y6aAyU^MZDCorK_?AvTN1(HpGMiwH08_)H8d@|#e4@2StTe>lw
zi=8k3{5$gl!XgL&fTl7*WeLj(tRJPUS=qAy<b_0WA1|c+KuZNSuwiw9^ggHRQuHg)
zuSLH>y52Z#RNYE^C-Ge3dx;+;ew6r0;%B6bBrhGkcJ$WKdq*D~eM)=2kPd!PFD8)>
zzmWy{?3@-w=tGkp5AzXDlPsR%pkanqh?#QGIFE$W9pyvJaN#Gj-ik@qOxDzPV-S&b
zO<)|6z8W;&xxAqX<g#keaqhS{B(cx@(4VH7K^-?AONwr^d6%9|gEq^S%9gkq(Rh1-
uBp-;QTs0O*@|{6@;mkRSvM|AHcfS?9S&G{@^t2Ae%)|Eb{{itl%>Do$0i3e{

literal 0
HcmV?d00001

diff --git a/test/__snapshots__/parse-and-disassemble.test.ts.snap b/test/__snapshots__/parse-and-disassemble.test.ts.snap
index b6afd60..17a70c8 100644
--- a/test/__snapshots__/parse-and-disassemble.test.ts.snap
+++ b/test/__snapshots__/parse-and-disassemble.test.ts.snap
@@ -30751,6 +30751,117 @@ exports[`Parsing and disassembling ref_types.0.wasm generates expected output 1`
 "
 `;
 
+exports[`Parsing and disassembling relaxed_simd.wasm generates expected output 1`] = `
+"(module
+  (func $func0 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    i8x16.relaxed_swizzle
+  )
+  (func $func1 (param $var0 v128) (result v128)
+    local.get $var0
+    i32x4.relaxed_trunc_f32x4_s
+  )
+  (func $func2 (param $var0 v128) (result v128)
+    local.get $var0
+    i32x4.relaxed_trunc_f32x4_u
+  )
+  (func $func3 (param $var0 v128) (result v128)
+    local.get $var0
+    i32x4.relaxed_trunc_f64x2_s_zero
+  )
+  (func $func4 (param $var0 v128) (result v128)
+    local.get $var0
+    i32x4.relaxed_trunc_f64x2_u_zero
+  )
+  (func $func5 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    f32x4.relaxed_madd
+  )
+  (func $func6 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    f32x4.relaxed_nmadd
+  )
+  (func $func7 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    f64x2.relaxed_madd
+  )
+  (func $func8 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    f64x2.relaxed_nmadd
+  )
+  (func $func9 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    i8x16.relaxed_laneselect
+  )
+  (func $func10 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    i16x8.relaxed_laneselect
+  )
+  (func $func11 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    i32x4.relaxed_laneselect
+  )
+  (func $func12 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    i64x2.relaxed_laneselect
+  )
+  (func $func13 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    f32x4.relaxed_min
+  )
+  (func $func14 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    f32x4.relaxed_max
+  )
+  (func $func15 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    f64x2.relaxed_min
+  )
+  (func $func16 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    f64x2.relaxed_max
+  )
+  (func $func17 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    i16x8.relaxed_q15mulr_s
+  )
+  (func $func18 (param $var0 v128) (param $var1 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    i16x8.dot_i8x16_i7x16_s
+  )
+  (func $func19 (param $var0 v128) (param $var1 v128) (param $var2 v128) (result v128)
+    local.get $var0
+    local.get $var1
+    local.get $var2
+    i32x4.dot_i8x16_i7x16_add_s
+  )
+)
+"
+`;
+
 exports[`Parsing and disassembling reloc.wasm generates expected output 1`] = `
 "(module
   (global $global0 (import "env" "STACKTOP") i32)
diff --git a/test/wabt-compatibility.test.ts b/test/wabt-compatibility.test.ts
index a7633e6..cc2d906 100644
--- a/test/wabt-compatibility.test.ts
+++ b/test/wabt-compatibility.test.ts
@@ -25,6 +25,7 @@ const WABT_FEATURES = {
   reference_types: true,
   sign_extension: true,
   simd: true,
+  relaxed_simd: true,
   sat_float_to_int: true,
   tail_call: true,
   threads: true,