[PATCH] Add support for symbolic large constant entries inside stackmaps

[Marius Wachtler]

Hi reames, lhames, ributzka,

This patch implements support for embedding symbols in the array of large constants inside a stackmap/patchpoint.
We (=Pyston project) embed in the LLVM IR we generate a lot of pointers to external constants. I would like to cache the JITed functions and therefore I need to make the embedded constants relocatable -> change the IR to refer to module variables instead which I can replace when loading the cached object.
Currently when a patchpoint has a constant variable as live argument it will materialize it in a register. Which we don't want because the live variables are rarely used (also the regalloc runs out of registers when having to many const variables as argument to the pp?!?... I filled PR23306). 
This patch emits a symbol reference inside the array of large constants in the stackmap. The stack map format is untouched by this patch.

Together with http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150330/269160.html this should make it possible to cache more JITed functions containing patchpoints.

REPOSITORY
  rL LLVM

http://reviews.llvm.org/D9176

Files:
  include/llvm/CodeGen/StackMaps.h
  lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
  lib/CodeGen/StackMaps.cpp
  test/CodeGen/X86/stackmap.ll

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D9176.24174.patch
Type: text/x-patch
Size: 8299 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150421/4f8c188f/attachment.bin>