Commit Graph

677 Commits

Author SHA1 Message Date
Bill Wendling 91d4e9edec Don't sink the instruction to before a landingpad instruction.
llvm-svn: 137672
2011-08-15 22:53:05 +00:00
Eli Friedman 8bc586e770 Update instcombine for atomic load/store.
llvm-svn: 137664
2011-08-15 22:09:40 +00:00
Bill Wendling e86965ee19 Duncan pointed out that the LandingPadInst might read memory. (It might also
write to memory.) Marking it as such makes some checks for immobility go away.

llvm-svn: 137655
2011-08-15 21:14:31 +00:00
Bill Wendling dd94d3426b Don't try to sink the landingpad instruction. It's immobile.
llvm-svn: 137629
2011-08-15 18:23:40 +00:00
Nick Lewycky 746e317953 This transform is not safe. Thanks to Eli for pointing that out!
llvm-svn: 137575
2011-08-14 04:51:49 +00:00
Nick Lewycky ae13df60a6 Don't attempt to add 'nsw' when intermediate instructions had no such guarantee.
llvm-svn: 137572
2011-08-14 03:41:33 +00:00
Nick Lewycky de49278c26 Teach instcombine to preserve the nsw bit by doing an after-the-fact analysis
when combining add and sub instructions. Patch by Pranav Bhandarkar!

llvm-svn: 137570
2011-08-14 01:45:19 +00:00
Nick Lewycky d405b7e2ae Small cleanups:
- use SmallVectorImpl& for the function argument.
  - ignore the operands on the GEP, even if they aren't constant! Much as we
    pretend the malloc succeeds, we pretend that malloc + whatever-you-GEP'd-by
    is not null. It's magic!

llvm-svn: 136757
2011-08-03 01:11:40 +00:00
Nick Lewycky 50f4966ceb Fix logical error when detecting lifetime intrinsics.
Don't replace a gep/bitcast with 'undef' because that will form a "free(undef)"
which in turn means "unreachable". What we wanted was a no-op. Instead, analyze
the whole tree and look for all the instructions we need to delete first, then
delete them second, not relying on the use_list to stay consistent.

llvm-svn: 136752
2011-08-03 00:43:35 +00:00
Nick Lewycky e8ae02dfb9 Teach InstCombine that lifetime intrincs aren't a real user on the result of a
malloc call.

llvm-svn: 136732
2011-08-02 22:08:01 +00:00
Bill Wendling f891bf8b30 Add the 'resume' instruction for the new EH rewrite.
This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).

llvm-svn: 136589
2011-07-31 06:30:59 +00:00
Rafael Espindola a3a44f3fc3 Add a small gep optimization I noticed was missing while reading some IL.
llvm-svn: 136585
2011-07-31 04:43:41 +00:00
Bill Wendling ad088e6724 Revert r136253, r136263, r136269, r136313, r136325, r136326, r136329, r136338,
r136339, r136341, r136369, r136387, r136392, r136396, r136429, r136430, r136444,
r136445, r136446, r136253 pending review.

llvm-svn: 136556
2011-07-30 05:42:50 +00:00
Eli Friedman 530341d748 Make sure to correctly clear the exact/nuw/nsw flags off of shifts when they are combined together. <rdar://problem/9859829>
llvm-svn: 136435
2011-07-29 00:18:19 +00:00
Chandler Carruth 9d7feab3e0 Rewrite the CMake build to use explicit dependencies between libraries,
specified in the same file that the library itself is created. This is
more idiomatic for CMake builds, and also allows us to correctly specify
dependencies that are missed due to bugs in the GenLibDeps perl script,
or change from compiler to compiler. On Linux, this returns CMake to
a place where it can relably rebuild several targets of LLVM.

I have tried not to change the dependencies from the ones in the current
auto-generated file. The only places I've really diverged are in places
where I was seeing link failures, and added a dependency. The goal of
this patch is not to start changing the dependencies, merely to move
them into the correct location, and an explicit form that we can control
and change when necessary.

This also removes a serialization point in the build because we don't
have to scan all the libraries before we begin building various tools.
We no longer have a step of the build that regenerates a file inside the
source tree. A few other associated cleanups fall out of this.

This isn't really finished yet though. After talking to dgregor he urged
switching to a single CMake macro to construct libraries with both
sources and dependencies in the arguments. Migrating from the two macros
to that style will be a follow-up patch.

Also, llvm-config is still generated with GenLibDeps.pl, which means it
still has slightly buggy dependencies. The internal CMake
'llvm-config-like' macro uses the correct explicitly specified
dependencies however. A future patch will switch llvm-config generation
(when using CMake) to be based on these deps as well.

This may well break Windows. I'm getting a machine set up now to dig
into any failures there. If anyone can chime in with problems they see
or ideas of how to solve them for Windows, much appreciated.

llvm-svn: 136433
2011-07-29 00:14:25 +00:00
Bill Wendling 6c923bb8d9 Merge the contents from exception-handling-rewrite to the mainline.
This adds the new instructions 'landingpad' and 'resume'.

llvm-svn: 136253
2011-07-27 20:18:04 +00:00
Frits van Bommel ede0dc6dda Shorten some expressions by using ArrayRef::slice().
llvm-svn: 135910
2011-07-25 15:13:01 +00:00
Jay Foad d1b7849d49 Convert GetElementPtrInst to use ArrayRef.
llvm-svn: 135904
2011-07-25 09:48:08 +00:00
Jay Foad 040dd82f44 Convert IRBuilder::CreateGEP and IRBuilder::CreateInBoundsGEP to use
ArrayRef.

llvm-svn: 135761
2011-07-22 08:16:57 +00:00
Jay Foad 71f19ac6af Fix an MSVC warning, caused by a case I missed when converting
ConstantExpr::getGetElementPtr to use ArrayRef.

llvm-svn: 135758
2011-07-22 07:54:01 +00:00
Eli Friedman 911e12f505 Clean up includes of llvm/Analysis/ConstantFolding.h so it's included where it's used and not included where it isn't.
llvm-svn: 135628
2011-07-20 21:57:23 +00:00
Jay Foad b992a635fb Convert SimplifyGEPInst to use ArrayRef.
llvm-svn: 135482
2011-07-19 15:07:52 +00:00
Jay Foad bf904773bb Convert TargetData::getIndexedOffset to use ArrayRef.
llvm-svn: 135478
2011-07-19 14:01:37 +00:00
Jay Foad f4b14a2b0d Use ArrayRef in ConstantFoldInstOperands and ConstantFoldCall.
llvm-svn: 135477
2011-07-19 13:32:40 +00:00
Frits van Bommel 717d7edd3e Migrate LLVM and Clang to use the new makeArrayRef(...) functions where previously explicit non-default constructors were used.
Mostly mechanical with some manual reformatting.

