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-rw-r--r--opt.c8
-rwxr-xr-xtests.sh16
-rw-r--r--tests/test_comma_redundant_false.out1
-rw-r--r--tests/test_comma_redundant_true.out1
4 files changed, 21 insertions, 5 deletions
diff --git a/opt.c b/opt.c
index fd2dc3c..1ece9be 100644
--- a/opt.c
+++ b/opt.c
@@ -595,9 +595,11 @@ static struct expr *optimize_comma_expr(const struct opt_state *state, struct ex
if (expr_never_returns(lhs)) {
debug_opt(state, "-O1: reachability: %e <==> %e\n", expr, lhs);
return extract_child_expr(expr, &expr->lhs);
- }
-
- if (optlevel >= 2 && lhs->pure) {
+ } else if ((lhs->always_true && rhs == &expr_true)
+ || (lhs->always_false && rhs == &expr_false)) {
+ debug_opt(state, "-O1: redundancy elimination: %e <==> %e\n", expr, lhs);
+ return extract_child_expr(expr, &expr->lhs);
+ } else if (optlevel >= 2 && lhs->pure) {
debug_opt(state, "-O2: purity: %e <==> %e\n", expr, rhs);
return extract_child_expr(expr, &expr->rhs);
}
diff --git a/tests.sh b/tests.sh
index 4006534..bd3f399 100755
--- a/tests.sh
+++ b/tests.sh
@@ -610,6 +610,8 @@ gnu_tests=(
test_not_reachability
test_comma_reachability
test_and_false_or_true
+ test_comma_redundant_true
+ test_comma_redundant_false
)
bfs_tests=(
@@ -2005,11 +2007,21 @@ function test_de_morgan_or() {
}
function test_and_false_or_true() {
- # Test (-a lhs(always_true) false) <==> (! lhs),
- # (-a lhs(always_false) true) <==> (! lhs)
+ # Test (-a lhs(always_true) -false) <==> (! lhs),
+ # (-a lhs(always_false) -true) <==> (! lhs)
bfs_diff basic -prune -false -o -true
}
+function test_comma_redundant_true() {
+ # Test (, lhs(always_true) -true) <==> lhs,
+ bfs_diff basic -prune , -true
+}
+
+function test_comma_redundant_false() {
+ # Test (, lhs(always_false) -false) <==> lhs,
+ bfs_diff basic -print -not -prune , -false
+}
+
function test_data_flow_depth() {
bfs_diff basic -depth +1 -depth -4
}
diff --git a/tests/test_comma_redundant_false.out b/tests/test_comma_redundant_false.out
new file mode 100644
index 0000000..15a13db
--- /dev/null
+++ b/tests/test_comma_redundant_false.out
@@ -0,0 +1 @@
+basic
diff --git a/tests/test_comma_redundant_true.out b/tests/test_comma_redundant_true.out
new file mode 100644
index 0000000..15a13db
--- /dev/null
+++ b/tests/test_comma_redundant_true.out
@@ -0,0 +1 @@
+basic