]> Cypherpunks repositories - gostls13.git/commitdiff
cmd/compile: move ppc64 over to new bounds check strategy
authorKeith Randall <khr@golang.org>
Wed, 18 Jun 2025 23:10:58 +0000 (16:10 -0700)
committerKeith Randall <khr@golang.org>
Tue, 5 Aug 2025 15:59:16 +0000 (08:59 -0700)
Change-Id: I25a9bbc247b2490e7e37ed843386f53a71822146
Reviewed-on: https://go-review.googlesource.com/c/go/+/682498
Reviewed-by: Paul Murphy <paumurph@redhat.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Keith Randall <khr@google.com>
src/cmd/compile/internal/ppc64/ssa.go
src/cmd/compile/internal/ssa/_gen/PPC64.rules
src/cmd/compile/internal/ssa/_gen/PPC64Ops.go
src/cmd/compile/internal/ssa/opGen.go
src/cmd/compile/internal/ssa/rewritePPC64.go
src/runtime/asm_ppc64x.s

index c1f2484bf4482a7f7e21283cf3f7fd09a6f59aa8..1086a9ccbf22dcdc5734511027df36791959c854 100644 (file)
@@ -14,6 +14,7 @@ import (
        "cmd/compile/internal/types"
        "cmd/internal/obj"
        "cmd/internal/obj/ppc64"
+       "internal/abi"
        "internal/buildcfg"
        "math"
        "strings"
@@ -1913,12 +1914,90 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                // AuxInt encodes how many buffer entries we need.
                p.To.Sym = ir.Syms.GCWriteBarrier[v.AuxInt-1]
 
-       case ssa.OpPPC64LoweredPanicBoundsA, ssa.OpPPC64LoweredPanicBoundsB, ssa.OpPPC64LoweredPanicBoundsC:
-               p := s.Prog(obj.ACALL)
+       case ssa.OpPPC64LoweredPanicBoundsRR, ssa.OpPPC64LoweredPanicBoundsRC, ssa.OpPPC64LoweredPanicBoundsCR, ssa.OpPPC64LoweredPanicBoundsCC:
+               // Compute the constant we put in the PCData entry for this call.
+               code, signed := ssa.BoundsKind(v.AuxInt).Code()
+               xIsReg := false
+               yIsReg := false
+               xVal := 0
+               yVal := 0
+               switch v.Op {
+               case ssa.OpPPC64LoweredPanicBoundsRR:
+                       xIsReg = true
+                       xVal = int(v.Args[0].Reg() - ppc64.REG_R3)
+                       yIsReg = true
+                       yVal = int(v.Args[1].Reg() - ppc64.REG_R3)
+               case ssa.OpPPC64LoweredPanicBoundsRC:
+                       xIsReg = true
+                       xVal = int(v.Args[0].Reg() - ppc64.REG_R3)
+                       c := v.Aux.(ssa.PanicBoundsC).C
+                       if c >= 0 && c <= abi.BoundsMaxConst {
+                               yVal = int(c)
+                       } else {
+                               // Move constant to a register
+                               yIsReg = true
+                               if yVal == xVal {
+                                       yVal = 1
+                               }
+                               p := s.Prog(ppc64.AMOVD)
+                               p.From.Type = obj.TYPE_CONST
+                               p.From.Offset = c
+                               p.To.Type = obj.TYPE_REG
+                               p.To.Reg = ppc64.REG_R3 + int16(yVal)
+                       }
+               case ssa.OpPPC64LoweredPanicBoundsCR:
+                       yIsReg = true
+                       yVal := int(v.Args[0].Reg() - ppc64.REG_R3)
+                       c := v.Aux.(ssa.PanicBoundsC).C
+                       if c >= 0 && c <= abi.BoundsMaxConst {
+                               xVal = int(c)
+                       } else {
+                               // Move constant to a register
+                               if xVal == yVal {
+                                       xVal = 1
+                               }
+                               p := s.Prog(ppc64.AMOVD)
+                               p.From.Type = obj.TYPE_CONST
+                               p.From.Offset = c
+                               p.To.Type = obj.TYPE_REG
+                               p.To.Reg = ppc64.REG_R3 + int16(xVal)
+                       }
+               case ssa.OpPPC64LoweredPanicBoundsCC:
+                       c := v.Aux.(ssa.PanicBoundsCC).Cx
+                       if c >= 0 && c <= abi.BoundsMaxConst {
