


LLVM-DIFF(1)            LLVM Command Guide           LLVM-DIFF(1)


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.

AUTHORS
       Maintained by the LLVM Team (<http://llvm.org>).














CVS                         2010-09-07                          1


