motiejus/zig
1
Fork 0
Code Releases Activity

wasm: load+store simd immediate values

Browse Source 
This implements loading and storing immediate values representing
a vector with exactly 128 bits. When the vector does not equal to
128 bits, or when the simd128 or relaxed-simd features are disabled
the value will be treated as an array instead.
This commit is contained in:
Luuk de Gram
2022-12-06 19:19:52 +01:00
parent 5a6b6992d8
commit 63b69e2c55
3 changed files with 189 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

172
src/arch/wasm/CodeGen.zig
View File

@@ -43,6 +43,10 @@ const WValue = union(enum) {
imm32: u32,
/// An immediate 64bit value
imm64: u64,
/// Index into the list of simd128 immediates. This `WValue` is
/// only possible in very rare cases, therefore it would be
/// a waste of memory to store the value in a 128 bit integer.
imm128: u32,
/// A constant 32bit float value
float32: f32,
/// A constant 64bit float value
@@ -116,6 +120,7 @@ const WValue = union(enum) {
.i64 => gen.free_locals_i64.append(gen.gpa, local_value) catch return,
.f32 => gen.free_locals_f32.append(gen.gpa, local_value) catch return,
.f64 => gen.free_locals_f64.append(gen.gpa, local_value) catch return,
.v128 => gen.free_locals_v128.append(gen.gpa, local_value) catch return,
}
value.* = undefined;
}
@@ -258,18 +263,18 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
8 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load8_s else return .i32_load8_u,
.i64 => if (args.signedness.? == .signed) return .i64_load8_s else return .i64_load8_u,
.f32, .f64 => unreachable,
.f32, .f64, .v128 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load16_s else return .i32_load16_u,
.i64 => if (args.signedness.? == .signed) return .i64_load16_s else return .i64_load16_u,
.f32, .f64 => unreachable,
.f32, .f64, .v128 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => if (args.signedness.? == .signed) return .i64_load32_s else return .i64_load32_u,
.i32 => return .i32_load,
.f32 => return .f32_load,
.f64 => unreachable,
.f64, .v128 => unreachable,
},
64 => switch (args.valtype1.?) {
.i64 => return .i64_load,
@@ -282,24 +287,25 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => return .i64_load,
.f32 => return .f32_load,
.f64 => return .f64_load,
.v128 => unreachable, // handled independently
},
.store => if (args.width) |width| {
switch (width) {
8 => switch (args.valtype1.?) {
.i32 => return .i32_store8,
.i64 => return .i64_store8,
.f32, .f64 => unreachable,
.f32, .f64, .v128 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => return .i32_store16,
.i64 => return .i64_store16,
.f32, .f64 => unreachable,
.f32, .f64, .v128 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => return .i64_store32,
.i32 => return .i32_store,
.f32 => return .f32_store,
.f64 => unreachable,
.f64, .v128 => unreachable,
},
64 => switch (args.valtype1.?) {
.i64 => return .i64_store,
@@ -314,6 +320,7 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => return .i64_store,
.f32 => return .f32_store,
.f64 => return .f64_store,
.v128 => unreachable, // handled independently
}
},
@@ -325,24 +332,27 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => return .i64_const,
.f32 => return .f32_const,
.f64 => return .f64_const,
.v128 => unreachable, // handled independently
},
.eqz => switch (args.valtype1.?) {
.i32 => return .i32_eqz,
.i64 => return .i64_eqz,
.f32, .f64 => unreachable,
.f32, .f64, .v128 => unreachable,
},
.eq => switch (args.valtype1.?) {
.i32 => return .i32_eq,
.i64 => return .i64_eq,
.f32 => return .f32_eq,
.f64 => return .f64_eq,
.v128 => unreachable, // handled independently
},
.ne => switch (args.valtype1.?) {
.i32 => return .i32_ne,
.i64 => return .i64_ne,
.f32 => return .f32_ne,
.f64 => return .f64_ne,
.v128 => unreachable, // handled independently
},
.lt => switch (args.valtype1.?) {
@@ -350,40 +360,47 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => if (args.signedness.? == .signed) return .i64_lt_s else return .i64_lt_u,
.f32 => return .f32_lt,
.f64 => return .f64_lt,
.v128 => unreachable, // handled independently
},
.gt => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_gt_s else return .i32_gt_u,
.i64 => if (args.signedness.? == .signed) return .i64_gt_s else return .i64_gt_u,
.f32 => return .f32_gt,
.f64 => return .f64_gt,
.v128 => unreachable, // handled independently
},
