diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 98bedfe20f5d98..10a9d9e899e007 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -2200,15 +2200,6 @@ def BTFTypeTag : TypeAttr {
   let LangOpts = [COnly];
 }
 
-def BPFFastCall : InheritableAttr,
-                  TargetSpecificAttr<TargetBPF> {
-  let Spellings = [Clang<"bpf_fastcall">];
-  let Subjects = SubjectList<[FunctionLike]>;
-  let Documentation = [BPFFastCallDocs];
-  let LangOpts = [COnly];
-  let SimpleHandler = 1;
-}
-
 def WebAssemblyExportName : InheritableAttr,
                             TargetSpecificAttr<TargetWebAssembly> {
   let Spellings = [Clang<"export_name">];
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index df36a2163b9f0b..19cbb9a0111a28 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -2345,25 +2345,6 @@ section.
   }];
 }
 
-def BPFFastCallDocs : Documentation {
-  let Category = DocCatType;
-  let Content = [{
-Functions annotated with this attribute are likely to be inlined by BPF JIT.
-It is assumed that inlined implementation uses less caller saved registers,
-than a regular function.
-Specifically, the following registers are likely to be preserved:
-- ``R0`` if function return value is ``void``;
-- ``R2-R5` if function takes 1 argument;
-- ``R3-R5` if function takes 2 arguments;
-- ``R4-R5` if function takes 3 arguments;
-- ``R5`` if function takes 4 arguments;
-
-For such functions Clang generates code pattern that allows BPF JIT
-to recognize and remove unnecessary spills and fills of the preserved
-registers.
-  }];
-}
-
 def MipsInterruptDocs : Documentation {
   let Category = DocCatFunction;
   let Heading = "interrupt (MIPS)";
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 09803712569755..e4f221ae55eefa 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -2422,8 +2422,6 @@ void CodeGenModule::ConstructAttributeList(StringRef Name,
       FuncAttrs.addAttribute(llvm::Attribute::NoCfCheck);
     if (TargetDecl->hasAttr<LeafAttr>())
       FuncAttrs.addAttribute(llvm::Attribute::NoCallback);
-    if (TargetDecl->hasAttr<BPFFastCallAttr>())
-      FuncAttrs.addAttribute("bpf_fastcall");
 
