diff options
Diffstat (limited to 'lisc')
| -rw-r--r-- | lisc/isel.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/lisc/isel.c b/lisc/isel.c index 056e66f..6d7f2a3 100644 --- a/lisc/isel.c +++ b/lisc/isel.c @@ -12,6 +12,11 @@ * - implement fast locals (the streak of * constant allocX in the first basic block) * - recognize complex addressing modes + * + * Invariant: the use counts that are used + * in sel() must be sound. This + * is not so trivial, maybe the + * dce should be moved out... */ typedef struct ANum ANum; @@ -86,6 +91,13 @@ fixargs(Ins *i, Fn *fn) } static void +chuse(Ref r, int du, Fn *fn) +{ + if (rtype(r) == RTmp) + fn->tmp[r.val].nuse += du; +} + +static void seladdr(Ref *r, ANum *an, Fn *fn) { Addr a; @@ -93,14 +105,17 @@ seladdr(Ref *r, ANum *an, Fn *fn) r0 = *r; if (rtype(r0) == RTmp) { + chuse(r0, -1, fn); r1 = an[r0.val].mem; if (req(r1, R)) { amatch(&a, r0, an, fn, 1); vgrow(&fn->mem, ++fn->nmem); fn->mem[fn->nmem-1] = a; r1 = MEM(fn->nmem-1); + chuse(a.base, +1, fn); + chuse(a.index, +1, fn); if (rtype(a.base) != RTmp) - if (req(a.index, R)) + if (rtype(a.index) != RTmp) an[r0.val].mem = r1; } *r = r1; @@ -130,6 +145,13 @@ sel(Ins i, ANum *an, Fn *fn) int64_t val; Ins *i0; + if (rtype(i.to) == RTmp) + if (!isreg(i.to) && !isreg(i.arg[0]) && !isreg(i.arg[1])) + if (fn->tmp[i.to.val].nuse == 0) { + chuse(i.arg[0], -1, fn); + chuse(i.arg[1], -1, fn); + return; + } i0 = curi; w = i.wide; switch (i.op) { |