llvm-svn: 135390
2011-07-18 12:00:32 +00:00
Chris Lattner 229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Jay Foad 5bd375a6cc Convert CallInst and InvokeInst APIs to use ArrayRef.
llvm-svn: 135265
2011-07-15 08:37:34 +00:00
Chris Lattner b1a1512119 start using the new helper methods a bit.
llvm-svn: 135251
2011-07-15 06:08:15 +00:00
Benjamin Kramer e6e1933f31 Change Intrinsic::getDeclaration and friends to take an ArrayRef.
llvm-svn: 135154
2011-07-14 17:45:39 +00:00
Evan Cheng b94674b325 It's not safe to fold (fptrunc (sqrt (fpext x))) to (sqrtf x) if there is another use of sqrt. rdar://9763193
llvm-svn: 135058
2011-07-13 19:08:16 +00:00
Jay Foad 57aa636794 Convert InsertValueInst and ExtractValueInst APIs to use ArrayRef.
llvm-svn: 135040
2011-07-13 10:26:04 +00:00
Jay Foad b804a2b751 Second attempt at de-constifying LLVM Types in FunctionType::get(),
StructType::get() and TargetData::getIntPtrType().

llvm-svn: 134982
2011-07-12 14:06:48 +00:00
Bill Wendling a78cd228c2 Revert r134893 and r134888 (and related patches in other trees). It was causing
an assert on Darwin llvm-gcc builds.

Assertion failed: (castIsValid(op, S, Ty) && "Invalid cast!"), function Create, file /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.llvm-gcc-i386-darwin9-RA/llvm.src/lib/VMCore/Instructions.cpp, li\
ne 2067.
etc.

http://smooshlab.apple.com:8013/builders/llvm-gcc-i386-darwin9-RA/builds/2354

--- Reverse-merging r134893 into '.':
U    include/llvm/Target/TargetData.h
U    include/llvm/DerivedTypes.h
U    tools/bugpoint/ExtractFunction.cpp
U    unittests/Support/TypeBuilderTest.cpp
U    lib/Target/ARM/ARMGlobalMerge.cpp
U    lib/Target/TargetData.cpp
U    lib/VMCore/Constants.cpp
U    lib/VMCore/Type.cpp
U    lib/VMCore/Core.cpp
U    lib/Transforms/Utils/CodeExtractor.cpp
U    lib/Transforms/Instrumentation/ProfilingUtils.cpp
U    lib/Transforms/IPO/DeadArgumentElimination.cpp
U    lib/CodeGen/SjLjEHPrepare.cpp
--- Reverse-merging r134888 into '.':
G    include/llvm/DerivedTypes.h
U    include/llvm/Support/TypeBuilder.h
U    include/llvm/Intrinsics.h
U    unittests/Analysis/ScalarEvolutionTest.cpp
U    unittests/ExecutionEngine/JIT/JITTest.cpp
U    unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp
U    unittests/VMCore/PassManagerTest.cpp
G    unittests/Support/TypeBuilderTest.cpp
U    lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
U    lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp
U    lib/VMCore/IRBuilder.cpp
G    lib/VMCore/Type.cpp
U    lib/VMCore/Function.cpp
G    lib/VMCore/Core.cpp
U    lib/VMCore/Module.cpp
U    lib/AsmParser/LLParser.cpp
U    lib/Transforms/Utils/CloneFunction.cpp
G    lib/Transforms/Utils/CodeExtractor.cpp
U    lib/Transforms/Utils/InlineFunction.cpp
U    lib/Transforms/Instrumentation/GCOVProfiling.cpp
U    lib/Transforms/Scalar/ObjCARC.cpp
U    lib/Transforms/Scalar/SimplifyLibCalls.cpp
U    lib/Transforms/Scalar/MemCpyOptimizer.cpp
G    lib/Transforms/IPO/DeadArgumentElimination.cpp
U    lib/Transforms/IPO/ArgumentPromotion.cpp
U    lib/Transforms/InstCombine/InstCombineCompares.cpp
U    lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
U    lib/Transforms/InstCombine/InstCombineCalls.cpp
U    lib/CodeGen/DwarfEHPrepare.cpp
U    lib/CodeGen/IntrinsicLowering.cpp
U    lib/Bitcode/Reader/BitcodeReader.cpp

llvm-svn: 134949
2011-07-12 01:15:52 +00:00
Jay Foad 56cc1530ee De-constify Types in FunctionType::get().
llvm-svn: 134888
2011-07-11 07:56:41 +00:00
Rafael Espindola 403256763f Don't duplicate the work done by a gep into a "bitcast" if the gep has
more than one use.

Fixes PR10322.

llvm-svn: 134883
2011-07-11 03:43:47 +00:00
Bob Wilson 3c68b626e7 Reapply a fixed version of r133285.
This tightens up checking for overflow in alloca sizes, based on feedback
from Duncan and John about the change in r132926.

llvm-svn: 134749
2011-07-08 22:09:33 +00:00
Benjamin Kramer 9eca5feff1 PR10267: Don't combine an equality compare with an AND into an inequality compare when the AND has more than one use.
This can pessimize code, inequalities are generally more expensive.

llvm-svn: 134379
2011-07-04 20:16:36 +00:00
Owen Anderson 2f37bdc392 Generalize @llvm.ctlz, @llvm.cttz, and @llvm.ctpop to work on vectors of integers, and fix the one optimization pass that I'm aware of that needs updating for this. At least one current target, ARM NEON, can implement these operations on vectors directly.
llvm-svn: 134265
2011-07-01 21:52:38 +00:00
Eli Friedman 2c980fafff PR10180: Fix a instcombine crash with FP vectors.
llvm-svn: 133756
2011-06-23 20:40:23 +00:00
Chris Lattner cc19efaa97 Revamp the "ConstantStruct::get" methods. Previously, these were scattered
all over the place in different styles and variants.  Standardize on two
preferred entrypoints: one that takes a StructType and ArrayRef, and one that
takes StructType and varargs.

In cases where there isn't a struct type convenient, we now add a
ConstantStruct::getAnon method (whose name will make more sense after a few
more patches land).  