.le => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_le_s else return .i32_le_u,
.i64 => if (args.signedness.? == .signed) return .i64_le_s else return .i64_le_u,
.f32 => return .f32_le,
.f64 => return .f64_le,
.v128 => unreachable, // handled independently
},
.ge => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_ge_s else return .i32_ge_u,
.i64 => if (args.signedness.? == .signed) return .i64_ge_s else return .i64_ge_u,
.f32 => return .f32_ge,
.f64 => return .f64_ge,
.v128 => unreachable, // handled independently
},
.clz => switch (args.valtype1.?) {
.i32 => return .i32_clz,
.i64 => return .i64_clz,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.ctz => switch (args.valtype1.?) {
.i32 => return .i32_ctz,
.i64 => return .i64_ctz,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.popcnt => switch (args.valtype1.?) {
.i32 => return .i32_popcnt,
.i64 => return .i64_popcnt,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.add => switch (args.valtype1.?) {
@@ -391,18 +408,21 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => return .i64_add,
.f32 => return .f32_add,
.f64 => return .f64_add,
.v128 => unreachable, // handled independently
},
.sub => switch (args.valtype1.?) {
.i32 => return .i32_sub,
.i64 => return .i64_sub,
.f32 => return .f32_sub,
.f64 => return .f64_sub,
.v128 => unreachable, // handled independently
},
.mul => switch (args.valtype1.?) {
.i32 => return .i32_mul,
.i64 => return .i64_mul,
.f32 => return .f32_mul,
.f64 => return .f64_mul,
.v128 => unreachable, // handled independently
},
.div => switch (args.valtype1.?) {
@@ -410,71 +430,84 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => if (args.signedness.? == .signed) return .i64_div_s else return .i64_div_u,
.f32 => return .f32_div,
.f64 => return .f64_div,
.v128 => unreachable, // handled independently
},
.rem => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_rem_s else return .i32_rem_u,
.i64 => if (args.signedness.? == .signed) return .i64_rem_s else return .i64_rem_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.@"and" => switch (args.valtype1.?) {
.i32 => return .i32_and,
.i64 => return .i64_and,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.@"or" => switch (args.valtype1.?) {
.i32 => return .i32_or,
.i64 => return .i64_or,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.xor => switch (args.valtype1.?) {
.i32 => return .i32_xor,
.i64 => return .i64_xor,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.shl => switch (args.valtype1.?) {
.i32 => return .i32_shl,
.i64 => return .i64_shl,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.shr => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_shr_s else return .i32_shr_u,
.i64 => if (args.signedness.? == .signed) return .i64_shr_s else return .i64_shr_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.rotl => switch (args.valtype1.?) {
.i32 => return .i32_rotl,
.i64 => return .i64_rotl,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.rotr => switch (args.valtype1.?) {
.i32 => return .i32_rotr,
.i64 => return .i64_rotr,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.abs => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_abs,
.f64 => return .f64_abs,
.v128 => unreachable, // handled independently
},
.neg => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_neg,
.f64 => return .f64_neg,
.v128 => unreachable, // handled independently
},
.ceil => switch (args.valtype1.?) {
.i64 => unreachable,
.i32 => return .f32_ceil, // when valtype is f16, we store it in i32.
.f32 => return .f32_ceil,
.f64 => return .f64_ceil,
.v128 => unreachable, // handled independently
},
.floor => switch (args.valtype1.?) {
.i64 => unreachable,
.i32 => return .f32_floor, // when valtype is f16, we store it in i32.
.f32 => return .f32_floor,
.f64 => return .f64_floor,
.v128 => unreachable, // handled independently
},
.trunc => switch (args.valtype1.?) {
.i32 => if (args.valtype2) |valty| switch (valty) {
@@ -482,40 +515,48 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => unreachable,
.f32 => if (args.signedness.? == .signed) return .i32_trunc_f32_s else return .i32_trunc_f32_u,
.f64 => if (args.signedness.? == .signed) return .i32_trunc_f64_s else return .i32_trunc_f64_u,
.v128 => unreachable, // handled independently
} else return .f32_trunc, // when no valtype2, it's an f16 instead which is stored in an i32.
