A zero-extension has no effect on the result of a comparison with 0 or 1.
Optimize away the extension.
Note: this simplification was already done but only when the
original size was 1 but it can be done for all sizes.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 17 +++++++----------
validation/optim/bool-zext-test.c | 1 -
2 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/simplify.c b/simplify.c
index b6c07ad9f..fb4bb3429 100644
--- a/simplify.c
+++ b/simplify.c
@@ -608,16 +608,13 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
return REPEAT_CSE;
case OP_ZEXT:
- if (def->orig_type->bit_size == 1) {
- // Convert:
- // zext.m %s <- (1) %a
- // setne.1 %r <- %s, $0
- // into:
- // setne.1 %s <- %a, $0
- // and same for setne/eq ... 0/1
- return replace_pseudo(insn, &insn->src1, def->src1);
- }
- break;
+ // Convert:
+ // *ext.m %s <- (1) %a
+ // setne.1 %r <- %s, $0
+ // into:
+ // setne.1 %s <- %a, $0
+ // and same for setne/eq ... 0/1
+ return replace_pseudo(insn, &insn->src1, def->src);
}
return 0;
}
diff --git a/validation/optim/bool-zext-test.c b/validation/optim/bool-zext-test.c
index f837ace20..138938b0a 100644
--- a/validation/optim/bool-zext-test.c
+++ b/validation/optim/bool-zext-test.c
@@ -6,7 +6,6 @@ _Bool neu1(unsigned char a) { return a != 1; }
/*
* check-name: bool-zext-test
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-excludes: zext\\.
--
2.18.0
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