[bigint] Define V8_ADVANCED_BIGINT_ALGORITHMS everywhere

It was previously only passed to compilation units in src/bigint/,
but inconsistencies arise when it's not passed to other compilation
units that #include src/bigint/bigint.h.

Fixed: chromium:1233397
Change-Id: Idb310d8c13bad12766699086574aa2c3869eb56c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3056452Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75941}

BUILD.gn

@@ -621,8 +621,8 @@ config("external_config") {
     defines += [ "USING_V8_SHARED" ]
   }
 
-  if(current_cpu == "riscv64") {
-    libs = [ "atomic"]
+  if (current_cpu == "riscv64") {
+    libs = [ "atomic" ]
   }
 }
 
@@ -926,6 +926,9 @@ config("features") {
   if (v8_allocation_site_tracking) {
     defines += [ "V8_ALLOCATION_SITE_TRACKING" ]
   }
+  if (v8_advanced_bigint_algorithms) {
+    defines += [ "V8_ADVANCED_BIGINT_ALGORITHMS" ]
+  }
 }
 
 config("toolchain") {
@@ -5012,8 +5015,6 @@ v8_source_set("v8_bigint") {
       "src/bigint/mul-fft.cc",
       "src/bigint/mul-toom.cc",
     ]
-
-    defines = [ "V8_ADVANCED_BIGINT_ALGORITHMS" ]
   }
 
   configs = [ ":internal_config" ]

src/bigint/bigint-internal.cc

@@ -7,6 +7,15 @@
 namespace v8 {
 namespace bigint {
 
+// Used for checking consistency between library and public header.
+#if DEBUG
+#if V8_ADVANCED_BIGINT_ALGORITHMS
+bool kAdvancedAlgorithmsEnabledInLibrary = true;
+#else
+bool kAdvancedAlgorithmsEnabledInLibrary = false;
+#endif  // V8_ADVANCED_BIGINT_ALGORITHMS
+#endif  // DEBUG
+
 ProcessorImpl::ProcessorImpl(Platform* platform) : platform_(platform) {}
 
 ProcessorImpl::~ProcessorImpl() { delete platform_; }

src/bigint/bigint.h

@@ -23,6 +23,8 @@ namespace bigint {
     std::cerr << "Assertion failed: " #cond "\n";     \
     abort();                                          \
   }
+
+extern bool kAdvancedAlgorithmsEnabledInLibrary;
 #else
 #define BIGINT_H_DCHECK(cond) (void(0))
 #endif
@@ -277,9 +279,13 @@ inline int MultiplyResultLength(Digits X, Digits Y) {
 constexpr int kBarrettThreshold = 13310;
 inline int DivideResultLength(Digits A, Digits B) {
 #if V8_ADVANCED_BIGINT_ALGORITHMS
+  BIGINT_H_DCHECK(kAdvancedAlgorithmsEnabledInLibrary);
   // The Barrett division algorithm needs one extra digit for temporary use.
   int kBarrettExtraScratch = B.len() >= kBarrettThreshold ? 1 : 0;
 #else
+  // If this fails, set -DV8_ADVANCED_BIGINT_ALGORITHMS in any compilation unit
+  // that #includes this header.
+  BIGINT_H_DCHECK(!kAdvancedAlgorithmsEnabledInLibrary);
   constexpr int kBarrettExtraScratch = 0;
 #endif
   return A.len() - B.len() + 1 + kBarrettExtraScratch;

test/bigint/BUILD.gn

@@ -22,8 +22,4 @@ v8_executable("bigint_shell") {
   configs = [ "../..:internal_config_base" ]
 
   sources = [ "bigint-shell.cc" ]
-
-  if (v8_advanced_bigint_algorithms) {
-    defines = [ "V8_ADVANCED_BIGINT_ALGORITHMS" ]
-  }
 }

test/mjsunit/harmony/bigint/div-special-cases.js

+// Copyright 2021 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Regression test for crbug.com/1233397.
+let y_power = 13311n * 64n; // Large enough to choose the Barrett algorithm.
+// A couple of digits and a couple of intra-digit bits larger.
+let x_power = y_power + 50n * 64n + 30n;
+let x = 2n ** x_power;
+let y = 2n ** y_power;
+let q = x / y;