From 037c716b6514cc717b7208457fb72085e4c278ab Mon Sep 17 00:00:00 2001 From: Quentin Carbonneaux Date: Fri, 10 Jul 2015 03:16:11 -0400 Subject: move ml prototype in a subdir --- TODO | 54 ------------------------------------------------------ 1 file changed, 54 deletions(-) delete mode 100644 TODO (limited to 'TODO') diff --git a/TODO b/TODO deleted file mode 100644 index e144c66..0000000 --- a/TODO +++ /dev/null @@ -1,54 +0,0 @@ -Features -- Operand classes for instructions -- Hints in register allocation -- Fixed register instructions (div, mul) - Is this part of "operand classes"? - -Instructions -- ADD SUB SDIV UDIV SREM UREM MUL LSL LSR ASL ASR -- SEXT ZEXT (we need 8, 16, 32, 64 bits) -- CMP ... -- ALLOC STORE LOAD (we need 8, 16, 32, 64 bits) -(- PTR) -- CALL BRZ JMP RET - -Machine -- SREG GREG -- Register use/defs for all instructions. - -Types -- Integer (32 & 64 bits) -(- Structure "{a,b,c}") -(- Pointer (to type "t")) - -Questions -- Q: Should we allow constant operands? - A: - It looks like `Con instructions are a bad idea because - they introduce spurious live ranges. - This was not a huge problem, modifications s in loc and - getreg only fixed this. Still, it makes use larger bit - vectors during the liveness analysis. -- Q: How to represent the IR? - A: - So far, a graph of basic blocks composed of quadruples - seems to be the most convenient. -- Q: Do we need types? - -Problems -- x = y op z [fixed using freeze] - if x is spilled, y can be moved to a spill location - to free one register for x, this is kind of stupid. - We can probably fix this by having a better heuristic - for spilling decisions. -- [tentative fix: 4fc98da] - Phi defined variables with spill location do not work. -- At the end of a block we call loc on all live variables, - if there are not enough registers, some variables get - assigned spill locations. We need to be able to spill - variables that are already in register. - NOTE: Following Braun & Hack we could do one pass - first that determines what variables are in register - at the end of loops. This sounds good because - back-edges are actually easier to detect than loop - headers! -- cgit 1.4.1