diff options
Diffstat (limited to 'ir/regalloc.c')
| -rw-r--r-- | ir/regalloc.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/ir/regalloc.c b/ir/regalloc.c index fae1a61..f43bcc7 100644 --- a/ir/regalloc.c +++ b/ir/regalloc.c @@ -2,7 +2,7 @@ /** Implements linear scan register allocation **/ -#if 0 +#if 1 #define DBG(...) if(ccopt.dbg.r) efmt(__VA_ARGS__) #else #define DBG(...) ((void)0) @@ -1000,12 +1000,19 @@ devirt(struct rega *ra, struct block *blk) bool dosave; /* pick scratch register, or any register that doesn't conflict with this instr's srcs/dst */ if (nspill > 0) { - for (reg = kisflt(ld.cls) ? mctarg->fpr0 : mctarg->gpr0;; ++reg) { - if (reg == ins->reg-1) continue; - for (int j = 0; j < i; ++j) - if (argref[j]->t == RREG && argref[j]->i == reg) continue; - break; + regset avail = kisflt(ld.cls) ? fpregset : gpregset; + if (ins->reg) rsclr(&avail, ins->reg-1); + for (int j = 0; j < nargref; ++j) { + struct interval *it; + if (argref[j]->t == RREG) rsclr(&avail, argref[j]->i); + else if (argref[j]->t == RTMP) { + it = &ra->intervals.temps[argref[j]->i]; + if (it->alloc.t == AREG) rsclr(&avail, it->alloc.a); + } } + assert(avail != 0); + if (reg &~ (fn->regusage | mctarg->rcallee)) reg &= ~(fn->regusage | mctarg->rcallee); + reg = lowestsetbit(avail); /* if not the designated scratch register, we need to save+restore */ if ((dosave = rstest(fn->regusage, reg) || rstest(mctarg->rcallee, reg))) { insertinstr(blk, curi++, mkinstr(Oxsave, 0, .l = mkref(RREG, reg))); |