Initial project import

tools/v/vlib/v3/insel/insel.v

@@ -0,0 +1,111 @@
+module insel
+
+import v3.mir
+import v3.ssa
+
+pub enum OperandKind {
+	value
+	block
+}
+
+pub struct Operand {
+pub:
+	kind OperandKind
+	id   int
+}
+
+pub struct Instruction {
+pub:
+	op       ssa.OpCode
+	operands []Operand
+	typ      ssa.TypeID
+}
+
+pub struct BasicBlock {
+pub:
+	id     int
+	name   string
+	instrs []Instruction
+}
+
+pub struct Function {
+pub:
+	id     int
+	name   string
+	abi    mir.FunctionAbi
+	blocks []BasicBlock
+}
+
+pub struct Module {
+pub:
+	target mir.Target
+	funcs  []Function
+}
+
+// select_ selects MIR instructions into a target-specific machine module shell.
+pub fn select_(mut m mir.Module) Module {
+	mut funcs := []Function{}
+	for f in m.funcs {
+		if f.is_c_extern {
+			continue
+		}
+		mut blocks := []BasicBlock{}
+		for block_id in f.blocks {
+			if block_id < 0 || block_id >= m.blocks.len {
+				continue
+			}
+			blk := m.blocks[block_id]
+			mut instrs := []Instruction{}
+			for val_id in blk.instrs {
+				if val_id <= 0 || val_id >= m.values.len {
+					continue
+				}
+				val := m.values[val_id]
+				if val.kind != .instruction {
+					continue
+				}
+				instr := m.instrs[val.index]
+				instrs << Instruction{
+					op:       instr.op
+					operands: select_operands(instr)
+					typ:      instr.typ
+				}
+			}
+			blocks << BasicBlock{
+				id:     blk.id
+				name:   blk.name
+				instrs: instrs
+			}
+		}
+		funcs << Function{
+			id:     f.id
+			name:   f.name
+			abi:    f.abi
+			blocks: blocks
+		}
+	}
+	return Module{
+		target: m.target
+		funcs:  funcs
+	}
+}
+
+fn select_operands(instr mir.Instruction) []Operand {
+	mut operands := []Operand{}
+	for i, operand in instr.operands {
+		kind := if instr.op == .br && i > 0 {
+			OperandKind.block
+		} else if instr.op == .phi && i % 2 == 1 {
+			OperandKind.block
+		} else if instr.op == .jmp {
+			OperandKind.block
+		} else {
+			OperandKind.value
+		}
+		operands << Operand{
+			kind: kind
+			id:   operand
+		}
+	}
+	return operands
+}