Summary:
This helps keep us honest -- there were a number of ways we could screw
up and still have passed this test.
Reviewers: asbirlea
Subscribers: llvm-commits, arsenm
Differential Revision: https://reviews.llvm.org/D22531
llvm-svn: 276053
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.
llvm-svn: 276051
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
llvm-svn: 276044
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
llvm-svn: 276043
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
llvm-svn: 276035
This patch adds function summary support to CFLAnders. It also comes
with a lot of tests! Woohoo!
Patch by Jia Chen.
Differential Revision: https://reviews.llvm.org/D22450
llvm-svn: 276026
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.
llvm-svn: 276025
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
llvm-svn: 276023
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.
llvm-svn: 276017
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();
llvm-svn: 276015
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".
llvm-svn: 276013
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.
llvm-svn: 276012
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.
llvm-svn: 276008
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
llvm-svn: 275989
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.
llvm-svn: 275988
D20859 and D20860 attempted to replace the SSE (V)CVTTPS2DQ and VCVTTPD2DQ truncating conversions with generic IR instead.
It turns out that the behaviour of these intrinsics is different enough from generic IR that this will cause problems, INF/NAN/out of range values are guaranteed to result in a 0x80000000 value - which plays havoc with constant folding which converts them to either zero or UNDEF. This is also an issue with the scalar implementations (which were already generic IR and what I was trying to match).
This patch changes both scalar and packed versions back to using x86-specific builtins.
It also deals with the other scalar conversion cases that are runtime rounding mode dependent and can have similar issues with constant folding.
A companion clang patch is at D22105
Differential Revision: https://reviews.llvm.org/D22106
llvm-svn: 275981
Recommitting after r274347 was reverted. This patch introduces some
classes to refactor the 3 and 4 register Thumb2 multiplication
instruction descriptions, plus improved tests for some of those
instructions.
Differential Revision: https://reviews.llvm.org/D21929
llvm-svn: 275979
The standard local dynamic model for TLS on ARM systems needs two
relocations:
- R_ARM_TLS_LDM32 (module idx)
- R_ARM_TLS_LDO32 (offset of object from origin of module TLS block)
In GNU style assembler we use symbol(tlsldm) and symbol(tlsldo) to
produce these relocations.
llvm-mc for ARM supports symbol(tlsldo) but does not support symbol(tlsldm).
This patch wires up the existing symbol(tlsldm) to R_ARM_TLS_LDM32.
TLS for ARM is defined in Addenda to, and Errata in, the ABI for the
ARM Architecture
Differential Revision: https://reviews.llvm.org/D22461
llvm-svn: 275977
As discussed on PR27654, this patch fixes the triples of a lot of aarch64 tests and enables lit tests on windows
This will hopefully help stop cases where windows developers break the aarch64 target
Differential Revision: https://reviews.llvm.org/D22191
llvm-svn: 275973
