Commit Graph

177 Commits

Author SHA1 Message Date
David Majnemer 42af3601c2 InstCombine: Simplify (A ^ B) or/and (A ^ B ^ C)
While we can already transform A | (A ^ B) into A | B, things get bad
once we have (A ^ B) | (A ^ B ^ Cst) because reassociation will morph
this into (A ^ B) | ((A ^ Cst) ^ B).  Our existing patterns fail once
this happens.

To fix this, we add a new pattern which looks through the tree of xor
binary operators to see that, in fact, there exists a redundant xor
operation.

What follows bellow is a correctness proof of the transform using CVC3.

$ cat t.cvc
A, B, C : BITVECTOR(64);

QUERY BVXOR(A, B) | BVXOR(BVXOR(B, C), A) = BVXOR(A, B) | C;
QUERY BVXOR(BVXOR(A, C), B) | BVXOR(A, B) = BVXOR(A, B) | C;

QUERY BVXOR(A, B) & BVXOR(BVXOR(B, C), A) = BVXOR(A, B) & ~C;
QUERY BVXOR(BVXOR(A, C), B) & BVXOR(A, B) = BVXOR(A, B) & ~C;

$ cvc3 < t.cvc
Valid.
Valid.
Valid.
Valid.

llvm-svn: 214342
2014-07-30 21:26:37 +00:00
Suyog Sarda b60ec909ca Added InstCombine transform for pattern "(A & B) ^ (A ^ B) -> (A | B)"
Patch idea by Ankit Jain !

Differential Revision: http://reviews.llvm.org/D4618

llvm-svn: 213677
2014-07-22 18:30:54 +00:00
Suyog Sarda d64faf6cae Added InstCombine Transform for patterns:
"((~A & B) | A) -> (A | B)" and "((A & B) | ~A) -> (~A | B)"

Original Patch credit to Ankit Jain !!

Differential Revision: http://reviews.llvm.org/D4591

llvm-svn: 213676
2014-07-22 18:09:41 +00:00
Suyog Sarda 521237cad6 This patch implements transform for pattern "(A | B) ^ (~A) -> (A | ~B)".
Patch Credit to Ankit Jain !!

Differential Revision: http://reviews.llvm.org/D4588

llvm-svn: 213662
2014-07-22 15:37:39 +00:00
Nick Lewycky 8561a49c27 Move optimization of some cases of (A & C1)|(B & C2) from instcombine to instsimplify. Patch by Rahul Jain, plus some last minute changes by me -- you can blame me for any bugs.
llvm-svn: 211252
2014-06-19 03:51:46 +00:00
Serge Pavlov 9ef66a8266 Reorder shuffle and binary operation.
This patch enables transformations:

    BinOp(shuffle(v1), shuffle(v2)) -> shuffle(BinOp(v1, v2))
    BinOp(shuffle(v1), const1) -> shuffle(BinOp, const2)

They allow to eliminate extra shuffles in some cases.

Differential Revision: http://reviews.llvm.org/D3525

llvm-svn: 208488
2014-05-11 08:46:12 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
Chandler Carruth 5f1f26e891 [Modules] Sink all the DEBUG_TYPE defines for InstCombine out of the
header files and into the cpp files.

These files will require more touches as the header files actually use
DEBUG(). Eventually, I'll have to introduce a matched #define and #undef
of DEBUG_TYPE for the header files, but that comes as step N of many to
clean all of this up.

llvm-svn: 206777
2014-04-21 19:51:41 +00:00
Chandler Carruth 8cd041ef19 [Modules] Move the ConstantRange class into the IR library. This is
a bit surprising, as the class is almost entirely abstracted away from
any particular IR, however it encodes the comparsion predicates which
mutate ranges as ICmp predicate codes. This is reasonable as they're
used for both instructions and constants. Thus, it belongs in the IR
library with instructions and constants.

llvm-svn: 202838
2014-03-04 12:24:34 +00:00
Chandler Carruth 820a908df7 [Modules] Move the LLVM IR pattern match header into the IR library, it
obviously is coupled to the IR.

