[clang] ANDROID: AArch64: Change default max-page-size from 4k to 16k (PR #70251)

[Kalesh Singh via cfe-commits]

https://github.com/Kalesh-Singh created https://github.com/llvm/llvm-project/pull/70251

File size increase were found negligible from sparseness and zero
block compression in f2fs and ext4 (supported filesystems for
Android's userdata partition).


>From 9a28c8670619cef36c24cfae426631098920fecc Mon Sep 17 00:00:00 2001
From: Kalesh Singh <kaleshsingh at google.com>
Date: Wed, 25 Oct 2023 13:31:42 -0700
Subject: [PATCH] ANDROID: AArch64: Change default max-page-size from 4k to 16k

File size increase were found negligible from sparseness and zero
block compression in f2fs and ext4 (supported filesystems for
Android's userdata partition).

Signed-off-by: Kalesh Singh <kaleshsingh at google.com>
---
 clang/lib/Driver/ToolChains/Linux.cpp | 17 ++++++++++++-----
 clang/test/Driver/android-link.cpp    |  3 ++-
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
index 735af54f114cef2..059ed0e8c06a160 100644
--- a/clang/lib/Driver/ToolChains/Linux.cpp
+++ b/clang/lib/Driver/ToolChains/Linux.cpp
@@ -233,11 +233,18 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     ExtraOpts.push_back("relro");
   }
 
-  // Android ARM/AArch64 use max-page-size=4096 to reduce VMA usage. Note, lld
-  // from 11 onwards default max-page-size to 65536 for both ARM and AArch64.
-  if ((Triple.isARM() || Triple.isAArch64()) && Triple.isAndroid()) {
-    ExtraOpts.push_back("-z");
-    ExtraOpts.push_back("max-page-size=4096");
+  // Note, lld from 11 onwards default max-page-size to 65536 for both ARM and
+  // AArch64.
+  if (Triple.isAndroid()) {
+    if (Triple.isARM()) {
+      // Android ARM uses max-page-size=4096 to reduce VMA usage.
+      ExtraOpts.push_back("-z");
+      ExtraOpts.push_back("max-page-size=4096");
+    } else if (Triple.isAArch64()) {
+      // Android AArch64 uses max-page-size=16384 to support 4k/16k page sizes.
+      ExtraOpts.push_back("-z");
+      ExtraOpts.push_back("max-page-size=16384");
+    }
   }
 
   if (GCCInstallation.getParentLibPath().contains("opt/rh/"))
diff --git a/clang/test/Driver/android-link.cpp b/clang/test/Driver/android-link.cpp
index fa9cbc5d0c7a554..f9bdd00507d7bc7 100644
--- a/clang/test/Driver/android-link.cpp
+++ b/clang/test/Driver/android-link.cpp
@@ -17,9 +17,10 @@
 //
 // RUN: %clang -target aarch64-none-linux-android \
 // RUN:   -### -v %s 2> %t
-// RUN: FileCheck -check-prefix=MAX-PAGE-SIZE < %t %s
+// RUN: FileCheck -check-prefix=MAX-PAGE-SIZE-AARCH64 < %t %s
 //
 // GENERIC-ARM: --fix-cortex-a53-843419
 // CORTEX-A53: --fix-cortex-a53-843419
 // CORTEX-A57-NOT: --fix-cortex-a53-843419
 // MAX-PAGE-SIZE: "-z" "max-page-size=4096"
+// MAX-PAGE-SIZE-AARCH64: "-z" "max-page-size=16384"