llvm-6502/lib/Bitcode/Reader
Jan Wen Voung d9a3bad448 Change encoding of instruction operands in bitcode binaries to be relative
to the instruction position.  The old encoding would give an absolute
ID which counts up within a function, and only resets at the next function.

I.e., Instead of having:

... = icmp eq i32 n-1, n-2
br i1 ..., label %bb1, label %bb2

it will now be roughly:

... = icmp eq i32 1, 2
br i1 1, label %bb1, label %bb2

This makes it so that ids remain relatively small and can be encoded
in fewer bits.

With this encoding, forward reference operands will be given
negative-valued IDs.  Use signed VBRs for the most common case
of forward references, which is phi instructions.

To retain backward compatibility we bump the bitcode version
from 0 to 1 to distinguish between the different encodings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165739 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-11 20:20:40 +00:00
..
BitcodeReader.cpp Change encoding of instruction operands in bitcode binaries to be relative 2012-10-11 20:20:40 +00:00
BitcodeReader.h Change encoding of instruction operands in bitcode binaries to be relative 2012-10-11 20:20:40 +00:00
BitReader.cpp
CMakeLists.txt
LLVMBuild.txt
Makefile