diff options
| -rw-r--r-- | src/compile.zig | 61 |
1 files changed, 42 insertions, 19 deletions
diff --git a/src/compile.zig b/src/compile.zig index 80279fb..d1cac8c 100644 --- a/src/compile.zig +++ b/src/compile.zig @@ -98,14 +98,18 @@ pub const BasicBlock = struct { fn finalize(self: *BasicBlock, allocator: Allocator) !void { std.debug.assert(self.instrs.items.len > 0); - for (self.instrs.items[0 .. self.instrs.items.len - 1]) |instr| { - std.debug.assert(switch (instr.type) { - inline else => |ty| !@hasDecl(@TypeOf(ty), "ends_block"), - }); + for (self.instrs.items, 0..) |instr, i| { + const is_last = i == self.instrs.items.len - 1; + if (instr.ends_block() != is_last) { + std.log.debug("Instruction at {s}last position must {s}end block. Found instruction {}. Block is: {}", .{ + if (is_last) "" else "not ", + if (is_last) "" else "not ", + instr, + self, + }); + unreachable; + } } - std.debug.assert(switch (self.instrs.getLast().type) { - inline else => |ty| @hasDecl(@TypeOf(ty), "ends_block"), - }); self.vreg_last_use = .empty; var set_at: std.AutoHashMapUnmanaged(VReg, usize) = .empty; @@ -155,6 +159,12 @@ pub const Instr = struct { ret: Return, }; + fn ends_block(self: Instr) bool { + return switch (self.type) { + inline else => |t| @hasDecl(@TypeOf(t), "ends_block"), + }; + } + pub const Constant = struct { dest: VReg, value: u64, @@ -389,15 +399,17 @@ fn compileProcedure( break :blk lvar; } else null; try pctx.compileBlock(proc.body); - const proc_res = pctx.vreg_ctr.get(); - try pctx.addInstr(.{ - .loc = .{ .start = 0, .end = 0 }, - .type = .{ .constant = .{ .dest = proc_res, .value = 0 } }, - }); - try pctx.addInstr(.{ - .loc = .{ .start = 0, .end = 0 }, - .type = .{ .ret = .{ .val = proc_res } }, - }); + if (!pctx.currentBlockEnded()) { + const proc_res = pctx.vreg_ctr.get(); + try pctx.addInstr(.{ + .loc = .{ .start = 0, .end = 0 }, + .type = .{ .constant = .{ .dest = proc_res, .value = 0 } }, + }); + try pctx.addInstr(.{ + .loc = .{ .start = 0, .end = 0 }, + .type = .{ .ret = .{ .val = proc_res } }, + }); + } var blocks = try ctx.allocator.alloc(BasicBlock, pctx.blocks.count()); var it = pctx.blocks.iterator(); var i: usize = 0; @@ -496,7 +508,7 @@ const ProcedureContext = struct { }); self.current_block = do; try self.compileBlock(@"while".do); - try self.addInstr(.{ + try self.addInstrUnlessEnded(.{ .loc = stmt.loc, .type = .{ .jump = .{ .to = cond_block } }, }); @@ -579,7 +591,7 @@ const ProcedureContext = struct { const t = try self.switchToNewBlock(); try self.compileBlock(@"if".then); - try self.addInstr(.{ + try self.addInstrUnlessEnded(.{ .loc = expr.loc, .type = .{ .jump = .{ .to = after } }, }); @@ -587,7 +599,7 @@ const ProcedureContext = struct { const f = if (@"if".@"else") |@"else"| blk: { const f = try self.switchToNewBlock(); try self.compileBlock(@"else"); - try self.addInstr(.{ + try self.addInstrUnlessEnded(.{ .loc = expr.loc, .type = .{ .jump = .{ .to = after } }, }); @@ -632,4 +644,15 @@ const ProcedureContext = struct { try self.blocks.getPtr(self.current_block).? .instrs.append(self.ctx.allocator, instr); } + + fn addInstrUnlessEnded(self: *ProcedureContext, instr: Instr) !void { + if (!self.currentBlockEnded()) try self.addInstr(instr); + } + + fn currentBlockEnded(self: *ProcedureContext) bool { + return if (self.blocks.get(self.current_block).?.instrs.getLastOrNull()) |instr| + instr.ends_block() + else + false; + } }; |