Index: lib/CodeGen/GlobalISel/LegalizerHelper.cpp =================================================================== --- lib/CodeGen/GlobalISel/LegalizerHelper.cpp +++ lib/CodeGen/GlobalISel/LegalizerHelper.cpp @@ -800,10 +800,14 @@ // Try to turn this into a merge of merges if we can use the requested type as // the source. - - // TODO: Pad with undef if DstTy > WideTy - if (NumMerge > 1 && WideTy.getSizeInBits() % SrcTy.getSizeInBits() == 0) { + if (NumMerge > 1) { int PartsPerMerge = WideTy.getSizeInBits() / SrcTy.getSizeInBits(); + if (WideTy.getSizeInBits() % SrcTy.getSizeInBits() != 0) + return UnableToLegalize; + + int RemainderBits = DstTy.getSizeInBits() % WideTy.getSizeInBits(); + int RemainderParts = RemainderBits / SrcTy.getSizeInBits(); + SmallVector Parts; SmallVector SubMerges; @@ -816,7 +820,22 @@ Parts.clear(); } - MIRBuilder.buildMerge(DstReg, SubMerges); + if (RemainderParts == 0) { + MIRBuilder.buildMerge(DstReg, SubMerges); + MI.eraseFromParent(); + return Legalized; + } + + assert(RemainderParts == 1); + + auto AnyExt = MIRBuilder.buildAnyExt( + WideTy, MI.getOperand(MI.getNumOperands() - 1).getReg()); + SubMerges.push_back(AnyExt.getReg(0)); + + LLT WiderDstTy = LLT::scalar(SubMerges.size() * WideTy.getSizeInBits()); + auto Merge = MIRBuilder.buildMerge(WiderDstTy, SubMerges); + MIRBuilder.buildTrunc(DstReg, Merge); + MI.eraseFromParent(); return Legalized; } Index: test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir =================================================================== --- test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir +++ test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir @@ -456,3 +456,65 @@ %8:_(s96) = G_MERGE_VALUES %0, %1, %2, %3, %4, %5 $vgpr0_vgpr1_vgpr2 = COPY %8 ... + +--- +name: test_merge_s56_s8_s8_s8_s8_s8_s8_s8 +body: | + bb.0: + ; CHECK-LABEL: name: test_merge_s56_s8_s8_s8_s8_s8_s8_s8 + ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0 + ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1 + ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2 + ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3 + ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4 + ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 5 + ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 6 + ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 8 + ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535 + ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C7]](s32) + ; CHECK: [[AND:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C8]] + ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 255 + ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[C1]](s32) + ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C9]] + ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND1]], [[AND]](s32) + ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C]](s32) + ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C9]] + ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[SHL]](s32) + ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[AND2]], [[COPY3]] + ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[OR]](s32) + ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 8 + ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C10]](s32) + ; CHECK: [[AND3:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C8]] + ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C3]](s32) + ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C9]] + ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND4]], [[AND3]](s32) + ; CHECK: [[COPY6:%[0-9]+]]:_(s32) = COPY [[C2]](s32) + ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY6]], [[C9]] + ; CHECK: [[COPY7:%[0-9]+]]:_(s32) = COPY [[SHL1]](s32) + ; CHECK: [[OR1:%[0-9]+]]:_(s32) = G_OR [[AND5]], [[COPY7]] + ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[OR1]](s32) + ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 8 + ; CHECK: [[COPY8:%[0-9]+]]:_(s32) = COPY [[C11]](s32) + ; CHECK: [[AND6:%[0-9]+]]:_(s32) = G_AND [[COPY8]], [[C8]] + ; CHECK: [[COPY9:%[0-9]+]]:_(s32) = COPY [[C5]](s32) + ; CHECK: [[AND7:%[0-9]+]]:_(s32) = G_AND [[COPY9]], [[C9]] + ; CHECK: [[SHL2:%[0-9]+]]:_(s32) = G_SHL [[AND7]], [[AND6]](s32) + ; CHECK: [[COPY10:%[0-9]+]]:_(s32) = COPY [[C4]](s32) + ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY10]], [[C9]] + ; CHECK: [[COPY11:%[0-9]+]]:_(s32) = COPY [[SHL2]](s32) + ; CHECK: [[OR2:%[0-9]+]]:_(s32) = G_OR [[AND8]], [[COPY11]] + ; CHECK: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[OR2]](s32) + ; CHECK: [[TRUNC3:%[0-9]+]]:_(s16) = G_TRUNC [[C6]](s32) + ; CHECK: [[MV:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[TRUNC]](s16), [[TRUNC1]](s16), [[TRUNC2]](s16), [[TRUNC3]](s16) + ; CHECK: [[TRUNC4:%[0-9]+]]:_(s56) = G_TRUNC [[MV]](s64) + ; CHECK: S_NOP 0, implicit [[TRUNC4]](s56) + %0:_(s8) = G_CONSTANT i8 0 + %1:_(s8) = G_CONSTANT i8 1 + %2:_(s8) = G_CONSTANT i8 2 + %3:_(s8) = G_CONSTANT i8 3 + %4:_(s8) = G_CONSTANT i8 4 + %5:_(s8) = G_CONSTANT i8 5 + %6:_(s8) = G_CONSTANT i8 6 + %7:_(s56) = G_MERGE_VALUES %0, %1, %2, %3, %4, %5, %6 + S_NOP 0, implicit %7 +... Index: unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp =================================================================== --- unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp +++ unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp @@ -9,6 +9,10 @@ #include "GISelMITest.h" +using namespace LegalizeActions; +using namespace LegalizeMutations; +using namespace LegalityPredicates; + namespace { class DummyGISelObserver : public GISelChangeObserver { @@ -853,4 +857,38 @@ EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF; } + +TEST_F(GISelMITest, LowerMergeValues) { + if (!TM) + return; + + const LLT S24 = LLT::scalar(24); + const LLT S9 = LLT::scalar(9); + const LLT S3 = LLT::scalar(3); + + DefineLegalizerInfo(A, { + getActionDefinitionsBuilder(G_UNMERGE_VALUES) + .widenScalarIf(typeIs(1, LLT::scalar(3)), changeTo(1, LLT::scalar(9))); + }); + + AInfo Info(MF->getSubtarget()); + DummyGISelObserver Observer; + LegalizerHelper Helper(*MF, Info, Observer, B); + B.setInsertPt(*EntryMBB, EntryMBB->end()); + + // 24 = 3 3 3 3 3 3 3 3 + // => 9 + // + // This can do 2 merges for the first parts, but has 2 leftover operands. + + + SmallVector MergeOps; + for (int I = 0; I != 8; ++I) + MergeOps.push_back(B.buildConstant(S3, I).getReg(0)); + + auto Merge = B.buildMerge(S24, MergeOps); + EXPECT_EQ(LegalizerHelper::LegalizeResult::UnableToLegalize, + Helper.lower(*Merge, 1, S9)); +} + } // namespace