     HasOptnone = TargetDecl->hasAttr<OptimizeNoneAttr>();
     if (auto *AllocSize = TargetDecl->getAttr<AllocSizeAttr>()) {
diff --git a/clang/test/CodeGen/bpf-attr-bpf-fastcall-1.c b/clang/test/CodeGen/bpf-attr-bpf-fastcall-1.c
deleted file mode 100644
index fa740d8e44ff51..00000000000000
--- a/clang/test/CodeGen/bpf-attr-bpf-fastcall-1.c
+++ /dev/null
@@ -1,24 +0,0 @@
-// REQUIRES: bpf-registered-target
-// RUN: %clang_cc1 -triple bpf -emit-llvm -disable-llvm-passes %s -o - | FileCheck %s
-
-#define __bpf_fastcall __attribute__((bpf_fastcall))
-
-void test(void) __bpf_fastcall;
-void (*ptr)(void) __bpf_fastcall;
-
-void foo(void) {
-  test();
-  (*ptr)();
-}
-
-// CHECK: @ptr = global ptr null
-// CHECK: define {{.*}} void @foo()
-// CHECK: entry:
-// CHECK:   call void @test() #[[call_attr:[0-9]+]]
-// CHECK:   %[[ptr:.*]] = load ptr, ptr @ptr, align 8
-// CHECK:   call void %[[ptr]]() #[[call_attr]]
-// CHECK:   ret void
-
-// CHECK: declare void @test() #[[func_attr:[0-9]+]]
-// CHECK: attributes #[[func_attr]] = { {{.*}}"bpf_fastcall"{{.*}} }
-// CHECK: attributes #[[call_attr]] = { "bpf_fastcall" }
diff --git a/clang/test/Misc/pragma-attribute-supported-attributes-list.test b/clang/test/Misc/pragma-attribute-supported-attributes-list.test
index a7e425e3d5f431..1a71556213bb16 100644
--- a/clang/test/Misc/pragma-attribute-supported-attributes-list.test
+++ b/clang/test/Misc/pragma-attribute-supported-attributes-list.test
@@ -22,7 +22,6 @@
 // CHECK-NEXT: AssumeAligned (SubjectMatchRule_objc_method, SubjectMatchRule_function)
 // CHECK-NEXT: Availability ((SubjectMatchRule_record, SubjectMatchRule_enum, SubjectMatchRule_enum_constant, SubjectMatchRule_field, SubjectMatchRule_function, SubjectMatchRule_namespace, SubjectMatchRule_objc_category, SubjectMatchRule_objc_implementation, SubjectMatchRule_objc_interface, SubjectMatchRule_objc_method, SubjectMatchRule_objc_property, SubjectMatchRule_objc_protocol, SubjectMatchRule_record, SubjectMatchRule_type_alias, SubjectMatchRule_variable))
 // CHECK-NEXT: AvailableOnlyInDefaultEvalMethod (SubjectMatchRule_type_alias)
-// CHECK-NEXT: BPFFastCall (SubjectMatchRule_hasType_functionType)
 // CHECK-NEXT: BPFPreserveAccessIndex (SubjectMatchRule_record)
 // CHECK-NEXT: BPFPreserveStaticOffset (SubjectMatchRule_record)
 // CHECK-NEXT: BTFDeclTag (SubjectMatchRule_variable, SubjectMatchRule_function, SubjectMatchRule_record, SubjectMatchRule_field, SubjectMatchRule_type_alias)
diff --git a/clang/test/Sema/bpf-attr-bpf-fastcall.c b/clang/test/Sema/bpf-attr-bpf-fastcall.c
deleted file mode 100644
index 178b1f50741e87..00000000000000
--- a/clang/test/Sema/bpf-attr-bpf-fastcall.c
+++ /dev/null
@@ -1,14 +0,0 @@
-// REQUIRES: bpf-registered-target
-// RUN: %clang_cc1 %s -triple bpf -verify
-
-__attribute__((bpf_fastcall)) int var; // expected-warning {{'bpf_fastcall' attribute only applies to functions and function pointers}}
-
-__attribute__((bpf_fastcall)) void func();
-__attribute__((bpf_fastcall(1))) void func_invalid(); // expected-error {{'bpf_fastcall' attribute takes no arguments}}
-
-void (*ptr1)(void) __attribute__((bpf_fastcall));
-void (*ptr2)(void);
-void foo(void) {
-  ptr2 = ptr1; // not an error
-  ptr1 = ptr2; // not an error
-}
diff --git a/llvm/lib/Target/BPF/BPFCallingConv.td b/llvm/lib/Target/BPF/BPFCallingConv.td
index a557211437e95f..ef4ef1930aa8fb 100644
--- a/llvm/lib/Target/BPF/BPFCallingConv.td
+++ b/llvm/lib/Target/BPF/BPFCallingConv.td
@@ -46,4 +46,3 @@ def CC_BPF32 : CallingConv<[
 ]>;
 
 def CSR : CalleeSavedRegs<(add R6, R7, R8, R9, R10)>;
-def CSR_PreserveAll : CalleeSavedRegs<(add R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10)>;
diff --git a/llvm/lib/Target/BPF/BPFISelLowering.cpp b/llvm/lib/Target/BPF/BPFISelLowering.cpp
index ff23d3b055d0d5..071fe004806e3e 100644
--- a/llvm/lib/Target/BPF/BPFISelLowering.cpp
+++ b/llvm/lib/Target/BPF/BPFISelLowering.cpp
@@ -402,21 +402,6 @@ SDValue BPFTargetLowering::LowerFormalArguments(
 
 const size_t BPFTargetLowering::MaxArgs = 5;
 
