[llvm] r358771 - Revert "[GlobalISel] Add legalization support for non-power-2 loads and stores"
Amara Emerson via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 19 10:42:13 PDT 2019
Author: aemerson
Date: Fri Apr 19 10:42:13 2019
New Revision: 358771
URL: http://llvm.org/viewvc/llvm-project?rev=358771&view=rev
Log:
Revert "[GlobalISel] Add legalization support for non-power-2 loads and stores"
This introduces some runtime failures which I'll need to investigate further.
Removed:
llvm/trunk/test/CodeGen/AArch64/GlobalISel/legalize-non-pow2-load-store.mir
Modified:
llvm/trunk/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
llvm/trunk/lib/Target/AArch64/AArch64LegalizerInfo.cpp
llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
Modified: llvm/trunk/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h?rev=358771&r1=358770&r2=358771&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h (original)
+++ llvm/trunk/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h Fri Apr 19 10:42:13 2019
@@ -639,10 +639,6 @@ public:
return actionIf(LegalizeAction::Unsupported,
LegalityPredicates::memSizeInBytesNotPow2(0));
}
- LegalizeRuleSet &lowerIfMemSizeNotPow2() {
- return actionIf(LegalizeAction::Lower,
- LegalityPredicates::memSizeInBytesNotPow2(0));
- }
LegalizeRuleSet &customIf(LegalityPredicate Predicate) {
// We have no choice but conservatively assume that a custom action with a
Modified: llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp?rev=358771&r1=358770&r2=358771&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/LegalizerHelper.cpp Fri Apr 19 10:42:13 2019
@@ -1482,57 +1482,11 @@ LegalizerHelper::lower(MachineInstr &MI,
LLT DstTy = MRI.getType(DstReg);
auto &MMO = **MI.memoperands_begin();
- if (DstTy.getSizeInBits() == MMO.getSizeInBits()) {
- if (MI.getOpcode() == TargetOpcode::G_LOAD) {
- // This load needs splitting into power of 2 sized loads.
- if (DstTy.isVector())
+ if (DstTy.getSizeInBits() == MMO.getSize() /* in bytes */ * 8) {
+ // In the case of G_LOAD, this was a non-extending load already and we're
+ // about to lower to the same instruction.
+ if (MI.getOpcode() == TargetOpcode::G_LOAD)
return UnableToLegalize;
- if (isPowerOf2_32(DstTy.getSizeInBits()))
- return UnableToLegalize; // Don't know what we're being asked to do.
-
- // Our strategy here is to generate anyextending loads for the smaller
- // types up to next power-2 result type, and then combine the two larger
- // result values together, before truncating back down to the non-pow-2
- // type.
- // E.g. v1 = i24 load =>
- // v2 = i32 load (2 byte)
- // v3 = i32 load (1 byte)
- // v4 = i32 shl v2, 16
- // v5 = i32 or v4, v3
- // v1 = i24 trunc v5
- // By doing this we generate the correct truncate which should get
- // combined away as an artifact with a matching extend.
- uint64_t LargeSplitSize = PowerOf2Floor(DstTy.getSizeInBits());
- uint64_t SmallSplitSize = DstTy.getSizeInBits() - LargeSplitSize;
-
- MachineFunction &MF = MIRBuilder.getMF();
- MachineMemOperand *LargeMMO =
- MF.getMachineMemOperand(&MMO, 0, LargeSplitSize / 8);
- MachineMemOperand *SmallMMO = MF.getMachineMemOperand(
- &MMO, LargeSplitSize / 8, SmallSplitSize / 8);
-
- LLT PtrTy = MRI.getType(PtrReg);
- unsigned AnyExtSize = NextPowerOf2(DstTy.getSizeInBits());
- LLT AnyExtTy = LLT::scalar(AnyExtSize);
- unsigned LargeLdReg = MRI.createGenericVirtualRegister(AnyExtTy);
- unsigned SmallLdReg = MRI.createGenericVirtualRegister(AnyExtTy);
- auto LargeLoad =
- MIRBuilder.buildLoad(LargeLdReg, PtrReg, *LargeMMO);
-
- auto OffsetCst =
- MIRBuilder.buildConstant(LLT::scalar(64), LargeSplitSize / 8);
- unsigned GEPReg = MRI.createGenericVirtualRegister(PtrTy);
- auto SmallPtr = MIRBuilder.buildGEP(GEPReg, PtrReg, OffsetCst.getReg(0));
- auto SmallLoad = MIRBuilder.buildLoad(SmallLdReg, SmallPtr.getReg(0),
- *SmallMMO);
-
- auto ShiftAmt = MIRBuilder.buildConstant(AnyExtTy, LargeSplitSize);
- auto Shift = MIRBuilder.buildShl(AnyExtTy, LargeLoad, ShiftAmt);
- auto Or = MIRBuilder.buildOr(AnyExtTy, Shift, SmallLoad);
- MIRBuilder.buildTrunc(DstReg, {Or.getReg(0)});
- MI.eraseFromParent();
- return Legalized;
- }
MIRBuilder.buildLoad(DstReg, PtrReg, MMO);
MI.eraseFromParent();
return Legalized;
@@ -1561,51 +1515,6 @@ LegalizerHelper::lower(MachineInstr &MI,
return UnableToLegalize;
}
- case TargetOpcode::G_STORE: {
- // Lower a non-power of 2 store into multiple pow-2 stores.
