isORCopyInst and isReadOrWriteToDSPReg functions were producing warning
that some statements my fall through.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D47876
llvm-svn: 334194
Simplify combineVectorTruncationWithPACKSS to just a SIGN_EXTEND_INREG followed by using the existing truncateVectorWithPACK instead of duplicating code.
llvm-svn: 334193
We do the same thing in rewriteSingleStoreAlloca.
Fixes PR37632.
Reviewers: chandlerc, davide, efriedma
Reviewed By: davide
Differential Revision: https://reviews.llvm.org/D47825
llvm-svn: 334187
This has two main components. First, widen
widen short constant loads in DAG when they have
the correct alignment. This is already done a bit in
AMDGPUCodeGenPrepare, since that has access to
DivergenceAnalysis. This can't help kernarg loads
created in the DAG. Start to use DAG divergence analysis
to help this case.
The second part is to avoid kernel argument lowering
breaking the alignment of short vector elements because
calling convention lowering wants to split everything
into legal register types.
When loading a split type, load the nearest 4-byte aligned
segment and shift to get the desired bits. This extra
load of the earlier argument piece ends up merging,
and the bit extract hopefully folds out.
There are a number of improvements and regressions with
this, but I think as-is this is a better compromise between
several of the worst parts of SelectionDAG.
Particularly when i16 is legal, this produces worse code
for i8 and i16 element vector kernel arguments. This is
partially due to the very weak load merging the DAG does.
It only looks for fairly specific combines between pairs
of loads which no longer appear. In particular this
causes v4i16 loads to be split into 2 components when
previously the two halves were merged.
Worse, because of the newly introduced shifts, there
is a lot more unnecessary vector packing and unpacking code
emitted. At least some of this is due to reporting
false for isTypeDesirableForOp for i16 as a workaround for
the lack of divergence information in the DAG. The cases
where this happens it doesn't actually matter, but the
relevant code in SimplifyDemandedBits doens't have the context
to know to ignore this.
The use of the scalar cache is probably more important
than the mess of mostly scalar instructions doing this packing
and unpacking. Future work can fix this, possibly by making better
use of the new DAG divergence information for controlling promotion
decisions, or adding another version of shift + trunc + shift
combines that doesn't only know about the used types.
llvm-svn: 334180
Summary: Prevent folding of operations with memory loads when one of the sources has undefined register update.
Reviewers: craig.topper
Subscribers: llvm-commits, mike.dvoretsky, ashlykov
Differential Revision: https://reviews.llvm.org/D47621
llvm-svn: 334175
Summary:
When the branch folder hoist code into a predecessor it adjust live-in's
in the blocks it hoist code from. However it fail to handle hoisted code
that contain a defed register that originally is live-in in the block
through a super register.
This is fixed by replacing the live-in handling code with calls to
utility functions in LivePhysRegs.
Reviewers: kparzysz, gberry, MatzeB, uweigand, aprantl
Reviewed By: kparzysz
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47529
llvm-svn: 334163
This is needed to get CC operand in right place, as expected by the
SchedModel.
Review: Ulrich Weigand
https://reviews.llvm.org/D47820
llvm-svn: 334161
When denormals are supported we are producing a full division for
1.0f / x. That still can be replaced by the faster version:
bool c = fabs(x) > 0x1.0p+96f;
float s = c ? 0x1.0p-32f : 1.0f;
x *= s;
return s * v_rcp_f32(x)
in case if requested accuracy is 2.5ulp or less. The same version
is used if denormals are not supported for non 1.0 numerators, where
just v_rcp_f32 is then used for 1.0 numerator.
The optimization of 1/x is extended to the case -1/x, which is the
same except for the resulting sign bit.
OpenCL conformance passed with both enabled and disabled denorms.
Differential Revision: https://reviews.llvm.org/D47805
llvm-svn: 334142
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.
llvm-svn: 334140
The bug report:
https://bugs.llvm.org/show_bug.cgi?id=36036
...requests a DAG change for this, but an IR canonicalization
probably handles most cases. If we still want to match this
pattern in the backend, there's a proposal for that too:
D47831
Alive proofs including nsw/nuw cases that were first noted in:
D46988
https://rise4fun.com/Alive/Kmp
This patch is largely copied from the existing code that was
initially added with:
D40984
...but I didn't see much gain from trying to share code.
llvm-svn: 334137
Fixes terrible code on targets without f16 support. The
legalization creates a mess that is difficult to recover
from. Also should avoid randomly breaking these tests
multiple times in sequence in future commits.