+                               xVal = int(c)
+                       } else {
+                               // Move constant to a register
+                               xIsReg = true
+                               p := s.Prog(ppc64.AMOVD)
+                               p.From.Type = obj.TYPE_CONST
+                               p.From.Offset = c
+                               p.To.Type = obj.TYPE_REG
+                               p.To.Reg = ppc64.REG_R3 + int16(xVal)
+                       }
+                       c = v.Aux.(ssa.PanicBoundsCC).Cy
+                       if c >= 0 && c <= abi.BoundsMaxConst {
+                               yVal = int(c)
+                       } else {
+                               // Move constant to a register
+                               yIsReg = true
+                               yVal = 1
+                               p := s.Prog(ppc64.AMOVD)
+                               p.From.Type = obj.TYPE_CONST
+                               p.From.Offset = c
+                               p.To.Type = obj.TYPE_REG
+                               p.To.Reg = ppc64.REG_R3 + int16(yVal)
+                       }
+               }
+               c := abi.BoundsEncode(code, signed, xIsReg, yIsReg, xVal, yVal)
+
+               p := s.Prog(obj.APCDATA)
+               p.From.SetConst(abi.PCDATA_PanicBounds)
+               p.To.SetConst(int64(c))
+               p = s.Prog(obj.ACALL)
                p.To.Type = obj.TYPE_MEM
                p.To.Name = obj.NAME_EXTERN
-               p.To.Sym = ssagen.BoundsCheckFunc[v.AuxInt]
-               s.UseArgs(16) // space used in callee args area by assembly stubs
+               p.To.Sym = ir.Syms.PanicBounds
 
        case ssa.OpPPC64LoweredNilCheck:
                if buildcfg.GOOS == "aix" {
index 1749811b84903099adbf7e4421948e77ebc5f23e..f5e381ac413fcf12eb04a75109a3ad7139e61372 100644 (file)
 // Publication barrier as intrinsic
 (PubBarrier ...) => (LoweredPubBarrier ...)
 
-(PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
-(PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
-(PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)
+(PanicBounds ...) => (LoweredPanicBoundsRR ...)
+(LoweredPanicBoundsRR [kind] x (MOVDconst [c]) mem) => (LoweredPanicBoundsRC [kind] x {PanicBoundsC{C:c}} mem)
+(LoweredPanicBoundsRR [kind] (MOVDconst [c]) y mem) => (LoweredPanicBoundsCR [kind] {PanicBoundsC{C:c}} y mem)
+(LoweredPanicBoundsRC [kind] {p} (MOVDconst [c]) mem) => (LoweredPanicBoundsCC [kind] {PanicBoundsCC{Cx:c, Cy:p.C}} mem)
+(LoweredPanicBoundsCR [kind] {p} (MOVDconst [c]) mem) => (LoweredPanicBoundsCC [kind] {PanicBoundsCC{Cx:p.C, Cy:c}} mem)
 
 // Optimizations
 // Note that PPC "logical" immediates come in 0:15 and 16:31 unsigned immediate forms,
index 1dae76366b7ec7ff30505ffea7b18e879d233c5f..983e46fb5ec608ca2b93369b909b295dbcf4ad65 100644 (file)
@@ -171,10 +171,7 @@ func init() {
                fpstore     = regInfo{inputs: []regMask{gp | sp | sb, fp}}
                fpstoreidx  = regInfo{inputs: []regMask{gp | sp | sb, gp | sp | sb, fp}}
                callerSave  = regMask(gp | fp | gr | xer)
-               r3          = buildReg("R3")
-               r4          = buildReg("R4")
-               r5          = buildReg("R5")
-               r6          = buildReg("R6")
+               first8      = buildReg("R3 R4 R5 R6 R7 R8 R9 R10")
        )
        ops := []opData{
                {name: "ADD", argLength: 2, reg: gp21, asm: "ADD", commutative: true},                              // arg0 + arg1
@@ -706,12 +703,16 @@ func init() {
                {name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ buildReg("R0 R3 R4 R5 R6 R7 R8 R9 R10 R14 R15 R16 R17 R20 R21 g")) | buildReg("R31"), outputs: []regMask{buildReg("R29")}}, clobberFlags: true, aux: "Int64"},
 
                {name: "LoweredPubBarrier", argLength: 1, asm: "LWSYNC", hasSideEffects: true}, // Do data barrier. arg0=memory
-               // There are three of these functions so that they can have three different register inputs.