It would be "really really nice" if the ConstantStruct::get and 
ConstantVector::get methods didn't make temporary std::vectors.

llvm-svn: 133412
2011-06-20 04:01:31 +00:00
Chad Rosier c76b9d8c2f Revert r133285. Causing odd failures on Dragonegg.
llvm-svn: 133301
2011-06-17 22:08:25 +00:00
Stuart Hastings 23be986a0c Relocate NUW test to cover all binary ops in a dynamic alloca expr.
Followup to 132926.  rdar://problem/9265821

llvm-svn: 133285
2011-06-17 20:21:52 +00:00
Stuart Hastings 351a3f881f Avoid fusing bitcasts with dynamic allocas if the amount-to-allocate
might overflow.  Re-typing the alloca to a larger type (e.g. double)
hoists a shift into the alloca, potentially exposing overflow in the
expression.  rdar://problem/9265821

llvm-svn: 132926
2011-06-13 18:48:49 +00:00
Benjamin Kramer c970849ea0 InstCombine: Fold A-b == C --> b == A-C if A and C are constants.
The backend already knew this trick.

llvm-svn: 132915
2011-06-13 15:24:24 +00:00
Benjamin Kramer 91f914ce21 InstCombine: Shrink ((zext X) & C1) == C2 to fold away the cast if the "zext" and the "and" have one use.
llvm-svn: 132897
2011-06-12 22:48:00 +00:00
Benjamin Kramer 35159c114c Simplify code. No functionality changes, name changes aside.
llvm-svn: 132896
2011-06-12 22:47:53 +00:00
Stuart Hastings 2380483355 Reapply 132348 with fixes. rdar://problem/6501862
llvm-svn: 132402
2011-06-01 16:42:47 +00:00
Stuart Hastings 9d6a06d536 Revert to pacify a buildbot. rdar://problem/6501862
llvm-svn: 132351
2011-05-31 19:56:35 +00:00
Stuart Hastings 780f723309 Followup to 132316; accept arbitrary constants, add with a constant,
sub with a non-constant.  Fix comments, enlarge test case.
rdar://problem/6501862

llvm-svn: 132348
2011-05-31 19:29:55 +00:00
Stuart Hastings 8284374b07 (1 - X) * (-2) -> (x - 1) * 2, for all positive nonzero powers of 2
rdar://problem/6501862

llvm-svn: 132316
2011-05-30 20:00:33 +00:00
Benjamin Kramer fd53a27f99 ConstantFoldInstOperands doesn't like compares, hand it off to instsimplify instead.
Fixes PR10040.

llvm-svn: 132254
2011-05-28 10:16:58 +00:00
Benjamin Kramer 749ef5f420 InstCombine: Make switch folding with equality compares more aggressive by trying instsimplify on the arm where we know the compared value.
Stuff like "x == y ? y : x&y" now folds into "x&y".

llvm-svn: 132185
2011-05-27 13:00:16 +00:00
Eli Friedman 35211c6091 Final step of instcombine debuginfo; switch a couple more places over to InsertNewInstWith, and use setDebugLoc for the cases which can't be easily handled by the automated mechanisms.
llvm-svn: 132167
2011-05-27 00:19:40 +00:00
Chad Rosier b362884ca9 Renamed llvm.x86.sse42.crc32 intrinsics; crc64 doesn't exist.
crc32.[8|16|32] have been renamed to .crc32.32.[8|16|32] and
crc64.[8|16|32] have been renamed to .crc32.64.[8|64].

llvm-svn: 132163
2011-05-26 23:13:19 +00:00
Eli Friedman 865866e7fe PR9998: ashr exact %x, 31 is not equivalent to sdiv exact %x, -2147483648.
llvm-svn: 132097
2011-05-25 23:26:20 +00:00
Eli Friedman 68aab459ae Make instcombine O(N) instead of O(N^2) in code where the same simplifiable constant is used many times.
Part of rdar://9471075.

llvm-svn: 131979
2011-05-24 18:52:07 +00:00
Chris Lattner 388cb8a57c rearrange two transforms, since one subsumes the other. Make the shift-exactness
xform recurse.

llvm-svn: 131888
2011-05-23 00:32:19 +00:00
Chris Lattner 8aff4f8efc Transform any logical shift of a power of two into an exact/NUW shift when
in a known-non-zero context.

llvm-svn: 131887
2011-05-23 00:21:50 +00:00
Chris Lattner 321c58fc41 use the valuetracking isPowerOfTwo function, which is more powerful than checking
for a constant directly.  Thanks to Duncan for pointing this out.

llvm-svn: 131885
2011-05-23 00:09:55 +00:00
Chris Lattner 162dfc3e6b add some random notes.
llvm-svn: 131862
2011-05-22 18:26:48 +00:00
Chris Lattner 7c99f19d9f Carve out a place in instcombine to put transformations which work knowing that their
result is non-zero.  Implement an example optimization (PR9814), which allows us to
transform:
  A / ((1 << B) >>u 2)
into:
  A >>u (B-2)

which we compile into:

_divu3:                                 ## @divu3
	leal	-2(%rsi), %ecx
	shrl	%cl, %edi
	movl	%edi, %eax
	ret

instead of:

_divu3:                                 ## @divu3
	movb	%sil, %cl
	movl	$1, %esi
	shll	%cl, %esi
	shrl	$2, %esi
	movl	%edi, %eax
	xorl	%edx, %edx
	divl	%esi, %eax
	ret

llvm-svn: 131860
2011-05-22 18:18:41 +00:00
Benjamin Kramer fda5dc4968 Revert "InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)"
It's better to do this in codegen, mul.with.overflow(X, 2) is more canonical because it has only one use on "X".

llvm-svn: 131798
2011-05-21 18:31:42 +00:00
Benjamin Kramer 691731eb9c InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)
llvm-svn: 131789
2011-05-21 09:22:06 +00:00
Evan Cheng e8d2e9eb35 Revert r131664 and fix it in instcombine instead. rdar://9467055
llvm-svn: 131708
2011-05-20 00:54:37 +00:00
Evan Cheng dc867ae1fc Add comment.
llvm-svn: 131659
2011-05-19 18:18:39 +00:00
Eli Friedman 6efb64ea8e Make the demanded bits/elements optimizations preserve debug line information.
I'm not sure this is quite ideal, but I can't really think of any better way to do it.

llvm-svn: 131616
2011-05-19 01:20:42 +00:00
Eli Friedman 41e509a33d More instcombine cleanup, towards improving debug line info.
llvm-svn: 131604
2011-05-18 23:58:37 +00:00
Eli Friedman 1754a25977 More instcombine simplifications towards better debug locations.
llvm-svn: 131596
2011-05-18 23:11:30 +00:00
Eli Friedman 49346010f8 More instcombine cleanup aimed towards improving debug line info.
llvm-svn: 131559
2011-05-18 19:57:14 +00:00
Eli Friedman 2fd66441c6 Switch more inst insertion in instcombine to IRBuilder.
llvm-svn: 131547
2011-05-18 18:10:28 +00:00
Eli Friedman 0b43b9ee98 Switch more inst insertion in instcombine to IRBuilder.
llvm-svn: 131544
2011-05-18 17:58:37 +00:00
Eli Friedman cde9c1628c Switch inst insertion in instcombine transform to IRBuilder.
llvm-svn: 131542
2011-05-18 17:31:55 +00:00
Stuart Hastings 728f6260b9 Fix inelegant initialization.
llvm-svn: 131538
2011-05-18 15:54:26 +00:00
Eli Friedman 96254a0d53 Start trying to make InstCombine preserve more debug info. The idea here is to set the debug location on the IRBuilder, which will be then right location in most cases. This should magically give many transformations debug locations, and fixing places which are missing a debug location will usually just means changing the code creating it to use the IRBuilder.
As an example, the change to InstCombineCalls catches a common case where a call to a bitcast of a function is rewritten.

