[llvm] b717365 - [MachineScheduler][NFCI] Add Offset and OffsetIsScalable args to shouldClusterMemOps (#73778)

via llvm-commits llvm-commits at lists.llvm.org
Wed Dec 6 07:30:53 PST 2023


Author: Alex Bradbury
Date: 2023-12-06T15:30:48Z
New Revision: b7173652163fa968e1df47fa211ce8a549489abd

URL: https://github.com/llvm/llvm-project/commit/b7173652163fa968e1df47fa211ce8a549489abd
DIFF: https://github.com/llvm/llvm-project/commit/b7173652163fa968e1df47fa211ce8a549489abd.diff

LOG: [MachineScheduler][NFCI] Add Offset and OffsetIsScalable args to shouldClusterMemOps (#73778)

These are picked up from getMemOperandsWithOffsetWidth but weren't then
being passed through to shouldClusterMemOps, which forces backends to
collect the information again if they want to use the kind of heuristics
typically used for the similar shouldScheduleLoadsNear function (e.g.
checking the offset is within 1 cache line).

This patch just adds the parameters, but doesn't attempt to use them.
There is potential to use them in the current PPC and AArch64
shouldClusterMemOps implementation, and I intend to use the offset in
the heuristic for RISC-V. I've left these for future patches in the
interest of being as incremental as possible.

As noted in the review and in an inline FIXME, an ElementCount-style abstraction may later be used to condense these two parameters to one argument. ElementCount isn't quite suitable as it doesn't support negative offsets.

Added: 
    

Modified: 
    llvm/include/llvm/CodeGen/TargetInstrInfo.h
    llvm/lib/CodeGen/MachineScheduler.cpp
    llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
    llvm/lib/Target/AArch64/AArch64InstrInfo.h
    llvm/lib/Target/AMDGPU/SIInsertHardClauses.cpp
    llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
    llvm/lib/Target/AMDGPU/SIInstrInfo.h
    llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
    llvm/lib/Target/PowerPC/PPCInstrInfo.h
    llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
    llvm/lib/Target/RISCV/RISCVInstrInfo.h

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/CodeGen/TargetInstrInfo.h b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
index dfd27aa91e9db..2bbe430dc68d9 100644
--- a/llvm/include/llvm/CodeGen/TargetInstrInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
@@ -1415,6 +1415,8 @@ class TargetInstrInfo : public MCInstrInfo {
   /// Get the base operand and byte offset of an instruction that reads/writes
   /// memory. This is a convenience function for callers that are only prepared
   /// to handle a single base operand.
+  /// FIXME: Move Offset and OffsetIsScalable to some ElementCount-style
+  /// abstraction that supports negative offsets.
   bool getMemOperandWithOffset(const MachineInstr &MI,
                                const MachineOperand *&BaseOp, int64_t &Offset,
                                bool &OffsetIsScalable,
@@ -1427,6 +1429,8 @@ class TargetInstrInfo : public MCInstrInfo {
   /// It returns false if base operands and offset could not be determined.
   /// It is not guaranteed to always recognize base operands and offsets in all
   /// cases.
+  /// FIXME: Move Offset and OffsetIsScalable to some ElementCount-style
+  /// abstraction that supports negative offsets.
   virtual bool getMemOperandsWithOffsetWidth(
       const MachineInstr &MI, SmallVectorImpl<const MachineOperand *> &BaseOps,
       int64_t &Offset, bool &OffsetIsScalable, unsigned &Width,
@@ -1497,12 +1501,18 @@ class TargetInstrInfo : public MCInstrInfo {
   /// to TargetPassConfig::createMachineScheduler() to have an effect.
   ///
   /// \p BaseOps1 and \p BaseOps2 are memory operands of two memory operations.
+  /// \p Offset1 and \p Offset2 are the byte offsets for the memory
+  /// operations.
+  /// \p OffsetIsScalable1 and \p OffsetIsScalable2 indicate if the offset is
+  /// scaled by a runtime quantity.
   /// \p ClusterSize is the number of operations in the resulting load/store
   /// cluster if this hook returns true.
   /// \p NumBytes is the number of bytes that will be loaded from all the
   /// clustered loads if this hook returns true.
   virtual bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                                   int64_t Offset1, bool OffsetIsScalable1,
                                    ArrayRef<const MachineOperand *> BaseOps2,
+                                   int64_t Offset2, bool OffsetIsScalable2,
                                    unsigned ClusterSize,
                                    unsigned NumBytes) const {
     llvm_unreachable("target did not implement shouldClusterMemOps()");

diff  --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 4add33ba0996a..c51ef33bfe54a 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1698,11 +1698,12 @@ class BaseMemOpClusterMutation : public ScheduleDAGMutation {
     SmallVector<const MachineOperand *, 4> BaseOps;
     int64_t Offset;
     unsigned Width;
+    bool OffsetIsScalable;
 