.i64 => switch (args.valtype2.?) {
.i32 => unreachable,
.i64 => unreachable,
.f32 => if (args.signedness.? == .signed) return .i64_trunc_f32_s else return .i64_trunc_f32_u,
.f64 => if (args.signedness.? == .signed) return .i64_trunc_f64_s else return .i64_trunc_f64_u,
.v128 => unreachable, // handled independently
},
.f32 => return .f32_trunc,
.f64 => return .f64_trunc,
.v128 => unreachable, // handled independently
},
.nearest => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_nearest,
.f64 => return .f64_nearest,
.v128 => unreachable, // handled independently
},
.sqrt => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_sqrt,
.f64 => return .f64_sqrt,
.v128 => unreachable, // handled independently
},
.min => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_min,
.f64 => return .f64_min,
.v128 => unreachable, // handled independently
},
.max => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_max,
.f64 => return .f64_max,
.v128 => unreachable, // handled independently
},
.copysign => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_copysign,
.f64 => return .f64_copysign,
.v128 => unreachable, // handled independently
},
.wrap => switch (args.valtype1.?) {
@@ -523,8 +564,10 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i32 => unreachable,
.i64 => return .i32_wrap_i64,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.i64, .f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.convert => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
@@ -532,12 +575,15 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i32 => if (args.signedness.? == .signed) return .f32_convert_i32_s else return .f32_convert_i32_u,
.i64 => if (args.signedness.? == .signed) return .f32_convert_i64_s else return .f32_convert_i64_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.f64 => switch (args.valtype2.?) {
.i32 => if (args.signedness.? == .signed) return .f64_convert_i32_s else return .f64_convert_i32_u,
.i64 => if (args.signedness.? == .signed) return .f64_convert_i64_s else return .f64_convert_i64_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.v128 => unreachable, // handled independently
},
.demote => if (args.valtype1.? == .f32 and args.valtype2.? == .f64) return .f32_demote_f64 else unreachable,
.promote => if (args.valtype1.? == .f64 and args.valtype2.? == .f32) return .f64_promote_f32 else unreachable,
@@ -546,6 +592,7 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
.i64 => if (args.valtype2.? == .f64) return .i64_reinterpret_f64 else unreachable,
.f32 => if (args.valtype2.? == .i32) return .f32_reinterpret_i32 else unreachable,
.f64 => if (args.valtype2.? == .i64) return .f64_reinterpret_i64 else unreachable,
.v128 => unreachable, // handled independently
},
.extend => switch (args.valtype1.?) {
.i32 => switch (args.width.?) {
@@ -560,6 +607,7 @@ fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
else => unreachable,
},
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
}
}
@@ -629,6 +677,10 @@ err_msg: *Module.ErrorMsg,
/// List of all locals' types generated throughout this declaration
/// used to emit locals count at start of 'code' section.
locals: std.ArrayListUnmanaged(u8),
/// List of simd128 immediates. Each value is stored as an array of bytes.
/// This list will only be populated for 128bit-simd values when the target features
/// are enabled also.
simd_immediates: std.ArrayListUnmanaged([16]u8) = .{},
/// The Target we're emitting (used to call intInfo)
target: std.Target,
/// Represents the wasm binary file that is being linked.
@@ -665,14 +717,17 @@ stack_alignment: u32 = 16,
/// It is illegal to store a non-i32 valtype in this list.
free_locals_i32: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `i64`.
/// It is illegal to store a non-i32 valtype in this list.
/// It is illegal to store a non-i64 valtype in this list.
free_locals_i64: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `f32`.
/// It is illegal to store a non-i32 valtype in this list.
/// It is illegal to store a non-f32 valtype in this list.
free_locals_f32: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `f64`.
/// It is illegal to store a non-i32 valtype in this list.
/// It is illegal to store a non-f64 valtype in this list.
free_locals_f64: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `v127`.