-               // When we check 0 <= c <= cap (A), then 0 <= b <= c (B), then 0 <= a <= b (C), we want the
-               // default registers to match so we don't need to copy registers around unnecessarily.
-               {name: "LoweredPanicBoundsA", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r5, r6}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
-               {name: "LoweredPanicBoundsB", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r4, r5}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
-               {name: "LoweredPanicBoundsC", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r3, r4}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
+
+               // LoweredPanicBoundsRR takes x and y, two values that caused a bounds check to fail.
+               // the RC and CR versions are used when one of the arguments is a constant. CC is used
+               // when both are constant (normally both 0, as prove derives the fact that a [0] bounds
+               // failure means the length must have also been 0).
+               // AuxInt contains a report code (see PanicBounds in genericOps.go).
+               {name: "LoweredPanicBoundsRR", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{first8, first8}}, typ: "Mem", call: true}, // arg0=x, arg1=y, arg2=mem, returns memory.
+               {name: "LoweredPanicBoundsRC", argLength: 2, aux: "PanicBoundsC", reg: regInfo{inputs: []regMask{first8}}, typ: "Mem", call: true},  // arg0=x, arg1=mem, returns memory.
+               {name: "LoweredPanicBoundsCR", argLength: 2, aux: "PanicBoundsC", reg: regInfo{inputs: []regMask{first8}}, typ: "Mem", call: true},  // arg0=y, arg1=mem, returns memory.
+               {name: "LoweredPanicBoundsCC", argLength: 1, aux: "PanicBoundsCC", reg: regInfo{}, typ: "Mem", call: true},                          // arg0=mem, returns memory.
 
                // (InvertFlags (CMP a b)) == (CMP b a)
                // So if we want (LessThan (CMP a b)) but we can't do that because a is a constant,
index 60f5278d7b8110f1c5b3c2e0d8c56a39ada6d38b..9cc7c3d771762496bf56bbce46065dbb5deebbc6 100644 (file)
@@ -2453,9 +2453,10 @@ const (
        OpPPC64LoweredAtomicOr32
        OpPPC64LoweredWB
        OpPPC64LoweredPubBarrier
-       OpPPC64LoweredPanicBoundsA
-       OpPPC64LoweredPanicBoundsB
-       OpPPC64LoweredPanicBoundsC
+       OpPPC64LoweredPanicBoundsRR
+       OpPPC64LoweredPanicBoundsRC
+       OpPPC64LoweredPanicBoundsCR
+       OpPPC64LoweredPanicBoundsCC
        OpPPC64InvertFlags
        OpPPC64FlagEQ
        OpPPC64FlagLT
@@ -33022,41 +33023,46 @@ var opcodeTable = [...]opInfo{
                reg:            regInfo{},
        },
        {
-               name:    "LoweredPanicBoundsA",
+               name:    "LoweredPanicBoundsRR",
                auxType: auxInt64,
                argLen:  3,
                call:    true,
                reg: regInfo{
                        inputs: []inputInfo{
-                               {0, 32}, // R5
-                               {1, 64}, // R6
+                               {0, 2040}, // R3 R4 R5 R6 R7 R8 R9 R10
+                               {1, 2040}, // R3 R4 R5 R6 R7 R8 R9 R10
                        },
                },
        },
        {
-               name:    "LoweredPanicBoundsB",
-               auxType: auxInt64,
-               argLen:  3,
+               name:    "LoweredPanicBoundsRC",
+               auxType: auxPanicBoundsC,
+               argLen:  2,
