mirror of
https://github.com/ziglang/zig.git
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This refactor inserts an offset table into wasm's data section where each offset points to the actual data region. This means we can keep offset indexes consistant and do not have to perform any computer to determine where in the data section something like a static string exists. Instead during runtime it will load the data offset onto the stack.
286 lines
6.8 KiB
Zig
286 lines
6.8 KiB
Zig
// SPDX-License-Identifier: MIT
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// Copyright (c) 2015-2021 Zig Contributors
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// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
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// The MIT license requires this copyright notice to be included in all copies
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// and substantial portions of the software.
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const testing = @import("std.zig").testing;
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// TODO: Add support for multi-byte ops (e.g. table operations)
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/// Wasm instruction opcodes
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///
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/// All instructions are defined as per spec:
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/// https://webassembly.github.io/spec/core/appendix/index-instructions.html
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pub const Opcode = enum(u8) {
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@"unreachable" = 0x00,
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nop = 0x01,
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block = 0x02,
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loop = 0x03,
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@"if" = 0x04,
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@"else" = 0x05,
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end = 0x0B,
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br = 0x0C,
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br_if = 0x0D,
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br_table = 0x0E,
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@"return" = 0x0F,
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call = 0x10,
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call_indirect = 0x11,
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drop = 0x1A,
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select = 0x1B,
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local_get = 0x20,
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local_set = 0x21,
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local_tee = 0x22,
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global_get = 0x23,
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global_set = 0x24,
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i32_load = 0x28,
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i64_load = 0x29,
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f32_load = 0x2A,
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f64_load = 0x2B,
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i32_load8_s = 0x2C,
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i32_load8_u = 0x2D,
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i32_load16_s = 0x2E,
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i32_load16_u = 0x2F,
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i64_load8_s = 0x30,
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i64_load8_u = 0x31,
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i64_load16_s = 0x32,
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i64_load16_u = 0x33,
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i64_load32_s = 0x34,
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i64_load32_u = 0x35,
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i32_store = 0x36,
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i64_store = 0x37,
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f32_store = 0x38,
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f64_store = 0x39,
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i32_store8 = 0x3A,
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i32_store16 = 0x3B,
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i64_store8 = 0x3C,
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i64_store16 = 0x3D,
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i64_store32 = 0x3E,
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memory_size = 0x3F,
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memory_grow = 0x40,
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i32_const = 0x41,
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i64_const = 0x42,
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f32_const = 0x43,
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f64_const = 0x44,
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i32_eqz = 0x45,
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i32_eq = 0x46,
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i32_ne = 0x47,
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i32_lt_s = 0x48,
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i32_lt_u = 0x49,
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i32_gt_s = 0x4A,
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i32_gt_u = 0x4B,
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i32_le_s = 0x4C,
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i32_le_u = 0x4D,
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i32_ge_s = 0x4E,
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i32_ge_u = 0x4F,
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i64_eqz = 0x50,
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i64_eq = 0x51,
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i64_ne = 0x52,
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i64_lt_s = 0x53,
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i64_lt_u = 0x54,
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i64_gt_s = 0x55,
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i64_gt_u = 0x56,
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i64_le_s = 0x57,
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i64_le_u = 0x58,
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i64_ge_s = 0x59,
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i64_ge_u = 0x5A,
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f32_eq = 0x5B,
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f32_ne = 0x5C,
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f32_lt = 0x5D,
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f32_gt = 0x5E,
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f32_le = 0x5F,
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f32_ge = 0x60,
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f64_eq = 0x61,
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f64_ne = 0x62,
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f64_lt = 0x63,
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f64_gt = 0x64,
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f64_le = 0x65,
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f64_ge = 0x66,
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i32_clz = 0x67,
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i32_ctz = 0x68,
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i32_popcnt = 0x69,
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i32_add = 0x6A,
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i32_sub = 0x6B,
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i32_mul = 0x6C,
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i32_div_s = 0x6D,
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i32_div_u = 0x6E,
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i32_rem_s = 0x6F,
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i32_rem_u = 0x70,
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i32_and = 0x71,
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i32_or = 0x72,
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i32_xor = 0x73,
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i32_shl = 0x74,
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i32_shr_s = 0x75,
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i32_shr_u = 0x76,
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i32_rotl = 0x77,
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i32_rotr = 0x78,
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i64_clz = 0x79,
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i64_ctz = 0x7A,
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i64_popcnt = 0x7B,
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i64_add = 0x7C,
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i64_sub = 0x7D,
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i64_mul = 0x7E,
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i64_div_s = 0x7F,
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i64_div_u = 0x80,
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i64_rem_s = 0x81,
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i64_rem_u = 0x82,
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i64_and = 0x83,
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i64_or = 0x84,
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i64_xor = 0x85,
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i64_shl = 0x86,
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i64_shr_s = 0x87,
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i64_shr_u = 0x88,
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i64_rotl = 0x89,
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i64_rotr = 0x8A,
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f32_abs = 0x8B,
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f32_neg = 0x8C,
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f32_ceil = 0x8D,
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f32_floor = 0x8E,
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f32_trunc = 0x8F,
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f32_nearest = 0x90,
