Commit Graph

80 Commits

Author SHA1 Message Date
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