We just set PreserveLCSSA to always true since we don't have an
analogous method `mustPreserveAnalysisID(LCSSA)`.
Also port LoopInfo verifier pass to test LoopUnrollPass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276063 91177308-0d34-0410-b5e6-96231b3b80d8
canTailDuplicate accepts two blocks and returns true if the first can be
duplicated into the second successfully. Use this function to
encapsulate the heuristic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276062 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Functions like "slice" and "drop_front" sound like they might mutate the
underlying object, but they don't. Warning on unused results would have
saved me an hour yesterday, and I'm sure I'm not the only one.
LLVM and Clang are clean wrt this warning after D22540.
Reviewers: majnemer
Subscribers: sanjoy, chandlerc, llvm-commits
Differential Revision: https://reviews.llvm.org/D22541
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276058 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously, the insertion point for stores was the last instruction in
Chain *before calling getVectorizablePrefixEndIdx*. Thus if
getVectorizablePrefixEndIdx didn't return Chain.size(), we still would
insert at the last instruction in Chain.
This patch changes our internal API a bit in an attempt to make it less
prone to this sort of error. As a result, we end up recalculating the
Chain's boundary instructions, but I think worrying about the speed hit
of this is a premature optimization right now.
Reviewers: asbirlea, tstellarAMD
Subscribers: mzolotukhin, arsenm, llvm-commits
Differential Revision: https://reviews.llvm.org/D22534
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276056 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The DEBUG message was hard to read because two Values were being printed
on the same line with only the delimiter "aliases". This change makes
us print each Value on its own line.
Reviewers: asbirlea
Subscribers: llvm-commits, arsenm, mzolotukhin
Differential Revision: https://reviews.llvm.org/D22533
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276055 91177308-0d34-0410-b5e6-96231b3b80d8
If 2.5 ulp is acceptable, denormals are not required, and
isn't a reciprocal which will already be handled, replace
with a faster fdiv.
Simplify the lowering tests by using per function
subtarget features.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276051 91177308-0d34-0410-b5e6-96231b3b80d8
This is a variant of scavengeRegister() that works for
enterBasicBlockEnd()/backward(). The benefit of the backward mode is
that it is not affected by incomplete kill flags.
This patch also changes
PrologEpilogInserter::doScavengeFrameVirtualRegs() to use the register
scavenger in backwards mode.
Differential Revision: http://reviews.llvm.org/D21885
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276044 91177308-0d34-0410-b5e6-96231b3b80d8
This adds two pieces:
- RegisterScavenger:::enterBasicBlockEnd() which behaves similar to
enterBasicBlock() but starts tracking at the end of the basic block.
- A RegisterScavenger::backward() method. It is subtly different
from the existing unprocess() method which only considers uses with
the kill flag set: If a value is dead at the end of a basic block with
a last use inside the basic block, unprocess() will fail to mark it as
live. However we cannot change/fix this behaviour because unprocess()
needs to perform the exact reverse operation of forward().
Differential Revision: http://reviews.llvm.org/D21873
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276043 91177308-0d34-0410-b5e6-96231b3b80d8
The pattern may look more obviously like a sext if written as:
define i32 @g(i16 %x) {
%zext = zext i16 %x to i32
%xor = xor i32 %zext, 32768
%add = add i32 %xor, -32768
ret i32 %add
}
We already have that fold in visitAdd().
Differential Revision: https://reviews.llvm.org/D22477
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276035 91177308-0d34-0410-b5e6-96231b3b80d8
This step builds on Lang Hames work to change Archive::child_iterator
for better interoperation with Error/Expected. Building on that it is now
possible to return an error message when the size field of an archive
contains non-decimal characters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276025 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds more specific edges to CFLAndersAliasAnalysis. The goal
of these edges is to give us more information about *how* two values
that MayAlias alias. With this, we can now tell cases like
a = b; // ergo, a may alias b
apart from
a = c;
b = c;
// so, a may alias b, but only because they were both assigned to c.
...And others.
Patch by Jia Chen.
Differential Revision: https://reviews.llvm.org/D22429
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276023 91177308-0d34-0410-b5e6-96231b3b80d8
This makes sure that space is actually available. With this change
running lld on a full file system causes it to exit with
failed to open foo: No space left on device
instead of crashing with a sigbus.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276017 91177308-0d34-0410-b5e6-96231b3b80d8
r274801 did not go far enough to allow gcov+tsan to cooperate. With this
commit it's possible to run the following code without false positives:
std::thread T1(fib), T2(fib);
T1.join(); T2.join();
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276015 91177308-0d34-0410-b5e6-96231b3b80d8
There's not much functional change, but it really is an architectural feature
(on v6T2, v7A, v7R and v7EM) rather than something each CPU implements
individually.
