[llvm] r366366 - GlobalISel: Handle more cases for widenScalar of G_MERGE_VALUES
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 17 13:22:38 PDT 2019
Author: arsenm
Date: Wed Jul 17 13:22:38 2019
New Revision: 366366
URL: http://llvm.org/viewvc/llvm-project?rev=366366&view=rev
Log:
GlobalISel: Handle more cases for widenScalar of G_MERGE_VALUES
Use an anyext to the requested type for the leftover operand to
produce a slightly wider type, and then truncate the final merge.
I have another implementation almost ready which handles arbitrary
widens, but I think it produces worse code in this example (which I
think is 90% due to not folding redundant copies or folding out
implicit_def users), so I wanted to add this as a baseline first.
Modified:
llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
llvm/trunk/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir
llvm/trunk/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
Modified: llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp?rev=366366&r1=366365&r2=366366&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp Wed Jul 17 13:22:38 2019
@@ -875,10 +875,14 @@ LegalizerHelper::widenScalarMergeValues(
// 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<Register, 4> Parts;
SmallVector<Register, 4> SubMerges;
@@ -891,7 +895,22 @@ LegalizerHelper::widenScalarMergeValues(
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;
}
Modified: llvm/trunk/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir?rev=366366&r1=366365&r2=366366&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values.mir Wed Jul 17 13:22:38 2019
@@ -535,3 +535,64 @@ body: |
%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 255
+ ; CHECK: [[TRUNC:%[0-9]+]]:_(s16) = G_TRUNC [[C7]](s32)
+ ; CHECK: [[TRUNC1:%[0-9]+]]:_(s16) = G_TRUNC [[C]](s32)
+ ; CHECK: [[AND:%[0-9]+]]:_(s16) = G_AND [[TRUNC1]], [[TRUNC]]
+ ; CHECK: [[C8:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+ ; CHECK: [[C9:%[0-9]+]]:_(s32) = G_CONSTANT i32 65535
+ ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY [[C8]](s32)
+ ; CHECK: [[AND1:%[0-9]+]]:_(s32) = G_AND [[COPY]], [[C9]]
+ ; CHECK: [[C10:%[0-9]+]]:_(s32) = G_CONSTANT i32 255
+ ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY [[C1]](s32)
+ ; CHECK: [[AND2:%[0-9]+]]:_(s32) = G_AND [[COPY1]], [[C10]]
+ ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[AND2]], [[AND1]](s32)
+ ; CHECK: [[TRUNC2:%[0-9]+]]:_(s16) = G_TRUNC [[SHL]](s32)
+ ; CHECK: [[OR:%[0-9]+]]:_(s16) = G_OR [[AND]], [[TRUNC2]]
+ ; CHECK: [[TRUNC3:%[0-9]+]]:_(s16) = G_TRUNC [[C2]](s32)
+ ; CHECK: [[AND3:%[0-9]+]]:_(s16) = G_AND [[TRUNC3]], [[TRUNC]]
+ ; CHECK: [[C11:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+ ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[C11]](s32)
+ ; CHECK: [[AND4:%[0-9]+]]:_(s32) = G_AND [[COPY2]], [[C9]]
+ ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY [[C3]](s32)
+ ; CHECK: [[AND5:%[0-9]+]]:_(s32) = G_AND [[COPY3]], [[C10]]
+ ; CHECK: [[SHL1:%[0-9]+]]:_(s32) = G_SHL [[AND5]], [[AND4]](s32)
+ ; CHECK: [[TRUNC4:%[0-9]+]]:_(s16) = G_TRUNC [[SHL1]](s32)
+ ; CHECK: [[OR1:%[0-9]+]]:_(s16) = G_OR [[AND3]], [[TRUNC4]]
+ ; CHECK: [[TRUNC5:%[0-9]+]]:_(s16) = G_TRUNC [[C4]](s32)
+ ; CHECK: [[AND6:%[0-9]+]]:_(s16) = G_AND [[TRUNC5]], [[TRUNC]]
+ ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 8
+ ; CHECK: [[COPY4:%[0-9]+]]:_(s32) = COPY [[C12]](s32)
+ ; CHECK: [[AND7:%[0-9]+]]:_(s32) = G_AND [[COPY4]], [[C9]]
+ ; CHECK: [[COPY5:%[0-9]+]]:_(s32) = COPY [[C5]](s32)
+ ; CHECK: [[AND8:%[0-9]+]]:_(s32) = G_AND [[COPY5]], [[C10]]
+ ; CHECK: [[SHL2:%[0-9]+]]:_(s32) = G_SHL [[AND8]], [[AND7]](s32)
+ ; CHECK: [[TRUNC6:%[0-9]+]]:_(s16) = G_TRUNC [[SHL2]](s32)
+ ; CHECK: [[OR2:%[0-9]+]]:_(s16) = G_OR [[AND6]], [[TRUNC6]]
+ ; CHECK: [[TRUNC7:%[0-9]+]]:_(s16) = G_TRUNC [[C6]](s32)
+ ; CHECK: [[MV:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[OR]](s16), [[OR1]](s16), [[OR2]](s16), [[TRUNC7]](s16)
+ ; CHECK: [[TRUNC8:%[0-9]+]]:_(s56) = G_TRUNC [[MV]](s64)
+ ; CHECK: S_NOP 0, implicit [[TRUNC8]](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
+...
Modified: llvm/trunk/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp?rev=366366&r1=366365&r2=366366&view=diff
==============================================================================
--- llvm/trunk/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp (original)
+++ llvm/trunk/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp Wed Jul 17 13:22:38 2019
@@ -9,6 +9,10 @@
#include "GISelMITest.h"
+using namespace LegalizeActions;
+using namespace LegalizeMutations;
+using namespace LegalityPredicates;
+
namespace {
class DummyGISelObserver : public GISelChangeObserver {
@@ -900,4 +904,34 @@ TEST_F(GISelMITest, WidenScalarBuildVect
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<Register, 7> 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
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