is that, for functions whose bodies are entirely guarded by an if-statement, it
can be profitable to pull the test out of the callee and into the caller.
This code has had some cursory testing, but still has a number of known issues
on the LLVM test suite.
llvm-svn: 73338
induction variable when the addrec to be expanded does not require
a wider type. This eliminates the need for IndVarSimplify to
micro-manage SCEV expansions, because SCEVExpander now
automatically expands them in the form that IndVarSimplify considers
to be canonical. (LSR still micro-manages its SCEV expansions,
because it's optimizing for the target, rather than for
other optimizations.)
Also, this uses the new getAnyExtendExpr, which has more clever
expression simplification logic than the IndVarSimplify code it
replaces, and this cleans up some ugly expansions in code such as
the included masked-iv.ll testcase.
llvm-svn: 73294
the relationship with MergeFunctions.cpp's isEquivalentOperation,
and make a trivial code reordering so that the two functions are
easier to compare.
Fix the name of Instruction::isSameOperationAs in MergeFunction.cpp's
isEquivalentOperation's comment, and fix a nearby 80-column violation.
llvm-svn: 73241
points to while analyzing all other fields.
Use FoldingSetNodeID to produce a good hash. This dramatically decreases run
times.
Emit thunks. This means that it can look at all functions regardless of what
the linkage is or if the address is taken, but unfortunately some small
functions can be even shorter than the thunk because our backend doesn't yet
realize it can just turn these into jumps. This means that this pass will
pessimize code on average.
llvm-svn: 73222
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
RewriteStoreUserOfWholeAlloca deal with tail padding because
isSafeUseOfBitCastedAllocation expects them to. Otherwise, we crash
trying to erase the bitcast.
llvm-svn: 72688
rewrite the comparison if there is any implicit extension or truncation
on the induction variable. I'm planning for IVUsers to eventually take
over some of the work of this code, and for it to be generalized.
llvm-svn: 72496
in the case where a loop exit value cannot be computed, instead of only in
some cases while using SCEVCouldNotCompute in others. This simplifies
getSCEVAtScope's callers.
llvm-svn: 72375
leave the original comparison in place if it has other uses, since the
other uses won't be dominated by the new comparison instruction.
llvm-svn: 72369
Fix by clearing the rewriter cache before deleting the trivially dead
instructions.
Also make InsertedExpressions use an AssertingVH to catch these
bugs easier.
llvm-svn: 72364
and it wasn't generating calls through @PLT for these functions.
hasLocalLinkage() is now false for available_externally,
I attempted to fix the inliner and dce to handle available_externally properly.
It passed make check.
llvm-svn: 72328
assuming that the use of the value is in a block dominated by the
"normal" destination. LangRef.html and other documentation sources
don't explicitly guarantee this, but it seems to be assumed in
other places in LLVM at least.
This fixes an assertion failure on the included testcase, which
is derived from the Ada testsuite.
FixUsesBeforeDefs is a temporary measure which I'm looking to
replace with a more capable solution.
llvm-svn: 72266
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
of the comparison is defined inside the loop. This fixes a
use-before-def problem, because the transformation puts a use
of the RHS outside the loop.
llvm-svn: 72149
instructions. It attempts to create high-level multi-operand GEPs,
though in cases where this isn't possible it falls back to casting
the pointer to i8* and emitting a GEP with that. Using GEP instructions
instead of ptrtoint+arithmetic+inttoptr helps pointer analyses that
don't use ScalarEvolution, such as BasicAliasAnalysis.
Also, make the AddrModeMatcher more aggressive in handling GEPs.
Previously it assumed that operand 0 of a GEP would require a register
in almost all cases. It now does extra checking and can do more
matching if operand 0 of the GEP is foldable. This fixes a problem
that was exposed by SCEVExpander using GEPs.
llvm-svn: 72093
without one. Use it where we were using abs on
int64_t objects.
(I strongly suspect the casts to unsigned in the
fragments in LoopStrengthReduce are not doing whatever
the original intent was, but the obvious change to
uint64_t doesn't work. Maybe later.)
llvm-svn: 71612
and generalize it so that it can be used by IndVarSimplify. Implement the
base IndVarSimplify transformation code using IVUsers. This removes
TestOrigIVForWrap and associated code, as ScalarEvolution now has enough
builtin overflow detection and folding logic to handle all the same cases,
and more. Run "opt -iv-users -analyze -disable-output" on your favorite
loop for an example of what IVUsers does.
