From 08f068cfd0b21a016bbd693d12fe0becb5e483f6 Mon Sep 17 00:00:00 2001
From: Andreas Gampe <agampe@google.com>
Date: Wed, 9 Apr 2014 17:28:11 -0700
Subject: [PATCH] AArch64 code alignment is 4 for OatWriter

OatWriter DCHECKs against ARM alignment, which is 8 and <= all
other architectures *except* AArch64, so that was fine before.

Change-Id: I55a11fe60cfbec889f2e8d8b0f489fe0930ebf6f
---
 compiler/oat_writer.cc | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/compiler/oat_writer.cc b/compiler/oat_writer.cc
index 2d45a2f65..eff2425bb 100644
--- a/compiler/oat_writer.cc
+++ b/compiler/oat_writer.cc
@@ -345,6 +345,36 @@ size_t OatWriter::InitOatCodeClassDef(size_t offset,
   return offset;
 }
 
+static void DCheckCodeAlignment(size_t offset, InstructionSet isa) {
+  switch (isa) {
+    case kArm:
+      // Fall-through.
+    case kThumb2:
+      DCHECK_ALIGNED(offset, kArmAlignment);
+      break;
+
+    case kArm64:
+      DCHECK_ALIGNED(offset, kArm64Alignment);
+      break;
+
+    case kMips:
+      DCHECK_ALIGNED(offset, kMipsAlignment);
+      break;
+
+    case kX86_64:
+      // Fall-through.
+    case kX86:
+      DCHECK_ALIGNED(offset, kX86Alignment);
+      break;
+
+    case kNone:
+      // Use a DCHECK instead of FATAL so that in the non-debug case the whole switch can
+      // be optimized away.
+      DCHECK(false);
+      break;
+  }
+}
+
 size_t OatWriter::InitOatCodeMethod(size_t offset, size_t oat_class_index,
                                     size_t __attribute__((unused)) class_def_index,
                                     size_t class_def_method_index,
@@ -376,7 +406,8 @@ size_t OatWriter::InitOatCodeMethod(size_t offset, size_t oat_class_index,
     } else {
       CHECK(quick_code != nullptr);
       offset = compiled_method->AlignCode(offset);
-      DCHECK_ALIGNED(offset, kArmAlignment);
+      DCheckCodeAlignment(offset, compiled_method->GetInstructionSet());
+
       uint32_t code_size = quick_code->size() * sizeof(uint8_t);
       CHECK_NE(code_size, 0U);
       uint32_t thumb_offset = compiled_method->CodeDelta();
@@ -826,7 +857,8 @@ size_t OatWriter::WriteCodeMethod(OutputStream* out, const size_t file_offset,
         relative_offset += aligned_code_delta;
         DCHECK_OFFSET();
       }
-      DCHECK_ALIGNED(relative_offset, kArmAlignment);
+      DCheckCodeAlignment(relative_offset, compiled_method->GetInstructionSet());
+
       uint32_t code_size = quick_code->size() * sizeof(uint8_t);
       CHECK_NE(code_size, 0U);
 
-- 
2.11.0