Some regressions in cases where it happens to be better
to pull the source modifier after the conversion.
llvm-svn: 334132
Summary:
This is [[ https://bugs.llvm.org/show_bug.cgi?id=37603 | PR37603 ]].
https://godbolt.org/g/VCMNpShttps://rise4fun.com/Alive/idM
When doing bit manipulations, it is quite common to calculate some bit mask,
and apply it to some value via `and`.
The typical C code looks like:
```
int mask_signed_add(int nbits) {
return (1 << nbits) - 1;
}
```
which is translated into (with `-O3`)
```
define dso_local i32 @mask_signed_add(int)(i32) local_unnamed_addr #0 {
%2 = shl i32 1, %0
%3 = add nsw i32 %2, -1
ret i32 %3
}
```
But there is a second, less readable variant:
```
int mask_signed_xor(int nbits) {
return ~(-(1 << nbits));
}
```
which is translated into (with `-O3`)
```
define dso_local i32 @mask_signed_xor(int)(i32) local_unnamed_addr #0 {
%2 = shl i32 -1, %0
%3 = xor i32 %2, -1
ret i32 %3
}
```
Since we created such a mask, it is quite likely that we will use it in `and` next.
And then we may get rid of `not` op by folding into `andn`.
But now that i have actually looked:
https://godbolt.org/g/VTUDmU
_some_ backend changes will be needed too.
We clearly loose `bzhi` recognition.
Reviewers: spatel, craig.topper, RKSimon
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47428
llvm-svn: 334127
Summary:
In D47428, i propose to choose the `~(-(1 << nbits))` as the canonical form of low-bit-mask formation.
As it is seen from these tests, there is a reason for that.
AArch64 currently better handles `~(-(1 << nbits))`, but not the more traditional `(1 << nbits) - 1` (sic!).
The other way around for X86.
It would be much better to canonicalize.
This patch is completely monkey-typing.
I don't really understand how this works :)
I have based it on `// x & (-1 >> (32 - y))` pattern.
Also, when we only have `BMI`, i wonder if we could use `BEXTR` with `start=0` ?
Related links:
https://bugs.llvm.org/show_bug.cgi?id=36419https://bugs.llvm.org/show_bug.cgi?id=37603https://bugs.llvm.org/show_bug.cgi?id=37610https://rise4fun.com/Alive/idM
Reviewers: craig.topper, spatel, RKSimon, javed.absar
Reviewed By: craig.topper
Subscribers: kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D47453
llvm-svn: 334125
These encodings correspond to the cases in the normal encoding scheme where there is no index and our modrm reading code initially decodes it as such. The VSIB handling code tried to compensate for this, but failed to add the base needed to make later code do the right thing.
Fixes PR37712.
llvm-svn: 334121
The index size is represented by the letter after the 'v'. The number represents the memory size. If an 'x' appears after the number its means the index register can be from VR128X/VR256X instead of VR128/VR256.
As vy512mem uses a VR256X index it should have an x.
And vz256mem uses a VR512 index so it shouldn't have an x.
I admit these names kind of suck and are confusing.
llvm-svn: 334120
As detailed on Agner's Microarchitecture doc (21.8 AMD Bobcat and Jaguar pipeline - Dependency-breaking instructions), all these instructions are dependency breaking and zero the destination register.
llvm-svn: 334119
Summary:
This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.
It contains only context for fsqrt.
Reviewers: spatel, hfinkel, arsenm
Reviewed By: spatel
Subscribers: hfinkel, wdng, andrew.w.kaylor, wristow, efriedma, nemanjai
Differential Revision: https://reviews.llvm.org/D47749
llvm-svn: 334113
Make TII isCopyInstr() return MachineOperands through pointer to pointer
instead via reference.
Patch by Nikola Prica.