-static void resetRegMaskBit(const TargetRegisterInfo *TRI, uint32_t *RegMask,
-                            MCRegister Reg) {
-  for (MCPhysReg SubReg : TRI->subregs_inclusive(Reg))
-    RegMask[SubReg / 32] &= ~(1u << (SubReg % 32));
-}
-
-static uint32_t *regMaskFromTemplate(const TargetRegisterInfo *TRI,
-                                     MachineFunction &MF,
-                                     const uint32_t *BaseRegMask) {
-  uint32_t *RegMask = MF.allocateRegMask();
-  unsigned RegMaskSize = MachineOperand::getRegMaskSize(TRI->getNumRegs());
-  memcpy(RegMask, BaseRegMask, sizeof(RegMask[0]) * RegMaskSize);
-  return RegMask;
-}
-
 SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
                                      SmallVectorImpl<SDValue> &InVals) const {
   SelectionDAG &DAG = CLI.DAG;
@@ -528,22 +513,6 @@ SDValue BPFTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   for (auto &Reg : RegsToPass)
     Ops.push_back(DAG.getRegister(Reg.first, Reg.second.getValueType()));
 
-  bool HasFastCall =
-      (CLI.CB && isa<CallInst>(CLI.CB) && CLI.CB->hasFnAttr("bpf_fastcall"));
-  const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
-  if (HasFastCall) {
-    uint32_t *RegMask = regMaskFromTemplate(
-        TRI, MF, TRI->getCallPreservedMask(MF, CallingConv::PreserveAll));
-    for (auto const &RegPair : RegsToPass)
-      resetRegMaskBit(TRI, RegMask, RegPair.first);
-    if (!CLI.CB->getType()->isVoidTy())
-      resetRegMaskBit(TRI, RegMask, BPF::R0);
-    Ops.push_back(DAG.getRegisterMask(RegMask));
-  } else {
-    Ops.push_back(
-        DAG.getRegisterMask(TRI->getCallPreservedMask(MF, CLI.CallConv)));
-  }
-
   if (InGlue.getNode())
     Ops.push_back(InGlue);
 
diff --git a/llvm/lib/Target/BPF/BPFInstrInfo.td b/llvm/lib/Target/BPF/BPFInstrInfo.td
index 4baeeb017699d6..2ee630e29790f3 100644
--- a/llvm/lib/Target/BPF/BPFInstrInfo.td
+++ b/llvm/lib/Target/BPF/BPFInstrInfo.td
@@ -677,7 +677,9 @@ let isBranch = 1, isTerminator = 1, hasDelaySlot=0, isBarrier = 1 in {
 }
 
 // Jump and link
-let isCall=1, hasDelaySlot=0, Uses = [R11] in {
+let isCall=1, hasDelaySlot=0, Uses = [R11],
+    // Potentially clobbered registers
+    Defs = [R0, R1, R2, R3, R4, R5] in {
   def JAL  : CALL<"call">;
   def JALX  : CALLX<"callx">;
 }
diff --git a/llvm/lib/Target/BPF/BPFMIPeephole.cpp b/llvm/lib/Target/BPF/BPFMIPeephole.cpp
index 58dad71b920552..f0edf706bd8fd7 100644
--- a/llvm/lib/Target/BPF/BPFMIPeephole.cpp
+++ b/llvm/lib/Target/BPF/BPFMIPeephole.cpp
@@ -24,8 +24,6 @@
 #include "BPFInstrInfo.h"
 #include "BPFTargetMachine.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/LivePhysRegs.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
@@ -321,7 +319,6 @@ struct BPFMIPreEmitPeephole : public MachineFunctionPass {
   bool in16BitRange(int Num);
   bool eliminateRedundantMov();
   bool adjustBranch();
-  bool insertMissingCallerSavedSpills();
 
 public:
 
@@ -336,7 +333,6 @@ struct BPFMIPreEmitPeephole : public MachineFunctionPass {
     Changed = eliminateRedundantMov();
     if (SupportGotol)
       Changed = adjustBranch() || Changed;
-    Changed |= insertMissingCallerSavedSpills();
     return Changed;
   }
 };
@@ -600,88 +596,6 @@ bool BPFMIPreEmitPeephole::adjustBranch() {
   return Changed;
 }
 
