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wasm linker: track overaligned uavs

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This commit is contained in:
Andrew Kelley
2025-01-13 19:37:18 -08:00
parent ba4521ac85
commit 4cc9cfa7e8
3 changed files with 38 additions and 8 deletions
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11
src/arch/wasm/CodeGen.zig
View File

@@ -161,6 +161,7 @@ const WValue = union(enum) {
uav_ref: struct {
ip_index: InternPool.Index,
offset: i32 = 0,
orig_ptr_ty: InternPool.Index = .none,
},
/// Offset from the bottom of the virtual stack, with the offset
/// pointing to where the value lives.
@@ -1062,9 +1063,9 @@ fn emitWValue(cg: *CodeGen, value: WValue) InnerError!void {
try cg.addInst(.{
.tag = .uav_ref,
.data = if (is_obj) .{
.uav_obj = try wasm.refUavObj(uav.ip_index),
.uav_obj = try wasm.refUavObj(uav.ip_index, uav.orig_ptr_ty),
} else .{
.uav_exe = try wasm.refUavExe(uav.ip_index),
.uav_exe = try wasm.refUavExe(uav.ip_index, uav.orig_ptr_ty),
},
});
} else {
@@ -1072,10 +1073,10 @@ fn emitWValue(cg: *CodeGen, value: WValue) InnerError!void {
.tag = .uav_ref_off,
.data = .{
.payload = if (is_obj) try cg.addExtra(Mir.UavRefOffObj{
.uav_obj = try wasm.refUavObj(uav.ip_index),
.uav_obj = try wasm.refUavObj(uav.ip_index, uav.orig_ptr_ty),
.offset = uav.offset,
}) else try cg.addExtra(Mir.UavRefOffExe{
.uav_exe = try wasm.refUavExe(uav.ip_index),
.uav_exe = try wasm.refUavExe(uav.ip_index, uav.orig_ptr_ty),
.offset = uav.offset,
}),
},
@@ -3093,7 +3094,7 @@ fn lowerPtr(cg: *CodeGen, ptr_val: InternPool.Index, prev_offset: u64) InnerErro
const offset: u64 = prev_offset + ptr.byte_offset;
return switch (ptr.base_addr) {
.nav => |nav| return .{ .nav_ref = .{ .nav_index = nav, .offset = @intCast(offset) } },
.uav => |uav| return .{ .uav_ref = .{ .ip_index = uav.val, .offset = @intCast(offset) } },
.uav => |uav| return .{ .uav_ref = .{ .ip_index = uav.val, .offset = @intCast(offset), .orig_ptr_ty = uav.orig_ty } },
.int => return cg.lowerConstant(try pt.intValue(Type.usize, offset), Type.usize),
.eu_payload => return cg.fail("Wasm TODO: lower error union payload pointer", .{}),
.opt_payload => |opt_ptr| return cg.lowerPtr(opt_ptr, offset),

2
src/codegen.zig
View File

@@ -675,7 +675,7 @@ fn lowerUavRef(
} else {
try wasm.uav_fixups.ensureUnusedCapacity(gpa, 1);
wasm.uav_fixups.appendAssumeCapacity(.{
.uavs_exe_index = try wasm.refUavExe(uav.val),
.uavs_exe_index = try wasm.refUavExe(uav.val, uav.orig_ty),
.offset = @intCast(code.items.len),
.addend = @intCast(offset),
});

