[llvm] 113114a - [GlobalISel] fix widenScalarUnmerge if widen type is not a multiple of destination type
Dominik Montada via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 29 06:52:27 PDT 2020
Author: Dominik Montada
Date: 2020-09-29T15:52:20+02:00
New Revision: 113114a5da60ef30731046f50fc1d67ff87897fc
URL: https://github.com/llvm/llvm-project/commit/113114a5da60ef30731046f50fc1d67ff87897fc
DIFF: https://github.com/llvm/llvm-project/commit/113114a5da60ef30731046f50fc1d67ff87897fc.diff
LOG: [GlobalISel] fix widenScalarUnmerge if widen type is not a multiple of destination type
Fix creation of illegal unmerge when widen was requested to a type which
is not a multiple of the destination type. E.g. when trying to widen
an s48 unmerge to s64 the existing code would create an illegal unmerge
from s64 to s48.
Instead, create further unmerges to a GCD type, then use this to remerge
these intermediate results to the actual destinations.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D88422
Added:
Modified:
llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index f8ca0e85ee82..e8bc4067c127 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();
diff --git a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
index 66f5804479fa..feb0c2366a95 100644
--- a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -3135,4 +3135,48 @@ TEST_F(AArch64GISelMITest, FewerElementsInsertVectorElt) {
EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
}
+// Test widen scalar of G_UNMERGE_VALUES
+TEST_F(AArch64GISelMITest, widenScalarUnmerge) {
+ setUp();
+ if (!TM)
+ return;
+
+ DefineLegalizerInfo(A, {});
+
+ LLT S96{LLT::scalar(96)};
+ LLT S64{LLT::scalar(64)};
+ LLT S48{LLT::scalar(48)};
+
+ auto Src = B.buildAnyExt(S96, Copies[0]);
+ auto Unmerge = B.buildUnmerge(S48, Src);
+
+ AInfo Info(MF->getSubtarget());
+ DummyGISelObserver Observer;
+ LegalizerHelper Helper(*MF, Info, Observer, B);
+
+ // Perform Legalization
+ B.setInsertPt(*EntryMBB, Unmerge->getIterator());
+
+ // This should create unmerges to a GCD type (S16), then remerge to S48
+ EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+ Helper.widenScalar(*Unmerge, 0, S64));
+
+ const auto *CheckStr = R"(
+ CHECK: [[COPY0:%[0-9]+]]:_(s64) = COPY
+ CHECK: [[COPY1:%[0-9]+]]:_(s64) = COPY
+ CHECK: [[COPY2:%[0-9]+]]:_(s64) = COPY
+ CHECK: [[ANYEXT:%[0-9]+]]:_(s96) = G_ANYEXT [[COPY0]]
+ CHECK: [[ANYEXT1:%[0-9]+]]:_(s192) = G_ANYEXT [[ANYEXT]]
+ CHECK: [[UNMERGE:%[0-9]+]]:_(s64), [[UNMERGE1:%[0-9]+]]:_(s64), [[UNMERGE2:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES [[ANYEXT1]]
+ CHECK: [[UNMERGE3:%[0-9]+]]:_(s16), [[UNMERGE4:%[0-9]+]]:_(s16), [[UNMERGE5:%[0-9]+]]:_(s16), [[UNMERGE6:%[0-9]+]]:_(s16) = G_UNMERGE_VALUES [[UNMERGE]]
+ CHECK: [[UNMERGE7:%[0-9]+]]:_(s16), [[UNMERGE8:%[0-9]+]]:_(s16), [[UNMERGE9:%[0-9]+]]:_(s16), [[UNMERGE10:%[0-9]+]]:_(s16) = G_UNMERGE_VALUES [[UNMERGE1]]
+ CHECK: [[UNMERGE11:%[0-9]+]]:_(s16), [[UNMERGE12:%[0-9]+]]:_(s16), [[UNMERGE13:%[0-9]+]]:_(s16), [[UNMERGE14:%[0-9]+]]:_(s16) = G_UNMERGE_VALUES [[UNMERGE2]]
+ CHECK: [[MERGE:%[0-9]+]]:_(s48) = G_MERGE_VALUES [[UNMERGE3]]:_(s16), [[UNMERGE4]]:_(s16), [[UNMERGE5]]:_(s16)
+ CHECK: [[MERGE1:%[0-9]+]]:_(s48) = G_MERGE_VALUES [[UNMERGE6]]:_(s16), [[UNMERGE7]]:_(s16), [[UNMERGE8]]:_(s16)
+ )";
+
+ // Check
+ EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
+}
+
} // namespace
More information about the llvm-commits
mailing list