                call:    true,
                reg: regInfo{
                        inputs: []inputInfo{
-                               {0, 16}, // R4
-                               {1, 32}, // R5
+                               {0, 2040}, // R3 R4 R5 R6 R7 R8 R9 R10
                        },
                },
        },
        {
-               name:    "LoweredPanicBoundsC",
-               auxType: auxInt64,
-               argLen:  3,
+               name:    "LoweredPanicBoundsCR",
+               auxType: auxPanicBoundsC,
+               argLen:  2,
                call:    true,
                reg: regInfo{
                        inputs: []inputInfo{
-                               {0, 8},  // R3
-                               {1, 16}, // R4
+                               {0, 2040}, // R3 R4 R5 R6 R7 R8 R9 R10
                        },
                },
        },
+       {
+               name:    "LoweredPanicBoundsCC",
+               auxType: auxPanicBoundsCC,
+               argLen:  1,
+               call:    true,
+               reg:     regInfo{},
+       },
        {
                name:   "InvertFlags",
                argLen: 1,
index e987ae9662884bf1964836ed653c3b8e08743a24..050ace83dea2d71ef35f6c3265d5c8d1a348b8a6 100644 (file)
@@ -540,6 +540,12 @@ func rewriteValuePPC64(v *Value) bool {
                return rewriteValuePPC64_OpPPC64LessEqual(v)
        case OpPPC64LessThan:
                return rewriteValuePPC64_OpPPC64LessThan(v)
+       case OpPPC64LoweredPanicBoundsCR:
+               return rewriteValuePPC64_OpPPC64LoweredPanicBoundsCR(v)
+       case OpPPC64LoweredPanicBoundsRC:
+               return rewriteValuePPC64_OpPPC64LoweredPanicBoundsRC(v)
+       case OpPPC64LoweredPanicBoundsRR:
+               return rewriteValuePPC64_OpPPC64LoweredPanicBoundsRR(v)
        case OpPPC64MFVSRD:
                return rewriteValuePPC64_OpPPC64MFVSRD(v)
        case OpPPC64MOVBZload:
@@ -667,7 +673,8 @@ func rewriteValuePPC64(v *Value) bool {
        case OpPPC64XORconst:
                return rewriteValuePPC64_OpPPC64XORconst(v)
        case OpPanicBounds:
-               return rewriteValuePPC64_OpPanicBounds(v)
+               v.Op = OpPPC64LoweredPanicBoundsRR
+               return true
        case OpPopCount16:
                return rewriteValuePPC64_OpPopCount16(v)
        case OpPopCount32:
@@ -6826,6 +6833,86 @@ func rewriteValuePPC64_OpPPC64LessThan(v *Value) bool {
                return true
        }
 }
+func rewriteValuePPC64_OpPPC64LoweredPanicBoundsCR(v *Value) bool {
+       v_1 := v.Args[1]
+       v_0 := v.Args[0]
+       // match: (LoweredPanicBoundsCR [kind] {p} (MOVDconst [c]) mem)
+       // result: (LoweredPanicBoundsCC [kind] {PanicBoundsCC{Cx:p.C, Cy:c}} mem)
+       for {
+               kind := auxIntToInt64(v.AuxInt)
+               p := auxToPanicBoundsC(v.Aux)
+               if v_0.Op != OpPPC64MOVDconst {
+                       break
+               }
+               c := auxIntToInt64(v_0.AuxInt)
+               mem := v_1
+               v.reset(OpPPC64LoweredPanicBoundsCC)
+               v.AuxInt = int64ToAuxInt(kind)
+               v.Aux = panicBoundsCCToAux(PanicBoundsCC{Cx: p.C, Cy: c})
+               v.AddArg(mem)
+               return true
+       }
+       return false
+}
+func rewriteValuePPC64_OpPPC64LoweredPanicBoundsRC(v *Value) bool {
+       v_1 := v.Args[1]
+       v_0 := v.Args[0]
+       // match: (LoweredPanicBoundsRC [kind] {p} (MOVDconst [c]) mem)