llvm-svn: 202818
2014-03-04 11:08:18 +00:00
Rafael Espindola 37dc9e19f5 Rename many DataLayout variables from TD to DL.
I am really sorry for the noise, but the current state where some parts of the
code use TD (from the old name: TargetData) and other parts use DL makes it
hard to write a patch that changes where those variables come from and how
they are passed along.

llvm-svn: 201827
2014-02-21 00:06:31 +00:00
Benjamin Kramer 94fc18d040 InstCombine: Teach icmp merging about the equivalence of bit tests and UGE/ULT with a power of 2.
This happens in bitfield code. While there reorganize the existing code
a bit.

llvm-svn: 201176
2014-02-11 21:09:03 +00:00
Benjamin Kramer 970f4959d4 InstCombine: Hoist 3 copies of AddOne/SubOne into a header.
llvm-svn: 199605
2014-01-19 16:56:10 +00:00
Benjamin Kramer 7a74bd4703 InstCombine: Replace a hand-rolled version of isKnownToBeAPowerOfTwo with the real thing.
llvm-svn: 199604
2014-01-19 16:48:41 +00:00
Nadav Rotem ea186b9515 Update the docs to match the function name.
llvm-svn: 194537
2013-11-13 01:12:01 +00:00
Nadav Rotem 0ed2fdb5af Fold (iszero(A&K1) | iszero(A&K2)) -> (A&(K1|K2)) != (K1|K2) if we know that K1 and K2 are 'one-hot' (only one bit is on).
llvm-svn: 194525
2013-11-12 22:38:59 +00:00
Tim Northover dc647a2603 InstCombine: allow unmasked icmps to be combined with logical ops
"(icmp op i8 A, B)" is equivalent to "(icmp op i8 (A & 0xff), B)" as a
degenerate case. Allowing this as a "masked" comparison when analysing "(icmp)
&/| (icmp)" allows us to combine them in more cases.

rdar://problem/7625728

llvm-svn: 189931
2013-09-04 11:57:17 +00:00
Tim Northover c0756c454c InstCombine: look for masked compares with subset relation
Even in cases which aren't universally optimisable like "(A & B) != 0 && (A &
C) != 0", the masks can make one of the comparisons completely redundant. In
this case, since we've gone to the effort of spotting masked comparisons we
should combine them.

rdar://problem/7625728

llvm-svn: 189930
2013-09-04 11:57:13 +00:00
Jim Grosbach d0de8ace8a InstCombine: Use isAllOnesValue() instead of explicit -1.
llvm-svn: 188563
2013-08-16 17:03:36 +00:00
Jim Grosbach 20e3b9ac30 InstCombine: Simplify if(x!=0 && x!=-1).
When both constants are positive or both constants are negative,
InstCombine already simplifies comparisons like this, but when
it's exactly zero and -1, the operand sorting ends up reversed
and the pattern fails to match. Handle that special case.

Follow up for rdar://14689217

llvm-svn: 188512
2013-08-16 00:15:20 +00:00
Craig Topper b94011fd28 Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.
llvm-svn: 186274
2013-07-14 04:42:23 +00:00
David Majnemer c2a990bc00 InstCombine: (icmp eq B, 0) | (icmp ult A, B) -> (icmp ule A, B-1)
This transform allows us to turn IR that looks like:
  %1 = icmp eq i64 %b, 0
  %2 = icmp ult i64 %a, %b
  %3 = or i1 %1, %2
  ret i1 %3

into:
  %0 = add i64 %b, -1
  %1 = icmp uge i64 %0, %a
  ret i1 %1

which means we go from lowering:
        cmpq    %rsi, %rdi
        setb    %cl
        testq   %rsi, %rsi
        sete    %al
        orb     %cl, %al
        ret

to lowering:
        decq    %rsi
        cmpq    %rdi, %rsi
        setae   %al
        ret

llvm-svn: 185677
2013-07-05 00:31:17 +00:00
Jakub Staszak 9de494e0ee Remove unneeded cast<>.
llvm-svn: 183363
2013-06-06 00:49:57 +00:00
Jakub Staszak 461d1fe6fc Use IRBuilder instead of ConstantInt methods.
llvm-svn: 183360
2013-06-06 00:37:23 +00:00
Michael J. Spencer df1ecbd734 Replace Count{Leading,Trailing}Zeros_{32,64} with count{Leading,Trailing}Zeros.
llvm-svn: 182680
2013-05-24 22:23:49 +00:00
David Majnemer 1fae195557 Reorders two transforms that collide with each other
One performs: (X == 13 | X == 14) -> X-13 <u 2
The other: (A == C1 || A == C2) -> (A & ~(C1 ^ C2)) == C1

