coalescer) handle sub-register classes.
- Add heuristics to avoid non-profitable cse. Given the current lack of live
range splitting, avoid cse when an expression has PHI use and the would be
new use is in a BB where the expression wasn't already being used.
llvm-svn: 98043
phi cycles. Adjust a few tests to keep dead instructions from being optimized
away. This (together with my previous change for phi cycles) fixes Apple
radar 7627077.
llvm-svn: 96057
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.
This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.
llvm-svn: 95975
reduce down to a single value. InstCombine already does this transformation
but DAG legalization may introduce new opportunities. This has turned out to
be important for ARM where 64-bit values are split up during type legalization:
InstCombine is not able to remove the PHI cycles on the 64-bit values but
the separate 32-bit values can be optimized. I measured the compile time
impact of this (running llc on 176.gcc) and it was not significant.
llvm-svn: 95951
only run for x86 with fastisel. I've found it being very effective in
eliminating some obvious dead code as result of formal parameter lowering
especially when tail call optimization eliminated the need for some of the loads
from fixed frame objects. It also shrinks a number of the tests. A couple of
tests no longer make sense and are now eliminated.
llvm-svn: 95493
stderr if in filetype=obj mode. This is a hack, and will
live until dwarf emission and other random stuff that is
not yet going through MCStreamer is upgraded. It only
impacts filetype=obj mode.
llvm-svn: 95166
$ cat t.ll
@g = global i32 42
$ llc t.ll -o t.o -filetype=obj
$ nm t.o
00000000 D _g
There is still a ton of work left. Instructions are not being encoded
yet apparently.
llvm-svn: 95162
the one used by the JIT. Remove all forms of
addPassesToEmitFileFinish except the one used by the static
code generator. Inline the remaining version of
addPassesToEmitFileFinish into its only caller.
llvm-svn: 95109
Remove most of old Mach-O Writer support, it has been replaced by MCMachOStreamer
Further refactoring to completely remove MachOWriter and drive the object file
writer with the AsmPrinter MCInst/MCSection logic is forthcoming.
llvm-svn: 93527
catch info can get misplaced when a selector ends up more than one block
removed from the parent invoke(s). This could happen when a landing pad is
shared by multiple invokes and is also a target of a normal edge from
elsewhere.
llvm-svn: 93456
For now, this pass is fairly conservative. It only perform the replacement when both the pre- and post- extension values are used in the block. It will miss cases where the post-extension values are live, but not used.
llvm-svn: 93278
by allowing backends to override routines that will default
the JIT and Static code generation to an appropriate code model
for the architecture.
Should fix PR 5773.
llvm-svn: 91824
running tail duplication when doing branch folding for if-conversion, and
we also want to be able to run tail duplication earlier to fix some
reg alloc problems. Move the CanFallThrough function from BranchFolding
to MachineBasicBlock so that it can be shared by TailDuplication.
llvm-svn: 89904
previously running CodePlacementOpt. Also print headers before
each dump in -print-machineinstrs mode, so that it's clear which
dump is which.
llvm-svn: 85681
use it to control tail merging when there is a tradeoff between performance
and code size. When there is only 1 instruction in the common tail, we have
been merging. That can be good for code size but is a definite loss for
performance. Now we will avoid tail merging in that case when the
optimization level is "Aggressive", i.e., "-O3". Radar 7338114.
Since the IfConversion pass invokes BranchFolding, it too needs to know
the optimization level. Note that I removed the RegisterPass instantiation
for IfConversion because it required a default constructor. If someone
wants to keep that for some reason, we can add a default constructor with
a hard-wired optimization level.
llvm-svn: 85346
constants out of loops. These aren't covered by the regular LICM
pass, because in LLVM IR constants don't require separate
instructions. They're not always covered by the MachineLICM pass
either, because it doesn't know how to unfold folded constant-pool
loads. This is somewhat experimental at this point, and off by
default.
llvm-svn: 82076
more properly belong. This allows removing the front-end conditionalized
SJLJ code, and cleans up the generated IR considerably. All of the
infrastructure code (calling _Unwind_SjLj_Register/Unregister, etc) is
added by the SjLjEHPrepare pass.
llvm-svn: 79250
TargetAsmInfo. This eliminates a dependency on TargetMachine.h from
TargetRegistry.h, which technically was a layering violation.
- Clients probably can only sensibly pass in the same TargetAsmInfo as the
TargetMachine has, but there are only limited clients of this API.
llvm-svn: 78928
pair instead of from a virtual method on TargetMachine. This cuts the final
ties of TargetAsmInfo to TargetMachine, meaning that MC can now use
TargetAsmInfo.
llvm-svn: 78802
and short. Well, it's kinda short. Definitely nasty and brutish.
