Add physical register defs to instructions used from stackified
instructions to prevent them from being scheduled into the middle of
a stack sequence. This is a conservative measure which may be loosened
in the future.
Differential Revision: http://reviews.llvm.org/D15252
llvm-svn: 254811
This is just prototype for load/store for i32 types. I'll add them to
the rest of the types if we like this direction.
Differential Revision: http://reviews.llvm.org/D15197
llvm-svn: 254807
When the notion of target specific memory intrinsics was introduced to EarlyCSE, the commit confused the notions of volatile and simple memory access. Since I'm about to start working on this area, cleanup the naming so that patches aren't horribly confusing. Note that the actual implementation was always bailing if the load or store wasn't simple.
Reminder:
- "volatile" - C++ volatile, can't remove any memory operations, but in principal unordered
- "ordered" - imposes ordering constraints on other nearby memory operations
- "atomic" - can't be split or sheared. In LLVM terms, all "ordered" operations are also atomic so the predicate "isAtomic" is often used.
- "simple" - a load which is none of the above. These are normal loads and what most of the optimizer works with.
llvm-svn: 254805
In 254760, I introduced the usage of a BumpPtrAllocator for the AnalysisUsage instances held by the PassManger. This turns out to have been incorrect since a BumpPtrAllocator does not run the destructors of objects when deallocating memory. Since a few of our SmallVector's had grown beyond their small size, we end up with some leaked memory. We need to use a SpecificBumpPtrAllocator instead.
llvm-svn: 254803
Full varargs support will depend on prologue/epilogue support, but this patch
gets us started with most of the basic infrastructure.
Differential Revision: http://reviews.llvm.org/D15231
llvm-svn: 254799
These instructions are not supported by all CPUs in 64-bit mode. Emitting them
causes Chromium to crash on start-up for users with such chips.
(GCC puts these instructions behind -msahf on 64-bit for the same reason.)
This patch adds FeatureLAHFSAHF, enables it by default for 32-bit targets
and modern CPUs, and changes X86InstrInfo::copyPhysReg back to the lowering
from before r244503 when the instructions are not available.
Differential Revision: http://reviews.llvm.org/D15240
llvm-svn: 254793
Before this patch the diagnostic handler was optional. If it was not
passed, the one in the LLVMContext was used.
That is probably not a pattern we want to follow. If each area has an
optional callback, there is a sea of callbacks and it is hard to follow
which one is called.
Doing this also found cases where the callback is a nice addition, like
testing that no errors or warnings are reported.
The other option is to always use the diagnostic handler in the
LLVMContext. That has a few problems
* To implement the C API we would have to set the diag handler and then
set it back to the original value.
* Code that creates the context might be far away from code that wants
the diagnostics.
I do have a patch that implements the second option and will send that as
an RFC.
llvm-svn: 254777
Summary:
In order to avoid calling pow function we generate repeated fmul when n is a
positive or negative whole number.
For each exponent we pre-compute Addition Chains in order to minimize the no.
of fmuls.
Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
We pre-compute addition chains for exponents upto 32 (which results in a max of
7 fmuls).
For eg:
4 = 2+2
5 = 2+3
6 = 3+3 and so on
Hence,
pow(x, 4.0) ==> y = fmul x, x
x = fmul y, y
ret x
For negative exponents, we simply compute the reciprocal of the final result.
Note: This transformation is only enabled under fast-math.
Patch by Mandeep Singh Grang <mgrang@codeaurora.org>
Reviewers: weimingz, majnemer, escha, davide, scanon, joerg
Subscribers: probinson, escha, llvm-commits
Differential Revision: http://reviews.llvm.org/D13994
llvm-svn: 254776
Currently `OperandBundleUse::operandsHaveAttr` computes its result
without being given a specific operand. This is problematic because it
forces us to say that, e.g., even non-pointer operands in `"deopt"`
operand bundles are `readonly`, which doesn't make sense.
This commit changes `operandsHaveAttr` to work in the context of a
specific operand, so that we can give the operand attributes that make
sense for the operands's `llvm::Type`.
llvm-svn: 254764
The LegacyPassManager was storing an instance of AnalysisUsage for each instance of each pass. In practice, most instances of a single pass class share the same dependencies. We can't rely on this because passes can (and some do) have dynamic dependencies based on instance options.
We can exploit the likely commonality by uniqueing the usage information after querying the pass, but before storing it into the pass manager. This greatly reduces memory consumption by the AnalysisUsage objects. For a long pass pipeline, I measured a decrease in memory consumption for this storage of about 50%. I have not measured on the default O3 pipeline, but I suspect it will see some benefit as well since many passes are repeated (e.g. InstCombine).
Differential Revision: http://reviews.llvm.org/D14677
llvm-svn: 254760
This commit adds a new target-independent calling convention for C++ TLS
access functions. It aims to minimize overhead in the caller by perserving as
many registers as possible.
The target-specific implementation for X86-64 is defined as following:
Arguments are passed as for the default C calling convention
The same applies for the return value(s)
The callee preserves all GPRs - except RAX and RDI
The access function makes C-style TLS function calls in the entry and exit
block, C-style TLS functions save a lot more registers than normal calls.
The added calling convention ties into the existing implementation of the
C-style TLS functions, so we can't simply use existing calling conventions
such as preserve_mostcc.
rdar://9001553
llvm-svn: 254737
This is a continuation of r253367.
These functions return is owned by the caller, so they return
std::unique_ptr now.
The call can fail, so the return is wrapped in ErrorOr.
They have a context where to report diagnostics, so they don't need to
take a string out parameter.