This lets IndVarSimplify eliminate IV casts and compute trip counts in
more cases. Also, this happens to finally fix the remaining testcases
in PR1301.
Now that IndVarSimplify is being more aggressive, it occasionally runs
into the problem where ScalarEvolutionExpander's code for avoiding
duplicate expansions makes it difficult to ensure that all expanded
instructions dominate all the instructions that will use them. As a
temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function
to fix up instructions inserted by SCEVExpander. Fortunately, this code
is contained, and can be easily removed once a more comprehensive
solution is available.
llvm-svn: 71535
method, fixing a crash on PR4146. While the store will
ultimately overwrite the "padded size" number of bits in memory,
the stored value may be a subset of this size. This function
only wants to handle the case where all bits are stored.
llvm-svn: 71224
the readnone. Since MallocInst is scheduled for deletion
it doesn't seem worth doing anything more subtle, such as
having mayWriteToMemory return true for MallocInst.
llvm-svn: 71077
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/
CodeGen/X86/change-compare-stride-1.ll
Failed with exit(1) at line 2
while running: grep {cmpq $-478,} change-compare-stride-1.ll.tmp
child process exited abnormally
llvm-svn: 71013
CallbackVH, with fixes. allUsesReplacedWith need to
walk the def-use chains and invalidate all users of a
value that is replaced. SCEVs of users need to be
recalcualted even if the new value is equivalent. Also,
make forgetLoopPHIs walk def-use chains, since any
SCEV that depends on a PHI should be recalculated when
more information about that PHI becomes available.
llvm-svn: 70927
ThreadEdge directly. This shares the code, but is just a refactoring.
* Make JumpThreading compute the set of loop headers and avoid threading
across them. This prevents jump threading from forming irreducible
loops (goodness) but also prevents it from threading in other cases that
are beneficial (see the comment above FindFunctionBackedges).
llvm-svn: 70820
makes ScalarEvolution::deleteValueFromRecords, and it's code that
subtly needed to be called before ReplaceAllUsesWith, unnecessary.
It also makes ValueDeletionListener unnecessary.
llvm-svn: 70645
of returning a list of pointers to Values that are deleted. This was
unsafe, because the pointers in the list are, by nature of what
RecursivelyDeleteDeadInstructions does, always dangling. Replace this
with a simple callback mechanism. This may eventually be removed if
all clients can reasonably be expected to use CallbackVH.
Use this to factor out the dead-phi-cycle-elimination code from LSR
utility function, and generalize it to use the
RecursivelyDeleteTriviallyDeadInstructions utility function.
This makes LSR more aggressive about eliminating dead PHI cycles;
adjust tests to either be less trivial or to simply expect fewer
instructions.
llvm-svn: 70636
of LSR. This makes the AddUsersIfInteresting phase of LSR a pure
analysis instead of a phase that potentially does CFG modifications.
The conditions where this code would actually perform a split are
rare, and in the cases where it actually would do a split the split
is usually undone by CodeGenPrepare, and in cases where splits
actually survive into codegen, they appear to hurt more often than
they help.
llvm-svn: 70625
target hooks canLosslesslyBitCastTo and isTruncateFree. This allows
targets to avoid worrying about handling all combinations of integer
and pointer types.
llvm-svn: 70555
with the persistent insertion point, and change IndVars to make
use of it. This fixes a bug where IndVars was holding on to a
stale insertion point and forcing the SCEVExpander to continue to
use it.
This fixes PR4038.
llvm-svn: 69892
have pointer types, though in contrast to C pointer types, SCEV
addition is never implicitly scaled. This not only eliminates the
need for special code like IndVars' EliminatePointerRecurrence
and LSR's own GEP expansion code, it also does a better job because
it lets the normal optimizations handle pointer expressions just
like integer expressions.
Also, since LLVM IR GEPs can't directly index into multi-dimensional
VLAs, moving the GEP analysis out of client code and into the SCEV
framework makes it easier for clients to handle multi-dimensional
VLAs the same way as other arrays.