Differential Revision: https://reviews.llvm.org/D47364
llvm-svn: 334105
If no alignment is set, the abi/preferred alignment of structs will be
used which may be higher than required. This can lead to extra padding
and in the end an increase in data size.
Differential Revision: https://reviews.llvm.org/D47633
llvm-svn: 334099
We should never get different CodeGen based on whether the code is being
compiled in debug mode so we must skip over @llvm.dbg.value (and similar)
calls.
Should fix at least the worst part of PR37690.
llvm-svn: 334090
Only the bottom 16-bits of BEXTR's control op are required (0:8 INDEX, 15:8 LENGTH).
Differential Revision: https://reviews.llvm.org/D47690
llvm-svn: 334083
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.
Differential Revision: https://reviews.llvm.org/D44928
llvm-svn: 334078
Add minimal support to lower function calls.
Support only functions with arguments/return that go through registers
and have type i32.
Patch by Petar Avramovic.
Differential Revision: https://reviews.llvm.org/D45627
llvm-svn: 334071
Fuchsia doesn't use __clear_cache, instead it provide zx_cache_flush
system call. Use it to flush instruction cache.
Differential Revision: https://reviews.llvm.org/D47753
llvm-svn: 334068
This is a fix for the problem arising in D47374 (PR37678):
https://bugs.llvm.org/show_bug.cgi?id=37678
We may not have throughput info because it's not specified in the model
or it's not available with variant scheduling, so assume that those
instructions can execute/complete at max-issue-width.
Differential Revision: https://reviews.llvm.org/D47723
llvm-svn: 334055
Summary: As it turns out, the lowering for the Mips16* family of target is the exact same thing as what the ops expands to, so the code handling them can be removed and the ops only enabled for the MipsSE* family of targets.
Reviewers: smaksimovic, atanasyan, abeserminji
Subscribers: sdardis, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D47703
llvm-svn: 334052
CodeGenPrepare pass move extension instructions close to load instructions in different BB, so they can be combined later. But the extension instructions can't move through logical and shift instructions in current implementation. This patch enables this enhancement, so we can eliminate more extension instructions.
Differential Revision: https://reviews.llvm.org/D45537
This is re-commit of r331783, which was reverted by r333305. The performance regression was caused by some unlucky alignment, not a code generation problem.
llvm-svn: 334049
There was only one place in the entire codebase where a non
default value was being passed, and that place was already hidden
in an implementation file. So we can delete the extra parameter
and all existing clients continue to work as they always have,
while making the interface a bit simpler.
Differential Revision: https://reviews.llvm.org/D47789
llvm-svn: 334046
Preserves the low bound of the !range. I don't think
it's legal to do anything with the top half since it's
theoretically reading garbage.
llvm-svn: 334045
Summary: This change uses fmf subflags to guard optimizations as well as unsafe. These changes originated from D46483.
Reviewers: spatel, hfinkel
Reviewed By: spatel
Subscribers: nemanjai
Differential Revision: https://reviews.llvm.org/D47389
llvm-svn: 334037
Similar to v4i32 SHL, convert v8i16 shift amounts to scale factors instead to improve performance and reduce instruction count. We were already doing this for constant shifts, this adds variable shift support.
Reduces the serial nature of the codegen, which relies on chains of plendvb/pand+pandn+por shifts.
This is a step towards adding support for vXi16 vector rotates.
Differential Revision: https://reviews.llvm.org/D47546
llvm-svn: 334023
Summary:
Allow extended parsing of variable assembler assignment syntax and modify X86 to permit
VAR = register assignment. As we emit these as .set directives when possible, we inline
such expressions in output assembly.
Fixes PR37425.
Reviewers: rnk, void, echristo
Reviewed By: rnk
Subscribers: nickdesaulniers, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D47545
llvm-svn: 334022
When legalizing illegal FP load results, this was
for some reason dropping the invariant and dereferencable
memory flags. There doesn't seem to be any reason for this,
and the equivalent isn't done for integer loads.
Fixes an issue in a future AMDGPU commit where some identical
loads fail to merge because one of the loads ends up
dropping the flags.
llvm-svn: 334020
Petar Jovanovic