Chris, does this approach look reasonable?

llvm-svn: 131516
2011-05-18 01:28:27 +00:00
Eli Friedman b9ed18f2cb Use ReplaceInstUsesWith instead of replaceAllUsesWith where appropriate in instcombine.
llvm-svn: 131512
2011-05-18 00:32:01 +00:00
Stuart Hastings 5bd18b6638 X86 pmovsx/pmovzx ignore the upper half of their inputs.
rdar://problem/6945110

llvm-svn: 131493
2011-05-17 22:13:31 +00:00
Stuart Hastings 66a82b966e Avoid combining GEPs that might overflow at runtime.
rdar://problem/9267970

Patch by Julien Lerouge!

llvm-svn: 131339
2011-05-14 05:55:10 +00:00
Eli Friedman 8a20e66926 PR9838: Fix transform introduced in r127064 to not trigger when only one side of the icmp is an exact shift.
llvm-svn: 130954
2011-05-05 21:59:18 +00:00
Duncan Sands 6b699f863f Remove unused variable.
llvm-svn: 130705
2011-05-02 18:41:29 +00:00
Duncan Sands a3e3699c88 Move some rem transforms out of instcombine and into instsimplify.
This automagically provides a transform noticed by my super-optimizer
as occurring quite often: "rem x, (select cond, x, 1)" -> 0.

llvm-svn: 130694
2011-05-02 16:27:02 +00:00
Benjamin Kramer 9aa91b1f4e InstCombine: Turn (zext A) udiv (zext B) into (zext (A udiv B)). Same for urem or constant B.
This obviously helps a lot if the division would be turned into a libcall
(think i64 udiv on i386), but div is also one of the few remaining instructions
on modern CPUs that become more expensive when the bitwidth gets bigger.

This also helps register pressure on i386 when dividing chars, divb needs
two 8-bit parts of a 16 bit register as input where divl uses two registers.

int foo(unsigned char a) { return a/10; }
int bar(unsigned char a, unsigned char b) { return a/b; }

compiles into (x86_64)
_foo:
  imull $205, %edi, %eax
  shrl  $11, %eax
  ret
_bar:
  movzbl        %dil, %eax
  divb  %sil, %al
  movzbl        %al, %eax
  ret

llvm-svn: 130615
2011-04-30 18:16:07 +00:00
Benjamin Kramer 57b3df59b9 Use SimplifyDemandedBits on div instructions.
This folds away silly stuff like (a&255)/1000 -> 0.

llvm-svn: 130614
2011-04-30 18:16:00 +00:00
Benjamin Kramer f0e3f04470 Balance parentheses.
llvm-svn: 130489
2011-04-29 08:41:23 +00:00
Benjamin Kramer 16f18ed7b5 InstCombine: turn (C1 << A) << C2) into (C1 << C2) << A)
Fixes PR9809.

llvm-svn: 130485
2011-04-29 08:15:41 +00:00
Benjamin Kramer cf9d1ad62e We require threse bits to be zero, too.
This shouldn't happen in practice because the icmp would be a constant.
Add a check so we don't miscompile code if something goes wrong.

llvm-svn: 130446
2011-04-28 21:38:51 +00:00
Benjamin Kramer 101720fb58 Fix a comment.
llvm-svn: 130428
2011-04-28 20:09:57 +00:00
Benjamin Kramer 4145c0d3b1 InstCombine: Merge "(trunc x) == C1 & (and x, CA) == C2" into a single and+icmp.
This happens when GVN widens loads. Part of PR6627.

llvm-svn: 130405
2011-04-28 16:58:40 +00:00
Duncan Sands 085ad3b81a Stop trying to have instcombine preserve LCSSA form: this was not
effective in avoiding recomputation of LCSSA form; the widespread
use of instsimplify (which looks through phi nodes) means it was
not preserving LCSSA form anyway; and instcombine is no longer
scheduled in the middle of the loop passes so this doesn't matter
anymore.

llvm-svn: 130301
2011-04-27 10:55:12 +00:00
Chris Lattner 1b06c71668 Transform: "icmp eq (trunc (lshr(X, cst1)), cst" to "icmp (and X, mask), cst"
when X has multiple uses.  This is useful for exposing secondary optimizations,
but the X86 backend isn't ready for this when X has a single use.  For example,
this can disable load folding.

This is inching towards resolving PR6627.

llvm-svn: 130238
2011-04-26 20:18:20 +00:00
Chris Lattner 31b106d7dd some random cleanups, no functionality change.
llvm-svn: 130237
2011-04-26 20:02:45 +00:00
Frits van Bommel d6d4f987b4 Rename a misleadingly-named variable.
llvm-svn: 129644
2011-04-16 14:32:34 +00:00
Jay Foad 7d03e9be47 Fix bug when checking phi operands in InstCombiner::visitPHINode(),
found by code inspection.

llvm-svn: 129641
2011-04-16 14:17:37 +00:00
Chris Lattner 0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Eli Friedman 2395626605 Add an instcombine for constructs like a | -(b != c); a select is more
canonical, and generally leads to better code.  Found while looking at
an article about saturating arithmetic.

llvm-svn: 129545
2011-04-14 22:41:27 +00:00
Bill Wendling b902f1dd88 Reapply r129401 with patch for clang.
llvm-svn: 129419
2011-04-13 00:36:11 +00:00
Bill Wendling dbfde42468 Revert r129401 for now. Clang is using the old way of doing things.
llvm-svn: 129403
2011-04-12 22:59:27 +00:00
Bill Wendling 47c24875a1 Remove the unaligned load intrinsics in favor of using native unaligned loads.
Now that we have a first-class way to represent unaligned loads, the unaligned
load intrinsics are superfluous.

First part of <rdar://problem/8460511>.

llvm-svn: 129401
2011-04-12 22:46:31 +00:00
Jay Foad 7c14a558fe Don't include Operator.h from InstrTypes.h.
llvm-svn: 129271
2011-04-11 09:35:34 +00:00
Nadav Rotem a069c6ce05 InstCombine optimizes gep(bitcast(x)) even when the bitcasts casts away address
space info. We crash with an assert in this case. This change checks that the
address space of the bitcasted pointer is the same as the gep ptr.

llvm-svn: 128884
2011-04-05 14:29:52 +00:00
Benjamin Kramer 50a281a871 While SimplifyDemandedBits constant folds this, we can't rely on it here.
It's possible to craft an input that hits the recursion limits in a way
that SimplifyDemandedBits doesn't simplify the icmp but ComputeMaskedBits
can infer which bits are zero.