The front-end generates the register/unregister calls into the SjLj runtime,
call-site indices and landing pad dispatch. The back end fills in the LSDA
with the call-site information provided by the front end. Catch blocks are
not yet implemented.
Built on Darwin and verified no llvm-core "make check" regressions.
llvm-svn: 78625
shouldn't do AU.setPreservesCFG(), because even though CodeGen passes
don't modify the LLVM IR CFG, they may modify the MachineFunction CFG,
and passes like MachineLoop are registered with isCFGOnly set to true.
llvm-svn: 77691
failures when building assorted projects with clang.
--- Reverse-merging r77654 into '.':
U include/llvm/CodeGen/Passes.h
U include/llvm/CodeGen/MachineFunctionPass.h
U include/llvm/CodeGen/MachineFunction.h
U include/llvm/CodeGen/LazyLiveness.h
U include/llvm/CodeGen/SelectionDAGISel.h
D include/llvm/CodeGen/MachineFunctionAnalysis.h
U include/llvm/Function.h
U lib/Target/CellSPU/SPUISelDAGToDAG.cpp
U lib/Target/PowerPC/PPCISelDAGToDAG.cpp
U lib/CodeGen/LLVMTargetMachine.cpp
U lib/CodeGen/MachineVerifier.cpp
U lib/CodeGen/MachineFunction.cpp
U lib/CodeGen/PrologEpilogInserter.cpp
U lib/CodeGen/MachineLoopInfo.cpp
U lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
D lib/CodeGen/MachineFunctionAnalysis.cpp
D lib/CodeGen/MachineFunctionPass.cpp
U lib/CodeGen/LiveVariables.cpp
llvm-svn: 77661
consecutive addresses togther. This makes it easier for the post-allocation pass
to form ldm / stm.
This is step 1. We are still missing a lot of ldm / stm opportunities because
of register allocation are not done in the desired order. More enhancements
coming.
llvm-svn: 73291
code in preparation for code generation. The main thing it does
is handle the case when eh.exception calls (and, in a future
patch, eh.selector calls) are far away from landing pads. Right
now in practice you only find eh.exception calls close to landing
pads: either in a landing pad (the common case) or in a landing
pad successor, due to loop passes shifting them about. However
future exception handling improvements will result in calls far
from landing pads:
(1) Inlining of rewinds. Consider the following case:
In function @f:
...
invoke @g to label %normal unwind label %unwinds
...
unwinds:
%ex = call i8* @llvm.eh.exception()
...
In function @g:
...
invoke @something to label %continue unwind label %handler
...
handler:
%ex = call i8* @llvm.eh.exception()
... perform cleanups ...
"rethrow exception"
Now inline @g into @f. Currently this is turned into:
In function @f:
...
invoke @something to label %continue unwind label %handler
...
handler:
%ex = call i8* @llvm.eh.exception()
... perform cleanups ...
invoke "rethrow exception" to label %normal unwind label %unwinds
unwinds:
%ex = call i8* @llvm.eh.exception()
...
However we would like to simplify invoke of "rethrow exception" into
a branch to the %unwinds label. Then %unwinds is no longer a landing
pad, and the eh.exception call there is then far away from any landing
pads.
(2) Using the unwind instruction for cleanups.
It would be nice to have codegen handle the following case:
invoke @something to label %continue unwind label %run_cleanups
...
handler:
... perform cleanups ...
unwind
This requires turning "unwind" into a library call, which
necessarily takes a pointer to the exception as an argument
(this patch also does this unwind lowering). But that means
you are using eh.exception again far from a landing pad.
(3) Bugpoint simplifications. When bugpoint is simplifying
exception handling code it often generates eh.exception calls
far from a landing pad, which then causes codegen to assert.
Bugpoint then latches on to this assertion and loses sight
of the original problem.
Note that it is currently rare for this pass to actually do
anything. And in fact it normally shouldn't do anything at
all given the code coming out of llvm-gcc! But it does fire
a few times in the testsuite. As far as I can see this is
almost always due to the LoopStrengthReduce codegen pass
introducing pointless loop preheader blocks which are landing
pads and only contain a branch to another block. This other
block contains an eh.exception call. So probably by tweaking
LoopStrengthReduce a bit this can be avoided.
llvm-svn: 72276
The following is checked:
* Operand counts: All explicit operands must be present.
* Register classes: All physical and virtual register operands must be
compatible with the register class required by the instruction descriptor.
* Register live intervals: Registers must be defined only once, and must be
defined before use.
The machine code verifier is enabled with the command-line option
'-verify-machineinstrs', or by defining the environment variable
LLVM_VERIFY_MACHINEINSTRS to the name of a file that will receive all the
verifier errors.
llvm-svn: 71918
Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.
Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'll change the JIT with a follow-up patch.
llvm-svn: 70343
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.
Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'm not 100% sure if it's necessary to change it there...
llvm-svn: 70270
Daniel Dunbar