[PATCH 0/2] fix testing if a OP_CALL's function is pure

[PATCH 0/2] fix testing if a OP_CALL's function is pure

[Luc Van Oostenryck]

kill_instruction() will only kill an OP_CALL corresponding to
a pure function but this can't be testing if the call is not
done directly via the function's symbols.

These 2 patches fix this by using the function's type always
available in the instruction itself.


Luc Van Oostenryck (2):
  add helper first_symbol()
  fix testing if a OP_CALL's function is pure

 lib.h      | 5 +++++
 simplify.c | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)


base-commit: 8f7e21cadc21f49819d003e560d4607d720c647f
-- 
2.29.0

[PATCH 1/2] add helper first_symbol()

[Luc Van Oostenryck]

This is just a wrapper around first_ptr_list().

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 lib.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib.h b/lib.h
index 0b1d4492e6bd..b4c3db93ab31 100644
--- a/lib.h
+++ b/lib.h
@@ -204,6 +204,11 @@ static inline pseudo_t first_pseudo(struct pseudo_list *head)
 	return first_ptr_list((struct ptr_list *)head);
 }
 
+static inline struct symbol *first_symbol(struct symbol_list *head)
+{
+	return first_ptr_list((struct ptr_list *)head);
+}
+
 static inline void concat_symbol_list(struct symbol_list *from, struct symbol_list **to)
 {
 	concat_ptr_list((struct ptr_list *)from, (struct ptr_list **)to);
-- 
2.29.0

[PATCH 2/2] fix testing if a OP_CALL's function is pure

[Luc Van Oostenryck]

kill_instruction() will kill an OP_CALL but only if it's a
forced kill or if the corresponding function is pure.

However, only functions called via a symbol pseudo are so killed.
Those called via a function pointer are not because only symbol
pseudos contain the function type needed to test the presence of
the MOD_PURE modifier.

Fix this by using the function type always available in the
instruction's ::fntypes member.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 simplify.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/simplify.c b/simplify.c
index 6caf6cbcf918..634a3ea66e91 100644
--- a/simplify.c
+++ b/simplify.c
@@ -351,9 +351,9 @@ int kill_insn(struct instruction *insn, int force)
 	case OP_CALL:
 		if (!force) {
 			/* a "pure" function can be killed too */
-			if (!(insn->func->type == PSEUDO_SYM))
-				return 0;
-			if (!(insn->func->sym->ctype.modifiers & MOD_PURE))
+			struct symbol *fntype = first_symbol(insn->fntypes);
+
+			if (!(fntype->ctype.modifiers & MOD_PURE))
 				return 0;
 		}
 		kill_use_list(insn->arguments);
-- 
2.29.0