diff options
Diffstat (limited to 'TODO')
| -rw-r--r-- | TODO | 45 |
1 files changed, 45 insertions, 0 deletions
@@ -0,0 +1,45 @@ +Conversion to SSA form, could maybe be done in two phases: +1. Build up initial tree of block parameters, something like +get_in(block b) { + b->visited = true + bitset gen = 0 + bitset in = 0 + + for i in b->insns { + if i.in1 not in gen { + add i.in1 to in + } + + if i.in2 not in gen { + add i.in2 to in + } + + add i.out to gen + } + + /* recursion, but presumably the user's programs are reasonable + * in size. Otherwise we can probably build up some piecewise + * construct that iterates normally until it converges or something + */ + bitset s1 = get_in(b->s1) + bitset s2 = get_in(b->s2) + + add from s1 not in gen to in + add from s2 not in gen to in +} + +2. Within each block, allocate unique temporary variables. + +This should result in SSA form with block arguments? + +In SSA form, calculate (approximate) value ranges. Assign each location +some value range, [min, max], and propagate functions that calculate the ranges +wherever possible. Where min==max, the location can be replaced by min and the +constants propagated. Generally already checked blocks would not need to be +checked, unless one of the input parameters' range was undefined but became +defined, or was a constant but became a range, or was positive/negative but the +range expanded to be negative/positive as well. + +Do register allocation + +Do instruction generation |