-static const unsigned CallerSavedRegs[] = {BPF::R0, BPF::R1, BPF::R2,
-                                           BPF::R3, BPF::R4, BPF::R5};
-
-struct BPFFastCall {
-  MachineInstr *MI;
-  unsigned LiveCallerSavedRegs;
-};
-
-static void collectBPFFastCalls(const TargetRegisterInfo *TRI,
-                                LivePhysRegs &LiveRegs, MachineBasicBlock &BB,
-                                SmallVectorImpl<BPFFastCall> &Calls) {
-  LiveRegs.init(*TRI);
-  LiveRegs.addLiveOuts(BB);
-  Calls.clear();
-  for (MachineInstr &MI : llvm::reverse(BB)) {
-    if (MI.isCall()) {
-      unsigned LiveCallerSavedRegs = 0;
-      for (MCRegister R : CallerSavedRegs) {
-        bool DoSpillFill = !MI.definesRegister(R, TRI) && LiveRegs.contains(R);
-        if (!DoSpillFill)
-          continue;
-        LiveCallerSavedRegs |= 1 << R;
-      }
-      if (LiveCallerSavedRegs)
-        Calls.push_back({&MI, LiveCallerSavedRegs});
-    }
-    LiveRegs.stepBackward(MI);
-  }
-}
-
-static int64_t computeMinFixedObjOffset(MachineFrameInfo &MFI,
-                                        unsigned SlotSize) {
-  int64_t MinFixedObjOffset = 0;
-  // Same logic as in X86FrameLowering::adjustFrameForMsvcCxxEh()
-  for (int I = MFI.getObjectIndexBegin(); I < MFI.getObjectIndexEnd(); ++I) {
-    if (MFI.isDeadObjectIndex(I))
-      continue;
-    MinFixedObjOffset = std::min(MinFixedObjOffset, MFI.getObjectOffset(I));
-  }
-  MinFixedObjOffset -=
-      (SlotSize + MinFixedObjOffset % SlotSize) & (SlotSize - 1);
-  return MinFixedObjOffset;
-}
-
-bool BPFMIPreEmitPeephole::insertMissingCallerSavedSpills() {
-  MachineFrameInfo &MFI = MF->getFrameInfo();
-  SmallVector<BPFFastCall, 8> Calls;
-  LivePhysRegs LiveRegs;
-  const unsigned SlotSize = 8;
-  int64_t MinFixedObjOffset = computeMinFixedObjOffset(MFI, SlotSize);
-  bool Changed = false;
-  for (MachineBasicBlock &BB : *MF) {
-    collectBPFFastCalls(TRI, LiveRegs, BB, Calls);
-    Changed |= !Calls.empty();
-    for (BPFFastCall &Call : Calls) {
-      int64_t CurOffset = MinFixedObjOffset;
-      for (MCRegister Reg : CallerSavedRegs) {
-        if (((1 << Reg) & Call.LiveCallerSavedRegs) == 0)
-          continue;
-        // Allocate stack object
-        CurOffset -= SlotSize;
-        MFI.CreateFixedSpillStackObject(SlotSize, CurOffset);
-        // Generate spill
-        BuildMI(BB, Call.MI->getIterator(), Call.MI->getDebugLoc(),
-                TII->get(BPF::STD))
-            .addReg(Reg)
-            .addReg(BPF::R10)
-            .addImm(CurOffset)
-            .addImm(0);
-        // Generate fill
-        BuildMI(BB, ++Call.MI->getIterator(), Call.MI->getDebugLoc(),
-                TII->get(BPF::LDD))
-            .addReg(Reg)
-            .addReg(BPF::R10)
-            .addImm(CurOffset)
-            .addImm(0);
-      }
-    }
-  }
-  return Changed;
-}
-
 } // end default namespace
 