The problem is that there are certain values of C1 and C2 that
trigger both transforms but the first one blocks out the second,
this generates suboptimal code.

Reordering the transforms should be better in every case and
allows us to do interesting stuff like turn:
  %shr = lshr i32 %X, 4
  %and = and i32 %shr, 15
  %add = add i32 %and, -14
  %tobool = icmp ne i32 %add, 0

into:
  %and = and i32 %X, 240
  %tobool = icmp ne i32 %and, 224

llvm-svn: 179493
2013-04-14 21:15:43 +00:00
Benjamin Kramer e89c705030 InstCombine: Check the operand types before merging fcmp ord & fcmp ord.
Fixes PR15737.

llvm-svn: 179417
2013-04-12 21:56:23 +00:00
Jim Grosbach bdbd73460c Tidy up a bit. No functional change.
llvm-svn: 178915
2013-04-05 21:20:12 +00:00
Jakub Staszak 2ef36b633b Simplify code. No functionality change.
llvm-svn: 176765
2013-03-09 11:18:59 +00:00
Bill Wendling 23242098e7 The transform is:
(or (bool?A:B),(bool?C:D)) --> (bool?(or A,C):(or B,D))

By the time the OR is visited, both the SELECTs have been visited and not
optimized and the OR itself hasn't been transformed so we do this transform in
the hopes that the new ORs will be optimized.

The transform is explicitly disabled for vector-selects until "codegen matures
to handle them better".

Patch by Muhammad Tauqir!

llvm-svn: 175380
2013-02-16 23:41:36 +00:00
Nadav Rotem 513bd8a73c InstCombine: canonicalize sext-and --> select
sext-not-and --> select.

Patch by Muhammad Tauqir Ahmad.

llvm-svn: 173901
2013-01-30 06:35:22 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
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
2013-01-02 11:36:10 +00:00
Jakub Staszak c48bbe7170 Add extra CHECK to make sure that 'or' instruction was replaced.
Also add an assert to avoid confusion in the code where is known that C1 <= C2.

llvm-svn: 171310
2012-12-31 18:26:42 +00:00
Jakub Staszak f584977df2 Grammo.
llvm-svn: 171272
2012-12-31 01:40:44 +00:00
Jakub Staszak ea2b9b9d67 Transform (A == C1 || A == C2) into (A & ~(C1 ^ C2)) == C1
if C1 and C2 differ only with one bit.
Fixes PR14708.

llvm-svn: 171270
2012-12-31 00:34:55 +00:00
Craig Topper ae48cb2e5a Formatting fixes. Remove some unnecessary 'else' after 'return'. No functional change.
llvm-svn: 170676
2012-12-20 07:15:54 +00:00
Craig Topper 9d4171afed Removing trailing whitespace
llvm-svn: 170675
2012-12-20 07:09:41 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
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
2012-12-03 16:50:05 +00:00
Shuxin Yang 6ea79e864d rdar://12329730 (defect 2)
Enhancement to InstCombine. Try to catch this opportunity:
  
 ---------------------------------------------------------------
 ((X^C1) >> C2) ^ C3  => (X>>C2) ^ ((C1>>C2)^C3)
  where the subexpression "X ^ C1" has more than one uses, and
  "(X^C1) >> C2" has single use. 
 ---------------------------------------------------------------- 

 Reviewed by Nadav (with minor change per his request).