/// It is illegal to store a non-v128 valtype in this list.
free_locals_v128: std.ArrayListUnmanaged(u32) = .{},
/// When in debug mode, this tracks if no `finishAir` was missed.
/// Forgetting to call `finishAir` will cause the result to not be
@@ -699,12 +754,14 @@ pub fn deinit(func: *CodeGen) void {
func.branches.deinit(func.gpa);
func.blocks.deinit(func.gpa);
func.locals.deinit(func.gpa);
func.simd_immediates.deinit(func.gpa);
func.mir_instructions.deinit(func.gpa);
func.mir_extra.deinit(func.gpa);
func.free_locals_i32.deinit(func.gpa);
func.free_locals_i64.deinit(func.gpa);
func.free_locals_f32.deinit(func.gpa);
func.free_locals_f64.deinit(func.gpa);
func.free_locals_v128.deinit(func.gpa);
func.* = undefined;
}
@@ -867,6 +924,17 @@ fn addImm64(func: *CodeGen, imm: u64) error{OutOfMemory}!void {
try func.addInst(.{ .tag = .i64_const, .data = .{ .payload = extra_index } });
}
/// Accepts the index into the list of 128bit-immediates
fn addImm128(func: *CodeGen, index: u32) error{OutOfMemory}!void {
const simd_values = func.simd_immediates.items[index];
const extra_index = @intCast(u32, func.mir_extra.items.len);
// tag + 128bit value
try func.mir_extra.ensureUnusedCapacity(func.gpa, 5);
func.mir_extra.appendAssumeCapacity(std.wasm.simdOpcode(.v128_const));
func.mir_extra.appendSliceAssumeCapacity(@alignCast(4, mem.bytesAsSlice(u32, &simd_values)));
try func.addInst(.{ .tag = .simd, .data = .{ .payload = extra_index } });
}
fn addFloat64(func: *CodeGen, float: f64) error{OutOfMemory}!void {
const extra_index = try func.addExtra(Mir.Float64.fromFloat64(float));
try func.addInst(.{ .tag = .f64_const, .data = .{ .payload = extra_index } });
@@ -924,6 +992,10 @@ fn typeToValtype(ty: Type, target: std.Target) wasm.Valtype {
},
else => wasm.Valtype.i32,
},
.Vector => switch (determineSimdStoreStrategy(ty, target)) {
.direct => wasm.Valtype.v128,
.unrolled => wasm.Valtype.i32,
},
else => wasm.Valtype.i32, // all represented as reference/immediate
};
}
@@ -950,6 +1022,7 @@ fn emitWValue(func: *CodeGen, value: WValue) InnerError!void {
.local => |idx| try func.addLabel(.local_get, idx.value),
.imm32 => |val| try func.addImm32(@bitCast(i32, val)),
.imm64 => |val| try func.addImm64(val),
.imm128 => |val| try func.addImm128(val),
.float32 => |val| try func.addInst(.{ .tag = .f32_const, .data = .{ .float32 = val } }),
.float64 => |val| try func.addFloat64(val),
.memory => |ptr| {
@@ -1016,6 +1089,10 @@ fn allocLocal(func: *CodeGen, ty: Type) InnerError!WValue {
log.debug("reusing local ({d}) of type {}\n", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
.v128 => if (func.free_locals_v128.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}\n", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
}
log.debug("new local of type {}\n", .{valtype});
// no local was free to be re-used, so allocate a new local instead
@@ -1098,7 +1175,6 @@ pub fn generate(
.gpa = bin_file.allocator,
.air = air,
.liveness = liveness,
// .values = .{},
.code = code,
.decl_index = func.owner_decl,
.decl = bin_file.options.module.?.declPtr(func.owner_decl),
@@ -1481,9 +1557,9 @@ fn memcpy(func: *CodeGen, dst: WValue, src: WValue, len: WValue) !void {
.imm64 => |val| val,
else => unreachable,
};
// if the size (length) is more than 1024 bytes, we use a runtime loop instead to prevent
// if the size (length) is more than 32 bytes, we use a runtime loop instead to prevent
// binary size bloat.