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f32_sqrt = 0x91,
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f32_add = 0x92,
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f32_sub = 0x93,
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f32_mul = 0x94,
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f32_div = 0x95,
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f32_min = 0x96,
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f32_max = 0x97,
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f32_copysign = 0x98,
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f64_abs = 0x99,
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f64_neg = 0x9A,
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f64_ceil = 0x9B,
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f64_floor = 0x9C,
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f64_trunc = 0x9D,
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f64_nearest = 0x9E,
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f64_sqrt = 0x9F,
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f64_add = 0xA0,
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f64_sub = 0xA1,
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f64_mul = 0xA2,
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f64_div = 0xA3,
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f64_min = 0xA4,
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f64_max = 0xA5,
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f64_copysign = 0xA6,
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i32_wrap_i64 = 0xA7,
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i32_trunc_f32_s = 0xA8,
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i32_trunc_f32_u = 0xA9,
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i32_trunc_f64_s = 0xB0,
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i32_trunc_f64_u = 0xB1,
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f32_convert_i32_s = 0xB2,
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f32_convert_i32_u = 0xB3,
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f32_convert_i64_s = 0xB4,
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f32_convert_i64_u = 0xB5,
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f32_demote_f64 = 0xB6,
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f64_convert_i32_s = 0xB7,
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f64_convert_i32_u = 0xB8,
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f64_convert_i64_s = 0xB9,
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f64_convert_i64_u = 0xBA,
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f64_promote_f32 = 0xBB,
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i32_reinterpret_f32 = 0xBC,
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i64_reinterpret_f64 = 0xBD,
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f32_reinterpret_i32 = 0xBE,
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f64_reinterpret_i64 = 0xBF,
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i32_extend8_s = 0xC0,
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i32_extend16_s = 0xC1,
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i64_extend8_s = 0xC2,
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i64_extend16_s = 0xC3,
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i64_extend32_s = 0xC4,
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_,
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};
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/// Returns the integer value of an `Opcode`. Used by the Zig compiler
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/// to write instructions to the wasm binary file
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pub fn opcode(op: Opcode) u8 {
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return @enumToInt(op);
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}
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test "Wasm - opcodes" {
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// Ensure our opcodes values remain intact as certain values are skipped due to them being reserved
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const i32_const = opcode(.i32_const);
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const end = opcode(.end);
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const drop = opcode(.drop);
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const local_get = opcode(.local_get);
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const i64_extend32_s = opcode(.i64_extend32_s);
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testing.expectEqual(@as(u16, 0x41), i32_const);
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testing.expectEqual(@as(u16, 0x0B), end);
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testing.expectEqual(@as(u16, 0x1A), drop);
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testing.expectEqual(@as(u16, 0x20), local_get);
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testing.expectEqual(@as(u16, 0xC4), i64_extend32_s);
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}
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/// Enum representing all Wasm value types as per spec:
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/// https://webassembly.github.io/spec/core/binary/types.html
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pub const Valtype = enum(u8) {
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i32 = 0x7F,
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i64 = 0x7E,
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f32 = 0x7D,
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f64 = 0x7C,
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};
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/// Returns the integer value of a `Valtype`
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pub fn valtype(value: Valtype) u8 {
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return @enumToInt(value);
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}
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test "Wasm - valtypes" {
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const _i32 = valtype(.i32);
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const _i64 = valtype(.i64);
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const _f32 = valtype(.f32);
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const _f64 = valtype(.f64);
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testing.expectEqual(@as(u8, 0x7F), _i32);
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testing.expectEqual(@as(u8, 0x7E), _i64);
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testing.expectEqual(@as(u8, 0x7D), _f32);
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testing.expectEqual(@as(u8, 0x7C), _f64);
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}
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/// Wasm module sections as per spec:
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/// https://webassembly.github.io/spec/core/binary/modules.html
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pub const Section = enum(u8) {
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custom,
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type,
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import,
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function,
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table,
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memory,
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global,
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@"export",
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start,
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element,
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code,
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data,
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};
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/// Returns the integer value of a given `Section`
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pub fn section(val: Section) u8 {
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return @enumToInt(val);
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}
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/// The kind of the type when importing or exporting to/from the host environment
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/// https://webassembly.github.io/spec/core/syntax/modules.html
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pub const ExternalKind = enum(u8) {
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function,
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table,
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memory,
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global,
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};
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/// Returns the integer value of a given `ExternalKind`
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pub fn externalKind(val: ExternalKind) u8 {
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return @enumToInt(val);
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}
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// types
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pub const element_type: u8 = 0x70;
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pub const function_type: u8 = 0x60;
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pub const result_type: u8 = 0x40;
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/// Represents a block which will not return a value
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pub const block_empty: u8 = 0x40;
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// binary constants
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pub const magic = [_]u8{ 0x00, 0x61, 0x73, 0x6D }; // \0asm
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pub const version = [_]u8{ 0x01, 0x00, 0x00, 0x00 }; // version 1
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// Each wasm page size is 64kB
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pub const page_size = 64 * 1024;
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