No test case as it depends on too many other things. Fixes PR9609.

llvm-svn: 128777
2011-04-02 18:50:58 +00:00
Benjamin Kramer 8b94c295c3 Fix comment.
llvm-svn: 128745
2011-04-01 22:29:18 +00:00
Benjamin Kramer 5cad45307e Tweaks to the icmp+sext-to-shifts optimization to address Frits' comments:
- Localize the check if an icmp has one use to a place where we know we're
  introducing something that's likely more expensive than a sext from i1.
- Add an assert to make sure a case that would lead to a miscompilation is
  folded away earlier.
- Fix a typo.

llvm-svn: 128744
2011-04-01 22:22:11 +00:00
Benjamin Kramer ac2d5657a6 Fix build.
llvm-svn: 128733
2011-04-01 20:15:16 +00:00
Benjamin Kramer d121765e64 InstCombine: Turn icmp + sext into bitwise/integer ops when the input has only one unknown bit.
int test1(unsigned x) { return (x&8) ? 0 : -1; }
int test3(unsigned x) { return (x&8) ? -1 : 0; }

before (x86_64):
_test1:
	andl	$8, %edi
	cmpl	$1, %edi
	sbbl	%eax, %eax
	ret
_test3:
	andl	$8, %edi
	cmpl	$1, %edi
	sbbl	%eax, %eax
	notl	%eax
	ret

after:
_test1:
	shrl	$3, %edi
	andl	$1, %edi
	leal	-1(%rdi), %eax
	ret
_test3:
	shll	$28, %edi
	movl	%edi, %eax
	sarl	$31, %eax
	ret

llvm-svn: 128732
2011-04-01 20:09:10 +00:00
Benjamin Kramer 398b8c5faf InstCombine: Move (sext icmp) transforms into their own method. No intended functionality change.
llvm-svn: 128731
2011-04-01 20:09:03 +00:00
Nadav Rotem d74b72b8a9 Instcombile optimization: extractelement(cast) -> cast(extractelement)
llvm-svn: 128683
2011-03-31 22:57:29 +00:00
Benjamin Kramer 5291054ef1 InstCombine: APFloat can't perform arithmetic on PPC double doubles, don't even try.
Thanks Eli!

llvm-svn: 128676
2011-03-31 21:35:49 +00:00
Benjamin Kramer be209ab8a2 InstCombine: Fix transform to use the swapped predicate.
Thanks Frits!

llvm-svn: 128628
2011-03-31 10:46:03 +00:00
Benjamin Kramer d159d94644 InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, y
llvm-svn: 128627
2011-03-31 10:12:22 +00:00
Benjamin Kramer a8c5d0872d InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
llvm-svn: 128626
2011-03-31 10:12:15 +00:00
Benjamin Kramer cbb18e91a8 InstCombine: Shrink "fcmp (fpext x), C" to "fcmp x, C" if C can be losslessly converted to the type of x.
Fixes PR9592.

llvm-svn: 128625
2011-03-31 10:12:07 +00:00
Benjamin Kramer 2ccfbc8b71 InstCombine: fold fcmp (fpext x), (fpext y) -> fcmp x, y.
llvm-svn: 128624
2011-03-31 10:11:58 +00:00
Benjamin Kramer 8564e0de96 InstCombine: If the divisor of an fdiv has an exact inverse, turn it into an fmul.
Fixes PR9587.

llvm-svn: 128546
2011-03-30 15:42:35 +00:00
Jay Foad 52131344a2 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad e0938d8a87 (Almost) always call reserveOperandSpace() on newly created PHINodes.
llvm-svn: 128535
2011-03-30 11:19:20 +00:00
Benjamin Kramer 272f2b0044 InstCombine: Add a few missing combines for ANDs and ORs of sign bit tests.
On x86 we now compile "if (a < 0 && b < 0)" into
	testl	%edi, %esi
	js	IF.THEN

llvm-svn: 128496
2011-03-29 22:06:41 +00:00
Nick Lewycky ebc2f3a68c Remove tabs I accidentally added.
llvm-svn: 128413
2011-03-28 17:48:26 +00:00
Jay Foad 1c83965f5a Make more use of PHINode::getNumIncomingValues().
llvm-svn: 128406
2011-03-28 13:03:10 +00:00
Frits van Bommel d14d991bf7 Add some debug output when -instcombine uses RAUW. This can make debug output for those cases much clearer since without this it only showed that the original instruction was removed, not what it was replaced with.
llvm-svn: 128399
2011-03-27 23:32:31 +00:00
Nick Lewycky 8544228d5a Teach the transformation that moves binary operators around selects to preserve
the subclass optional data.

llvm-svn: 128388
2011-03-27 19:51:23 +00:00
Benjamin Kramer 1f90da127f Use APInt's umul_ov instead of rolling our own overflow detection.
llvm-svn: 128380
2011-03-27 15:04:38 +00:00
Nick Lewycky 83167df787 Add a small missed optimization: turn X == C ? X : Y into X == C ? C : Y. This
removes one use of X which helps it pass the many hasOneUse() checks.

In my analysis, this turns up very often where X = A >>exact B and that can't be
simplified unless X has one use (except by increasing the lifetime of A which is
generally a performance loss).

llvm-svn: 128373
2011-03-27 07:30:57 +00:00
Devang Patel aad34d882d Try to not lose variable's debug info during instcombine.
This is done by lowering dbg.declare intrinsic into dbg.value intrinsic.
Radar 9143931.

llvm-svn: 127834
2011-03-17 22:18:16 +00:00
Eric Christopher 2139d3148f If we don't know how long a string is we can't fold an _chk version to the
normal version.

Fixes rdar://9123638

llvm-svn: 127636
2011-03-15 00:25:41 +00:00
Jin-Gu Kang b452db02f0 This case is solved by Scalar Replacement of Aggregates (DT) and
Early CSE pass so this patch reverts it to original source code.

llvm-svn: 127574
2011-03-14 01:21:00 +00:00
Jin-Gu Kang b7538c71e1 Add comment as following:
load and store reference same memory location, the memory location
is represented by getelementptr with two uses (load and store) and
the getelementptr's base is alloca with single use. At this point,
instructions from alloca to store can be removed.
(this pattern is generated when bitfield is accessed.)
For example,
%u = alloca %struct.test, align 4               ; [#uses=1]
%0 = getelementptr inbounds %struct.test* %u, i32 0, i32 0;[#uses=2]
%1 = load i8* %0, align 4                       ; [#uses=1]
%2 = and i8 %1, -16                             ; [#uses=1]
%3 = or i8 %2, 5                                ; [#uses=1]
store i8 %3, i8* %0, align 4

llvm-svn: 127565
2011-03-13 14:05:51 +00:00
Jin-Gu Kang 2e939f7c3c This patch removes some of useless instructions generated by bitfield access.
llvm-svn: 127539
2011-03-12 12:18:44 +00:00
Benjamin Kramer 51897bcd3e InstCombine: Fix a thinko where transform an icmp under the assumption that it's a zero comparison when it's not.
Fixes PR9454.

