diff options
Diffstat (limited to 'src/codegen/c.zig')
| -rw-r--r-- | src/codegen/c.zig | 97 |
1 files changed, 56 insertions, 41 deletions
diff --git a/src/codegen/c.zig b/src/codegen/c.zig index 0391fa4c84..4603477404 100644 --- a/src/codegen/c.zig +++ b/src/codegen/c.zig @@ -15,7 +15,6 @@ const Decl = Module.Decl; const trace = @import("../tracy.zig").trace; const LazySrcLoc = Module.LazySrcLoc; const Air = @import("../Air.zig"); -const Zir = @import("../Zir.zig"); const Liveness = @import("../Liveness.zig"); const Mutability = enum { Const, Mut }; @@ -2805,49 +2804,48 @@ fn airSwitchBr(f: *Function, inst: Air.Inst.Index) !CValue { } fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue { - const air_datas = f.air.instructions.items(.data); - const air_extra = f.air.extraData(Air.Asm, air_datas[inst].ty_pl.payload); - const zir = f.object.dg.decl.getFileScope().zir; - const extended = zir.instructions.items(.data)[air_extra.data.zir_index].extended; - const zir_extra = zir.extraData(Zir.Inst.Asm, extended.operand); - const asm_source = zir.nullTerminatedString(zir_extra.data.asm_source); - const outputs_len = @truncate(u5, extended.small); - const args_len = @truncate(u5, extended.small >> 5); - const clobbers_len = @truncate(u5, extended.small >> 10); - _ = clobbers_len; // TODO honor these - const is_volatile = @truncate(u1, extended.small >> 15) != 0; - const outputs = @bitCast([]const Air.Inst.Ref, f.air.extra[air_extra.end..][0..outputs_len]); - const args = @bitCast([]const Air.Inst.Ref, f.air.extra[air_extra.end + outputs.len ..][0..args_len]); - - if (outputs_len > 1) { + const ty_pl = f.air.instructions.items(.data)[inst].ty_pl; + const extra = f.air.extraData(Air.Asm, ty_pl.payload); + const is_volatile = @truncate(u1, extra.data.flags >> 31) != 0; + const clobbers_len = @truncate(u31, extra.data.flags); + var extra_i: usize = extra.end; + const outputs = @bitCast([]const Air.Inst.Ref, f.air.extra[extra_i..][0..extra.data.outputs_len]); + extra_i += outputs.len; + const inputs = @bitCast([]const Air.Inst.Ref, f.air.extra[extra_i..][0..extra.data.inputs_len]); + extra_i += inputs.len; + + if (!is_volatile and f.liveness.isUnused(inst)) return CValue.none; + + if (outputs.len > 1) { return f.fail("TODO implement codegen for asm with more than 1 output", .{}); } - if (f.liveness.isUnused(inst) and !is_volatile) - return CValue.none; - - var extra_i: usize = zir_extra.end; - const output_constraint: ?[]const u8 = out: { - var i: usize = 0; - while (i < outputs_len) : (i += 1) { - const output = zir.extraData(Zir.Inst.Asm.Output, extra_i); - extra_i = output.end; - break :out zir.nullTerminatedString(output.data.constraint); + const output_constraint: ?[]const u8 = for (outputs) |output| { + if (output != .none) { + return f.fail("TODO implement codegen for non-expr asm", .{}); } - break :out null; - }; - const args_extra_begin = extra_i; + const constraint = std.mem.sliceTo(std.mem.sliceAsBytes(f.air.extra[extra_i..]), 0); + // This equation accounts for the fact that even if we have exactly 4 bytes + // for the string, we still use the next u32 for the null terminator. + extra_i += constraint.len / 4 + 1; + + break constraint; + } else null; const writer = f.object.writer(); - for (args) |arg| { - const input = zir.extraData(Zir.Inst.Asm.Input, extra_i); - extra_i = input.end; - const constraint = zir.nullTerminatedString(input.data.constraint); + const inputs_extra_begin = extra_i; + + for (inputs) |input| { + const constraint = std.mem.sliceTo(std.mem.sliceAsBytes(f.air.extra[extra_i..]), 0); + // This equation accounts for the fact that even if we have exactly 4 bytes + // for the string, we still use the next u32 for the null terminator. + extra_i += constraint.len / 4 + 1; + if (constraint[0] == '{' and constraint[constraint.len - 1] == '}') { const reg = constraint[1 .. constraint.len - 1]; - const arg_c_value = try f.resolveInst(arg); + const arg_c_value = try f.resolveInst(input); try writer.writeAll("register "); - try f.renderType(writer, f.air.typeOf(arg)); + try f.renderType(writer, f.air.typeOf(input)); try writer.print(" {s}_constant __asm__(\"{s}\") = ", .{ reg, reg }); try f.writeCValue(writer, arg_c_value); @@ -2856,21 +2854,38 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue { return f.fail("TODO non-explicit inline asm regs", .{}); } } + + { + var clobber_i: u32 = 0; + while (clobber_i < clobbers_len) : (clobber_i += 1) { + const clobber = std.mem.sliceTo(std.mem.sliceAsBytes(f.air.extra[extra_i..]), 0); + // This equation accounts for the fact that even if we have exactly 4 bytes + // for the string, we still use the next u32 for the null terminator. + extra_i += clobber.len / 4 + 1; + + // TODO honor these + } + } + + const asm_source = std.mem.sliceAsBytes(f.air.extra[extra_i..])[0..extra.data.source_len]; + const volatile_string: []const u8 = if (is_volatile) "volatile " else ""; try writer.print("__asm {s}(\"{s}\"", .{ volatile_string, asm_source }); if (output_constraint) |_| { return f.fail("TODO: CBE inline asm output", .{}); } - if (args.len > 0) { + if (inputs.len > 0) { if (output_constraint == null) { try writer.writeAll(" :"); } try writer.writeAll(": "); - extra_i = args_extra_begin; - for (args) |_, index| { - const input = zir.extraData(Zir.Inst.Asm.Input, extra_i); - extra_i = input.end; - const constraint = zir.nullTerminatedString(input.data.constraint); + extra_i = inputs_extra_begin; + for (inputs) |_, index| { + const constraint = std.mem.sliceTo(std.mem.sliceAsBytes(f.air.extra[extra_i..]), 0); + // This equation accounts for the fact that even if we have exactly 4 bytes + // for the string, we still use the next u32 for the null terminator. + extra_i += constraint.len / 4 + 1; + if (constraint[0] == '{' and constraint[constraint.len - 1] == '}') { const reg = constraint[1 .. constraint.len - 1]; if (index > 0) { |