     MemOpInfo(SUnit *SU, ArrayRef<const MachineOperand *> BaseOps,
-              int64_t Offset, unsigned Width)
+              int64_t Offset, bool OffsetIsScalable, unsigned Width)
         : SU(SU), BaseOps(BaseOps.begin(), BaseOps.end()), Offset(Offset),
-          Width(Width) {}
+          Width(Width), OffsetIsScalable(OffsetIsScalable) {}
 
     static bool Compare(const MachineOperand *const &A,
                         const MachineOperand *const &B) {
@@ -1831,8 +1832,10 @@ void BaseMemOpClusterMutation::clusterNeighboringMemOps(
           SUnit2ClusterInfo[MemOpa.SU->NodeNum].second + MemOpb.Width;
     }
 
-    if (!TII->shouldClusterMemOps(MemOpa.BaseOps, MemOpb.BaseOps, ClusterLength,
-                                  CurrentClusterBytes))
+    if (!TII->shouldClusterMemOps(MemOpa.BaseOps, MemOpa.Offset,
+                                  MemOpa.OffsetIsScalable, MemOpb.BaseOps,
+                                  MemOpb.Offset, MemOpb.OffsetIsScalable,
+                                  ClusterLength, CurrentClusterBytes))
       continue;
 
     SUnit *SUa = MemOpa.SU;
@@ -1899,7 +1902,8 @@ void BaseMemOpClusterMutation::collectMemOpRecords(
     unsigned Width;
     if (TII->getMemOperandsWithOffsetWidth(MI, BaseOps, Offset,
                                            OffsetIsScalable, Width, TRI)) {
-      MemOpRecords.push_back(MemOpInfo(&SU, BaseOps, Offset, Width));
+      MemOpRecords.push_back(
+          MemOpInfo(&SU, BaseOps, Offset, OffsetIsScalable, Width));
 
       LLVM_DEBUG(dbgs() << "Num BaseOps: " << BaseOps.size() << ", Offset: "
                         << Offset << ", OffsetIsScalable: " << OffsetIsScalable

diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 6f4c6f5ad073d..93b8295f4f3ef 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -4238,8 +4238,9 @@ static bool shouldClusterFI(const MachineFrameInfo &MFI, int FI1,
 ///
 /// Only called for LdSt for which getMemOperandWithOffset returns true.
 bool AArch64InstrInfo::shouldClusterMemOps(
-    ArrayRef<const MachineOperand *> BaseOps1,
-    ArrayRef<const MachineOperand *> BaseOps2, unsigned ClusterSize,
+    ArrayRef<const MachineOperand *> BaseOps1, int64_t OpOffset1,
+    bool OffsetIsScalable1, ArrayRef<const MachineOperand *> BaseOps2,
+    int64_t OpOffset2, bool OffsetIsScalable2, unsigned ClusterSize,
     unsigned NumBytes) const {
   assert(BaseOps1.size() == 1 && BaseOps2.size() == 1);
   const MachineOperand &BaseOp1 = *BaseOps1.front();

diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.h b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
index b259efb9f2e77..e97ff0a9758d6 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
@@ -179,7 +179,9 @@ class AArch64InstrInfo final : public AArch64GenInstrInfo {
                            int64_t &MinOffset, int64_t &MaxOffset);
 
   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                           int64_t Offset1, bool OffsetIsScalable1,
                            ArrayRef<const MachineOperand *> BaseOps2,
+                           int64_t Offset2, bool OffsetIsScalable2,
                            unsigned ClusterSize,
                            unsigned NumBytes) const override;
 

diff  --git a/llvm/lib/Target/AMDGPU/SIInsertHardClauses.cpp b/llvm/lib/Target/AMDGPU/SIInsertHardClauses.cpp
index 50f8ad4433c6d..442ae4dd7b34f 100644
--- a/llvm/lib/Target/AMDGPU/SIInsertHardClauses.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInsertHardClauses.cpp
@@ -232,7 +232,10 @@ class SIInsertHardClauses : public MachineFunctionPass {
               // scheduler it limits the size of the cluster to avoid increasing
               // register pressure too much, but this pass runs after register
               // allocation so there is no need for that kind of limit.
-              !SII->shouldClusterMemOps(CI.BaseOps, BaseOps, 2, 2)))) {
+              // We also lie about the Offset and OffsetIsScalable parameters,
+              // as they aren't used in the SIInstrInfo implementation.
+              !SII->shouldClusterMemOps(CI.BaseOps, 0, false, BaseOps, 0, false,
+                                        2, 2)))) {
           // Finish the current clause.
           Changed |= emitClause(CI, SII);
           CI = ClauseInfo();

