TargetPassConfig::addMachinePasses() does some housekeeping first:
Handling the -print-machineinstrs flag and doing an initial printing
"After Instruction Selection". There is no reason for RegUsageInfoProp
to run before those two steps.
llvm-svn: 285422
The core of the change is supposed to be NFC, however it also fixes
what I believe was an undefined behavior when calling:
va_start(ValueArgs, Desc);
with Desc being a StringRef.
Differential Revision: https://reviews.llvm.org/D25342
llvm-svn: 283671
As discussed in https://reviews.llvm.org/D22666, our current mechanism to
support -pg profiling, where we insert calls to mcount(), or some similar
function, is fundamentally broken. We insert these calls in the frontend, which
means they get duplicated when inlining, and so the accumulated execution
counts for the inlined-into functions are wrong.
Because we don't want the presence of these functions to affect optimizaton,
they should be inserted in the backend. Here's a pass which would do just that.
The knowledge of the name of the counting function lives in the frontend, so
we're passing it here as a function attribute. Clang will be updated to use
this mechanism.
Differential Revision: https://reviews.llvm.org/D22825
llvm-svn: 280347
By default, this hook tells GlobalISel to abort (report a fatal error)
when it encounters an error. The alternative will be to fall back on
SDISel.
This fall back will be removed when the bring-up of GlobalISel is over.
llvm-svn: 279879
Summary:
This is a pretty trivial, but I thought it was worth just checking that nobody feels it's completely the wrong thing to be doing.
The motivation is that when starting a new backend, you often start with a minimal stub, pretty much just FooTargetMachine and FooTargetInfo. Once that's built, you might naturally try `llc -march=foo myinput.ll` and it seems more developer-friendly if this ends up asserting due to the lack of MCAsmInfo with an informative message rather than just segfaulting.
Reviewers: MatzeB, chandlerc
Subscribers: bogner, llvm-commits
Differential Revision: https://reviews.llvm.org/D23443
llvm-svn: 279061
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.
llvm-svn: 278902
Summary:
In this patch we implement the following parts of XRay:
- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.
There are some caveats here:
1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.
2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.
Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk
Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits
Differential Revision: http://reviews.llvm.org/D19904
llvm-svn: 275367
Avoid exposing a cl::opt in a public header and instead promote this
option in the API.
Alternatively, we could land the cl::opt in CommandFlags.h so that
it is available to every tool, but we would still have to find an
option for clang.
llvm-svn: 275348
IPRA try to optimize caller saved register by propagating register
usage information from callee to caller so it is beneficial to have
caller saved registers compare to callee saved registers when IPRA
is enabled. Please find more detailed explanation here
https://groups.google.com/d/msg/llvm-dev/XRzGhJ9wtZg/tjAJqb0eEgAJ.
This change makes local function do not have any callee preserved
register when IPRA is enabled. A simple test case is also added to
verify this change.
Patch by Vivek Pandya <vivekvpandya@gmail.com>
Differential Revision: http://reviews.llvm.org/D21561
llvm-svn: 275347
The createRegAllocPass reads and writes to a global variable 'Registry'
via calls to getDefault and setDefault. Run this under a call_once to
avoid races.
llvm-svn: 274875
StratifiedSets (as implemented) is very fast, but its accuracy is also
limited. If we take a more aggressive andersens-like approach, we can be
way more accurate, but we'll also end up being slower.
So, we've decided to split CFLAA into CFLSteensAA and CFLAndersAA.
Long-term, we want to end up in a place where CFLSteens is queried
first; if it can provide an answer, great (since queries are basically
map lookups). Otherwise, we'll fall back to CFLAnders, BasicAA, etc.
This patch splits everything out so we can try to do something like
that when we get a reasonable CFLAnders implementation.
Patch by Jia Chen.
Differential Revision: http://reviews.llvm.org/D21910
llvm-svn: 274589
Adds a MachineFunctionPass that scans the body to find calls, and
update the register mask with the one saved by the
RegUsageInfoCollector analysis in PhysicalRegisterUsageInfo.
Patch by Vivek Pandya <vivekvpandya@gmail.com>
Differential Revision: http://reviews.llvm.org/D21180
llvm-svn: 272414
Add an option to enable the analysis of MachineFunction register
usage to extract the list of clobbered registers.
When enabled, the CodeGen order is changed to be bottom up on the Call
Graph.
The analysis is split in two parts, RegUsageInfoCollector is the
MachineFunction Pass that runs post-RA and collect the list of
clobbered registers to produce a register mask.
An immutable pass, RegisterUsageInfo, stores the RegMask produced by
RegUsageInfoCollector, and keep them available. A future tranformation
pass will use this information to update every call-sites after
instruction selection.
Patch by Vivek Pandya <vivekvpandya@gmail.com>
Differential Revision: http://reviews.llvm.org/D20769
llvm-svn: 272403
Refactor LiveIntervals::renameDisconnectedComponents() to be a pass.
Also change the name to "RenameIndependentSubregs":
- renameDisconnectedComponents() worked on a MachineFunction at a time
so it is a natural candidate for a machine function pass.
- The algorithm is testable with a .mir test now.
- This also fixes a problem where the lazy renaming as part of the
MachineScheduler introduced IMPLICIT_DEF instructions after the number
of a nodes in a region were counted leading to a mismatch.
Differential Revision: http://reviews.llvm.org/D20507
llvm-svn: 271345
PrologEpilogInserter has these 3 phases, which are related, but not
all of them are needed by all targets. This patch reorganizes PEI's
varous functions around those phases for more clear separation. It also
introduces a new TargetMachine hook, usesPhysRegsForPEI, which is true
for non-virtual targets. When it is true, all the phases operate as
before, and PEI requires the AllVRegsAllocated property on
MachineFunctions. Otherwise, CSR spilling and scavenging are skipped and
only prolog/epilog insertion/frame finalization is done.
Differential Revision: http://reviews.llvm.org/D18366
llvm-svn: 269750
Many files include Passes.h but only a fraction needs to know about the
TargetPassConfig class. Move it into an own header. Also rename
Passes.cpp to TargetPassConfig.cpp while we are at it.
llvm-svn: 269011
Nirav Dave