[AArch64][GlobalISel] Legalize ptr shuffle vector to s64 (#116013)
This converts all ptr element shuffle vectors to s64, so that the
existing vector legalization handling can lower them as needed. This
prevents a lot of fallbacks that currently try to generate things like
`<2 x ptr> G_EXT`.
I'm not sure if bitcast/inttoptr/ptrtoint is intended to be necessary
for vectors of pointers, but it uses buildCast for the casts, which now
generates a ptrtoint/inttoptr.
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalityPredicates.cpp b/llvm/lib/CodeGen/GlobalISel/LegalityPredicates.cpp
index b7541ef..30c2d08 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalityPredicates.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalityPredicates.cpp
@@ -101,6 +101,12 @@
};
}
+LegalityPredicate LegalityPredicates::isPointerVector(unsigned TypeIdx) {
+ return [=](const LegalityQuery &Query) {
+ return Query.Types[TypeIdx].isPointerVector();
+ };
+}
+
LegalityPredicate LegalityPredicates::elementTypeIs(unsigned TypeIdx,
LLT EltTy) {
return [=](const LegalityQuery &Query) {
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 062dbbe..321760e 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -3697,6 +3697,41 @@
return Legalized;
}
+// This bitcasts a shuffle vector to a different type currently of the same
+// element size. Mostly used to legalize ptr vectors, where ptrtoint/inttoptr
+// will be used instead.
+//
+// <16 x p0> = G_CONCAT_VECTORS <4 x p0>, <4 x p0>, mask
+// ===>
+// <4 x s64> = G_PTRTOINT <4 x p0>
+// <4 x s64> = G_PTRTOINT <4 x p0>
+// <16 x s64> = G_CONCAT_VECTORS <4 x s64>, <4 x s64>, mask
+// <16 x p0> = G_INTTOPTR <16 x s64>
+LegalizerHelper::LegalizeResult
+LegalizerHelper::bitcastShuffleVector(MachineInstr &MI, unsigned TypeIdx,
+ LLT CastTy) {
+ auto ShuffleMI = cast<GShuffleVector>(&MI);
+ LLT DstTy = MRI.getType(ShuffleMI->getReg(0));
+ LLT SrcTy = MRI.getType(ShuffleMI->getReg(1));
+
+ // We currently only handle vectors of the same size.
+ if (TypeIdx != 0 ||
+ CastTy.getScalarSizeInBits() != DstTy.getScalarSizeInBits() ||
+ CastTy.getElementCount() != DstTy.getElementCount())
+ return UnableToLegalize;
+
+ LLT NewSrcTy = SrcTy.changeElementType(CastTy.getScalarType());
+
+ auto Inp1 = MIRBuilder.buildCast(NewSrcTy, ShuffleMI->getReg(1));
+ auto Inp2 = MIRBuilder.buildCast(NewSrcTy, ShuffleMI->getReg(2));
+ auto Shuf =
+ MIRBuilder.buildShuffleVector(CastTy, Inp1, Inp2, ShuffleMI->getMask());
+ MIRBuilder.buildCast(ShuffleMI->getReg(0), Shuf);
+
+ MI.eraseFromParent();
+ return Legalized;
+}
+
/// This attempts to bitcast G_EXTRACT_SUBVECTOR to CastTy.
///
/// <vscale x 8 x i1> = G_EXTRACT_SUBVECTOR <vscale x 16 x i1>, N
@@ -4133,6 +4168,8 @@
return bitcastInsertVectorElt(MI, TypeIdx, CastTy);
case TargetOpcode::G_CONCAT_VECTORS:
return bitcastConcatVector(MI, TypeIdx, CastTy);
+ case TargetOpcode::G_SHUFFLE_VECTOR:
+ return bitcastShuffleVector(MI, TypeIdx, CastTy);
case TargetOpcode::G_EXTRACT_SUBVECTOR:
return bitcastExtractSubvector(MI, TypeIdx, CastTy);
case TargetOpcode::G_INSERT_SUBVECTOR:
diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index d910e33..be34700 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -600,12 +600,13 @@
return buildCopy(Dst, Src);
unsigned Opcode;
- if (SrcTy.isPointer() && DstTy.isScalar())
+ if (SrcTy.isPointerOrPointerVector())
Opcode = TargetOpcode::G_PTRTOINT;
- else if (DstTy.isPointer() && SrcTy.isScalar())
+ else if (DstTy.isPointerOrPointerVector())
Opcode = TargetOpcode::G_INTTOPTR;
else {
- assert(!SrcTy.isPointer() && !DstTy.isPointer() && "n G_ADDRCAST yet");
+ assert(!SrcTy.isPointerOrPointerVector() &&
+ !DstTy.isPointerOrPointerVector() && "no G_ADDRCAST yet");
Opcode = TargetOpcode::G_BITCAST;
}
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
index c8f0106..9c1bbaf 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
@@ -840,13 +840,15 @@
getActionDefinitionsBuilder(G_PTRTOINT)
.legalFor({{s64, p0}, {v2s64, v2p0}})
.widenScalarToNextPow2(0, 64)
- .clampScalar(0, s64, s64);
+ .clampScalar(0, s64, s64)
+ .clampMaxNumElements(0, s64, 2);
getActionDefinitionsBuilder(G_INTTOPTR)
.unsupportedIf([&](const LegalityQuery &Query) {
return Query.Types[0].getSizeInBits() != Query.Types[1].getSizeInBits();
})
- .legalFor({{p0, s64}, {v2p0, v2s64}});
+ .legalFor({{p0, s64}, {v2p0, v2s64}})
+ .clampMaxNumElements(1, s64, 2);
// Casts for 32 and 64-bit width type are just copies.
// Same for 128-bit width type, except they are on the FPR bank.
@@ -1053,7 +1055,7 @@
if (DstTy != SrcTy)
return false;
return llvm::is_contained(
- {v2s64, v2p0, v2s32, v4s32, v4s16, v16s8, v8s8, v8s16}, DstTy);
+ {v2s64, v2s32, v4s32, v4s16, v16s8, v8s8, v8s16}, DstTy);
})
// G_SHUFFLE_VECTOR can have scalar sources (from 1 x s vectors), we
// just want those lowered into G_BUILD_VECTOR
@@ -1079,7 +1081,12 @@
.clampNumElements(0, v8s8, v16s8)
.clampNumElements(0, v4s16, v8s16)
.clampNumElements(0, v4s32, v4s32)
- .clampNumElements(0, v2s64, v2s64);
+ .clampNumElements(0, v2s64, v2s64)
+ .bitcastIf(isPointerVector(0), [=](const LegalityQuery &Query) {
+ // Bitcast pointers vector to i64.
+ const LLT DstTy = Query.Types[0];
+ return std::pair(0, LLT::vector(DstTy.getElementCount(), 64));
+ });
getActionDefinitionsBuilder(G_CONCAT_VECTORS)
.legalFor({{v4s32, v2s32}, {v8s16, v4s16}, {v16s8, v8s8}})