+       // result: (LoweredPanicBoundsCC [kind] {PanicBoundsCC{Cx:c, Cy:p.C}} mem)
+       for {
+               kind := auxIntToInt64(v.AuxInt)
+               p := auxToPanicBoundsC(v.Aux)
+               if v_0.Op != OpPPC64MOVDconst {
+                       break
+               }
+               c := auxIntToInt64(v_0.AuxInt)
+               mem := v_1
+               v.reset(OpPPC64LoweredPanicBoundsCC)
+               v.AuxInt = int64ToAuxInt(kind)
+               v.Aux = panicBoundsCCToAux(PanicBoundsCC{Cx: c, Cy: p.C})
+               v.AddArg(mem)
+               return true
+       }
+       return false
+}
+func rewriteValuePPC64_OpPPC64LoweredPanicBoundsRR(v *Value) bool {
+       v_2 := v.Args[2]
+       v_1 := v.Args[1]
+       v_0 := v.Args[0]
+       // match: (LoweredPanicBoundsRR [kind] x (MOVDconst [c]) mem)
+       // result: (LoweredPanicBoundsRC [kind] x {PanicBoundsC{C:c}} mem)
+       for {
+               kind := auxIntToInt64(v.AuxInt)
+               x := v_0
+               if v_1.Op != OpPPC64MOVDconst {
+                       break
+               }
+               c := auxIntToInt64(v_1.AuxInt)
+               mem := v_2
+               v.reset(OpPPC64LoweredPanicBoundsRC)
+               v.AuxInt = int64ToAuxInt(kind)
+               v.Aux = panicBoundsCToAux(PanicBoundsC{C: c})
+               v.AddArg2(x, mem)
+               return true
+       }
+       // match: (LoweredPanicBoundsRR [kind] (MOVDconst [c]) y mem)
+       // result: (LoweredPanicBoundsCR [kind] {PanicBoundsC{C:c}} y mem)
+       for {
+               kind := auxIntToInt64(v.AuxInt)
+               if v_0.Op != OpPPC64MOVDconst {
+                       break
+               }
+               c := auxIntToInt64(v_0.AuxInt)
+               y := v_1
+               mem := v_2
+               v.reset(OpPPC64LoweredPanicBoundsCR)
+               v.AuxInt = int64ToAuxInt(kind)
+               v.Aux = panicBoundsCToAux(PanicBoundsC{C: c})
+               v.AddArg2(y, mem)
+               return true
+       }
+       return false
+}
 func rewriteValuePPC64_OpPPC64MFVSRD(v *Value) bool {
        v_0 := v.Args[0]
        b := v.Block
@@ -12981,60 +13068,6 @@ func rewriteValuePPC64_OpPPC64XORconst(v *Value) bool {
        }
        return false
 }
-func rewriteValuePPC64_OpPanicBounds(v *Value) bool {
-       v_2 := v.Args[2]
-       v_1 := v.Args[1]
-       v_0 := v.Args[0]
-       // match: (PanicBounds [kind] x y mem)
-       // cond: boundsABI(kind) == 0
-       // result: (LoweredPanicBoundsA [kind] x y mem)
-       for {
-               kind := auxIntToInt64(v.AuxInt)
-               x := v_0
-               y := v_1
-               mem := v_2
-               if !(boundsABI(kind) == 0) {
-                       break
-               }
-               v.reset(OpPPC64LoweredPanicBoundsA)
-               v.AuxInt = int64ToAuxInt(kind)
-               v.AddArg3(x, y, mem)
-               return true
-       }
-       // match: (PanicBounds [kind] x y mem)
-       // cond: boundsABI(kind) == 1
-       // result: (LoweredPanicBoundsB [kind] x y mem)
-       for {
-               kind := auxIntToInt64(v.AuxInt)
-               x := v_0
-               y := v_1
-               mem := v_2
-               if !(boundsABI(kind) == 1) {
-                       break
-               }
-               v.reset(OpPPC64LoweredPanicBoundsB)
-               v.AuxInt = int64ToAuxInt(kind)
-               v.AddArg3(x, y, mem)
-               return true
