and extern_weak_odr. These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global. In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time. This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function. If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body. The
code generators on the other hand map weak and weak_odr linkage
to the same thing.
llvm-svn: 66339
get nice and happy stack traces when we crash in an optimizer or codegen. For
example, an abort put in UnswitchLoops now looks like this:
Stack dump:
0. Program arguments: clang pr3399.c -S -O3
1. <eof> parser at end of file
2. per-module optimization passes
3. Running pass 'CallGraph Pass Manager' on module 'pr3399.c'.
4. Running pass 'Loop Pass Manager' on function '@foo'
5. Running pass 'Unswitch loops' on basic block '%for.inc'
Abort
llvm-svn: 66260
arbitrary functions to be run when a crash happens. Delete
RemoveDirectoryOnSignal as it is dead and has never had clients.
Change PrintStackTraceOnErrorSignal to be implemented in terms of
AddSignalHandler.
I updated the Win32 versions of these APIs, but can't test them.
If there are any problems, I'd be happy to fix them as well.
llvm-svn: 66072
because less bytes are allocated and subobject construction is gone.
For reference how it works, see BasicBlock.h.
Btw. it is very assuring to see that somebody has invented
this ilist-embedded sentinel technique before me :-)
llvm-svn: 66026
While the patch is clearly correct in itself, it's become
apparent other places are assuming debug intrinsics are
marked as touching memory...this needs more testing.
llvm-svn: 65992
arbitrary vector sizes. Add an optional MinSplatBits parameter to specify
a minimum for the splat element size. Update the PPC target to use the
revised interface.
llvm-svn: 65899
User drivers based on llvmc must all share the initialization code.
Putting main() into libCompilerDriver is not a very good idea IMO (and ld gave
me some strange EH-related error anyway).
llvm-svn: 65825
Move the code from 'llvmc/driver' into a new CompilerDriver library, and change
the build system accordingly. Makes it easier for projects using LLVM to build
their own llvmc-based drivers.
Tested with objdir != srcdir.
llvm-svn: 65821
its sentinel. This is quite a win when a function really has a basic block.
When the function is just a declaration (and stays so) the old way did not
allocate a sentinel. So this change is most beneficial when the ratio of
function definition to declaration is high. I.e. linkers etc. Incidentally
these are the most resource demanding applications, so I expect that the
reduced malloc traffic, locality and space savings outweigh the cost of
addition of two pointers to Function.
llvm-svn: 65776
