complement notes in 11.04

notes/7.md

@@ -0,0 +1,56 @@
+# Code Generation 2
+
+## Stack Machine
+
+Consider two instructions
+* `push i`
+* `add i`
+
+It is not efficient because all stack is considered as memory (which is slower than register).
+
+### Utilizing Register Files
+
+Keep the top of the stack in a register, so `add` requires only a single memory access.
+
+* `acc <- i`
+* `push acc`
+* `pop`
+* `add`
+
+
+### Code Generation From Stack Machine
+
+Assume that stack grows towards lower addresses.
+
+
+## MIPS
+
+32 regs
+
+`$sp`, `$a0`, `$t1`
+
+* `lw`
+* `add`
+* `sw`
+* `addi`
+* `li`
+* `mv`
+
+
+Converting Stack to MIPS ISA
+
+* `acc <- i`
+  * `li $a0 i`
+
+### Optimizing
+
+
+
+## Branch
+
+`beq $1 $2 lbl`
+`b lbl`
+
+
+## Function
+