diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-11-16 16:47:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-07 21:04:33 -0700 |
| commit | a25eb46654bcc274b81af4f6aee2ea640c067e8a (patch) | |
| tree | 7faa35d0492c87877b66a541c60437e2e9efbb2a /flow.c | |
| parent | c040f2e0eedcea68618679bd97e3587fb904f602 (diff) | |
| download | sparse-dev-a25eb46654bcc274b81af4f6aee2ea640c067e8a.tar.gz | |
If we find an exclusive dominating load, see if we can follow it further.
In particular, we could check if the loaded value then gets used in a test,
so that the test ends up dominating the instruction..
This just adds the hooks. We don't actually try to find any test instructions.
Diffstat (limited to 'flow.c')
| -rw-r--r-- | flow.c | 25 |
1 files changed, 21 insertions, 4 deletions
@@ -206,6 +206,15 @@ static int dominates(pseudo_t pseudo, struct instruction *insn, return 1; } +static pseudo_t load_dominator(struct instruction *insn, struct instruction *dom) +{ + /* + * We should eventually see if we can determine a more precise + * value by seeing if the load value gets tested.. + */ + return dom->target; +} + static int find_dominating_parents(pseudo_t pseudo, struct instruction *insn, struct basic_block *bb, unsigned long generation, struct phi_list **dominators, int local, int loads) @@ -216,6 +225,7 @@ static int find_dominating_parents(pseudo_t pseudo, struct instruction *insn, loads = 0; FOR_EACH_PTR(bb->parents, parent) { struct instruction *one; + pseudo_t target; struct phi *phi; FOR_EACH_PTR_REVERSE(parent->insns, one) { @@ -230,8 +240,12 @@ static int find_dominating_parents(pseudo_t pseudo, struct instruction *insn, } if (!dominance) continue; - if (one->opcode == OP_LOAD && !loads) - continue; + target = one->target; + if (one->opcode == OP_LOAD) { + if (!loads) + continue; + target = load_dominator(insn, one); + } goto found_dominator; } END_FOR_EACH_PTR_REVERSE(one); no_dominance: @@ -244,7 +258,7 @@ no_dominance: continue; found_dominator: - phi = alloc_phi(parent, one->target); + phi = alloc_phi(parent, target); add_phi(dominators, phi); } END_FOR_EACH_PTR(parent); return 1; @@ -338,7 +352,10 @@ found: return 0; if (dom) { - convert_load_insn(insn, dom->target); + pseudo_t target = dom->target; + if (dom->opcode == OP_LOAD) + target = load_dominator(insn, dom); + convert_load_insn(insn, target); return 1; } |