llvm-svn: 168615
2012-11-26 21:44:25 +00:00
NAKAMURA Takumi 00d2a107fb InstCombineAndOrXor.cpp: Escape bracket in doxygen description. [-Wdocumentation]
llvm-svn: 168013
2012-11-15 00:35:50 +00:00
Sylvestre Ledru 91ce36c986 Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767
llvm-svn: 164768
2012-09-27 10:14:43 +00:00
Sylvestre Ledru 721cffd53a Fix a typo 'iff' => 'if'
llvm-svn: 164767
2012-09-27 09:59:43 +00:00
Manman Ren c2bc2d106b InstCombine: fix a bug when combining (fcmp cc0 x, y) && (fcmp cc1 x, y).
uno && ueq was converted to ueq, it should be converted to uno.

llvm-svn: 158441
2012-06-14 05:57:42 +00:00
Chad Rosier faa3894628 Fix combine of uno && ord -> false so that the ordering of the fcmps doesn't
matter.
rdar://11579835

llvm-svn: 158084
2012-06-06 17:22:40 +00:00
Benjamin Kramer 9d5849f51d Fix suspicous hasOneUse() check, found by PVS Studio (PR12357).
llvm-svn: 157592
2012-05-28 20:52:48 +00:00
Chad Rosier 7813dcee30 Add instcombine patterns for the following transformations:
(x & y) | (x ^ y) -> x | y 
 (x & y) + (x ^ y) -> x | y 

Patch by Manman Ren.
rdar://10770603

llvm-svn: 155674
2012-04-26 23:29:14 +00:00
Chris Lattner b1e2e1e091 eliminate an unneeded branch, part of PR12357
llvm-svn: 153458
2012-03-26 19:13:57 +00:00
Eli Friedman e06535b2f6 In InstCombiner::visitOr, make sure we reverse the operand swap used for checking for or-of-xor operations after those checks; a later check expects that any constant will be in Op1. PR12234.
llvm-svn: 152884
2012-03-16 00:52:42 +00:00
Bill Wendling f2c78f344e Restrict this transformation to equality conditions.
This transformation is not correct for not-equal conditions:

(trunc x) != C1 & (and x, CA) != C2 -> (and x, CA|CMAX) != C1|C2

Let
  C1 == 0
  C2 == 0
  CA == 0xFF0000
  CMAX == 0xFF
and truncating to i8.

The original truth table:

    x   | A: trunc x != 0 | B: x & 0xFF0000 != 0 | A & B != 0
--------------------------------------------------------------
0x00000 |        0        |          0           |     0
0x00001 |        1        |          0           |     0
0x10000 |        0        |          1           |     0
0x10001 |        1        |          1           |     1

The truth table of the replacement:

    x   | x & 0xFF00FF != 0
----------------------------
0x00000 |        0
0x00001 |        1
0x10000 |        1
0x10001 |        1

So they are different.

llvm-svn: 151691
2012-02-29 01:46:50 +00:00
Craig Topper a2886c21d9 Convert assert(0) to llvm_unreachable
llvm-svn: 149967
2012-02-07 05:05:23 +00:00
Benjamin Kramer baba1aa001 Make helper static.
llvm-svn: 149865
2012-02-06 11:28:19 +00:00
David Blaikie 46a9f016c5 More dead code removal (using -Wunreachable-code)
llvm-svn: 148578
2012-01-20 21:51:11 +00:00
Benjamin Kramer f7fe24f40a Move assert to the right place.
llvm-svn: 147779
2012-01-09 17:36:29 +00:00
Benjamin Kramer f9d0cc0160 InstCombine: Teach foldLogOpOfMaskedICmpsHelper that sign bit tests are bit tests.
This subsumes several other transforms while enabling us to catch more cases.

llvm-svn: 147777
2012-01-09 17:23:27 +00:00
Benjamin Kramer 6609f741b9 Tweak my last commit to be less conservative about uses.
We still save an instruction when just the "and" part is replaced.
Also change the code to match comments more closely.

llvm-svn: 147753
2012-01-08 21:12:51 +00:00
Benjamin Kramer da37e15345 InstCombine: If we have a bit test and a sign test anded/ored together, merge the sign bit into the bit test.
This is common in bit field code, e.g. checking if the first or the last bit of a bit field is set.

