tree 486c10dca0811b036a0cd5f80c02650ac43b11a5
parent 7d8c6776d7bdcc04411154aa215ba5909939192a
author Vladimir Marko <vmarko@google.com> 1426759622 +0000
committer Vladimir Marko <vmarko@google.com> 1427788577 +0100

Fixed layout for dex caches in boot image.

Define a fixed layout for dex cache arrays (type, method,
string and field arrays) for dex caches in the boot image.
This gives those arrays fixed offsets from the boot image
code and allows PC-relative addressing of their elements.

Use the PC-relative load on arm64 for relevant instructions,
i.e. invoke-static, invoke-direct, const-string,
const-class, check-cast and instance-of. This reduces the
arm64 boot.oat on Nexus 9 by 1.1MiB.

This CL provides the infrastructure and shows on the arm64
the gains that we can achieve by having fixed dex cache
arrays' layout. To fully use this for the boot images, we
need to implement the PC-relative addressing for other
architectures. To achieve similar gains for apps, we need
to move the dex cache arrays to a .bss section of the oat
file. These changes will be implemented in subsequent CLs.

(Also remove some compiler_driver.h dependencies to reduce
incremental build times.)

Change-Id: Ib1859fa4452d01d983fd92ae22b611f45a85d69b