Some existing regression tests show improved optimization.
test/CodeGen/ARM/2007-03-13-InstrSched.ll in particular improved to
the point where if-conversion started kicking in; I turned it off
for this test to preserve the intent of the test.
llvm-svn: 69258
sext around sext(shorter IV + constant), using a
longer IV instead, when it can figure out the
add can't overflow. This comes up a lot in
subscripting; mainly affects 64 bit.
llvm-svn: 69123
llvm.dbg.region.end instrinsic. This nested llvm.dbg.func.start/llvm.dbg.region.end pair now enables DW_TAG_inlined_subroutine support in code generator.
llvm-svn: 69118
strncat :(
strncat(foo, "bar", 99)
would be optimized to
memcpy(foo+strlen(foo), "bar", 100, 1)
instead of
memcpy(foo+strlen(foo), "bar", 4, 1)"
Patch by Benjamin Kramer!
llvm-svn: 68905
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
the inliner; prevents nondeterministic behavior
when the same address is reallocated.
Don't build call graph nodes for debug intrinsic calls;
they're useless, and there were typically a lot of them.
llvm-svn: 67311
and was deleting Instructions without clearing the
corresponding map entry. This led to nondeterministic
behavior if the same address got allocated to another
Instruction within a short time.
llvm-svn: 67306
it is not APInt clean, but even when it is it needs to be evaluated carefully
to determine whether it is actually profitable.
This fixes a crash on PR3806
llvm-svn: 67134
changes.
For InvokeInst now all arguments begin at op_begin().
The Callee, Cont and Fail are now faster to get by
access relative to op_end().
This patch introduces some temporary uglyness in CallSite.
Next I'll bring CallInst up to a similar scheme and then
the uglyness will magically vanish.
This patch also exposes all the reliance of the libraries
on InvokeInst's operand ordering. I am thinking of taking
care of that too.
llvm-svn: 66920
right; did the wrong thing when there are exactly 11
non-debug instructions, followed by debug info.
Remove a FIXME since it's apparently been fixed along the way.
llvm-svn: 66840
in the Ada testcase. Reverting this only covers up
the real problem, which is a nasty conceptual difficulty
in the phi elimination pass: when eliminating phi nodes
in landing pads, the register copies need to come before
the invoke, not at the end of the basic block which is
too late... See PR3784.
llvm-svn: 66826
from a switch table. Multiple table entries that
branch to the same place were being sorted by the
pointer value of the ConstantInt*; changed to sort
by the actual value of the ConstantInt.
llvm-svn: 66749
allocations. Apparently the assumption is there is an
instruction (terminator?) following the allocation so I
am allowing the same assumption.
llvm-svn: 66716
and extern_weak_odr. These are the same as the non-odr versions,
except that they indicate that the global will only be overridden
by an *equivalent* global. In C, a function with weak linkage can
be overridden by a function which behaves completely differently.
This means that IP passes have to skip weak functions, since any
deductions made from the function definition might be wrong, since
the definition could be replaced by something completely different
at link time. This is not allowed in C++, thanks to the ODR
(One-Definition-Rule): if a function is replaced by another at
link-time, then the new function must be the same as the original
function. If a language knows that a function or other global can
only be overridden by an equivalent global, it can give it the
weak_odr linkage type, and the optimizers will understand that it
is alright to make deductions based on the function body. The
code generators on the other hand map weak and weak_odr linkage
to the same thing.
llvm-svn: 66339
to find a tiny mouse hole to squeeze through, it struck
me that globals without a name can be considered internal
since they can't be referenced from outside the current
module. This patch makes GlobalOpt give them internal
linkage. Also done for aliases even though they always
have names, since in my opinion anonymous aliases should
be allowed for consistency with global variables and
functions. So if that happens one day, this code is ready!
llvm-svn: 66267
If non constant local GV named A is used by a constant local GV named B (e.g. llvm.dbg.variable) and B is not used by anyone else then eliminate A as well as B.
In other words, debug info should not interfere in removal of unused GV.
--This life, and those below, will be ignored--
M test/Transforms/GlobalOpt/2009-03-03-dbg.ll
M lib/Transforms/IPO/GlobalOpt.cpp
llvm-svn: 66167
