diff options
Diffstat (limited to 'src/codegen/c.zig')
| -rw-r--r-- | src/codegen/c.zig | 147 |
1 files changed, 129 insertions, 18 deletions
diff --git a/src/codegen/c.zig b/src/codegen/c.zig index 4964f17cd3..95ce95f2e5 100644 --- a/src/codegen/c.zig +++ b/src/codegen/c.zig @@ -883,22 +883,27 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO // TODO use a different strategy for add that communicates to the optimizer // that wrapping is UB. - .add, .ptr_add => try airBinOp( f, inst, " + "), - .addwrap => try airWrapOp(f, inst, " + ", "addw_"), + .add, .ptr_add => try airBinOp (f, inst, " + "), // TODO use a different strategy for sub that communicates to the optimizer // that wrapping is UB. - .sub, .ptr_sub => try airBinOp( f, inst, " - "), - .subwrap => try airWrapOp(f, inst, " - ", "subw_"), + .sub, .ptr_sub => try airBinOp (f, inst, " - "), // TODO use a different strategy for mul that communicates to the optimizer // that wrapping is UB. - .mul => try airBinOp( f, inst, " * "), - .mulwrap => try airWrapOp(f, inst, " * ", "mulw_"), + .mul => try airBinOp (f, inst, " * "), // TODO use a different strategy for div that communicates to the optimizer // that wrapping is UB. .div => try airBinOp( f, inst, " / "), .rem => try airBinOp( f, inst, " % "), - // TODO implement modulus division - .mod => try airBinOp( f, inst, " mod "), + .mod => try airBinOp( f, inst, " mod "), // TODO implement modulus division + + .addwrap => try airWrapOp(f, inst, " + ", "addw_"), + .subwrap => try airWrapOp(f, inst, " - ", "subw_"), + .mulwrap => try airWrapOp(f, inst, " * ", "mulw_"), + + .add_sat => try airSatOp(f, inst, "adds_"), + .sub_sat => try airSatOp(f, inst, "subs_"), + .mul_sat => try airSatOp(f, inst, "muls_"), + .shl_sat => try airSatOp(f, inst, "shls_"), .cmp_eq => try airBinOp(f, inst, " == "), .cmp_gt => try airBinOp(f, inst, " > "), @@ -908,16 +913,14 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO .cmp_neq => try airBinOp(f, inst, " != "), // bool_and and bool_or are non-short-circuit operations - .bool_and => try airBinOp(f, inst, " & "), - .bool_or => try airBinOp(f, inst, " | "), - .bit_and => try airBinOp(f, inst, " & "), - .bit_or => try airBinOp(f, inst, " | "), - .xor => try airBinOp(f, inst, " ^ "), - - .shr => try airBinOp(f, inst, " >> "), - .shl => try airBinOp(f, inst, " << "), - - .not => try airNot( f, inst), + .bool_and => try airBinOp(f, inst, " & "), + .bool_or => try airBinOp(f, inst, " | "), + .bit_and => try airBinOp(f, inst, " & "), + .bit_or => try airBinOp(f, inst, " | "), + .xor => try airBinOp(f, inst, " ^ "), + .shr => try airBinOp(f, inst, " >> "), + .shl, .shl_exact => try airBinOp(f, inst, " << "), + .not => try airNot (f, inst), .optional_payload => try airOptionalPayload(f, inst), .optional_payload_ptr => try airOptionalPayload(f, inst), @@ -1309,6 +1312,114 @@ fn airWrapOp( return ret; } +fn airSatOp(f: *Function, inst: Air.Inst.Index, fn_op: [*:0]const u8) !CValue { + if (f.liveness.isUnused(inst)) + return CValue.none; + + const bin_op = f.air.instructions.items(.data)[inst].bin_op; + const inst_ty = f.air.typeOfIndex(inst); + const int_info = inst_ty.intInfo(f.object.dg.module.getTarget()); + const bits = int_info.bits; + + switch (bits) { + 8, 16, 32, 64, 128 => {}, + else => return f.object.dg.fail("TODO: C backend: airSatOp for non power of 2 integers", .{}), + } + + // if it's an unsigned int with non-arbitrary bit size then we can just add + if (bits > 64) { + return f.object.dg.fail("TODO: C backend: airSatOp for large integers", .{}); + } + + var min_buf: [80]u8 = undefined; + const min = switch (int_info.signedness) { + .unsigned => "0", + else => switch (inst_ty.tag()) { + .c_short => "SHRT_MIN", + .c_int => "INT_MIN", + .c_long => "LONG_MIN", + .c_longlong => "LLONG_MIN", + .isize => "INTPTR_MIN", + else => blk: { + // compute the type minimum based on the bitcount (bits) + const val = -1 * std.math.pow(i65, 2, @intCast(i65, bits - 1)); + break :blk std.fmt.bufPrint(&min_buf, "{d}", .{val}) catch |err| switch (err) { + error.NoSpaceLeft => unreachable, + else => |e| return e, + }; + }, + }, + }; + + var max_buf: [80]u8 = undefined; + const max = switch (inst_ty.tag()) { + .c_short => "SHRT_MAX", + .c_ushort => "USHRT_MAX", + .c_int => "INT_MAX", + .c_uint => "UINT_MAX", + .c_long => "LONG_MAX", + .c_ulong => "ULONG_MAX", + .c_longlong => "LLONG_MAX", + .c_ulonglong => "ULLONG_MAX", + .isize => "INTPTR_MAX", + .usize => "UINTPTR_MAX", + else => blk: { + const pow_bits = switch (int_info.signedness) { + .signed => bits - 1, + .unsigned => bits, + }; + const val = std.math.pow(u65, 2, pow_bits) - 1; + break :blk std.fmt.bufPrint(&max_buf, "{}", .{val}) catch |err| switch (err) { + error.NoSpaceLeft => unreachable, + else => |e| return e, + }; + }, + }; + + const lhs = try f.resolveInst(bin_op.lhs); + const rhs = try f.resolveInst(bin_op.rhs); + const w = f.object.writer(); + + const ret = try f.allocLocal(inst_ty, .Mut); + try w.print(" = zig_{s}", .{fn_op}); + + switch (inst_ty.tag()) { + .isize => try w.writeAll("isize"), + .c_short => try w.writeAll("short"), + .c_int => try w.writeAll("int"), + .c_long => try w.writeAll("long"), + .c_longlong => try w.writeAll("longlong"), + else => { + const prefix_byte: u8 = switch (int_info.signedness) { + .signed => 'i', + .unsigned => 'u', + }; + for ([_]u8{ 8, 16, 32, 64 }) |nbits| { + if (bits <= nbits) { + try w.print("{c}{d}", .{ prefix_byte, nbits }); + break; + } + } else { + unreachable; + } + }, + } + + try w.writeByte('('); + try f.writeCValue(w, lhs); + try w.writeAll(", "); + try f.writeCValue(w, rhs); + + if (int_info.signedness == .signed) { + try w.print(", {s}", .{min}); + } + + try w.print(", {s});", .{max}); + try f.object.indent_writer.insertNewline(); + + return ret; +} + fn airNot(f: *Function, inst: Air.Inst.Index) !CValue { if (f.liveness.isUnused(inst)) return CValue.none; |