The llc command line options for enabling/disabling passes are local to CodeGen/Passes.cpp. This patch associates those options with standard pass IDs so they work regardless of how the target configures the passes.

A target has two ways of overriding standard passes:
1) Redefine the pass pipeline (override TargetPassConfig::add%Stage)
2) Replace or suppress individiual passes with TargetPassConfig::substitutePass.

In both cases, the command line options associated with the pass override the target default.

For example, say a target wants to disable machine instruction scheduling by default:

- The target calls disablePass(MachineSchedulerID) but otherwise does not override any TargetPassConfig methods.

- Without any llc options, no scheduler is run.

- With -enable-misched, the standard machine scheduler is run and honors the -misched=... flag to select the scheduler variant, which may be used for performance evaluation or testing.

Sorry overridePass is ugly. I haven't thought of a better way without replacing the cl::opt framework. I hope to do that one day...

I haven't figured out why CodeGen uses char& for pass IDs. AnalysisID is much easier to use and less bug prone. I'm using it wherever I can for internal implementation. Maybe later we can change the global pass ID definitions as well.

llvm-svn: 150563

Added TargetPassConfig::disablePass/substitutePass as a general mechanism to override specific passes.

llvm-svn: 150562

llvm-svn: 150553

llvm-svn: 150552

llvm-svn: 150550

Pretend that regmask interference ends at the 'dead' slot, even when
there is other interference ending at the 'reg' slot of the same
instruction.

llvm-svn: 150531

Perform all comparisons at instruction granularity, and make sure
register masks on uses count in both gaps.

llvm-svn: 150530

Only accept register masks when looking for an 'overlapping' def. When
Overlap is not set, the function searches for a proper definition of
Reg.

This means MI->modifiesRegister() considers register masks, but
MI->definesRegister() doesn't.

llvm-svn: 150529

When a physreg is live in to a basic block, look for any instruction in
the block that clobbers the physreg.

The instruction doesn't have to properly redefine the register, any
overlapping clobber is OK.

This slightly changes live ranges when compiling with register masks.

llvm-svn: 150528

The old DenseMap hashed order was very confusing.

llvm-svn: 150527

llvm-svn: 150525

The MachO back-end needs to emit the garbage collection flags specified in the
module flags. This is a WIP, so the front-end hasn't been modified to emit these
flags just yet. Documentation and front-end switching to occur soon.

llvm-svn: 150507

llvm-svn: 150496

only be live in to a block if it is the function entry point or a landing pad.

llvm-svn: 150494

that are greater than the vector element type. For example BUILD_VECTOR
of type <1 x i1> with a constant i8 operand.
This patch fixes the assertion.

llvm-svn: 150477

llvm-svn: 150471

Rename getExceptionAddressRegister() to getExceptionPointerRegister() for consistency with setExceptionPointerRegister(...).

llvm-svn: 150460

llvm-svn: 150457

marking them as "live-in" into a BB ruins some invariants that the back-end
tries to maintain.

llvm-svn: 150437

llvm-svn: 150436

The scheduler will sometimes check the implicit-def list on instructions
to properly handle pre-colored DAG edges.

Also check any register mask operands for physreg clobbers.

llvm-svn: 150428

llvm-svn: 150411

llvm-svn: 150404

Fix a bug in DAGCombine for the optimization of BUILD_VECTOR. We cant generate a shuffle node from two vectors of different types.

llvm-svn: 150383

This patch addresses the problem of poor code generation for the zext
v8i8 -> v8i32 on AVX machines. The codegen often scalarizes ANY_EXTEND nodes.
The DAGCombiner has two optimizations that can mitigate the problem. First,
if all of the operands of a BUILD_VECTOR node are extracted from an ZEXT/ANYEXT
nodes, then it is possible to create a new simplified BUILD_VECTOR which uses
UNDEFS/ZERO values to eliminate the scalar ZEXT/ANYEXT nodes.
Second, another dag combine optimization lowers BUILD_VECTOR into a shuffle
vector instruction.

In the case of zext v8i8->v8i32 on AVX, a value in an XMM register is to be
shuffled into a wide YMM register.

This patch modifes the second optimization and allows the creation of
shuffle vectors even when the newly generated vector and the original vector
from which we extract the values are of different types.

llvm-svn: 150340

Patch by Kai Nacke!

llvm-svn: 150307

In case the MachineScheduling pass I'm working on doesn't work well
for another target, they can completely override it. This also adds a
hook immediately after the RegAlloc pass to cleanup immediately after
vregs go away. We may want to fold it into the postRA hook later.

llvm-svn: 150298

When using register masks, registers like %rip are clobbered by the
register mask. LICM should still be able to hoist instructions reading
%rip from a loop containing calls.

llvm-svn: 150288

Again the goal is to produce identical assembly with register mask
operands enabled.

llvm-svn: 150287

llvm-svn: 150286

It can be necessary to detach a register mask pointer from its
MachineOperand. This method is convenient for checking clobbered
physregs on a detached bitmask pointer.

llvm-svn: 150261

This makes global live range splitting behave identically with and
without register mask operands.

This is not necessarily the best way of using register masks for live
range splitting.  It would be more efficient to first split global live
ranges around calls (i.e., register masks), and reserve the fine grained
per-physreg interference guidance for global live ranges that do not
cross calls.

For now the goal is to produce identical assembly when enabling register
masks.

llvm-svn: 150259

llvm-svn: 150258

Put instruction names into an indexed string table on the side, removing a pointer from MCInstrDesc.

Make them accessible through MCInstrInfo. They are only used for debugging purposes so this doesn't
have an impact on performance. X86MCTargetDesc.o goes from 630K to 461K on x86_64.

llvm-svn: 150245

llvm-svn: 150233

Creates a configurable regalloc pipeline.

Ensure specific llc options do what they say and nothing more: -reglloc=... has no effect other than selecting the allocator pass itself. This patch introduces a new umbrella flag, "-optimize-regalloc", to enable/disable the optimizing regalloc "superpass". This allows for example testing coalscing and scheduling under -O0 or vice-versa.

When a CodeGen pass requires the MachineFunction to have a particular property, we need to explicitly define that property so it can be directly queried rather than naming a specific Pass. For example, to check for SSA, use MRI->isSSA, not addRequired<PHIElimination>.

CodeGen transformation passes are never "required" as an analysis

ProcessImplicitDefs does not require LiveVariables.

We have a plan to massively simplify some of the early passes within the regalloc superpass.

llvm-svn: 150226

llvm-svn: 150225

llvm-svn: 150224

When checking a local live range for interference, restrict the binary
search to the single block.

llvm-svn: 150220

Provide API to get a list of register mask slots and bits in a basic
block.

llvm-svn: 150219