 INITIALIZE_PASS(BPFMIPreEmitPeephole, "bpf-mi-pemit-peephole",
diff --git a/llvm/lib/Target/BPF/BPFRegisterInfo.cpp b/llvm/lib/Target/BPF/BPFRegisterInfo.cpp
index 69e1318954a973..84af6806abb36c 100644
--- a/llvm/lib/Target/BPF/BPFRegisterInfo.cpp
+++ b/llvm/lib/Target/BPF/BPFRegisterInfo.cpp
@@ -40,17 +40,6 @@ BPFRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   return CSR_SaveList;
 }
 
-const uint32_t *
-BPFRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
-                                      CallingConv::ID CC) const {
-  switch (CC) {
-  default:
-    return CSR_RegMask;
-  case CallingConv::PreserveAll:
-    return CSR_PreserveAll_RegMask;
-  }
-}
-
 BitVector BPFRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
   BitVector Reserved(getNumRegs());
   markSuperRegs(Reserved, BPF::W10); // [W|R]10 is read only frame pointer
diff --git a/llvm/lib/Target/BPF/BPFRegisterInfo.h b/llvm/lib/Target/BPF/BPFRegisterInfo.h
index db868769a1579a..f7dea75ebea6f9 100644
--- a/llvm/lib/Target/BPF/BPFRegisterInfo.h
+++ b/llvm/lib/Target/BPF/BPFRegisterInfo.h
@@ -26,9 +26,6 @@ struct BPFRegisterInfo : public BPFGenRegisterInfo {
 
   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
 
-  const uint32_t *getCallPreservedMask(const MachineFunction &MF,
-                                       CallingConv::ID) const override;
-
   BitVector getReservedRegs(const MachineFunction &MF) const override;
 