33
src/link/Wasm.zig
View File

@@ -189,6 +189,9 @@ navs_exe: std.AutoArrayHashMapUnmanaged(InternPool.Nav.Index, ZcuDataExe) = .emp
uavs_obj: std.AutoArrayHashMapUnmanaged(InternPool.Index, ZcuDataObj) = .empty,
/// Tracks ref count to optimize LEB encodings for UAV references.
uavs_exe: std.AutoArrayHashMapUnmanaged(InternPool.Index, ZcuDataExe) = .empty,
/// Sparse table of uavs that need to be emitted with greater alignment than
/// the default for the type.
overaligned_uavs: std.AutoArrayHashMapUnmanaged(InternPool.Index, Alignment) = .empty,
/// When the key is an enum type, this represents a `@tagName` function.
zcu_funcs: std.AutoArrayHashMapUnmanaged(InternPool.Index, ZcuFunc) = .empty,
nav_exports: std.AutoArrayHashMapUnmanaged(NavExport, Zcu.Export.Index) = .empty,
@@ -1945,6 +1948,7 @@ pub const DataSegmentId = enum(u32) {
const zcu = wasm.base.comp.zcu.?;
const ip = &zcu.intern_pool;
const ip_index = i.key(wasm).*;
if (wasm.overaligned_uavs.get(ip_index)) |a| return a;
const ty: Zcu.Type = .fromInterned(ip.typeOf(ip_index));
const result = ty.abiAlignment(zcu);
assert(result != .none);
@@ -3085,6 +3089,7 @@ pub fn deinit(wasm: *Wasm) void {
wasm.navs_obj.deinit(gpa);
wasm.uavs_exe.deinit(gpa);
wasm.uavs_obj.deinit(gpa);
wasm.overaligned_uavs.deinit(gpa);
wasm.zcu_funcs.deinit(gpa);
wasm.nav_exports.deinit(gpa);
wasm.uav_exports.deinit(gpa);
@@ -4397,10 +4402,22 @@ pub fn symbolNameIndex(wasm: *Wasm, name: String) Allocator.Error!SymbolTableInd
return @enumFromInt(gop.index);
}
pub fn refUavObj(wasm: *Wasm, ip_index: InternPool.Index) !UavsObjIndex {
pub fn refUavObj(wasm: *Wasm, ip_index: InternPool.Index, orig_ptr_ty: InternPool.Index) !UavsObjIndex {
const comp = wasm.base.comp;
const zcu = comp.zcu.?;
const ip = &zcu.intern_pool;
const gpa = comp.gpa;
assert(comp.config.output_mode == .Obj);
if (orig_ptr_ty != .none) {
const abi_alignment = Zcu.Type.fromInterned(ip.typeOf(ip_index)).abiAlignment(zcu);
const explicit_alignment = ip.indexToKey(orig_ptr_ty).ptr_type.flags.alignment;
if (explicit_alignment.compare(.gt, abi_alignment)) {
const gop = try wasm.overaligned_uavs.getOrPut(gpa, ip_index);
gop.value_ptr.* = if (gop.found_existing) gop.value_ptr.maxStrict(explicit_alignment) else explicit_alignment;
}
}
const gop = try wasm.uavs_obj.getOrPut(gpa, ip_index);
if (!gop.found_existing) gop.value_ptr.* = .{
// Lowering the value is delayed to avoid recursion.
@@ -4410,10 +4427,22 @@ pub fn refUavObj(wasm: *Wasm, ip_index: InternPool.Index) !UavsObjIndex {
return @enumFromInt(gop.index);
}
pub fn refUavExe(wasm: *Wasm, ip_index: InternPool.Index) !UavsExeIndex {
pub fn refUavExe(wasm: *Wasm, ip_index: InternPool.Index, orig_ptr_ty: InternPool.Index) !UavsExeIndex {
const comp = wasm.base.comp;
const zcu = comp.zcu.?;
const ip = &zcu.intern_pool;
const gpa = comp.gpa;
assert(comp.config.output_mode != .Obj);
if (orig_ptr_ty != .none) {
const abi_alignment = Zcu.Type.fromInterned(ip.typeOf(ip_index)).abiAlignment(zcu);
const explicit_alignment = ip.indexToKey(orig_ptr_ty).ptr_type.flags.alignment;
if (explicit_alignment.compare(.gt, abi_alignment)) {
const gop = try wasm.overaligned_uavs.getOrPut(gpa, ip_index);
gop.value_ptr.* = if (gop.found_existing) gop.value_ptr.maxStrict(explicit_alignment) else explicit_alignment;
}
}
const gop = try wasm.uavs_exe.getOrPut(gpa, ip_index);
if (gop.found_existing) {
gop.value_ptr.count += 1;