if (length > 1024) break :blk;
if (length > 32) break :blk;
var offset: u32 = 0;
const lhs_base = dst.offset();
const rhs_base = src.offset();
@@ -1612,7 +1688,6 @@ fn isByRef(ty: Type, target: std.Target) bool {
=> return false,
.Array,
.Vector,
.Frame,
.Union,
=> return ty.hasRuntimeBitsIgnoreComptime(),
@@ -1625,6 +1700,7 @@ fn isByRef(ty: Type, target: std.Target) bool {
}
return ty.hasRuntimeBitsIgnoreComptime();
},
.Vector => return determineSimdStoreStrategy(ty, target) == .unrolled,
.Int => return ty.intInfo(target).bits > 64,
.Float => return ty.floatBits(target) > 64,
.ErrorUnion => {
@@ -1647,6 +1723,26 @@ fn isByRef(ty: Type, target: std.Target) bool {
}
}
const SimdStoreStrategy = enum {
direct,
unrolled,
};
/// For a given vector type, returns the `SimdStoreStrategy`.
/// This means when a given type is 128 bits and either the simd128 or relaxed-simd
/// features are enabled, the function will return `.direct`. This would allow to store
/// it using a instruction, rather than an unrolled version.
fn determineSimdStoreStrategy(ty: Type, target: std.Target) SimdStoreStrategy {
std.debug.assert(ty.zigTypeTag() == .Vector);
if (ty.bitSize(target) != 128) return .unrolled;
const hasFeature = std.Target.wasm.featureSetHas;
const features = target.cpu.features;
if (hasFeature(features, .relaxed_simd) or hasFeature(features, .simd128)) {
return .direct;
}
return .unrolled;
}
/// Creates a new local for a pointer that points to memory with given offset.
/// This can be used to get a pointer to a struct field, error payload, etc.
/// By providing `modify` as action, it will modify the given `ptr_value` instead of making a new
@@ -2187,10 +2283,29 @@ fn store(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, offset: u32) InnerE
const len = @intCast(u32, ty.abiSize(func.target));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.Struct, .Array, .Union, .Vector => if (isByRef(ty, func.target)) {
.Struct, .Array, .Union => if (isByRef(ty, func.target)) {
const len = @intCast(u32, ty.abiSize(func.target));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.Vector => switch (determineSimdStoreStrategy(ty, func.target)) {
.unrolled => {
const len = @intCast(u32, ty.abiSize(func.target));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.direct => {
try func.emitWValue(lhs);
try func.lowerToStack(rhs);
// TODO: Add helper functions for simd opcodes
const extra_index = @intCast(u32, func.mir_extra.items.len);
// stores as := opcode, offset, alignment (opcode::memarg)
try func.mir_extra.appendSlice(func.gpa, &[_]u32{
std.wasm.simdOpcode(.v128_store),
offset + lhs.offset(),
ty.abiAlignment(func.target),
});
return func.addInst(.{ .tag = .simd, .data = .{ .payload = extra_index } });
},
},
.Pointer => {
if (ty.isSlice()) {
// store pointer first
@@ -2289,6 +2404,19 @@ fn load(func: *CodeGen, operand: WValue, ty: Type, offset: u32) InnerError!WValu
// load local's value from memory by its stack position
try func.emitWValue(operand);
if (ty.zigTypeTag() == .Vector) {
// TODO: Add helper functions for simd opcodes
const extra_index = @intCast(u32, func.mir_extra.items.len);
// stores as := opcode, offset, alignment (opcode::memarg)
try func.mir_extra.appendSlice(func.gpa, &[_]u32{
std.wasm.simdOpcode(.v128_load),
offset + operand.offset(),
ty.abiAlignment(func.target),
});
try func.addInst(.{ .tag = .simd, .data = .{ .payload = extra_index } });
return WValue{ .stack = {} };
}
const abi_size = @intCast(u8, ty.abiSize(func.target));
const opcode = buildOpcode(.{
.valtype1 = typeToValtype(ty, func.target),
@@ -2766,10 +2894,24 @@ fn lowerConstant(func: *CodeGen, arg_val: Value, ty: Type) InnerError!WValue {
const int_val = Value.initPayload(&payload.base);
return func.lowerConstant(int_val, struct_obj.backing_int_ty);
},
.Vector => {
assert(determineSimdStoreStrategy(ty, target) == .direct);
var buf: [16]u8 = undefined;
val.writeToMemory(ty, func.bin_file.base.options.module.?, &buf);
return func.storeSimdImmd(buf);
},
else => |zig_type| return func.fail("Wasm TODO: LowerConstant for zigTypeTag {}", .{zig_type}),
}
}
/// Stores the value as a 128bit-immediate value by storing it inside
/// the list and returning the index into this list as `WValue`.
