Commit Graph

20 Commits

Author SHA1 Message Date
4b74df7229 SimplifyLibCalls: Add basic optimization of memchr calls.
This is just memchr(x, y, 0) -> nullptr and constant folding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232896 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-21 15:36:21 +00:00
529919ff31 DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 02:37:25 +00:00
d59c5f9a06 Add missing includes. make_unique proliferated everywhere.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230909 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-01 21:28:53 +00:00
37be0d7c43 [SimplifyLibCalls] Don't confuse strcpy_chk for stpcpy_chk.
This was introduced in a faulty refactoring (r225640, mea culpa):
the tests weren't testing the return values, so, for both
__strcpy_chk and __stpcpy_chk, we would return the end of the
buffer (matching stpcpy) instead of the beginning (for strcpy).

The root cause was the prefix "__" being ignored when comparing,
which made us always pick LibFunc::stpcpy_chk.
Pass the LibFunc::Func directly to avoid this kind of error.
Also, make the testcases as explicit as possible to prevent this.

The now-useful testcases expose another, entangled, stpcpy problem,
with the further simplification.  This was introduced in a
refactoring (r225640) to match the original behavior.

However, this leads to problems when successive simplifications
generate several similar instructions, none of which are removed
by the custom replaceAllUsesWith.

For instance, InstCombine (the main user) doesn't erase the
instruction in its custom RAUW.  When trying to simplify say
__stpcpy_chk:
- first, an stpcpy is created (fortified simplifier),
- second, a memcpy is created (normal simplifier), but the
  stpcpy call isn't removed.
- third, InstCombine later revisits the instructions,
  and simplifies the first stpcpy to a memcpy.  We now have
  two memcpys.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227250 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-27 21:52:16 +00:00
b67fc33fa5 [PM] Replace an abuse of inheritance to override a single function with
a more direct approach: a type-erased glorified function pointer. Now we
can pass a function pointer into this for the easy case and we can even
pass a lambda into it in the interesting case in the instruction
combiner.

I'll be using this shortly to simplify the interfaces to InstCombiner,
but this helps pave the way and seems like a better design for the
libcall simplifier utility.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226640 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-21 02:11:59 +00:00
61d6dc41fa [SimplifyLibCalls] Don't try to simplify indirect calls.
It turns out, all callsites of the simplifier are guarded by a check for
CallInst::getCalledFunction (i.e., to make sure the callee is direct).

This check wasn't done when trying to further optimize a simplified fortified
libcall, introduced by a refactoring in r225640.

Fix that, add a testcase, and document the requirement.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225895 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 00:55:05 +00:00
2cec3e9c11 [SimplifyLibCalls] Factor out fortified libcall handling.
This lets us remove CGP duplicate.

Differential Revision: http://reviews.llvm.org/D6541


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225640 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 17:22:43 +00:00
fe2d64e0f6 [SimplifyLibCalls] Factor out str/mem libcall optimizations.
Put them in a separate function, so we can reuse them to further
simplify fortified libcalls as well.

Differential Revision: http://reviews.llvm.org/D6540


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225639 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-12 17:20:06 +00:00
dc18ebc4b1 Shrinkify libcalls: use float versions of double libm functions with fast-math (bug 17850)
When a call to a double-precision libm function has fast-math semantics 
(via function attribute for now because there is no IR-level FMF on calls), 
we can avoid fpext/fptrunc operations and use the float version of the call
if the input and output are both float.

We already do this optimization using a command-line option; this patch just
adds the ability for fast-math to use the existing functionality.

I moved the cl::opt from InstructionCombining into SimplifyLibCalls because
it's only ever used internally to that class.

Modified the existing test cases to use the unsafe-fp-math attribute rather
than repeating all tests.

This patch should solve: http://llvm.org/bugs/show_bug.cgi?id=17850

Differential Revision: http://reviews.llvm.org/D5893



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220390 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-22 15:29:23 +00:00
d8214db086 fold: sqrt(x * x * y) -> fabs(x) * sqrt(y)
If a square root call has an FP multiplication argument that can be reassociated,
then we can hoist a repeated factor out of the square root call and into a fabs().

In the simplest case, this:

   y = sqrt(x * x);

becomes this:

   y = fabs(x);

This patch relies on an earlier optimization in instcombine or reassociate to put the
multiplication tree into a canonical form, so we don't have to search over
every permutation of the multiplication tree.

Because there are no IR-level FastMathFlags for intrinsics (PR21290), we have to
use function-level attributes to do this optimization. This needs to be fixed
for both the intrinsics and in the backend.

Differential Revision: http://reviews.llvm.org/D5787



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219944 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-16 18:48:17 +00:00
3f349b2ba8 Optimize away fabs() calls when input is squared (known positive).
Eliminate library calls and intrinsic calls to fabs when the input 
is a squared value.

Note that no unsafe-math / fast-math assumptions are needed for
this optimization.

Differential Revision: http://reviews.llvm.org/D5777



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219717 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 20:43:11 +00:00
52675f31e5 Reapply fix in r217988 (reverted in r217989) and remove the alternative fix committed in r217987.
This type isn't owned polymorphically (as demonstrated by making the
dtor protected and everything still compiling) so just address the
warning by protecting the base dtor and making the derived class final.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 22:27:36 +00:00
f8b9ec99b8 Revert "Fix -Wnon-virtual-dtor warning introduced in r217982."
An alternative fix was already committed.

This reverts commit r217988.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217989 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 22:17:59 +00:00
be048a0770 Fix -Wnon-virtual-dtor warning introduced in r217982.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217988 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 22:15:40 +00:00
0a1dc0d78f Fixing the sanitizer build failure:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/12868/steps/annotate/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217987 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 22:09:38 +00:00
14f9a54a8b Refactoring SimplifyLibCalls to remove static initializers and generally cleaning up the code.
Summary: This eliminates ~200 lines of code mostly file scoped struct definitions that were unnecessary.

Reviewers: chandlerc, resistor

Reviewed By: resistor

Subscribers: morisset, resistor, llvm-commits

Differential Revision: http://reviews.llvm.org/D5364

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217982 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-17 20:55:46 +00:00
6f1b92a0d4 Reformat blank lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209106 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-19 04:43:26 +00:00
2920a71663 instcombine: Migrate math library call simplifications
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167815 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-13 04:16:17 +00:00
b69bf6be1b Add method for replacing instructions to LibCallSimplifier
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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167681 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-11 03:51:43 +00:00
5e8904576a Implement new LibCallSimplifier class
This patch implements the new LibCallSimplifier class as outlined in [1].
In addition to providing the new base library simplification infrastructure,
all the fortified library call simplifications were moved over to the new
infrastructure.  The rest of the library simplification optimizations will
be moved over with follow up patches.

NOTE: The original fortified library call simplifier located in the
SimplifyFortifiedLibCalls class was not removed because it is still
used by CodeGenPrepare.  This class will eventually go away too.

[1] http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-August/052283.html

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165873 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-13 16:45:24 +00:00