A sign-extension following a zero-extension can always
be simplified into a single zero-extension since the
intermediate value is guaranted to have a zero sign bit.
Simplify away such instructions.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 3 +++
validation/optim/zext-sext.c | 1 -
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index 8d1ffb134..65ea87d94 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1080,6 +1080,9 @@ static int simplify_cast(struct instruction *insn)
break;
case OP_ZEXT:
switch (insn->opcode) {
+ case OP_SEXT:
+ insn->opcode = OP_ZEXT;
+ /* fall through */
case OP_ZEXT:
insn->orig_type = def->orig_type;
return replace_pseudo(insn, &insn->src, def->src);
diff --git a/validation/optim/zext-sext.c b/validation/optim/zext-sext.c
index b0964b542..1fe3900d1 100644
--- a/validation/optim/zext-sext.c
+++ b/validation/optim/zext-sext.c
@@ -6,7 +6,6 @@ int foo(unsigned char offset)
/*
* check-name: zext-sext
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-excludes: sext\\.
--
2.18.0
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