   bool eliminateFrameIndex(MachineBasicBlock::iterator MI, int SPAdj,
diff --git a/llvm/test/CodeGen/BPF/bpf-fastcall-1.ll b/llvm/test/CodeGen/BPF/bpf-fastcall-1.ll
deleted file mode 100644
index fd81314a495ef8..00000000000000
--- a/llvm/test/CodeGen/BPF/bpf-fastcall-1.ll
+++ /dev/null
@@ -1,46 +0,0 @@
-; RUN: llc -O2 --march=bpfel %s -o - | FileCheck %s
-
-; Generated from the following C code:
-;
-;   #define __bpf_fastcall __attribute__((bpf_fastcall))
-;
-;   void bar(void) __bpf_fastcall;
-;   void buz(long i, long j, long k);
-;
-;   void foo(long i, long j, long k) {
-;     bar();
-;     buz(i, j, k);
-;   }
-;
-; Using the following command:
-;
-;   clang --target=bpf -emit-llvm -O2 -S -o - t.c
-;
-; (unnecessary attrs removed maually)
-
-; Check that function marked with bpf_fastcall does not clobber R1-R5.
-
-define dso_local void @foo(i64 noundef %i, i64 noundef %j, i64 noundef %k) {
-entry:
-  tail call void @bar() #1
-  tail call void @buz(i64 noundef %i, i64 noundef %j, i64 noundef %k)
-  ret void
-}
-
-; CHECK:      foo:
-; CHECK:      # %bb.0:
-; CHECK-NEXT:   *(u64 *)(r10 - 8) = r1
-; CHECK-NEXT:   *(u64 *)(r10 - 16) = r2
-; CHECK-NEXT:   *(u64 *)(r10 - 24) = r3
-; CHECK-NEXT:   call bar
-; CHECK-NEXT:   r3 = *(u64 *)(r10 - 24)
-; CHECK-NEXT:   r2 = *(u64 *)(r10 - 16)
-; CHECK-NEXT:   r1 = *(u64 *)(r10 - 8)
-; CHECK-NEXT:   call buz
-; CHECK-NEXT:   exit
-
-declare dso_local void @bar() #0
-declare dso_local void @buz(i64 noundef, i64 noundef, i64 noundef)
-
-attributes #0 = { "bpf_fastcall" }
-attributes #1 = { nounwind "bpf_fastcall" }
diff --git a/llvm/test/CodeGen/BPF/bpf-fastcall-2.ll b/llvm/test/CodeGen/BPF/bpf-fastcall-2.ll
deleted file mode 100644
index e3e29cdddca8ea..00000000000000
--- a/llvm/test/CodeGen/BPF/bpf-fastcall-2.ll
+++ /dev/null
@@ -1,68 +0,0 @@
-; RUN: llc -O2 --march=bpfel %s -o - | FileCheck %s
-
-; Generated from the following C code:
-;
-;   #define __bpf_fastcall __attribute__((bpf_fastcall))
-;
-;   void bar(void) __bpf_fastcall;
-;   void buz(long i, long j);
-;
-;   void foo(long i, long j, long k, long l) {
-;     bar();
-;     if (k > 42l)
-;       buz(i, 1);
-;     else
-;       buz(1, j);
-;   }
-;
-; Using the following command:
-;
-;   clang --target=bpf -emit-llvm -O2 -S -o - t.c
-;
-; (unnecessary attrs removed maually)
-
-; Check that function marked with bpf_fastcall does not clobber R1-R5.
-; Use R1 in one branch following call and R2 in another branch following call.
-
-define dso_local void @foo(i64 noundef %i, i64 noundef %j, i64 noundef %k, i64 noundef %l) {
-entry:
-  tail call void @bar() #0
-  %cmp = icmp sgt i64 %k, 42
-  br i1 %cmp, label %if.then, label %if.else
-
-if.then:
-  tail call void @buz(i64 noundef %i, i64 noundef 1)
-  br label %if.end
-
-if.else:
-  tail call void @buz(i64 noundef 1, i64 noundef %j)
-  br label %if.end
-
-if.end:
-  ret void
-}
-
-; CHECK:      foo:                                    # @foo
-; CHECK:      # %bb.0:                                # %entry
-; CHECK-NEXT:   *(u64 *)(r10 - 8) = r1
-; CHECK-NEXT:   *(u64 *)(r10 - 16) = r2
-; CHECK-NEXT:   *(u64 *)(r10 - 24) = r3
-; CHECK-NEXT:   call bar
-; CHECK-NEXT:   r3 = *(u64 *)(r10 - 24)
-; CHECK-NEXT:   r2 = *(u64 *)(r10 - 16)
-; CHECK-NEXT:   r1 = *(u64 *)(r10 - 8)
-; CHECK-NEXT:   r4 = 43
-; CHECK-NEXT:   if r4 s> r3 goto [[ELSE:.*]]