The main functional change is the default behaviour you get when specifying
only "-triple".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276013 91177308-0d34-0410-b5e6-96231b3b80d8
Also verify that we never try to set the size of a vreg associated
to a register class.
Report an error when we encounter that in MIR. Fix a testcase that
hit that error and had a size for no reason.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276012 91177308-0d34-0410-b5e6-96231b3b80d8
We skipped over ReturnInsts which didn't return an argument which would
lead us to incorrectly conclude that an argument returned by another
ReturnInst was 'returned'.
This reverts commit r275756.
This fixes PR28610.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276008 91177308-0d34-0410-b5e6-96231b3b80d8
I've been hitting those already while working on SCCP and I think
it's be useful to provide a more explanatory diagnostic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276007 91177308-0d34-0410-b5e6-96231b3b80d8
- Use unique_ptr instead of managing a container of new'd pointers.
- Use range based for loops.
No functional change is intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276001 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently, InstCombine is already able to fold expressions of the form `logic(cast(A), cast(B))` to the simpler form `cast(logic(A, B))`, where logic designates one of `and`/`or`/`xor`. This transformation is implemented in `foldCastedBitwiseLogic()` in InstCombineAndOrXor.cpp. However, this optimization will not be performed if both `A` and `B` are `icmp` instructions. The decision to preclude casts of `icmp` instructions originates in r48715 in combination with r261707, and can be best understood by the title of the former one:
> Transform (zext (or (icmp), (icmp))) to (or (zext (cimp), (zext icmp))) if at least one of the (zext icmp) can be transformed to eliminate an icmp.
Apparently, it introduced a transformation that is a reverse of the transformation that is done in `foldCastedBitwiseLogic()`. Its purpose is to expose pairs of `zext icmp` that would subsequently be optimized by `transformZExtICmp()` in InstCombineCasts.cpp. Therefore, in order to avoid an endless loop of switching back and forth between these two transformations, the one in `foldCastedBitwiseLogic()` has been restricted to exclude `icmp` instructions which is mirrored in the responsible check:
`if ((!isa<ICmpInst>(Cast0Src) || !isa<ICmpInst>(Cast1Src)) && ...`
This check seems to sort out more cases than necessary because:
- the reverse transformation is obviously done for `or` instructions only
- and also not every `zext icmp` pair is necessarily the result of this reverse transformation
Therefore we now remove this check and replace it by a more finegrained one in `shouldOptimizeCast()` that now rejects only those `logic(zext(icmp), zext(icmp))` that would be able to be optimized by `transformZExtICmp()`, which also avoids the mentioned endless loop. That means we are now able to also simplify expressions of the form `logic(cast(icmp), cast(icmp))` to `cast(logic(icmp, icmp))` (`cast` being an arbitrary `CastInst`).
As an example, consider the following IR snippet
```
%1 = icmp sgt i64 %a, %b
%2 = zext i1 %1 to i8
%3 = icmp slt i64 %a, %c
%4 = zext i1 %3 to i8
%5 = and i8 %2, %4
```
which would now be transformed to
```
%1 = icmp sgt i64 %a, %b
%2 = icmp slt i64 %a, %c
%3 = and i1 %1, %2
%4 = zext i1 %3 to i8
```
This issue became apparent when experimenting with the programming language Julia, which makes use of LLVM. Currently, Julia lowers its `Bool` datatype to LLVM's `i8` (also see https://github.com/JuliaLang/julia/pull/17225). In fact, the above IR example is the lowered form of the Julia snippet `(a > b) & (a < c)`. Like shown above, this may introduce `zext` operations, casting between `i1` and `i8`, which could for example hinder ScalarEvolution and Polly on certain code.
Reviewers: grosser, vtjnash, majnemer
Subscribers: majnemer, llvm-commits
Differential Revision: https://reviews.llvm.org/D22511
Contributed-by: Matthias Reisinger
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275989 91177308-0d34-0410-b5e6-96231b3b80d8
Only if the value is negative or positive is what matters,
so use a constant that doesn't require an instruction to
materialize.
These should really just emit the write exec directly,
but for stick with the kill pseudo-terminator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275988 91177308-0d34-0410-b5e6-96231b3b80d8
