[turboshaft] initialize constant_value_ to an empty value

Milad Fa · V8 LUCI CQ · commit f6bef09b3b0a · 2024-05-02T11:10:40.000Z
gcc-10 seems to have a bug were not initializing this value throws this compilation error: ``` src/compiler/turboshaft/assembler.h:680:16: error: ‘<anonymous>’ is used uninitialized in this function [-Werror=uninitialized] 680 | return Get(); ``` https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86465 Bug: v8:12783 Change-Id: I7a5fee5009b866a801326fba734c156c3cfdb1b0 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5503350 Reviewed-by: Nico Hartmann <nicohartmann@chromium.org> Commit-Queue: Milad Farazmand <mfarazma@redhat.com> Cr-Commit-Position: refs/heads/main@{#93675}
diff --git a/src/compiler/turboshaft/index.h b/src/compiler/turboshaft/index.h
@@ -671,7 +671,7 @@ class ConstOrV {
   template <typename U,
             typename = std::enable_if_t<std::is_constructible_v<V<T>, V<U>>>>
   ConstOrV(V<U> index)  // NOLINT(runtime/explicit)
-      : constant_value_(), value_(index) {}
+      : constant_value_(std::nullopt), value_(index) {}
 
   bool is_constant() const { return constant_value_.has_value(); }
   constant_type constant_value() const {