llvm-svn: 147749
2012-01-08 18:32:24 +00:00
Pete Cooper ebf98c1304 Refactor code used in InstCombine::FoldAndOfICmps to new file.
This will be used by SimplifyCfg in a later commit.

llvm-svn: 146803
2011-12-17 01:20:32 +00:00
Benjamin Kramer 547b6c5ecd Stop emitting instructions with the name "tmp" they eat up memory and have to be uniqued, without any benefit.
If someone prefers %tmp42 to %42, run instnamer.

llvm-svn: 140634
2011-09-27 20:39:19 +00:00
Eli Friedman 61d7c8a065 Fix an infinite loop where a transform in InstCombiner::visitAnd claims a construct is changed when it is not. (See included testcase.)
Patch by Xiaoyi Guo.

llvm-svn: 140072
2011-09-19 21:58:15 +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
Benjamin Kramer e6e1933f31 Change Intrinsic::getDeclaration and friends to take an ArrayRef.
llvm-svn: 135154
2011-07-14 17:45:39 +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
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
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
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
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
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
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
Chris Lattner 9f0ac0dd8b tidy up a bit.
llvm-svn: 125546
2011-02-15 01:56:08 +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 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
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 311aa63c87 reduce indentation
llvm-svn: 123514
2011-01-15 05:40:29 +00:00
Duncan Sands fbb9ac3cca Add a generic expansion transform: A op (B op' C) -> (A op B) op' (A op C)
if both A op B and A op C simplify.  This fires fairly often but doesn't
make that much difference.  On gcc-as-one-file it removes two "and"s and
turns one branch into a select.

llvm-svn: 122399
2010-12-22 13:36:08 +00:00
Benjamin Kramer f7957d0463 Add a check missing from my last commit and avoid a potential overflow situation.
llvm-svn: 122258
2010-12-20 20:00:31 +00:00
Benjamin Kramer 2bca3a67b3 Reduce indentation.
llvm-svn: 122249
2010-12-20 16:21:59 +00:00
Benjamin Kramer 68531baea9 Teach InstCombine to merge (icmp ult (X + CA), C1) | (icmp eq X, C2) into (icmp ult (X + CA), C1 + 1) if C2 + CA == C1.
InstCombine creates these so now we compile x == 23 || x == 24 || x == 25 to
  %x.off = add i32 %x, -23
  %1 = icmp ult i32 %x.off, 3
instead of
  %x.off = add i32 %x, -23
  %1 = icmp ult i32 %x.off, 2
  %cmp3 = icmp eq i32 %x, 25
  %ret2 = or i1 %1, %cmp3

llvm-svn: 122248
2010-12-20 16:18:51 +00:00
Duncan Sands 0488d564e1 Rename SimplifyDistributed to the more meaningfull name SimplifyByFactorizing.
llvm-svn: 120051
2010-11-23 20:42:39 +00:00
Duncan Sands adc7771f18 Exploit distributive laws (eg: And distributes over Or, Mul over Add, etc) in a
fairly systematic way in instcombine.  Some of these cases were already dealt
with, in which case I removed the existing code.  The case of Add has a bunch of
funky logic which covers some of this plus a few variants (considers shifts to be
a form of multiplication), which I didn't touch.  The simplification performed is:
A*B+A*C -> A*(B+C).  The improvement is to do this in cases that were not already
handled [such as A*B-A*C -> A*(B-C), which was reported on the mailing list], and
also to do it more often by not checking for "only one use" if "B+C" simplifies.

llvm-svn: 120024
2010-11-23 14:23:47 +00:00
Duncan Sands c89ac07e7a Move some those Xor simplifications which don't require creating new
instructions out of InstCombine and into InstructionSimplify.  While
there, introduce an m_AllOnes pattern to simplify matching with integers
and vectors with all bits equal to one.