- // E.g. split an i24 store into an i16 store + i8 store.
- // We do this by first extending the stored value to the next largest power
- // of 2 type, and then using truncating stores to store the components.
- // By doing this, likewise with G_LOAD, generate an extend that can be
- // artifact-combined away instead of leaving behind extracts.
- unsigned SrcReg = MI.getOperand(0).getReg();
- unsigned PtrReg = MI.getOperand(1).getReg();
- LLT SrcTy = MRI.getType(SrcReg);
- MachineMemOperand &MMO = **MI.memoperands_begin();
- if (SrcTy.getSizeInBits() != MMO.getSizeInBits())
- return UnableToLegalize;
- if (SrcTy.isVector())
- return UnableToLegalize;
- if (isPowerOf2_32(SrcTy.getSizeInBits()))
- return UnableToLegalize; // Don't know what we're being asked to do.
-
- // Extend to the next pow-2.
- const LLT ExtendTy = LLT::scalar(NextPowerOf2(SrcTy.getSizeInBits()));
- auto ExtVal = MIRBuilder.buildAnyExt(ExtendTy, SrcReg);
-
- // Obtain the smaller value by shifting away the larger value.
- uint64_t LargeSplitSize = PowerOf2Floor(SrcTy.getSizeInBits());
- uint64_t SmallSplitSize = SrcTy.getSizeInBits() - LargeSplitSize;
- auto ShiftAmt = MIRBuilder.buildConstant(ExtendTy, LargeSplitSize);
- auto SmallVal = MIRBuilder.buildLShr(ExtendTy, ExtVal, ShiftAmt);
-
- // Generate the GEP and truncating stores.
- LLT PtrTy = MRI.getType(PtrReg);
- auto OffsetCst =
- MIRBuilder.buildConstant(LLT::scalar(64), LargeSplitSize / 8);
- unsigned GEPReg = MRI.createGenericVirtualRegister(PtrTy);
- auto SmallPtr = MIRBuilder.buildGEP(GEPReg, PtrReg, OffsetCst.getReg(0));
-
- MachineFunction &MF = MIRBuilder.getMF();
- MachineMemOperand *LargeMMO =
- MF.getMachineMemOperand(&MMO, 0, LargeSplitSize / 8);
- MachineMemOperand *SmallMMO =
- MF.getMachineMemOperand(&MMO, LargeSplitSize / 8, SmallSplitSize / 8);
- MIRBuilder.buildStore(ExtVal.getReg(0), PtrReg, *LargeMMO);
- MIRBuilder.buildStore(SmallVal.getReg(0), SmallPtr.getReg(0), *SmallMMO);
- MI.eraseFromParent();
- return Legalized;
- }
case TargetOpcode::G_CTLZ_ZERO_UNDEF:
case TargetOpcode::G_CTTZ_ZERO_UNDEF:
case TargetOpcode::G_CTLZ:
Modified: llvm/trunk/lib/Target/AArch64/AArch64LegalizerInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64LegalizerInfo.cpp?rev=358771&r1=358770&r2=358771&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64LegalizerInfo.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64LegalizerInfo.cpp Fri Apr 19 10:42:13 2019
@@ -235,12 +235,14 @@ AArch64LegalizerInfo::AArch64LegalizerIn
.legalForTypesWithMemDesc({{s32, p0, 8, 8},
{s32, p0, 16, 8}})
.clampScalar(0, s8, s64)
- .lowerIfMemSizeNotPow2()
+ .widenScalarToNextPow2(0)
+ // TODO: We could support sum-of-pow2's but the lowering code doesn't know
+ // how to do that yet.
+ .unsupportedIfMemSizeNotPow2()
// Lower any any-extending loads left into G_ANYEXT and G_LOAD
.lowerIf([=](const LegalityQuery &Query) {
return Query.Types[0].getSizeInBits() != Query.MMODescrs[0].SizeInBits;
})
- .widenScalarToNextPow2(0)
.clampMaxNumElements(0, s32, 2)
.clampMaxNumElements(0, s64, 1)
.customIf(IsPtrVecPred);
@@ -248,8 +250,6 @@ AArch64LegalizerInfo::AArch64LegalizerIn
getActionDefinitionsBuilder(G_STORE)
.legalForTypesWithMemDesc({{s8, p0, 8, 8},
{s16, p0, 16, 8},
- {s32, p0, 8, 8},
- {s32, p0, 16, 8},
{s32, p0, 32, 8},
{s64, p0, 64, 8},
{p0, p0, 64, 8},
@@ -260,7 +260,10 @@ AArch64LegalizerInfo::AArch64LegalizerIn
{v4s32, p0, 128, 8},
{v2s64, p0, 128, 8}})
.clampScalar(0, s8, s64)
- .lowerIfMemSizeNotPow2()
+ .widenScalarToNextPow2(0)
+ // TODO: We could support sum-of-pow2's but the lowering code doesn't know
+ // how to do that yet.
