extractelement operations into a bitcast of the pointer,
then a gep, then a scalar load. Disable this when the vector
only has one element, because it leads to infinite loops in
instcombine (PR4908).
This transformation seems like a really bad idea to me, as it
will likely disable CSE of vector load/stores etc and can be
better done in the code generator when profitable. This
goes all the way back to the first days of packed types,
r25299 specifically.
I'll let those people who care about the performance of vector
code decide what to do with this.
llvm-svn: 81185
- I think there are more instances of this, but I think they are fixed in Dan's
incoming patch. This one was preventing me from doing a bugpoint reduction
though.
llvm-svn: 81103
Constant uniquing tables. This allows distinct ConstantExpr objects
with the same operation and different flags.
Even though a ConstantExpr "a + b" is either always overflowing or
never overflowing (due to being a ConstantExpr), it's still necessary
to be able to represent it both with and without overflow flags at
the same time within the IR, because the safety of the flag may
depend on the context of the use. If the constant really does overflow,
it wouldn't ever be safe to use with the flag set, however the use
may be in code that is never actually executed.
This also makes it possible to merge all the flags tests into a single test.
llvm-svn: 80998
changes: SimplifyDemandedBits can't use the builder yet because it
has the wrong insertion point. This fixes a crash building
MultiSource/Benchmarks/PAQ8p
llvm-svn: 80537
is itself a bitcast. Since we have gep(bitcast(bitcast(y))) in this
case, just wait for the two bitcasts to get zapped. This prevents
instcombine from confusing some aliasing stuff, and allows it to
directly eliminate the load in the testcase.
llvm-svn: 80508
workslist and is set to insert new instructions before the current one.
Convert a bunch of stuff that used to call InsertNewInstBefore over to
use it, greatly simplifying code and making it more natural.
There is still a lot more to go, but this is a good start.
llvm-svn: 80492
if the operand is not an instruction.
Simplify most uses of AddOperandsToWorkList to use AddValue and
inline it into the one remaining callsite.
llvm-svn: 80488
former looks too much like AddUsersToWorkList and keeps
confusing me.
Remove AddSoonDeadInstToWorklist and change its two callers
to do the same thing in a simpler way.
llvm-svn: 80486
into their callers. simplify ReplaceInstUsesWith. Make
EraseInstFromFunction only add operands to the worklist if
there aren't too many of them (this was a scalability win
for crazy programs that was only infrequently enforced).
Switch more code to using EraseInstFromFunction instead of
duplicating it inline. Change some fcmp/icmp optimizations
to modify fcmp/icmp in place instead of creating a new one
and deleting the old one just to change the predicate.
llvm-svn: 80483
and introduce a new Instruction::isIdenticalTo which tests for full
identity, including the SubclassOptionalData flags. Also, fix the
Instruction::clone implementations to preserve the SubclassOptionalData
flags. Finally, teach several optimizations how to handle
SubclassOptionalData correctly, given these changes.
This fixes the counterintuitive behavior of isIdenticalTo not comparing
the full value, and clone not returning an identical clone, as well as
some subtle bugs that could be caused by these.
Thanks to Nick Lewycky for reporting this, and for an initial patch!
llvm-svn: 80038
the new load by the old load instead of by the extract element because
a store could have occurred between the load and extract element.
llvm-svn: 78891
appropriate. Patch per report on llvmdev. No testcase because the
original report didn't come with a testcase, and I can't come up with a case
that actually fails.
llvm-svn: 77986
- Some clients which used DOUT have moved to DEBUG. We are deprecating the
"magic" DOUT behavior which avoided calling printing functions when the
statement was disabled. In addition to being unnecessary magic, it had the
downside of leaving code in -Asserts builds, and of hiding potentially
unnecessary computations.
llvm-svn: 77019
also apply to vectors. This allows us to compile this:
#include <emmintrin.h>
__m128i a(__m128 a, __m128 b) { return a==a & b==b; }
__m128i b(__m128 a, __m128 b) { return a!=a | b!=b; }
to:
_a:
cmpordps %xmm1, %xmm0
ret
_b:
cmpunordps %xmm1, %xmm0
ret
with clang instead of to a ton of horrible code.
llvm-svn: 76863
Getelementptrs that are defined to wrap are virtually useless to
optimization, and getelementptrs that are undefined on any kind
of overflow are too restrictive -- it's difficult to ensure that
all intermediate addresses are within bounds. I'm going to take
a different approach.