With this there are no call to getGlobalContext in lib/LTO.
llvm-svn: 254721
Since BuildMI() automatically adds the implicit operands for a new instruction,
adding the old instructions CC operand resulted in that there were two CC imp-def
operands, where only one was marked as dead. This caused buildSchedGraph() to
miss dependencies on the CC reg.
Review by Ulrich Weigand
llvm-svn: 254714
Add new x86 pass which replaces address calculations in load or store instructions with def register of existing LEA (must be in the same basic block), if the LEA calculates address that differs only by a displacement. Works only with -Os or -Oz.
Differential Revision: http://reviews.llvm.org/D13294
llvm-svn: 254712
For PowerPC64 we cannot just pass SP extracted from @llvm.stackrestore to
_asan_allocas_unpoison due to specific ABI requirements
(http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#DYNAM-STACK).
This patch adds the value returned by @llvm.get.dynamic.area.offset to
extracted from @llvm.stackrestore stack pointer, so dynamic allocas unpoisoning
stuff would work correctly on PowerPC64.
Patch by Max Ostapenko.
Differential Revision: http://reviews.llvm.org/D15108
llvm-svn: 254707
Summary:
If we remove the MMOs from Load/Store instructions,
they are treated as volatile. This makes other optimization passes unhappy.
eg. Load/Store Optimization
So, it looks better to merge, not remove.
Reviewers: gberry, mcrosier
Subscribers: gberry, llvm-commits
Differential Revision: http://reviews.llvm.org/D14797
llvm-svn: 254694
This class is turning into a useful interface, rather than an implementation
detail, so I'm dropping the 'Base' suffix.
No functional change.
llvm-svn: 254693
with its source instead of forcing the values on GPRs.
This improves the lowering of vector code when such bitcasts happen in the
middle of vector computations.
rdar://problem/23691584
llvm-svn: 254684
Re-comitting with a change that avoids undefined uses getting put into
the VRegUses list.
The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
(not used for now)
The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.
Differential Revision: http://reviews.llvm.org/D9068
llvm-svn: 254683
This is a revised version of r254655 which uses a Printable wrapper
class to avoid ambiguous overload problems.
Differential Revision: http://reviews.llvm.org/D14348
llvm-svn: 254681
Summary:
computeRegisterLiveness and analyzePhysReg are currently getting
confused about liveness in some cases, breaking copyPhysReg's
calculation of whether AX is dead in some cases. Work around this issue
temporarily by assuming that AX is always live.
See detail in: https://llvm.org/bugs/show_bug.cgi?id=25033#c7
And associated bugs PR24535 PR25033 PR24991 PR24992 PR25201.
This workaround makes the code correct but slightly inefficient, but it
seems to confuse the machine instr verifier which now things EAX was
undefined in some cases where it's being conservatively saved /
restored.
Reviewers: majnemer, sanjoy
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15198
llvm-svn: 254680
With the latest refactoring and code sharing patches landed,
it is possible to unify the value profile implementation between
raw and indexed profile. This is the patch in raw profile reader
that uses the common interface.
Differential Revision: http://reviews.llvm.org/D15056
llvm-svn: 254677
CFI emits jump slots for indirect functions as a byte array
constant, and declares function-typed aliases to these constants.
This change fixes AsmPrinter to emit these aliases as function
symbols and not data symbols.
llvm-svn: 254674
This change adds support for an optional weight when merging profile data with the llvm-profdata tool.
Weights are specified by adding an option ':<weight>' suffix to the input file names.
Adding support for arbitrary weighting of input profile data allows for relative importance to be placed on the
input data from multiple training runs.
Both sampled and instrumented profiles are supported.
Reviewers: dnovillo, bogner, davidxl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D14547
llvm-svn: 254669
Code generation often exposes redundant physical register copies through
virtual registers such as:
%vreg = COPY %PHYSREG
...
%PHYSREG = COPY %vreg
There are cases where no intervening clobber of %PHYSREG occurs, and the
later copy could therefore be removed. In some cases this further allows
us to remove the initial copy.
This patch contains a motivating example which comes from the x86 build
of Chrome, specifically cc::ResourceProvider::UnlockForRead uses
libstdc++'s implementation of hash_map. That example has two tests live
at the same time, and after machine sinking LLVM has confused itself
enough and things spilling EFLAGS is a great idea even though it's
never restored and the comparison results are both live.
Before this patch we have:
DEC32m %RIP, 1, %noreg, <ga:@L>, %noreg, %EFLAGS<imp-def>
%vreg1<def> = COPY %EFLAGS; GR64:%vreg1
%EFLAGS<def> = COPY %vreg1; GR64:%vreg1
JNE_1 <BB#1>, %EFLAGS<imp-use>
Both copies are useless. This patch tries to eliminate the later copy in
a generic manner.
dec is especially confusing to LLVM when compared with sub.
I wrote this patch to treat all physical registers generically, but only
remove redundant copies of non-allocatable physical registers because
the allocatable ones caused issues (e.g. when calling conventions weren't
properly modeled) and should be handled later by the register allocator
anyways.
The following tests used to failed when the patch also replaced allocatable
registers:
CodeGen/X86/StackColoring.ll
CodeGen/X86/avx512-calling-conv.ll
CodeGen/X86/copy-propagation.ll
CodeGen/X86/inline-asm-fpstack.ll
CodeGen/X86/musttail-varargs.ll
CodeGen/X86/pop-stack-cleanup.ll
CodeGen/X86/preserve_mostcc64.ll
CodeGen/X86/tailcallstack64.ll
CodeGen/X86/this-return-64.ll
This happens because COPY has other special meaning for e.g. dependency
breakage and x87 FP stack.
Note that all other backends' tests pass.
Reviewers: qcolombet
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15157
llvm-svn: 254665