+ .unsupportedIfMemSizeNotPow2()
.lowerIf([=](const LegalityQuery &Query) {
return Query.Types[0].isScalar() &&
Query.Types[0].getSizeInBits() != Query.MMODescrs[0].SizeInBits;
Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll?rev=358771&r1=358770&r2=358771&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-fallback.ll Fri Apr 19 10:42:13 2019
@@ -54,6 +54,26 @@ false:
}
+; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to legalize instruction: %3:_(s32) = G_LOAD %1:_(p0) :: (load 3 from `i24* undef`, align 1) (in function: odd_type_load)
+; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for odd_type_load
+; FALLBACK-WITH-REPORT-OUT-LABEL: odd_type_load
+define i32 @odd_type_load() {
+entry:
+ %ld = load i24, i24* undef, align 1
+ %cst = zext i24 %ld to i32
+ ret i32 %cst
+}
+
+ ; General legalizer inability to handle types whose size wasn't a power of 2.
+; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to legalize instruction: G_STORE %1:_(s42), %0:_(p0) :: (store 6 into %ir.addr, align 8) (in function: odd_type)
+; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for odd_type
+; FALLBACK-WITH-REPORT-OUT-LABEL: odd_type:
+define void @odd_type(i42* %addr) {
+ %val42 = load i42, i42* %addr
+ store i42 %val42, i42* %addr
+ ret void
+}
+
; FALLBACK-WITH-REPORT-ERR: remark: <unknown>:0:0: unable to legalize instruction: G_STORE %1:_(<7 x s32>), %0:_(p0) :: (store 28 into %ir.addr, align 32) (in function: odd_vector)
; FALLBACK-WITH-REPORT-ERR: warning: Instruction selection used fallback path for odd_vector
; FALLBACK-WITH-REPORT-OUT-LABEL: odd_vector:
Removed: llvm/trunk/test/CodeGen/AArch64/GlobalISel/legalize-non-pow2-load-store.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/legalize-non-pow2-load-store.mir?rev=358770&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/legalize-non-pow2-load-store.mir (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/legalize-non-pow2-load-store.mir (removed)
@@ -1,49 +0,0 @@
-# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
-# RUN: llc -march=aarch64 -run-pass=legalizer %s -o - -verify-machineinstrs | FileCheck %s
---- |
- target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
- target triple = "aarch64"
-
- define i32 @load_store_test(i24* %ptr, i24* %ptr2) {
- %val = load i24, i24* %ptr
- store i24 %val, i24* %ptr2
- ret i32 0
- }
-
-...
----
-name: load_store_test
-alignment: 2
-tracksRegLiveness: true
-body: |
- bb.1 (%ir-block.0):
- liveins: $x0, $x1
-
- ; CHECK-LABEL: name: load_store_test
- ; CHECK: liveins: $x0, $x1
- ; CHECK: [[COPY:%[0-9]+]]:_(p0) = COPY $x0
- ; CHECK: [[COPY1:%[0-9]+]]:_(p0) = COPY $x1
- ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
- ; CHECK: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[COPY]](p0) :: (load 2 from %ir.ptr, align 4)
- ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 2
- ; CHECK: [[GEP:%[0-9]+]]:_(p0) = G_GEP [[COPY]], [[C1]](s64)
- ; CHECK: [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD [[GEP]](p0) :: (load 1 from %ir.ptr + 2, align 4)
- ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 16
- ; CHECK: [[SHL:%[0-9]+]]:_(s32) = G_SHL [[LOAD]], [[C2]](s32)
- ; CHECK: [[OR:%[0-9]+]]:_(s32) = G_OR [[SHL]], [[LOAD1]]
- ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY [[OR]](s32)
- ; CHECK: [[LSHR:%[0-9]+]]:_(s32) = G_LSHR [[COPY2]], [[C2]](s32)
- ; CHECK: [[GEP1:%[0-9]+]]:_(p0) = G_GEP [[COPY1]], [[C1]](s64)
- ; CHECK: G_STORE [[COPY2]](s32), [[COPY1]](p0) :: (store 2 into %ir.ptr2, align 4)
- ; CHECK: G_STORE [[LSHR]](s32), [[GEP1]](p0) :: (store 1 into %ir.ptr2 + 2, align 4)
- ; CHECK: $w0 = COPY [[C]](s32)
- ; CHECK: RET_ReallyLR implicit $w0
- %0:_(p0) = COPY $x0
- %1:_(p0) = COPY $x1
- %3:_(s32) = G_CONSTANT i32 0
- %2:_(s24) = G_LOAD %0(p0) :: (load 3 from %ir.ptr, align 4)
- G_STORE %2(s24), %1(p0) :: (store 3 into %ir.ptr2, align 4)
- $w0 = COPY %3(s32)
- RET_ReallyLR implicit $w0
-
-...
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