llvm-svn: 127464
2011-03-11 11:37:40 +00:00
Benjamin Kramer b49b964b98 InstCombine: Turn umul_with_overflow into mul nuw if we can prove that it cannot overflow.
This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

llvm-svn: 127418
2011-03-10 18:40:14 +00:00
Eli Friedman a81a82dcaf PR9346: Prevent SimplifyDemandedBits from incorrectly introducing
INT_MIN % -1.

llvm-svn: 127306
2011-03-09 01:28:35 +00:00
Devang Patel fbb482b314 llvm.dbg.declare intrinsic does not use any llvm::Values. It's magic!
llvm-svn: 127282
2011-03-08 22:12:11 +00:00
Nick Lewycky afc8098c9e Reorder comments to put them the right way around.
llvm-svn: 127220
2011-03-08 06:29:47 +00:00
Nick Lewycky e467979d0a Add more analysis of the sign bit of an srem instruction. If the LHS is negative
then the result could go either way. If it's provably positive then so is the
srem. Fixes PR9343 #7!

llvm-svn: 127146
2011-03-07 01:50:10 +00:00
Nick Lewycky 92db8e8e39 ConstantInt has some getters which return ConstantInt's or ConstantVector's of
the value splatted into every element. Extend this to getTrue and getFalse which
by providing new overloads that take Types that are either i1 or <N x i1>. Use
it in InstCombine to add vector support to some code, fixing PR8469!

llvm-svn: 127116
2011-03-06 03:36:19 +00:00
Benjamin Kramer 08c913b6e6 InstCombine: We know the number of items initially added to the worklist map, reserve space early to avoid rehashing.
llvm-svn: 127089
2011-03-05 16:43:46 +00:00
Nick Lewycky 9719a719c7 Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.

This fixes PR9343 #4 #5 and #8!

llvm-svn: 127064
2011-03-05 05:19:11 +00:00
Nick Lewycky 25cc338d88 Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison into
true/false or "icmp slt/sge Y, 0".

llvm-svn: 127063
2011-03-05 04:28:48 +00:00
Anders Carlsson da80afef99 Make InstCombiner::FoldAndOfICmps create a ConstantRange that's the
intersection of the LHS and RHS ConstantRanges and return "false" when
the range is empty.

This simplifies some code and catches some extra cases.

llvm-svn: 126744
2011-03-01 15:05:01 +00:00
Nick Lewycky 66f4f22f7b srem doesn't actually have the same resulting sign as its numerator, you could
also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.

llvm-svn: 126644
2011-02-28 09:17:39 +00:00
Nick Lewycky 174a705497 Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 from
PR9343.

llvm-svn: 126643
2011-02-28 08:31:40 +00:00
Nick Lewycky 6b445419b0 The sign of an srem instruction is the sign of its dividend (the first
argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!

llvm-svn: 126635
2011-02-28 06:20:05 +00:00
Chris Lattner adf38b3e09 change instcombine to not turn a call to non-varargs bitcast of
function prototype into a call to a varargs prototype.  We do
allow the xform if we have a definition, but otherwise we don't
want to risk that we're changing the abi in a subtle way.  On
X86-64, for example, varargs require passing stuff in %al.

llvm-svn: 126363
2011-02-24 05:10:56 +00:00
Benjamin Kramer 5b7a4e0195 Move "A | ~(A & ?) -> -1" from InstCombine to InstructionSimplify.
llvm-svn: 126082
2011-02-20 15:20:01 +00:00
Benjamin Kramer d5d7f37beb InstCombine: Add a bunch of combines of the form x | (y ^ z).
We usually catch this kind of optimization through InstSimplify's distributive
magic, but or doesn't distribute over xor in general.

"A | ~(A | B) -> A | ~B" hits 24 times on gcc.c.

llvm-svn: 126081
2011-02-20 13:23:43 +00:00
Eli Friedman ef200db4fd PR9218: SimplifyDemandedVectorElts can return a non-null value that is not
the instruction passed in.  Make sure to account for this correctly, instead
of looping infinitely.

llvm-svn: 126058
2011-02-19 22:42:40 +00:00
Duncan Sands 84653b3674 Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is no
overflow.  These subsume some existing equality transforms, so zap those.

llvm-svn: 125843
2011-02-18 16:25:37 +00:00
Chris Lattner a8fed47eed have instcombine preserve nsw/nuw/exact when sinking
common operations through a phi. 

llvm-svn: 125790
2011-02-17 23:01:49 +00:00
Chris Lattner 75ae5a45ff fix typo
llvm-svn: 125787
2011-02-17 22:32:54 +00:00
Chris Lattner abb8eb2c63 fix instcombine merging GEPs through a PHI to only make the
result inbounds if all of the inputs are inbounds.

llvm-svn: 125785
2011-02-17 22:21:26 +00:00
Chris Lattner d406764d52 add is always integer, thanks to Frits for noticing this.
llvm-svn: 125774
2011-02-17 20:55:29 +00:00
Duncan Sands e522001171 Transform "A + B >= A + C" into "B >= C" if the adds do not wrap. Likewise for some
variations (some of these were already present so I unified the code).  Spotted by my
auto-simplifier as occurring a lot.

llvm-svn: 125734
2011-02-17 07:46:37 +00:00
Chris Lattner 5592071768 preserve NUW/NSW when transforming add x,x
llvm-svn: 125711
2011-02-17 02:23:02 +00:00
Duncan Sands 75b5d27b84 Spelling fix: consequtive -> consecutive.
llvm-svn: 125563
2011-02-15 09:23:02 +00:00
Nadav Rotem 67d67a0385 Fix 9216 - Endless loop in InstCombine pass.
The pattern "A&(A^B) -> A & ~B" recreated itself because ~B is
actually a xor -1.

llvm-svn: 125557
2011-02-15 07:13:48 +00:00
Devang Patel 8d53ac81ec Do not forget DebugLoc!
llvm-svn: 125547
2011-02-15 02:02:30 +00:00
Chris Lattner 9f0ac0dd8b tidy up a bit.
llvm-svn: 125546
2011-02-15 01:56:08 +00:00
Chris Lattner 69229316aa convert ConstantVector::get to use ArrayRef.
llvm-svn: 125537
2011-02-15 00:14:00 +00:00
Chris Lattner 34442e6ebf revert my ConstantVector patch, it seems to have made the llvm-gcc
builders unhappy.

llvm-svn: 125504
2011-02-14 18:15:46 +00:00
Chris Lattner d9f5b88548 Switch ConstantVector::get to use ArrayRef instead of a pointer+size
idiom.  Change various clients to simplify their code.

llvm-svn: 125487
2011-02-14 07:55:32 +00:00
Chris Lattner 9bd7fdff58 remove a now-unneccesary cast.
llvm-svn: 125464
2011-02-13 18:30:09 +00:00
Chris Lattner 43273affb9 implement instcombine folding for things like (x >> c) < 42.
We were previously simplifying divisions, but not right shifts!

llvm-svn: 125454
2011-02-13 08:07:21 +00:00
Chris Lattner d369f575d7 refactor some code out into a helper method.
llvm-svn: 125451
2011-02-13 07:43:07 +00:00
Benjamin Kramer 1800d823de Also fold (A+B) == A -> B == 0 when the add is commuted.
llvm-svn: 125411
2011-02-11 21:46:48 +00:00
Chris Lattner d3c0e05f51 When lowering an inbounds gep, the intermediate adds can have
unsigned overflow (e.g. due to a negative array index), but
the scales on array size multiplications are known to not
sign wrap.

llvm-svn: 125409
2011-02-11 21:37:43 +00:00
Chris Lattner d86ded17ad implement the first part of PR8882: when lowering an inbounds
gep to explicit addressing, we know that none of the intermediate
computation overflows.