-; CHECK-NEXT: # %bb.1:                                # %if.then
-; CHECK-NEXT:   r2 = 1
-; CHECK-NEXT:   goto [[END:.*]]
-; CHECK-NEXT: [[ELSE]]:                               # %if.else
-; CHECK-NEXT:   r1 = 1
-; CHECK-NEXT: [[END]]:                                # %if.end
-; CHECK-NEXT:   call buz
-; CHECK-NEXT:   exit
-
-declare dso_local void @bar() #0
-declare dso_local void @buz(i64 noundef, i64 noundef)
-
-attributes #0 = { "bpf_fastcall" }
diff --git a/llvm/test/CodeGen/BPF/bpf-fastcall-3.ll b/llvm/test/CodeGen/BPF/bpf-fastcall-3.ll
deleted file mode 100644
index 81ca4e1ac57bc7..00000000000000
--- a/llvm/test/CodeGen/BPF/bpf-fastcall-3.ll
+++ /dev/null
@@ -1,62 +0,0 @@
-; RUN: llc -O2 --march=bpfel %s -o - | FileCheck %s
-
-; Generated from the following C code:
-;
-; #define __bpf_fastcall __attribute__((bpf_fastcall))
-;
-; void quux(void *);
-; void bar(long) __bpf_fastcall;
-; void buz(long i, long j);
-;
-; void foo(long i, long j) {
-;   long k;
-;   bar(i);
-;   bar(i);
-;   buz(i, j);
-;   quux(&k);
-; }
-;
-; Using the following command:
-;
-;   clang --target=bpf -emit-llvm -O2 -S -o - t.c
-;
-; (unnecessary attrs removed maually)
-
-; Check that function marked with bpf_fastcall does not clobber R1-R5.
-; Check that spills/fills wrapping the call use and reuse lowest stack offsets.
-
-define dso_local void @foo(i64 noundef %i, i64 noundef %j) {
-entry:
-  %k = alloca i64, align 8
-  tail call void @bar(i64 noundef %i) #0
-  tail call void @bar(i64 noundef %i) #0
-  tail call void @buz(i64 noundef %i, i64 noundef %j)
-  call void @quux(ptr noundef nonnull %k)
-  ret void
-}
-
-; CHECK:      # %bb.0:
-; CHECK-NEXT:   r3 = r1
-; CHECK-NEXT:   *(u64 *)(r10 - 16) = r2
-; CHECK-NEXT:   *(u64 *)(r10 - 24) = r3
-; CHECK-NEXT:   call bar
-; CHECK-NEXT:   r3 = *(u64 *)(r10 - 24)
-; CHECK-NEXT:   r2 = *(u64 *)(r10 - 16)
-; CHECK-NEXT:   r1 = r3
-; CHECK-NEXT:   *(u64 *)(r10 - 16) = r2
-; CHECK-NEXT:   *(u64 *)(r10 - 24) = r3
-; CHECK-NEXT:   call bar
-; CHECK-NEXT:   r3 = *(u64 *)(r10 - 24)
-; CHECK-NEXT:   r2 = *(u64 *)(r10 - 16)
-; CHECK-NEXT:   r1 = r3
-; CHECK-NEXT:   call buz
-; CHECK-NEXT:   r1 = r10
-; CHECK-NEXT:   r1 += -8
-; CHECK-NEXT:   call quux
-; CHECK-NEXT:   exit
-
-declare dso_local void @bar(i64 noundef) #0
-declare dso_local void @buz(i64 noundef, i64 noundef)
-declare dso_local void @quux(ptr noundef)
-
-attributes #0 = { "bpf_fastcall" }
diff --git a/llvm/test/CodeGen/BPF/bpf-fastcall-regmask-1.ll b/llvm/test/CodeGen/BPF/bpf-fastcall-regmask-1.ll
deleted file mode 100644
index 857d2f000d1d5a..00000000000000
--- a/llvm/test/CodeGen/BPF/bpf-fastcall-regmask-1.ll
+++ /dev/null
@@ -1,110 +0,0 @@
-; RUN: llc -O2 --march=bpfel \
-; RUN:   -print-after=stack-slot-coloring %s \
-; RUN:   -o /dev/null 2>&1 | FileCheck %s
-
-; Generated from the following C code:
-;
-;   #define __bpf_fastcall __attribute__((bpf_fastcall))
-;
-;   void bar1(void) __bpf_fastcall;
-;   void buz1(long i, long j, long k);
-;   void foo1(long i, long j, long k) {
-;     bar1();
-;     buz1(i, j, k);
-;   }
-;
-;   long bar2(void) __bpf_fastcall;
-;   void buz2(long i, long j, long k);
-;   void foo2(long i, long j, long k) {
-;     bar2();
-;     buz2(i, j, k);
-;   }
-;
-;   void bar3(long) __bpf_fastcall;
-;   void buz3(long i, long j, long k);
-;   void foo3(long i, long j, long k) {
-;     bar3(i);
-;     buz3(i, j, k);
-;   }
-;