diff  --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index b5b456d691254..0a06fa88b6b10 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -541,7 +541,9 @@ static bool memOpsHaveSameBasePtr(const MachineInstr &MI1,
 }
 
 bool SIInstrInfo::shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                                      int64_t Offset1, bool OffsetIsScalable1,
                                       ArrayRef<const MachineOperand *> BaseOps2,
+                                      int64_t Offset2, bool OffsetIsScalable2,
                                       unsigned ClusterSize,
                                       unsigned NumBytes) const {
   // If the mem ops (to be clustered) do not have the same base ptr, then they

diff  --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.h b/llvm/lib/Target/AMDGPU/SIInstrInfo.h
index e388b5550cb10..0ce31ac6d54ec 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.h
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.h
@@ -234,7 +234,9 @@ class SIInstrInfo final : public AMDGPUGenInstrInfo {
       const TargetRegisterInfo *TRI) const final;
 
   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                           int64_t Offset1, bool OffsetIsScalable1,
                            ArrayRef<const MachineOperand *> BaseOps2,
+                           int64_t Offset2, bool OffsetIsScalable2,
                            unsigned ClusterSize,
                            unsigned NumBytes) const override;
 

diff  --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
index 49d003db8ffc9..21cd27d627113 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -2877,8 +2877,9 @@ static bool isClusterableLdStOpcPair(unsigned FirstOpc, unsigned SecondOpc,
 }
 
 bool PPCInstrInfo::shouldClusterMemOps(
-    ArrayRef<const MachineOperand *> BaseOps1,
-    ArrayRef<const MachineOperand *> BaseOps2, unsigned ClusterSize,
+    ArrayRef<const MachineOperand *> BaseOps1, int64_t OpOffset1,
+    bool OffsetIsScalable1, ArrayRef<const MachineOperand *> BaseOps2,
+    int64_t OpOffset2, bool OffsetIsScalable2, unsigned ClusterSize,
     unsigned NumBytes) const {
 
   assert(BaseOps1.size() == 1 && BaseOps2.size() == 1);

diff  --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.h b/llvm/lib/Target/PowerPC/PPCInstrInfo.h
index a8dc7d6d0e37a..2f0b9498411ae 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrInfo.h
+++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.h
@@ -532,7 +532,9 @@ class PPCInstrInfo : public PPCGenInstrInfo {
   /// Returns true if the two given memory operations should be scheduled
   /// adjacent.
   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                           int64_t Offset1, bool OffsetIsScalable1,
                            ArrayRef<const MachineOperand *> BaseOps2,
+                           int64_t Offset2, bool OffsetIsScalable2,
                            unsigned ClusterSize,
                            unsigned NumBytes) const override;
 

diff  --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index 8d79fc44a208e..1dcff7eb563e2 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -2266,8 +2266,9 @@ static bool memOpsHaveSameBasePtr(const MachineInstr &MI1,
 }
 
 bool RISCVInstrInfo::shouldClusterMemOps(
-    ArrayRef<const MachineOperand *> BaseOps1,
-    ArrayRef<const MachineOperand *> BaseOps2, unsigned ClusterSize,
+    ArrayRef<const MachineOperand *> BaseOps1, int64_t Offset1,
+    bool OffsetIsScalable1, ArrayRef<const MachineOperand *> BaseOps2,
+    int64_t Offset2, bool OffsetIsScalable2, unsigned ClusterSize,
     unsigned NumBytes) const {
   // If the mem ops (to be clustered) do not have the same base ptr, then they
   // should not be clustered

diff  --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
index 0954286a419bd..7e1d3f3118065 100644
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -158,7 +158,9 @@ class RISCVInstrInfo : public RISCVGenInstrInfo {
       const TargetRegisterInfo *TRI) const override;
 
   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
+                           int64_t Offset1, bool OffsetIsScalable1,
                            ArrayRef<const MachineOperand *> BaseOps2,
+                           int64_t Offset2, bool OffsetIsScalable2,
                            unsigned ClusterSize,
                            unsigned NumBytes) const override;
 


        


More information about the llvm-commits mailing list