NAME

       llvm-diff - LLVM structural 'diff'

SYNOPSIS

       llvm-diff [options] module 1 module 2 [global name ...]

DESCRIPTION

       llvm-diff  compares  the  structure  of  two  LLVM modules, primarily focusing on differences in function
       definitions.  Insignificant differences, such as changes in the ordering of globals or in  the  names  of
       local values, are ignored.

       An  input module will be interpreted as an assembly file if its name ends in '.ll';  otherwise it will be
       read in as a bitcode file.

       If a list of global names is given, just the values with those names are compared; otherwise, all  global
       values  are  compared,  and  diagnostics  are produced for globals which only appear in one module or the
       other.

       llvm-diff compares two functions by comparing their basic blocks, beginning with the  entry  blocks.   If
       the  terminators  seem  to  match,  then  the  corresponding  successors are compared; otherwise they are
       ignored.  This algorithm is very sensitive to changes in control flow, which tend to stop any  downstream
       changes from being detected.

       llvm-diff  is  intended as a debugging tool for writers of LLVM passes and frontends.  It does not have a
       stable output format.

EXIT STATUS

       If llvm-diff finds no differences between the modules, it  will  exit  with  0  and  produce  no  output.
       Otherwise it will exit with a non-zero value.

BUGS

       Many important differences, like changes in linkage or function attributes, are not diagnosed.

       Changes  in  memory  behavior  (for  example, coalescing loads) can cause massive detected differences in
       blocks.

AUTHOR

       Maintained by The LLVM Team (http://llvm.org/).

COPYRIGHT

       2003-2014, LLVM Project