The paper for the new SSA construction nicely leave the question
of GOTOs as en exercice for the student.
This patch is such an exercice.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
linearize.h | 1 +
ssa.c | 20 +++++++++++++++++++-
ssa.h | 1 +
3 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/linearize.h b/linearize.h
index 30f34aa8f..eba0323d0 100644
--- a/linearize.h
+++ b/linearize.h
@@ -237,6 +237,7 @@ struct basic_block {
union {
struct { // SSA construction
unsigned int sealed:1;
+ unsigned int unsealable:1;
};
struct { // liveness
struct pseudo_list *needs, *defines;
diff --git a/ssa.c b/ssa.c
index 32e440669..d8fa32d93 100644
--- a/ssa.c
+++ b/ssa.c
@@ -81,7 +81,7 @@ void store_var(struct basic_block *bb, struct symbol *var, pseudo_t val)
void seal_bb(struct basic_block *bb)
{
struct instruction *insn;
- if (bb->sealed)
+ if (bb->sealed || bb->unsealable)
return;
FOR_EACH_PTR(bb->insns, insn) {
struct symbol *var;
@@ -96,3 +96,21 @@ void seal_bb(struct basic_block *bb)
} END_FOR_EACH_PTR(insn);
bb->sealed = 1;
}
+
+void seal_gotos(struct entrypoint *ep)
+{
+ struct basic_block *bb;
+
+ FOR_EACH_PTR(ep->bbs, bb) {
+ if (bb->sealed)
+ continue;
+ if (bb->unsealable)
+ bb->unsealable = 0;
+ seal_bb(bb);
+ } END_FOR_EACH_PTR(bb);
+
+ // cleanup these fields as they are aliased to ::needs & ::defines
+ FOR_EACH_PTR(ep->bbs, bb) {
+ bb->sealed = bb->unsealable = 0;
+ } END_FOR_EACH_PTR(bb);
+}
diff --git a/ssa.h b/ssa.h
index 484c2b418..e88b857b5 100644
--- a/ssa.h
+++ b/ssa.h
@@ -7,5 +7,6 @@
pseudo_t load_var(struct basic_block *bb, struct symbol *var);
void store_var(struct basic_block *bb, struct symbol *var, pseudo_t val);
void seal_bb(struct basic_block *bb);
+void seal_gotos(struct entrypoint *ep);
#endif
--
2.14.0
--
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