Because of this, we cannot use the Simplify* APIs, as they can assert-fail on unreachable code. Since it's not easy to determine
if a given threading will cause a block to become unreachable, simply defer simplifying simplification to later InstCombine and/or
DCE passes.
llvm-svn: 115082
register pressure and thus excess spills, which we don't currently recover from well. This should
be re-evaluated in the future if our ability to generate good spills/splits improves.
Partial fix for <rdar://problem/7635585>.
llvm-svn: 114919
This reverts revision 114633. It was breaking llvm-gcc-i386-linux-selfhost.
It seems there is a downstream bug that is exposed by
-cgp-critical-edge-splitting=0. When that bug is fixed, this patch can go back
in.
Note that the changes to tailcallfp2.ll are not reverted. They were good are
required.
llvm-svn: 114859
Splitting critical edges at the merge point only addressed part of the issue; it is also possible for non-post-domination
to occur when the path from the load to the merge has branches in it. Unfortunately, full anticipation analysis is
time-consuming, so for now approximate it. This is strictly more conservative than real anticipation, so we will miss
some cases that real PRE would allow, but we also no longer insert loads into paths where they didn't exist before. :-)
This is a very slight net positive on SPEC for me (0.5% on average). Most of the benchmarks are largely unaffected, but
when it pays off it pays off decently: 181.mcf improves by 4.5% on my machine.
llvm-svn: 114785
"external" even when doing lazy bitcode loading. This was broken because
a function that is not materialized fails the !isDeclaration() test.
llvm-svn: 114666
truncates are free only in the case where the extended type is legal but the
load type is not. If both types are illegal, such as when they are too big,
the load may not be legalized into an extended load.
llvm-svn: 114568
load when the type of the load is not legal, even if truncates are not free.
The load is going to be legalized to an extending load anyway.
llvm-svn: 114488
walking the asm arguments once and stashing their Values. This is
wrong because the same memory location can be in the list twice, and
if the first one has a sunkaddr substituted, the stashed value for the
second one will be wrong (use-after-free). PR 8154.
llvm-svn: 114104
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
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
not unrolling loops that contain calls that would be better off getting inlined. This mostly
comes up when an interleaved devirtualization pass has devirtualized a call which the inliner
will inline on a future pass. Thus, rather than blocking all loops containing calls, add
a metric for "inline candidate calls" and block loops containing those instead.
llvm-svn: 113535
unrolling threshold to the optimize-for-size threshold. Basically, for loops containing calls, unrolling
can still be profitable as long as the loop is REALLY small.
llvm-svn: 113439
The threshold value of 50 is arbitrary, and I chose it simply by analogy to the inlining thresholds, where
the baseline unrolling threshold is slightly smaller than the baseline inlining threshold. This could
undoubtedly use some tuning.
llvm-svn: 113306
turning (fptrunc (sqrt (fpext x))) -> (sqrtf x) is great, but we have
to delete the original sqrt as well. Not doing so causes us to do
two sqrt's when building with -fmath-errno (the default on linux).
llvm-svn: 113260
Switch from isWeakForLinker to mayBeOverridden which is more accurate.
Add more statistics and debugging info. Add comments. Move static function
outside anonymous namespace.
llvm-svn: 113190
in the duplicated block instead of duplicating them.
Duplicating them into the end of the loop and the preheader
means that we got a phi node in the header of the loop,
which prevented LICM from hoisting them. GVN would
usually come around later and merge the duplicated
instructions so we'd get reasonable output... except that
anything dependent on the shoulda-been-hoisted value can't
be hoisted. In PR5319 (which this fixes), a memory value
didn't get promoted.
llvm-svn: 113134
Loop::hasLoopInvariantOperands method. Remove
a useless and confusing Loop::isLoopInvariant(Instruction)
method, which didn't do what you thought it did.
No functionality change.
llvm-svn: 113133
location is being re-stored to the memory location. We would get
a dangling pointer from the SSAUpdate data structure and miss a
use. This fixes PR8068
llvm-svn: 113042
I'm sure it is harmless. Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory. Instead, simply pass
in the type and name explicitly, which is all that was used anyway.
llvm-svn: 112810
on llvmdev: SRoA is introducing MMX datatypes like <1 x i64>,
which then cause random problems because the X86 backend is
producing mmx stuff without inserting proper emms calls.
In the short term, force off MMX datatypes. In the long term,
the X86 backend should not select generic vector types to MMX
registers. This is being worked on, but won't be done in time
for 2.8. rdar://8380055
llvm-svn: 112696
two are weak, we make them thunks to a new strong function) so don't iterate
through the function list as we're modifying it.
Also add back the outermost loop which got removed during the cleanups.
llvm-svn: 112595
This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's
handling of and/or of i1's), but never manifested before. This patch adds a tracking set to prevent this case.
llvm-svn: 112589
instead of PromoteMemToReg. This allows it to stop using DF and DT,
eliminating a computation of DT and DF from clang -O3. Clang is now
down to 2 runs of DomFrontier.
llvm-svn: 112457
assertingvh so we get a violent explosion if the pointer dangles.
2) Fix AliasSetTracker::deleteValue to remove call sites with
by-pointer comparisons instead of by-alias queries. Using
findAliasSetForCallSite can cause alias sets to get merged
when they shouldn't, and can also miss alias sets when the
call is readonly.
#2 fixes PR6889, which only repros with a .c file :(
llvm-svn: 112452
LICM correctly. When sinking an instruction, it should not add
entries for the sunk instruction to the AST, it should remove
the entry for the sunk instruction. The blocks being sunk to
are not in the loop, so their instructions shouldn't be in the
AST (yet)!
llvm-svn: 112447
keeping them around until the pass is destroyed, keep them
around a) just when useful (not for outer loops) and b) destroy
them right after we use them. This should reduce memory use
and fixes potential bugs where a loop is deleted and another
loop gets allocated to the same address.
llvm-svn: 112446
LSRInstance data structures up to date. This fixes some
pessimizations caused by stale data which will be exposed
in an upcoming change.
llvm-svn: 112440
Benjamin Kramer