fn storeSimdImmd(func: *CodeGen, value: [16]u8) !WValue {
const index = @intCast(u32, func.simd_immediates.items.len);
try func.simd_immediates.append(func.gpa, value);
return WValue{ .imm128 = index };
}
fn emitUndefined(func: *CodeGen, ty: Type) InnerError!WValue {
switch (ty.zigTypeTag()) {
.Bool, .ErrorSet => return WValue{ .imm32 = 0xaaaaaaaa },

27
src/arch/wasm/Emit.zig
View File

@@ -240,6 +240,7 @@ pub fn emitMir(emit: *Emit) InnerError!void {
.i64_ctz => try emit.emitTag(tag),
.extended => try emit.emitExtended(inst),
.simd => try emit.emitSimd(inst),
}
}
}
@@ -341,11 +342,14 @@ fn emitMemArg(emit: *Emit, tag: Mir.Inst.Tag, inst: Mir.Inst.Index) !void {
const extra_index = emit.mir.instructions.items(.data)[inst].payload;
const mem_arg = emit.mir.extraData(Mir.MemArg, extra_index).data;
try emit.code.append(@enumToInt(tag));
try encodeMemArg(mem_arg, emit.code.writer());
}
fn encodeMemArg(mem_arg: Mir.MemArg, writer: anytype) !void {
// wasm encodes alignment as power of 2, rather than natural alignment
const encoded_alignment = @ctz(mem_arg.alignment);
try leb128.writeULEB128(emit.code.writer(), encoded_alignment);
try leb128.writeULEB128(emit.code.writer(), mem_arg.offset);
try leb128.writeULEB128(writer, encoded_alignment);
try leb128.writeULEB128(writer, mem_arg.offset);
}
fn emitCall(emit: *Emit, inst: Mir.Inst.Index) !void {
@@ -426,6 +430,25 @@ fn emitExtended(emit: *Emit, inst: Mir.Inst.Index) !void {
}
}
fn emitSimd(emit: *Emit, inst: Mir.Inst.Index) !void {
const extra_index = emit.mir.instructions.items(.data)[inst].payload;
const opcode = emit.mir.extra[extra_index];
const writer = emit.code.writer();
try emit.code.append(0xFD);
try leb128.writeULEB128(writer, opcode);
switch (@intToEnum(std.wasm.SimdOpcode, opcode)) {
.v128_store, .v128_load => {
const mem_arg = emit.mir.extraData(Mir.MemArg, extra_index + 1).data;
try encodeMemArg(mem_arg, writer);
},
.v128_const => {
const simd_value = emit.mir.extra[extra_index + 1 ..][0..4];
try writer.writeAll(std.mem.asBytes(simd_value));
},
else => |tag| return emit.fail("TODO: Implement simd instruction: {s}\n", .{@tagName(tag)}),
}
}
fn emitMemFill(emit: *Emit) !void {
try emit.code.append(0xFC);
try emit.code.append(0x0B);

8
src/arch/wasm/Mir.zig
View File

@@ -518,6 +518,12 @@ pub const Inst = struct {
///
/// The `data` field depends on the extension instruction
extended = 0xFC,
/// The instruction consists of a simd opcode.
/// The actual simd-opcode is found at payload's index.
///
/// The `data` field depends on the simd instruction and
/// may contain additional data.
simd = 0xFD,
/// Contains a symbol to a function pointer
/// uses `label`
///
@@ -578,7 +584,7 @@ pub fn deinit(self: *Mir, gpa: std.mem.Allocator) void {
self.* = undefined;
}
pub fn extraData(self: Mir, comptime T: type, index: usize) struct { data: T, end: usize } {
pub fn extraData(self: *const Mir, comptime T: type, index: usize) struct { data: T, end: usize } {
const fields = std.meta.fields(T);
var i: usize = index;
var result: T = undefined;