- 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
Revert patches that caused the problem. Evan, please investigate and reapply
when you've discovered the problem.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34399 91177308-0d34-0410-b5e6-96231b3b80d8
- When coalescing a copy MI, if its destination is "dead", propagate the
property to the source MI's destination if there are no intervening uses.
- Detect dead function live-in's and remove them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34383 91177308-0d34-0410-b5e6-96231b3b80d8
rework the hacks that had us passing OStream in. We pass in std::ostream*
instead, check for null, and then dispatch to the correct print() method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32636 91177308-0d34-0410-b5e6-96231b3b80d8
LiveRanges, creates a new LiveInterval from them. The LiveRanges should
have existed already in another LiveInterval, but removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31780 91177308-0d34-0410-b5e6-96231b3b80d8
number of copies, potentially defining live ranges that appear to have
differing value numbers that become identical when coallsced. Among other
things, this fixes CodeGen/X86/shift-coalesce.ll and PR687.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29968 91177308-0d34-0410-b5e6-96231b3b80d8
instructions which define each value#) to simplify and improve the coallescer.
In particular, this patch:
1. Implements iterative coallescing.
2. Reverts an unsafe hack from handlePhysRegDef, superceeding it with a
better solution.
3. Implements PR865, "coallescing" away the second copy in code like:
A = B
...
B = A
This also includes changes to symbolically print registers in intervals
when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29862 91177308-0d34-0410-b5e6-96231b3b80d8
targets to register custom legalizers for ConstantFP in case there isn't a
fixed list of constants that can be generated. On some architectures (ia64?)
all fp immediates are legal.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25769 91177308-0d34-0410-b5e6-96231b3b80d8
numbering values in live ranges for physical registers.
The alpha backend currently generates code that looks like this:
vreg = preg
...
preg = vreg
use preg
...
preg = vreg
use preg
etc. Because vreg contains the value of preg coming in, each of the
copies back into preg contain that initial value as well.
In the case of the Alpha, this allows this testcase:
void "foo"(int %blah) {
store int 5, int *%MyVar
store int 12, int* %MyVar2
ret void
}
to compile to:
foo:
ldgp $29, 0($27)
ldiq $0,5
stl $0,MyVar
ldiq $0,12
stl $0,MyVar2
ret $31,($26),1
instead of:
foo:
ldgp $29, 0($27)
bis $29,$29,$0
ldiq $1,5
bis $0,$0,$29
stl $1,MyVar
ldiq $1,12
bis $0,$0,$29
stl $1,MyVar2
ret $31,($26),1
This does not seem to have any noticable effect on X86 code.
This fixes PR535.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20536 91177308-0d34-0410-b5e6-96231b3b80d8
Make only one print method to avoid overloaded virtual warnings when \
compiled with -Woverloaded-virtual
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18589 91177308-0d34-0410-b5e6-96231b3b80d8
* Add const_iterator stuff
* Add a print method, which means that I can now call dump() from the
debugger.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16612 91177308-0d34-0410-b5e6-96231b3b80d8
LiveInterval>. This saves some space and removes the pointer
indirection caused by following the pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15167 91177308-0d34-0410-b5e6-96231b3b80d8
* Inline some functions
* Eliminate some comparisons from the release build
This is good for another .3 on gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15144 91177308-0d34-0410-b5e6-96231b3b80d8
will soon be renamed) into their own file. The new file should not emit
DEBUG output or have other side effects. The LiveInterval class also now
doesn't know whether its working on registers or some other thing.
In the future we will want to use the LiveInterval class and friends to do
stack packing. In addition to a code simplification, this will allow us to
do it more easily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15134 91177308-0d34-0410-b5e6-96231b3b80d8
Use an explicit LiveRange class to represent ranges instead of an std::pair.
This is a minor cleanup, but is really intended to make a future patch simpler
and less invasive.
Alkis, could you please take a look at LiveInterval::liveAt? I suspect that
you can add an operator<(unsigned) to LiveRange, allowing us to speed up the
upper_bound call by quite a bit (this would also apply to other callers of
upper/lower_bound). I would do it myself, but I still don't understand that
crazy liveAt function, despite the comment. :)
Basically I would like to see this:
LiveRange dummy(index, index+1);
Ranges::const_iterator r = std::upper_bound(ranges.begin(),
ranges.end(),
dummy);
Turn into:
Ranges::const_iterator r = std::upper_bound(ranges.begin(),
ranges.end(),
index);
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15130 91177308-0d34-0410-b5e6-96231b3b80d8
