Oliver Stannard 8f832fce3b [Thumb1] Re-write emitThumbRegPlusImmediate
This was motivated by a bug which caused code like this to be
miscompiled:
  declare void @take_ptr(i8*)
  define void @test() {
    %addr1.32 = alloca i8
    %addr2.32 = alloca i32, i32 1028
    call void @take_ptr(i8* %addr1)
    ret void
  }

This was emitting the following assembly to get the value of %addr1:
  add r0, sp, #1020
  add r0, r0, #8
However, "add r0, r0, #8" is not a valid Thumb1 instruction, and this
could not be assembled. The generated object file contained this,
resulting in r0 holding SP+8 rather tha SP+1028:
  add r0, sp, #1020
  add r0, sp, #8

This function looked like it could have caused miscompilations for
other combinations of registers and offsets (though I don't think it is
currently called with these), and the heuristic it used did not match
the emitted code in all cases.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222125 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-17 11:18:10 +00:00
2014-10-16 22:48:02 +00:00

Low Level Virtual Machine (LLVM)
================================

This directory and its subdirectories contain source code for the Low Level
Virtual Machine, a toolkit for the construction of highly optimized compilers,
optimizers, and runtime environments.

LLVM is open source software. You may freely distribute it under the terms of
the license agreement found in LICENSE.txt.

Please see the documentation provided in docs/ for further
assistance with LLVM, and in particular docs/GettingStarted.rst for getting
started with LLVM and docs/README.txt for an overview of LLVM's
documentation setup.

If you're writing a package for LLVM, see docs/Packaging.rst for our
suggestions.
Description
LLVM backend for 6502
Readme 277 MiB
Languages
C++ 48.7%
LLVM 38.5%
Assembly 10.2%
C 0.9%
Python 0.4%
Other 1.2%