can be eliminated by the allocator is the destination and source targets the
same register. The most common case is when the source and destination registers
are in different class. For example, on x86 mov32to32_ targets GR32_ which
contains a subset of the registers in GR32.
The allocator can do 2 things:
1. Set the preferred allocation for the destination of a copy to that of its source.
2. After allocation is done, change the allocation of a copy destination (if
legal) so the copy can be eliminated.
This eliminates 443 extra moves from 403.gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43662 91177308-0d34-0410-b5e6-96231b3b80d8
(almost) a register copy. However, it always coalesced to the register of the
RHS (the super-register). All uses of the result of a EXTRACT_SUBREG are sub-
register uses which adds subtle complications to load folding, spiller rewrite,
etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42899 91177308-0d34-0410-b5e6-96231b3b80d8
Changes related modules so VNInfo's are not copied. This decrease
copy coalescing time by 45% and overall compilation time by 10% on siod.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41579 91177308-0d34-0410-b5e6-96231b3b80d8
- Fix some minor bugs related to special markers on val# def. ~0U means
undefined, ~1U means dead val#.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40916 91177308-0d34-0410-b5e6-96231b3b80d8
kill instruction #, and source register number (iff the value# is defined by a
copy).
- Now def instruction # is set for every value#, not just for copy defined ones.
- Update some outdated code related inactive live ranges.
- Kill info not yet set. That's next patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40913 91177308-0d34-0410-b5e6-96231b3b80d8
with a general target hook to identify rematerializable instructions. Some
instructions are only rematerializable with specific operands, such as loads
from constant pools, while others are always rematerializable. This hook
allows both to be identified as being rematerializable with the same
mechanism.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37644 91177308-0d34-0410-b5e6-96231b3b80d8
simultaneously. Move that pass to SimpleRegisterCoalescing.
This makes it easier to implement alternative register allocation and
coalescing strategies while maintaining reuse of the existing live
interval analysis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37520 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
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
of dead def live interval at 1 to avoid multiple def's targeting the same
register. The previous patch missed a case where the source operand is live-in.
In that case, remove the whole interval.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35512 91177308-0d34-0410-b5e6-96231b3b80d8
to be really bad. Once they are joined they are not broken apart. Also, physical
intervals cannot be spilled!
Added a heuristic as a workaround for this. Be careful coalescing with a
physical register if the virtual register uses are "far". Check if there are
uses in the same loop as the source (copy instruction). Check if it is in the
loop preheader, etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35134 91177308-0d34-0410-b5e6-96231b3b80d8
entry (0x8b056f0, LLVM BB @0x8b01b30, ID#0):
Live Ins: %r0 %r1 %r2 %r3
%reg1032 = tMOVrr %r3<kill>
%reg1033 = tMOVri8 1
%reg1034 = tMOVri8 0
tCMPi8 %reg1029<kill>, 0
tBcc mbb<entry,0x8b06a10>, 0
Successors according to CFG: 0x8b06980 0x8b06a10
entry (0x8b06980, LLVM BB @0x8b01b30, ID#12):
Predecessors according to CFG: 0x8b056f0
%reg1036 = tMOVrr %reg1034<kill>
Successors according to CFG: 0x8b06a10
entry (0x8b06a10, LLVM BB @0x8b01b30, ID#13):
Predecessors according to CFG: 0x8b056f0 0x8b06980
%reg1024<dead> = tMOVrr %reg1030<kill>
...
reg1030 and r1 have already been joined. When reg1024 and reg1030 are joined,
r1 live range from function entry to the tMOVrr instruction are dead. Eliminate
r1 from the livein set of the entry BB, not the BB where the copy is.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34866 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
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
by 40%, FreeBench/fourinarow by 20%, and many other programs 10-25%.
On PPC, this speeds up fourinarow by 18%, and probably other things as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31504 91177308-0d34-0410-b5e6-96231b3b80d8
Turn on -Wunused and -Wno-unused-parameter. Clean up most of the resulting
fall out by removing unused variables. Remaining warnings have to do with
unused functions (I didn't want to delete code without review) and unused
variables in generated code. Maintainers should clean up the remaining
issues when they see them. All changes pass DejaGnu tests and Olden.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31380 91177308-0d34-0410-b5e6-96231b3b80d8
actually *removes* one of the operands, instead of just assigning both operands
the same register. This make reasoning about instructions unnecessarily complex,
because you need to know if you are before or after register allocation to match
up operand #'s with the target description file.
Changing this also gets rid of a bunch of hacky code in various places.
This patch also includes changes to fold loads into cmp/test instructions in
the X86 backend, along with a significant simplification to the X86 spill
folding code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30108 91177308-0d34-0410-b5e6-96231b3b80d8
