[PATCH 3/4] add a flag for volatile memops

[Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>]

When simplifying memops, it's needed to check if the memops
is a volatile access or not. This is currently done by checking
insn->type->ctype.modifiers & MOD_VOLATILE which is rather long
but also incorrect for bitfields.

Prepare to fix this by adding a flag to struct instruction directly
telling if the access is volatile.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
 flow.c      | 2 +-
 linearize.c | 2 ++
 linearize.h | 1 +
 memops.c    | 4 ++--
 simplify.c  | 2 +-
 5 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/flow.c b/flow.c
index 9483938fb..3796c75fa 100644
--- a/flow.c
+++ b/flow.c
@@ -174,7 +174,7 @@ static int bb_has_side_effects(struct basic_block *bb)
 		case OP_LOAD:
 			if (!insn->type)
 				return 1;
-			if (insn->type->ctype.modifiers & MOD_VOLATILE)
+			if (insn->is_volatile)
 				return 1;
 			continue;
 
diff --git a/linearize.c b/linearize.c
index 2e9a56383..1444e655b 100644
--- a/linearize.c
+++ b/linearize.c
@@ -946,6 +946,7 @@ static pseudo_t add_load(struct entrypoint *ep, struct access_data *ad)
 
 	insn->target = new;
 	insn->offset = ad->offset;
+	insn->is_volatile = insn->type && (insn->type->ctype.modifiers & MOD_VOLATILE);
 	use_pseudo(insn, ad->address, &insn->src);
 	add_one_insn(ep, insn);
 	return new;
@@ -961,6 +962,7 @@ static void add_store(struct entrypoint *ep, struct access_data *ad, pseudo_t va
 
 	store = alloc_typed_instruction(OP_STORE, ad->btype);
 	store->offset = ad->offset;
+	store->is_volatile = store->type && (store->type->ctype.modifiers & MOD_VOLATILE);
 	use_pseudo(store, value, &store->target);
 	use_pseudo(store, ad->address, &store->src);
 	add_one_insn(ep, store);
diff --git a/linearize.h b/linearize.h
index f7b5c3f44..d72051e4c 100644
--- a/linearize.h
+++ b/linearize.h
@@ -112,6 +112,7 @@ struct instruction {
 		struct /* memops */ {
 			pseudo_t addr;
 			unsigned int offset;
+			unsigned int is_volatile:1;
 		};
 		struct /* binops and sel */ {
 			pseudo_t src1, src2, src3;
diff --git a/memops.c b/memops.c
index df2e4d6c2..7732b5858 100644
--- a/memops.c
+++ b/memops.c
@@ -99,7 +99,7 @@ static void simplify_loads(struct basic_block *bb)
 			/* Check for illegal offsets.. */
 			check_access(insn);
 
-			if (insn->type->ctype.modifiers & MOD_VOLATILE)
+			if (insn->is_volatile)
 				continue;
 
 			RECURSE_PTR_REVERSE(insn, dom) {
@@ -160,7 +160,7 @@ static void kill_dominated_stores(struct basic_block *bb)
 
 			if (!insn->type)
 				continue;
-			if (insn->type->ctype.modifiers & MOD_VOLATILE)
+			if (insn->is_volatile)
 				continue;
 
 			local = local_pseudo(pseudo);
diff --git a/simplify.c b/simplify.c
index ef98b205a..0e9b0381f 100644
--- a/simplify.c
+++ b/simplify.c
@@ -289,7 +289,7 @@ int kill_insn(struct instruction *insn, int force)
 		break;
 
 	case OP_LOAD:
-		if (!force && insn->type->ctype.modifiers & MOD_VOLATILE)
+		if (!force && insn->is_volatile)
 			return 0;
 		kill_use(&insn->src);
 		break;
-- 
2.18.0