maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[GISel][CombinerHelper] Combine shuffle_vector scalar to build_vector 

Teach the combiner helper how to replace shuffle_vector of scalars
into build_vector.
I am not particularly happy about having to add this combine, but we
currently get those from <1 x iN> from the IR.

Bonus: This fixes an assert in the shuffle_vector combines since before
this patch, we were expecting vector types.
This commit is contained in:
Quentin Colombet 2019-10-30 17:16:55 -07:00
parent 9baf4958cd
commit f0eeb3c7a7
2 changed files with 65 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
View File

@ -190,7 +190,7 @@ bool CombinerHelper::matchCombineShuffleVector(MachineInstr &MI,
Register Src1 = MI.getOperand(1).getReg();
LLT SrcType = MRI.getType(Src1);
unsigned DstNumElts = DstType.getNumElements();
unsigned SrcNumElts = SrcType.getNumElements();
unsigned SrcNumElts = SrcType.isVector() ? SrcType.getNumElements() : 1;
// If the resulting vector is smaller than the size of the source
// vectors being concatenated, we won't be able to replace the
@ -254,7 +254,7 @@ void CombinerHelper::applyCombineShuffleVector(MachineInstr &MI,
Builder.setInsertPt(*MI.getParent(), MI);
Register NewDstReg = MRI.cloneVirtualRegister(DstReg);
Builder.buildConcatVectors(NewDstReg, Ops);
Builder.buildMerge(NewDstReg, Ops);
MI.eraseFromParent();
replaceRegWith(MRI, DstReg, NewDstReg);

63
llvm/test/CodeGen/AArch64/GlobalISel/prelegalizercombiner-shuffle-vector.mir
View File

@ -351,3 +351,66 @@ body: |
%6:_(<4 x p0>) = G_SHUFFLE_VECTOR %4(<2 x p0>), %5(<2 x p0>), shufflemask(0,1,2,3)
RET_ReallyLR implicit %6
...
# Check that shuffle_vector on scalars gets combined into build_vector.
---
name: shuffle_vector_on_scalars_to_build_vector_ptr
tracksRegLiveness: true
body: |
bb.1:
liveins: $x0, $x1
; CHECK-LABEL: name: shuffle_vector_on_scalars_to_build_vector_ptr
; CHECK: liveins: $x0, $x1
; CHECK: [[COPY:%[0-9]+]]:_(p0) = COPY $x0
; CHECK: [[COPY1:%[0-9]+]]:_(p0) = COPY $x1
; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<4 x p0>) = G_BUILD_VECTOR [[COPY]](p0), [[COPY1]](p0), [[COPY]](p0), [[COPY1]](p0)
; CHECK: RET_ReallyLR implicit [[BUILD_VECTOR]](<4 x p0>)
%0:_(p0) = COPY $x0
%1:_(p0) = COPY $x1
%6:_(<4 x p0>) = G_SHUFFLE_VECTOR %0, %1, shufflemask(0,1,0,1)
RET_ReallyLR implicit %6
...
# Check that shuffle_vector on scalars gets combined into build_vector,
# even if we swap the order of the operands.
---
name: shuffle_vector_on_scalars_to_build_vector_swap_ptr
tracksRegLiveness: true
body: |
bb.1:
liveins: $x0, $x1
; CHECK-LABEL: name: shuffle_vector_on_scalars_to_build_vector_swap_ptr
; CHECK: liveins: $x0, $x1
; CHECK: [[COPY:%[0-9]+]]:_(p0) = COPY $x0
; CHECK: [[COPY1:%[0-9]+]]:_(p0) = COPY $x1
; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<2 x p0>) = G_BUILD_VECTOR [[COPY1]](p0), [[COPY]](p0)
; CHECK: RET_ReallyLR implicit [[BUILD_VECTOR]](<2 x p0>)
%0:_(p0) = COPY $x0
%1:_(p0) = COPY $x1
%6:_(<2 x p0>) = G_SHUFFLE_VECTOR %0, %1, shufflemask(1,0)
RET_ReallyLR implicit %6
...
# Check that we properly use undef values when shuffle_vector
# on scalars gets lowered to build_vector.
---
name: shuffle_vector_on_scalars_to_build_vector_with_undef
tracksRegLiveness: true
body: |
bb.1:
liveins: $x0, $x1
; CHECK-LABEL: name: shuffle_vector_on_scalars_to_build_vector_with_undef
; CHECK: liveins: $x0, $x1
; CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY $x0
; CHECK: [[COPY1:%[0-9]+]]:_(s64) = COPY $x1
; CHECK: [[DEF:%[0-9]+]]:_(s64) = G_IMPLICIT_DEF
; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<4 x s64>) = G_BUILD_VECTOR [[COPY]](s64), [[DEF]](s64), [[DEF]](s64), [[COPY1]](s64)
; CHECK: RET_ReallyLR implicit [[BUILD_VECTOR]](<4 x s64>)
%0:_(s64) = COPY $x0
%1:_(s64) = COPY $x1
%6:_(<4 x s64>) = G_SHUFFLE_VECTOR %0, %1, shufflemask(0,-1,-1,1)
RET_ReallyLR implicit %6
...