GitLab

fallthrough block (because it may be placed somewhereone else)

macro.

argument
we need to know whether a block is an exception block by looking at all
the exceptional clauses.

replacing most uses of HashMap with LinkedHashMap. This will reduce (if not eliminate) undeterminism in the compilation.
Copied LinkedHashMap implementation to local so that I can implement encode/decode and other necessary methods

1. asm call do not use all argument registers (otherwise it will keep
them alive)
2. spilling a register that is used and defined in one instruction will
result in creating one new temporary, instead of two
3. spilling now deals with floating point
4. SELECT with int8 is implemented using conditional jump (cmov cannot
take reg8)
5. postcall convention now deals correctly with fp return values
6. reg alloc conservative() was wrong in a few commits ago, fixed it
7. in liveness analysis, when finding a move between a temp and a
register, find the color for the register (such as RAX for EAX)

1. compiler knows all the registers
2. but only 64bits register is a color (for reg alloc)
3. backend records the length of GPR for each operand during instruction
selection
4. after reg alloc, when replacing temp with a color, find corresponding
GPR for the length recorded before

currently we only use 64bit registers, extend/truncate result if it is
not 64bits. This is awful. Going to use all the registers, for example,
AL, AX, EAX, RAX, but will not use AH (so reg alloc is simpler)