This is actually a deficiency in ValueTracking's matchSelectPattern(),
but a codegen test is the simplest way to expose the bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285429 91177308-0d34-0410-b5e6-96231b3b80d8
Currently computeKnownBits returns the common known zero/one bits for all elements of vector data, when we may only be interested in one/some of the elements.
This patch adds a DemandedElts argument that allows us to specify the elements we actually care about. The original computeKnownBits implementation calls with a DemandedElts demanding all elements to match current behaviour. Scalar types set this to 1.
The approach was found to be easier than trying to add a per-element known bits solution, for a similar usefulness given the combines where computeKnownBits is typically used.
I've only added support for a few opcodes so far (the ones that have proven straightforward to test), all others will default to demanding all elements but can be updated in due course.
DemandedElts support could similarly be added to computeKnownBitsForTargetNode in a future commit.
Differential Revision: https://reviews.llvm.org/D25691
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285296 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Clang's intrinsic header currently tries to negate the third operand of a vfmadd mask3 in order to create vfmsub, but this fails isel. This patch adds scalar vfmsub and vfnmsub mask3 that we can use instead to avoid the negate. This is consistent with the packed instructions.
Reviewers: igorb, delena
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25933
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285173 91177308-0d34-0410-b5e6-96231b3b80d8
We already have (V)PMOVZX* combining support, this is the beginning of handling (V)PMOVSX* similarly - other combines in combineVSZext can be generalized in future patches.
This unearthed an interesting bug in that we were generating illegal build vectors on 32-bit targets - it was proving difficult to create a test for it from PMOVZX, but it fired immediately with PMOVSX. I've created a more general form of the existing getConstVector to handle these cases - ideally this should be handled in non-target-specific code but I couldn't find an equivalent.
Differential Revision: https://reviews.llvm.org/D25874
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285072 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Do *not* perform combines such as:
vector_shuffle<4,1,2,3>(build_vector(Ud, C0, C1 C2), scalar_to_vector(X))
->
build_vector(X, C0, C1, C2)
Keeping the shuffle allows lowering the constant build_vector to a materialized
constant vector (such as a vector-load from the constant-pool or some other idiom).
Reviewers: delena, igorb, spatel, mkuper, andreadb, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25524
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285063 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The one tricky thing about this is that the sign/zero_extend_inreg uses v64i8 as an input type which isn't legal without BWI support. Though the vpmovsxbq and vpmovzxbq instructions themselves don't require BWI. To support this we need to add custom lowering for ZERO_EXTEND_VECTOR_INREG with v64i8 input. This can mostly reuse the existing sign extend code with a couple checks for sign extend vs zero extend added.
Reviewers: delena, RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25594
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285053 91177308-0d34-0410-b5e6-96231b3b80d8
Use isConstOrConstSplat helper.
Also use APInt instead of getZExtValue directly to avoid out of range issues.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285033 91177308-0d34-0410-b5e6-96231b3b80d8
If a 64-bit value is tested against a bit which is known to be in the range
[0..31) (modulo 64), we can use the 32-bit BT instruction, which has a slightly
shorter encoding.
Differential Revision: https://reviews.llvm.org/D25862
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0 - X --> 0, if the sub is NUW
0 - X --> 0, if X is 0 or the minimum signed value and the sub is NSW
0 - X --> X, if X is 0 or the minimum signed value
This is the DAG equivalent of:
https://reviews.llvm.org/rL284649
plus the fold for the NUW case which already existed in InstSimplify.
Note that we miss a vector fold because of a deficiency in the DAG version of
computeKnownBits().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284844 91177308-0d34-0410-b5e6-96231b3b80d8
These are the backend equivalents for the tests added in r284627.
The patterns may emerge late, so we should have folds for these in the DAG too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284842 91177308-0d34-0410-b5e6-96231b3b80d8
As discussed in D24815, let's start the process of killing off the broken fast-math global
state housed in TargetOptions and eliminate the need for function-level fast-math attributes.
Here we enable two similar folds that are possible when we don't care about signed-zero:
fadd nsz x, 0 --> x
fsub nsz 0, x --> -x
Note that although the test cases include a 'sin' function call, I'm side-stepping the
FMF-on-calls question (and lack of support in the DAG) for now. It's not needed for these
tests - isNegatibleForFree/GetNegatedExpression just look through a ISD::FSIN node.
Also, when we create an FNEG node and propagate the Flags of the FSUB to it, this doesn't
actually do anything today because Flags are silently dropped for any node that is not a
binary operator.
Differential Revision: https://reviews.llvm.org/D25297
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284824 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The original heuristic to break critical edge during machine sink is relatively conservertive: when there is only one instruction sinkable to the critical edge, it is likely that the machine sink pass will not break the critical edge. This leads to many speculative instructions executed at runtime. However, with profile info, we could model the splitting benefits: if the critical edge has 50% taken rate, it would always be beneficial to split the critical edge to avoid the speculated runtime instructions. This patch uses profile to guide critical edge splitting in machine sink pass.
The performance impact on speccpu2006 on Intel sandybridge machines:
spec/2006/fp/C++/444.namd 25.3 +0.26%
spec/2006/fp/C++/447.dealII 45.96 -0.10%
spec/2006/fp/C++/450.soplex 41.97 +1.49%
spec/2006/fp/C++/453.povray 36.83 -0.96%
spec/2006/fp/C/433.milc 23.81 +0.32%
spec/2006/fp/C/470.lbm 41.17 +0.34%
spec/2006/fp/C/482.sphinx3 48.13 +0.69%
spec/2006/int/C++/471.omnetpp 22.45 +3.25%
spec/2006/int/C++/473.astar 21.35 -2.06%
spec/2006/int/C++/483.xalancbmk 36.02 -2.39%
spec/2006/int/C/400.perlbench 33.7 -0.17%
spec/2006/int/C/401.bzip2 22.9 +0.52%
spec/2006/int/C/403.gcc 32.42 -0.54%
spec/2006/int/C/429.mcf 39.59 +0.19%
spec/2006/int/C/445.gobmk 26.98 -0.00%
spec/2006/int/C/456.hmmer 24.52 -0.18%
spec/2006/int/C/458.sjeng 28.26 +0.02%
spec/2006/int/C/462.libquantum 55.44 +3.74%
spec/2006/int/C/464.h264ref 46.67 -0.39%
geometric mean +0.20%
Manually checked 473 and 471 to verify the diff is in the noise range.
Reviewers: rengolin, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24818
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284757 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
While promoting *_EXTEND_VECTOR_INREG nodes whose inputs are already
promoted, perform the appropriate sign extension for the promoted node
before doing the *_EXTEND_VECTOR_INREG operation. If not, the undefined
high-order bits of the promoted operand may (a) be garbage inc ase of
zext) or (b) contribute the wrong sign-bit (in case of sext)
Updated the promote-vec3.ll test after this change. The diff shows
explicit zeroing in case of zext and intermediate sign extension in case
of sext.
Reviewers: RKSimon
Subscribers: llvm-commits, srhines
Differential Revision: https://reviews.llvm.org/D25790
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284752 91177308-0d34-0410-b5e6-96231b3b80d8
