(landing pad) when an exception unwinds through the call. This doesn't
quite match the way the dwarf unwinder works: by default it only jumps to
the landing pad if the catch or filter specification matches, and otherwise
it keeps on unwinding. There are two ways of specifying to the unwinder
that it should "always" (more on why there are quotes here later) jump to
the landing pad: follow the specification by a 0 typeid, or follow it by
the typeid for the NULL typeinfo. GCC does the first, and this patch makes
LLVM do the same as gcc. However there is a problem: the unwinder performs
optimizations based on C++ semantics (it only expects destructors to be
run if the 0 typeid fires - known as "cleanups"), meaning it assumes that no
exceptions will be raised and that the raised exception will be reraised
at the end of the cleanup code. So if someone writes their own LLVM code
using the exception intrinsics they will get a nasty surprise if they don't
follow these rules. The other possibility of using the typeid corresponding
to NULL (catch-all) causes the unwinder to make no assumptions, so this is
probably what we should use in the long-run. However since we are still
having trouble getting exception handling working properly, for the moment
it seems best to closely imitate GCC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37399 91177308-0d34-0410-b5e6-96231b3b80d8
simplifies the code in DwarfWriter, allows for multiple filters and
makes it trivial to specify filters accompanied by cleanups or catch-all
specifications (see next patch). What a deal! Patch blessed by Anton.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37398 91177308-0d34-0410-b5e6-96231b3b80d8
smaller than the preferred alignment, but so that the target can actually
specify a minimum alignment if needed. This fixes some objc protocol
failures Devang tracked down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37373 91177308-0d34-0410-b5e6-96231b3b80d8
v1 =
r2 = move v1
= op r2<kill>
...
r2 = move v1
= op r2<kill>
Clear the first r2 kill if v1 and r2 are joined.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37050 91177308-0d34-0410-b5e6-96231b3b80d8
functions. This partly fixes PR1414: now we're restricted only to one
personality function per eh frame, not per module. Further work on
"multiple personalities" topic needs representative example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37018 91177308-0d34-0410-b5e6-96231b3b80d8
1. Fix PR1380
2. Apply Duncan's patch from PR1410
3. Insert workaround for "one personality function per module" as noted in PR1414
4. Emit correct debug frames for x86/linux. This partly fixes DebugInfo/2006-11-06-StackTrace.cpp: stack trace is
shown correctly, but arguments for function on top of stack are displayed incorrectly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37015 91177308-0d34-0410-b5e6-96231b3b80d8
Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36652 91177308-0d34-0410-b5e6-96231b3b80d8
- A register def / use now implicitly affects sub-register liveness but does
not affect liveness information of super-registers.
- Def of a larger register (if followed by a use later) is treated as
read/mod/write of a smaller register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36434 91177308-0d34-0410-b5e6-96231b3b80d8
long live interval that has low usage density.
1. Change order of coalescing to join physical registers with virtual
registers first before virtual register intervals become too long.
2. Check size and usage density to determine if it's worthwhile to join.
3. If joining is aborted, assign virtual register live interval allocation
preference field to the physical register.
4. Register allocator should try to allocate to the preferred register
first (if available) to create identify moves that can be eliminated.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36218 91177308-0d34-0410-b5e6-96231b3b80d8
