At expansion phase, when simplified, all constants are truncated
to the size of the operations that generate them.
This should be done during simplification too because:
*) if some constants are sometimes truncated and sometimes
sign-extended, CSE will miss some opportunities.
*) it's not possible to sign-extend them because it's not
always known if the constant is used in a signed context or not.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 2 +-
validation/optim/canonical-sub-cte.c | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/simplify.c b/simplify.c
index db7a1e47ff0a..3935552bd6fa 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1118,7 +1118,7 @@ static int simplify_constant_rightside(struct instruction *insn)
case OP_SUB:
if (value) {
insn->opcode = OP_ADD;
- insn->src2 = value_pseudo(-value);
+ insn->src2 = eval_unop(OP_NEG, insn->size, insn->src2);
return REPEAT_CSE;
}
/* Fall through */
diff --git a/validation/optim/canonical-sub-cte.c b/validation/optim/canonical-sub-cte.c
index 223be96fa5a5..c0072884b1e6 100644
--- a/validation/optim/canonical-sub-cte.c
+++ b/validation/optim/canonical-sub-cte.c
@@ -3,7 +3,6 @@ int sub_cte(int x) { return (x - 1) != (x + -1); }
/*
* check-name: canonical-sub-cte
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-contains: ret\\..*\\$0
--
2.28.0