This could use review: it seems that the shifts certainly wouldn't
overflow, but could the intermediate adds overflow if there is a 
negative index?

Previously the testcase would instcombine to:

define i1 @test(i64 %i) {
  %p1.idx.mask = and i64 %i, 4611686018427387903
  %cmp = icmp eq i64 %p1.idx.mask, 1000
  ret i1 %cmp
}

now we get:

define i1 @test(i64 %i) {
  %cmp = icmp eq i64 %i, 1000
  ret i1 %cmp
}

llvm-svn: 125271
2011-02-10 07:11:16 +00:00
Chris Lattner 6b657aed33 Enhance a bunch of transformations in instcombine to start generating
exact/nsw/nuw shifts and have instcombine infer them when it can prove
that the relevant properties are true for a given shift without them.

Also, a variety of refactoring to use the new patternmatch logic thrown
in for good luck.  I believe that this takes care of a bunch of related
code quality issues attached to PR8862.

llvm-svn: 125267
2011-02-10 05:36:31 +00:00
Chris Lattner 98457101fc Enhance the "compare with shift" and "compare with div"
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts.  For example, these (which
are the same except the first is 'exact' sdiv:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %A = sdiv i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

compile down to:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %1 = icmp eq i64 %X, 0
  ret i1 %1
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %X.off = add i64 %X, 4
  %1 = icmp ult i64 %X.off, 9
  ret i1 %1
}

This happens when you do something like:
  (ptr1-ptr2) == 42

where the pointers are pointers to non-unit types.

llvm-svn: 125266
2011-02-10 05:23:05 +00:00
Chris Lattner dcef03fba2 more cleanups, notably bitcast isn't used for "signed to unsigned type
conversions". :)

llvm-svn: 125265
2011-02-10 05:17:27 +00:00
Chris Lattner 7d0e43ff8b A bunch of cleanups and simplifications using the new PatternMatch predicates
and generally tidying things up.  Only very trivial functionality changes
like now doing (-1 - A) -> (~A) for vectors too.

 InstCombineAddSub.cpp |  296 +++++++++++++++++++++-----------------------------
 1 file changed, 126 insertions(+), 170 deletions(-)

llvm-svn: 125264
2011-02-10 05:14:58 +00:00
Chris Lattner 768003c59e teach SimplifyDemandedBits that exact shifts demand the bits they
are shifting out since they do require them to be zeros.  Similarly
for NUW/NSW bits of shl

llvm-svn: 125263
2011-02-10 05:09:34 +00:00
Chris Lattner 9e4aa0259f Teach instsimplify some tricks about exact/nuw/nsw shifts.
improve interfaces to instsimplify to take this info.

llvm-svn: 125196
2011-02-09 17:15:04 +00:00
Chris Lattner b940091388 Rework InstrTypes.h so to reduce the repetition around the NSW/NUW/Exact
versions of creation functions.  Eventually, the "insertion point" versions
of these should just be removed, we do have IRBuilder afterall.

Do a massive rewrite of much of pattern match.  It is now shorter and less
redundant and has several other widgets I will be using in other patches.
Among other changes, m_Div is renamed to m_IDiv (since it only matches 
integer divides) and m_Shift is gone (it used to match all binops!!) and
we now have m_LogicalShift for the one client to use.

Enhance IRBuilder to have "isExact" arguments to things like CreateUDiv
and reduce redundancy within IRbuilder by having these methods chain to
each other more instead of duplicating code.

llvm-svn: 125194
2011-02-09 17:00:45 +00:00
Chris Lattner 35315d065b enhance vmcore to know that udiv's can be exact, and add a trivial
instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862

llvm-svn: 124992
2011-02-06 21:44:57 +00:00
Dan Gohman c6f0bda839 Conservatively, clear optional flags, such as nsw, when performing
reassociation. No testcase, because I wasn't able to create a testcase
which actually demonstrates a problem.

llvm-svn: 124713
2011-02-02 02:05:46 +00:00
Anders Carlsson f23a6da271 Recognize and simplify
(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0

llvm-svn: 124567
2011-01-30 22:01:13 +00:00
Frits van Bommel 2a55951d08 Call SimplifyFDivInst() in InstCombiner::visitFDiv().
llvm-svn: 124535
2011-01-29 17:50:27 +00:00
Frits van Bommel c2549661af Move InstCombine's knowledge of fdiv to SimplifyInstruction().
llvm-svn: 124534
2011-01-29 15:26:31 +00:00
Duncan Sands 771e82a863 My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC
benchmarks, and that it can be simplified to X/Y.  (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case).  This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too.  This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too.  It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.

llvm-svn: 124487
2011-01-28 16:51:11 +00:00
Nick Lewycky b074e32641 Fold select + select where both selects are on the same condition.
llvm-svn: 124469
2011-01-28 03:28:10 +00:00
Ted Kremenek 3c4408ceb6 Null initialize a few variables flagged by
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.

llvm-svn: 124073
2011-01-23 17:05:06 +00:00
Owen Anderson a834200dbe Just because we have determined that an (fcmp | fcmp) is true for A < B,
A == B, and A > B, does not mean we can fold it to true.  We still need to
check for A ? B (A unordered B).

llvm-svn: 123993
2011-01-21 19:39:42 +00:00
Chris Lattner b5e15d1907 fix PR9013, an infinite loop in instcombine.
llvm-svn: 123968
2011-01-21 05:29:50 +00:00
Chris Lattner f4ca47bda8 update obsolete comment.
llvm-svn: 123965
2011-01-21 05:08:26 +00:00
Nick Lewycky 6a083cf820 Don't try to pull vector bitcasts that change the number of elements through
a select. A vector select is pairwise on each element so we'd need a new
condition with the right number of elements to select on. Fixes PR8994.