Remove a few optimizations that depended on this flag.
llvm-svn: 76437
insertelement/extractelement.
I'm not entirely sure this is precisely what we want to do: should we
prefer bitcast(insertelement) or insertelement(bitcast)? Similarly. should we
prefer extractelement(bitcast) or bitcast(extractelement)?
llvm-svn: 76345
GEPOperator's hasNoPointer0verflow(), and make a few places in instcombine
that create GEPs that may overflow clear the NoOverflow value. Among
other things, this partially addresses PR2831.
llvm-svn: 76252
in a convenient manner, factoring out some common code from
InstructionCombining and ValueTracking. Move the contents of
BinaryOperators.h into Operator.h and use Operator to generalize them
to support ConstantExprs as well as Instructions.
llvm-svn: 76232
This adds location info for all llvm_unreachable calls (which is a macro now) in
!NDEBUG builds.
In NDEBUG builds location info and the message is off (it only prints
"UREACHABLE executed").
llvm-svn: 75640
(I think it's reasonably clear that we want to have a canonical form for
constructs like this; if anyone thinks that a select is not the best
canonical form, please tell me.)
llvm-svn: 75531
the changes are allowed by not calling this function for bitcasts.
The Instruction::AShr case is dead because
SimplifyDemandedInstructionBits handles that case.
llvm-svn: 75514
This involves temporarily hard wiring some parts to use the global context. This isn't ideal, but it's
the only way I could figure out to make this process vaguely incremental.
llvm-svn: 75445
Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.
llvm-svn: 75379
failures.
To support this, add some utility functions to Type to help support
vector/scalar-independent code. Change ConstantInt::get and
ConstantFP::get to support vector types, and add an overload to
ConstantInt::get that uses a static IntegerType type, for
convenience.
Introduce a new getConstant method for ScalarEvolution, to simplify
common use cases.
llvm-svn: 73431
integer and floating-point opcodes, introducing
FAdd, FSub, and FMul.
For now, the AsmParser, BitcodeReader, and IRBuilder all preserve
backwards compatability, and the Core LLVM APIs preserve backwards
compatibility for IR producers. Most front-ends won't need to change
immediately.
This implements the first step of the plan outlined here:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt
llvm-svn: 72897
instcombine doesn't know when it's safe. To partially compensate
for this, introduce new code to do this transformation in
dagcombine, which can use UnsafeFPMath.
llvm-svn: 72872
Instcombine to be more aggressive about using SimplifyDemandedBits
on shift nodes. This allows a shift to be simplified to zero in the
included test case.
llvm-svn: 72204
integer types, unless they are already strange. This prevents it from
turning the code produced by SROA into crazy libcalls and stuff that
the code generator can't handle. In the attached example, the result
was an i96 multiply that caused the x86 backend to assert.
Note that if TargetData had an idea of what the legal types are for
a target that this could be used to stop instcombine from introducing
i64 muls, as Scott wanted.
llvm-svn: 68598
to/from integer types that are not intptr_t to convert to intptr_t
then do an integer conversion to the dest type. This exposes the
cast to the optimizer.
llvm-svn: 67638
1. Make instcombine always canonicalize trunc x to i1 into an icmp(x&1). This
exposes the AND to other instcombine xforms and is more of what the code
generator expects.
2. Rewrite the remaining trunc pattern match to use 'match', which
simplifies it a lot.
llvm-svn: 67635
linkage: the value may be replaced with something
different at link time. (Frontends that want to
allow values to be loaded out of weak constants can
give their constants weak_odr linkage).
llvm-svn: 67407
allocations. Apparently the assumption is there is an
instruction (terminator?) following the allocation so I
am allowing the same assumption.
llvm-svn: 66716
use, check also for the case where it has two uses,
the other being a llvm.dbg.declare. This is needed so
debug info doesn't affect codegen.
llvm-svn: 65970
Chris Lattner