diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp | 71 |
1 files changed, 48 insertions, 23 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp index f8ca0e8..e8bc406 100644 --- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp +++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp @@ -1605,35 +1605,60 @@ LegalizerHelper::widenScalarUnmergeValues(MachineInstr &MI, unsigned TypeIdx, auto Unmerge = MIRBuilder.buildUnmerge(WideTy, WideSrc); - // Create a sequence of unmerges to the original results. since we may have - // widened the source, we will need to pad the results with dead defs to cover - // the source register. - // e.g. widen s16 to s32: - // %1:_(s16), %2:_(s16), %3:_(s16) = G_UNMERGE_VALUES %0:_(s48) + // Create a sequence of unmerges and merges to the original results. Since we + // may have widened the source, we will need to pad the results with dead defs + // to cover the source register. + // e.g. widen s48 to s64: + // %1:_(s48), %2:_(s48) = G_UNMERGE_VALUES %0:_(s96) // // => - // %4:_(s64) = G_ANYEXT %0:_(s48) - // %5:_(s32), %6:_(s32) = G_UNMERGE_VALUES %4 ; Requested unmerge - // %1:_(s16), %2:_(s16) = G_UNMERGE_VALUES %5 ; unpack to original regs - // %3:_(s16), dead %7 = G_UNMERGE_VALUES %6 ; original reg + extra dead def - + // %4:_(s192) = G_ANYEXT %0:_(s96) + // %5:_(s64), %6, %7 = G_UNMERGE_VALUES %4 ; Requested unmerge + // ; unpack to GCD type, with extra dead defs + // %8:_(s16), %9, %10, %11 = G_UNMERGE_VALUES %5:_(s64) + // %12:_(s16), %13, dead %14, dead %15 = G_UNMERGE_VALUES %6:_(s64) + // dead %16:_(s16), dead %17, dead %18, dead %18 = G_UNMERGE_VALUES %7:_(s64) + // %1:_(s48) = G_MERGE_VALUES %8:_(s16), %9, %10 ; Remerge to destination + // %2:_(s48) = G_MERGE_VALUES %11:_(s16), %12, %13 ; Remerge to destination + const LLT GCDTy = getGCDType(WideTy, DstTy); const int NumUnmerge = Unmerge->getNumOperands() - 1; - const int PartsPerUnmerge = WideTy.getSizeInBits() / DstTy.getSizeInBits(); - - for (int I = 0; I != NumUnmerge; ++I) { - auto MIB = MIRBuilder.buildInstr(TargetOpcode::G_UNMERGE_VALUES); - - for (int J = 0; J != PartsPerUnmerge; ++J) { - int Idx = I * PartsPerUnmerge + J; - if (Idx < NumDst) - MIB.addDef(MI.getOperand(Idx).getReg()); - else { - // Create dead def for excess components. - MIB.addDef(MRI.createGenericVirtualRegister(DstTy)); + const int PartsPerRemerge = DstTy.getSizeInBits() / GCDTy.getSizeInBits(); + + // Directly unmerge to the destination without going through a GCD type + // if possible + if (PartsPerRemerge == 1) { + const int PartsPerUnmerge = WideTy.getSizeInBits() / DstTy.getSizeInBits(); + + for (int I = 0; I != NumUnmerge; ++I) { + auto MIB = MIRBuilder.buildInstr(TargetOpcode::G_UNMERGE_VALUES); + + for (int J = 0; J != PartsPerUnmerge; ++J) { + int Idx = I * PartsPerUnmerge + J; + if (Idx < NumDst) + MIB.addDef(MI.getOperand(Idx).getReg()); + else { + // Create dead def for excess components. + MIB.addDef(MRI.createGenericVirtualRegister(DstTy)); + } } + + MIB.addUse(Unmerge.getReg(I)); } + } else { + SmallVector<Register, 16> Parts; + for (int J = 0; J != NumUnmerge; ++J) + extractGCDType(Parts, GCDTy, Unmerge.getReg(J)); + + SmallVector<Register, 8> RemergeParts; + for (int I = 0; I != NumDst; ++I) { + for (int J = 0; J < PartsPerRemerge; ++J) { + const int Idx = I * PartsPerRemerge + J; + RemergeParts.emplace_back(Parts[Idx]); + } - MIB.addUse(Unmerge.getReg(I)); + MIRBuilder.buildMerge(MI.getOperand(I).getReg(), RemergeParts); + RemergeParts.clear(); + } } MI.eraseFromParent(); |