llvm-svn: 119536
2010-11-17 18:52:15 +00:00
Duncan Sands 641baf1646 Generalize the reassociation transform in SimplifyCommutative (now renamed to
SimplifyAssociativeOrCommutative) "(A op C1) op C2" -> "A op (C1 op C2)",
which previously was only done if C1 and C2 were constants, to occur whenever
"C1 op C2" simplifies (a la InstructionSimplify).  Since the simplifying operand
combination can no longer be assumed to be the right-hand terms, consider all of
the possible permutations.  When compiling "gcc as one big file", transform 2
(i.e. using right-hand operands) fires about 4000 times but it has to be said
that most of the time the simplifying operands are both constants.  Transforms
3, 4 and 5 each fired once.  Transform 6, which is an existing transform that
I didn't change, never fired.  With this change, the testcase is now optimized
perfectly with one run of instcombine (previously it required instcombine +
reassociate + instcombine, and it may just have been luck that this worked).

llvm-svn: 119002
2010-11-13 15:10:37 +00:00
Owen Anderson c237a849e3 Re-apply r113679, which was reverted in r113720, which added a paid of new instcombine transforms
to expose greater opportunities for store narrowing in codegen.  This patch fixes a potential
infinite loop in instcombine caused by one of the introduced transforms being overly aggressive.

llvm-svn: 113763
2010-09-13 17:59:27 +00:00
Eric Christopher 26abd3e0c2 Revert 113679, it was causing an infinite loop in a testcase that I've sent
on to Owen.

llvm-svn: 113720
2010-09-12 06:09:23 +00:00
Owen Anderson 70f4524427 Invert and-of-or into or-of-and when doing so would allow us to clear bits of the and's mask.
This can result in increased opportunities for store narrowing in code generation.  Update a number of
tests for this change.  This fixes <rdar://problem/8285027>.

Additionally, because this inverts the order of ors and ands, some patterns for optimizing or-of-and-of-or
no longer fire in instances where they did originally.  Add a simple transform which recaptures most of these
opportunities: if we have an or-of-constant-or and have failed to fold away the inner or, commute the order 
of the two ors, to give the non-constant or a chance for simplification instead.

llvm-svn: 113679
2010-09-11 05:48:06 +00:00
Benjamin Kramer 77ab138f84 This transform is also performed by InstructionSimplify, remove the duplicate.
llvm-svn: 113608
2010-09-10 19:52:35 +00:00
Owen Anderson 3fe002dfb5 Generalize instcombine's support for combining multiple bit checks into a single test. Patch by Dirk Steinke!
llvm-svn: 113423
2010-09-08 22:16:17 +00:00
Owen Anderson 8f306a779b Re-apply the infamous r108614, with a fix pointed out by Dirk Steinke.
llvm-svn: 110036
2010-08-02 09:32:13 +00:00
Daniel Dunbar 0b636a24c7 Speculatively revert r108614, "Another attempt at getting the clang self-host to
like my instcombine patch.", in an attempt to fix Clang i386 bootstrap.
 - Also PR7719.

llvm-svn: 109953
2010-07-31 19:51:11 +00:00
Owen Anderson 7d2818b073 Another attempt at getting the clang self-host to like my instcombine patch.
llvm-svn: 108614
2010-07-17 06:56:35 +00:00
Eric Christopher 15a81cddb4 Also revert 108422, it's causing some test failures.
Working on testcases for Owen.

llvm-svn: 108494
2010-07-16 01:36:12 +00:00
Owen Anderson eaf64d5c1e Speculatively revert r108429 to fix the clang self-host.
llvm-svn: 108436
2010-07-15 18:18:57 +00:00
Owen Anderson eb08d01061 Per Chris' suggestion, get rid of the select canonicalization and just add
the corresponding or-icmp-and pattern.  This has the added benefit of doing
the matching earlier, and thus being less susceptible to being confused by
earlier transforms.

llvm-svn: 108429
2010-07-15 17:24:23 +00:00
Owen Anderson 7151dfd48a Reapply r108378, with bugfixes, testcase, and improved comment formatting.
This now passes LIT, nighty test, and llvm-gcc bootstrap on my machine.

llvm-svn: 108422
2010-07-15 15:00:23 +00:00