llvm-svn: 123963
2011-01-21 02:30:43 +00:00
Duncan Sands 8fb2c3827c At -O123 the early-cse pass is run before instcombine has run. According to my
auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0.
This patch adds this transform and some related logic to InstructionSimplify
and removes some of the logic from instcombine (unfortunately not all because
there are several situations in which instcombine can improve things by making
new instructions, whereas instsimplify is not allowed to do this).  At -O2 this
often results in more than 15% more simplifications by early-cse, and results in
hundreds of lines of bitcode being eliminated from the testsuite.  I did see some
small negative effects in the testsuite, for example a few additional instructions
in three programs.  One program, 483.xalancbmk, got an additional 35 instructions,
which seems to be due to a function getting an additional instruction and then
being inlined all over the place.

llvm-svn: 123911
2011-01-20 13:21:55 +00:00
Chris Lattner adb1a233b1 remove a dead check, this was needed before we had an explicit veto on uses of phis.
llvm-svn: 123569
2011-01-16 05:37:55 +00:00
Chris Lattner d55581ded8 enhance FoldOpIntoPhi in instcombine to try harder when a phi has
multiple uses.  In some cases, all the uses are the same operation,
so instcombine can go ahead and promote the phi.  In the testcase
this pushes an add out of the loop.

llvm-svn: 123568
2011-01-16 05:28:59 +00:00
Chris Lattner ea7131a062 remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false in the
first line of the function because it isn't a good idea, even for compares.

llvm-svn: 123566
2011-01-16 05:14:26 +00:00
Chris Lattner ff2e737714 more cleanups: use the IR builder.
llvm-svn: 123565
2011-01-16 05:08:00 +00:00
Chris Lattner 25ce280511 tidy up code.
llvm-svn: 123564
2011-01-16 04:37:29 +00:00
Chris Lattner 9c10d587f6 implement an instcombine xform that canonicalizes casts outside of and-with-constant operations.
This fixes rdar://8808586 which observed that we used to compile:


union xy {
        struct x { _Bool b[15]; } x;
        __attribute__((packed))
        struct y {
                __attribute__((packed)) unsigned long b0to7;
                __attribute__((packed)) unsigned int b8to11;
                __attribute__((packed)) unsigned short b12to13;
                __attribute__((packed)) unsigned char b14;
        } y;
};

struct x
foo(union xy *xy)
{
        return xy->x;
}

into:

_foo:                                   ## @foo
	movq	(%rdi), %rax
	movabsq	$1095216660480, %rcx    ## imm = 0xFF00000000
	andq	%rax, %rcx
	movabsq	$-72057594037927936, %rdx ## imm = 0xFF00000000000000
	andq	%rax, %rdx
	movzbl	%al, %esi
	orq	%rdx, %rsi
	movq	%rax, %rdx
	andq	$65280, %rdx            ## imm = 0xFF00
	orq	%rsi, %rdx
	movq	%rax, %rsi
	andq	$16711680, %rsi         ## imm = 0xFF0000
	orq	%rdx, %rsi
	movl	%eax, %edx
	andl	$-16777216, %edx        ## imm = 0xFFFFFFFFFF000000
	orq	%rsi, %rdx
	orq	%rcx, %rdx
	movabsq	$280375465082880, %rcx  ## imm = 0xFF0000000000
	movq	%rax, %rsi
	andq	%rcx, %rsi
	orq	%rdx, %rsi
	movabsq	$71776119061217280, %r8 ## imm = 0xFF000000000000
	andq	%r8, %rax
	orq	%rsi, %rax
	movzwl	12(%rdi), %edx
	movzbl	14(%rdi), %esi
	shlq	$16, %rsi
	orl	%edx, %esi
	movq	%rsi, %r9
	shlq	$32, %r9
	movl	8(%rdi), %edx
	orq	%r9, %rdx
	andq	%rdx, %rcx
	movzbl	%sil, %esi
	shlq	$32, %rsi
	orq	%rcx, %rsi
	movl	%edx, %ecx
	andl	$-16777216, %ecx        ## imm = 0xFFFFFFFFFF000000
	orq	%rsi, %rcx
	movq	%rdx, %rsi
	andq	$16711680, %rsi         ## imm = 0xFF0000
	orq	%rcx, %rsi
	movq	%rdx, %rcx
	andq	$65280, %rcx            ## imm = 0xFF00
	orq	%rsi, %rcx
	movzbl	%dl, %esi
	orq	%rcx, %rsi
	andq	%r8, %rdx
	orq	%rsi, %rdx
	ret

We now compile this into:

_foo:                                   ## @foo
## BB#0:                                ## %entry
	movzwl	12(%rdi), %eax
	movzbl	14(%rdi), %ecx
	shlq	$16, %rcx
	orl	%eax, %ecx
	shlq	$32, %rcx
	movl	8(%rdi), %edx
	orq	%rcx, %rdx
	movq	(%rdi), %rax
	ret

A small improvement :-)

llvm-svn: 123520
2011-01-15 06:32:33 +00:00
Chris Lattner e20dd530d0 one more instcombine variant that is needed to work with future changes,
no functionality change currently.

llvm-svn: 123517
2011-01-15 05:50:18 +00:00
Chris Lattner 497459d5fd fix typo
llvm-svn: 123516
2011-01-15 05:42:47 +00:00
Chris Lattner f3c4eefff8 Catch ~x < cst just like ~x < ~y, we currently handle this through
means that are about to disappear.

llvm-svn: 123515
2011-01-15 05:41:33 +00:00
Chris Lattner 311aa63c87 reduce indentation
llvm-svn: 123514
2011-01-15 05:40:29 +00:00
Duncan Sands 7f60dc1eb0 Move some shift transforms out of instcombine and into InstructionSimplify.
While there, I noticed that the transform "undef >>a X -> undef" was wrong.
For example if X is 2 then the top two bits must be equal, so the result can
not be anything.  I fixed this in the constant folder as well.  Also, I made
the transform for "X << undef" stronger: it now folds to undef always, even
though X might be zero.  This is in accordance with the LangRef, but I must
admit that it is fairly aggressive.  Also, I added "i32 X << 32 -> undef"
following the LangRef and the constant folder, likewise fairly aggressive.

llvm-svn: 123417
2011-01-14 00:37:45 +00:00
Owen Anderson 0022a4b417 Remove dead variable, const-ref-ize an APInt.
llvm-svn: 123248
2011-01-11 18:26:37 +00:00
Owen Anderson d490c2d2ae Fix a random missed optimization by making InstCombine more aggressive when determining which bits are demanded by
a comparison against a constant.

llvm-svn: 123203
2011-01-11 00:36:45 +00:00
Chandler Carruth cf414cf0a6 Teach instcombine about the rest of the SSE and SSE2 conversion
intrinsics element dependencies. Reviewed by Nick.

llvm-svn: 123161
2011-01-10 07:19:37 +00:00
Tobias Grosser cc21c4aa98 Instcombine: Fix pattern where the sext did not dominate the icmp using it
llvm-svn: 123121
2011-01-09 16:00:11 +00:00