Differential Revision: http://llvm-reviews.chandlerc.com/D620

llvm-svn: 179661

Nadav reported a performance regression due to the work I did to
merge the library call simplifier into instcombine [1].  The issue
is that a new LibCallSimplifier object is being created whenever
InstCombiner::runOnFunction is called.  Every time a LibCallSimplifier
object is used to optimize a call it creates a hash table to map from
a function name to an object that optimizes functions of that name.
For short-lived LibCallSimplifier instances this is quite inefficient.
Especially for cases where no calls are actually simplified.

This patch fixes the issue by dropping the hash table and implementing
an explicit lookup function to correlate the function name to the object
that optimizes functions of that name.  This avoids the cost of always
building and destroying the hash table in cases where the LibCallSimplifier
object is short-lived and avoids the cost of building the table when no
simplifications are actually preformed.

On a benchmark containing 100,000 calls where none of them are simplified
I noticed a 30% speedup.  On a benchmark containing 100,000 calls where
all of them are simplified I noticed an 8% speedup.

[1] http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130304/167639.html

llvm-svn: 176840

llvm-svn: 176397

For each function that we optimize we initialize a new list of lib functions. For each function name we malloc memory. This patch changes the Libcall map to use BumpPtrAllocator. Now we malloc only once. This speeds up instcombine by a few % on a large c++ program.

llvm-svn: 176170

The 'nobuiltin' attribute is applied to call sites to indicate that LLVM should
not treat the callee function as a built-in function. I.e., it shouldn't try to
replace that function with different code.

llvm-svn: 175835

llvm-svn: 175476

llvm-svn: 175470

isn't using the default calling convention.  However, if the transformation is
from a call to inline IR, then the calling convention doesn't matter.
rdar://13157990

llvm-svn: 174724

into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366

Rename the 'Attributes' class to 'Attribute'. It's going to represent a single attribute in the future.

llvm-svn: 170502

Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131

This patch migrates the puts optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

All the simplifiers from simplify-libcalls have now been migrated to
instcombine.  Yay!  Just a few other bits to migrate (prototype attribute
inference and a few statistics) and simplify-libcalls can finally be put
to rest.

llvm-svn: 168925

This patch migrates the fputs optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168893

This patch migrates the fwrite optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168892

This patch migrates the fprintf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168891

This patch migrates the sprintf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168677

When I migrated the toascii simplifier in r168580 Benjamin Kramer noticed
a bug in one of the comments that I migrated.

llvm-svn: 168605

This patch migrates the printf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168604

This patch migrates the toascii optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168580

This patch migrates the isascii optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168579

This patch migrates the isdigit optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168578

This patch migrates the *abs optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168574

This patch migrates the ffs* optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 168571

This patch migrates the math library call simplifications from the
simplify-libcalls pass into the instcombine library call simplifier.

I have typically migrated just one simplifier at a time, but the math
simplifiers are interdependent because:

   1. CosOpt, PowOpt, and Exp2Opt all depend on UnaryDoubleFPOpt.
   2. CosOpt, PowOpt, Exp2Opt, and UnaryDoubleFPOpt all depend on
      the option -enable-double-float-shrink.

These two factors made migrating each of these simplifiers individually
more of a pain than it would be worth.  So, I migrated them all together.

llvm-svn: 167815

The library call simplifier folds memcmp calls with all constant arguments
to a constant.  For example:

  memcmp("foo", "foo", 3) ->  0
  memcmp("hel", "foo", 3) ->  1
  memcmp("foo", "hel", 3) -> -1

The folding is implemented in terms of the system memcmp that LLVM gets
linked with.  It currently just blindly uses the value returned from
the system memcmp as the folded constant.

This patch normalizes the values returned from the system memcmp to
(-1, 0, 1) so that we get consistent results across multiple platforms.
The test cases were adjusted accordingly.

llvm-svn: 167726

This patch migrates the memset optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167689

This patch migrates the memmove optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167687

This patch migrates the memcpy optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167686

This patch migrates the memcmp optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167683

This patch migrates the strstr optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167682

In some cases the library call simplifier may need to replace instructions
other than the library call being simplified.  In those cases it may be
necessary for clients of the simplifier to override how the replacements
are actually done.  As such, a new overrideable method for replacing
instructions was added to LibCallSimplifier.

A new subclass of LibCallSimplifier is also defined which overrides
the instruction replacement method.  This is because the instruction
combiner defines its own replacement method which updates the worklist
when instructions are replaced.

llvm-svn: 167681

This patch migrates the strcspn optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167675

Several of the simplifiers migrated from the simplify-libcalls pass to
the instcombine pass were not correctly checking the target library
information to gate the simplifications.  This patch ensures that the
check is made.

llvm-svn: 167660

This patch migrates the strspn optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167568

getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.

These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.

Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)

After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.

Summary of reverted revisions:

r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
         Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
         since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
         on the address space.
llvm-svn: 167221

This patch migrates the strto* optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167119

This patch migrates the strpbrk optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167105

This patch migrates the strlen optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167103

This patch migrates the strncpy optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

llvm-svn: 167102

This patch migrates the stpcpy optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.  Note that the
__stpcpy_chk simplifications were migrated in a previous commit.

llvm-svn: 167083