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wasm: support pointers in cmpxchg

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This commit is contained in:
Luuk de Gram 2023-04-25 19:52:36 +02:00
parent 7c09e09457
commit b26a46d05b
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GPG Key ID: A8CFE58E4DC7D664
1 changed files with 29 additions and 16 deletions
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45
src/arch/wasm/CodeGen.zig
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@ -6631,11 +6631,13 @@ fn airCmpxchg(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const expected_val = try func.resolveInst(extra.expected_value);
const new_val = try func.resolveInst(extra.new_value);
const cmp_result = try func.allocLocal(Type.bool);
const ptr_val = if (func.useAtomicFeature()) val: {
const val_local = try func.allocLocal(ty);
try func.emitWValue(ptr_operand);
try func.emitWValue(expected_val);
try func.emitWValue(new_val);
try func.lowerToStack(expected_val);
try func.lowerToStack(new_val);
try func.addAtomicMemArg(switch (ty.abiSize(func.target)) {
1 => .i32_atomic_rmw8_cmpxchg_u,
2 => .i32_atomic_rmw16_cmpxchg_u,
@ -6648,32 +6650,43 @@ fn airCmpxchg(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
});
try func.addLabel(.local_tee, val_local.local.value);
_ = try func.cmp(.stack, expected_val, ty, .eq);
try func.addLabel(.local_set, cmp_result.local.value);
break :val val_local;
} else val: {
if (ty.abiSize(func.target) > 8) {
return func.fail("TODO: Implement `@cmpxchg` for types larger than abi size of 8 bytes", .{});
}
const ptr_val = try WValue.toLocal(try func.load(ptr_operand, ty, 0), func, ty);
try func.lowerToStack(ptr_operand);
try func.emitWValue(new_val);
try func.lowerToStack(new_val);
try func.emitWValue(ptr_val);
const cmp_tmp = try func.cmp(ptr_val, expected_val, ty, .eq);
const cmp_result = try cmp_tmp.toLocal(func, Type.bool);
try func.emitWValue(cmp_result);
_ = try func.cmp(ptr_val, expected_val, ty, .eq);
try func.addLabel(.local_tee, cmp_result.local.value);
try func.addTag(.select);
try func.store(.stack, .stack, ty, 0);
try func.emitWValue(cmp_result);
break :val ptr_val;
};
try func.addImm32(-1);
try func.addTag(.i32_xor);
try func.addImm32(1);
try func.addTag(.i32_and);
const and_result = try WValue.toLocal(.stack, func, Type.bool);
const result_ptr = try func.allocStack(result_ty);
try func.store(result_ptr, and_result, Type.bool, @intCast(u32, ty.abiSize(func.target)));
try func.store(result_ptr, ptr_val, ty, 0);
const result_ptr = if (isByRef(result_ty, func.target)) val: {
try func.emitWValue(cmp_result);
try func.addImm32(-1);
try func.addTag(.i32_xor);
try func.addImm32(1);
try func.addTag(.i32_and);
const and_result = try WValue.toLocal(.stack, func, Type.bool);
const result_ptr = try func.allocStack(result_ty);
try func.store(result_ptr, and_result, Type.bool, @intCast(u32, ty.abiSize(func.target)));
try func.store(result_ptr, ptr_val, ty, 0);
break :val result_ptr;
} else val: {
try func.addImm32(0);
try func.emitWValue(ptr_val);
try func.emitWValue(cmp_result);
try func.addTag(.select);
break :val try WValue.toLocal(.stack, func, result_ty);
};
return func.finishAir(inst, result_ptr, &.{ extra.ptr, extra.new_value, extra.expected_value });
}