-;   long bar4(long, long) __bpf_fastcall;
-;   void buz4(long i, long j, long k);
-;   void foo4(long i, long j, long k) {
-;     bar4(i, j);
-;     buz4(i, j, k);
-;   }
-;
-; Using the following command:
-;
-;   clang --target=bpf -emit-llvm -O2 -S -o - t.c
-;
-; (unnecessary attrs removed maually)
-
-; Check regmask for calls to functions marked with bpf_fastcall:
-; - void function w/o parameters
-; - non-void function w/o parameters
-; - void function with parameters
-; - non-void function with parameters
-
-declare dso_local void @bar1() #0
-declare dso_local void @buz1(i64 noundef, i64 noundef, i64 noundef)
-define dso_local void @foo1(i64 noundef %i, i64 noundef %j, i64 noundef %k) {
-entry:
-  tail call void @bar1() #1
-  tail call void @buz1(i64 noundef %i, i64 noundef %j, i64 noundef %k)
-  ret void
-}
-
-; CHECK:      JAL @bar1, <regmask $r0 $r1 $r2 $r3 $r4 $r5 $r6 $r7 $r8 $r9 $r10
-; CHECK-SAME:                     $w0 $w1 $w2 $w3 $w4 $w5 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit-def $r11
-; CHECK:      JAL @buz1, <regmask $r6 $r7 $r8 $r9 $r10 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit $r2, implicit $r3, implicit-def $r11
-
-declare dso_local i64 @bar2() #0
-declare dso_local void @buz2(i64 noundef, i64 noundef, i64 noundef)
-define dso_local void @foo2(i64 noundef %i, i64 noundef %j, i64 noundef %k) {
-entry:
-  tail call i64 @bar2() #1
-  tail call void @buz2(i64 noundef %i, i64 noundef %j, i64 noundef %k)
-  ret void
-}
-
-; CHECK:      JAL @bar2, <regmask $r1 $r2 $r3 $r4 $r5 $r6 $r7 $r8 $r9 $r10
-; CHECK-SAME:                     $w1 $w2 $w3 $w4 $w5 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit-def $r11, implicit-def dead $r0
-; CHECK:      JAL @buz2, <regmask $r6 $r7 $r8 $r9 $r10 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit $r2, implicit $r3, implicit-def $r11
-
-declare dso_local void @bar3(i64) #0
-declare dso_local void @buz3(i64 noundef, i64 noundef, i64 noundef)
-define dso_local void @foo3(i64 noundef %i, i64 noundef %j, i64 noundef %k) {
-entry:
-  tail call void @bar3(i64 noundef %i) #1
-  tail call void @buz3(i64 noundef %i, i64 noundef %j, i64 noundef %k)
-  ret void
-}
-
-; CHECK:      JAL @bar3, <regmask $r0 $r2 $r3 $r4 $r5 $r6 $r7 $r8 $r9 $r10
-; CHECK-SAME:                     $w0 $w2 $w3 $w4 $w5 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit-def $r11
-; CHECK:      JAL @buz3, <regmask $r6 $r7 $r8 $r9 $r10 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit $r2, implicit $r3, implicit-def $r11
-
-declare dso_local i64 @bar4(i64 noundef, i64 noundef) #0
-declare dso_local void @buz4(i64 noundef, i64 noundef, i64 noundef)
-define dso_local void @foo4(i64 noundef %i, i64 noundef %j, i64 noundef %k) {
-entry:
-  tail call i64 @bar4(i64 noundef %i, i64 noundef %j) #1
-  tail call void @buz4(i64 noundef %i, i64 noundef %j, i64 noundef %k)
-  ret void
-}
-
-; CHECK:      JAL @bar4, <regmask $r3 $r4 $r5 $r6 $r7 $r8 $r9 $r10
-; CHECK-SAME:                     $w3 $w4 $w5 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit $r2, implicit-def $r11, implicit-def dead $r0
-; CHECK:      JAL @buz4, <regmask $r6 $r7 $r8 $r9 $r10 $w6 $w7 $w8 $w9 $w10>
-; CHECK-SAME:          , implicit $r11, implicit $r1, implicit $r2, implicit $r3, implicit-def $r11
-
-attributes #0 = { "bpf_fastcall" }
-attributes #1 = { nounwind "bpf_fastcall" }