-       }
-       // match: (PanicBounds [kind] x y mem)
-       // cond: boundsABI(kind) == 2
-       // result: (LoweredPanicBoundsC [kind] x y mem)
-       for {
-               kind := auxIntToInt64(v.AuxInt)
-               x := v_0
-               y := v_1
-               mem := v_2
-               if !(boundsABI(kind) == 2) {
-                       break
-               }
-               v.reset(OpPPC64LoweredPanicBoundsC)
-               v.AuxInt = int64ToAuxInt(kind)
-               v.AddArg3(x, y, mem)
-               return true
-       }
-       return false
-}
 func rewriteValuePPC64_OpPopCount16(v *Value) bool {
        v_0 := v.Args[0]
        b := v.Block
index 96c87afac8c92ff5584f10381cb5a5ce11f8d436..ecfc7c167100e3f6ac5fe96c86b7e6db258fadfb 100644 (file)
@@ -1349,67 +1349,30 @@ TEXT runtime·debugCallPanicked(SB),NOSPLIT,$32-16
        TW      $31, R0, R0
        RET
 #endif
-// Note: these functions use a special calling convention to save generated code space.
-// Arguments are passed in registers, but the space for those arguments are allocated
-// in the caller's stack frame. These stubs write the args into that stack space and
-// then tail call to the corresponding runtime handler.
-// The tail call makes these stubs disappear in backtraces.
-TEXT runtime·panicIndex<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicIndex<ABIInternal>(SB)
-TEXT runtime·panicIndexU<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicIndexU<ABIInternal>(SB)
-TEXT runtime·panicSliceAlen<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSliceAlen<ABIInternal>(SB)
-TEXT runtime·panicSliceAlenU<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSliceAlenU<ABIInternal>(SB)
-TEXT runtime·panicSliceAcap<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSliceAcap<ABIInternal>(SB)
-TEXT runtime·panicSliceAcapU<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSliceAcapU<ABIInternal>(SB)
-TEXT runtime·panicSliceB<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicSliceB<ABIInternal>(SB)
-TEXT runtime·panicSliceBU<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicSliceBU<ABIInternal>(SB)
-TEXT runtime·panicSlice3Alen<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R5, R3
-       MOVD    R6, R4
-       JMP     runtime·goPanicSlice3Alen<ABIInternal>(SB)
-TEXT runtime·panicSlice3AlenU<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R5, R3
-       MOVD    R6, R4
-       JMP     runtime·goPanicSlice3AlenU<ABIInternal>(SB)
-TEXT runtime·panicSlice3Acap<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R5, R3
-       MOVD    R6, R4
-       JMP     runtime·goPanicSlice3Acap<ABIInternal>(SB)
-TEXT runtime·panicSlice3AcapU<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R5, R3
-       MOVD    R6, R4
-       JMP     runtime·goPanicSlice3AcapU<ABIInternal>(SB)
-TEXT runtime·panicSlice3B<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSlice3B<ABIInternal>(SB)
-TEXT runtime·panicSlice3BU<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R4, R3
-       MOVD    R5, R4
-       JMP     runtime·goPanicSlice3BU<ABIInternal>(SB)
-TEXT runtime·panicSlice3C<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicSlice3C<ABIInternal>(SB)
-TEXT runtime·panicSlice3CU<ABIInternal>(SB),NOSPLIT,$0-16
-       JMP     runtime·goPanicSlice3CU<ABIInternal>(SB)
-TEXT runtime·panicSliceConvert<ABIInternal>(SB),NOSPLIT,$0-16
-       MOVD    R5, R3
-       MOVD    R6, R4
-       JMP     runtime·goPanicSliceConvert<ABIInternal>(SB)
+
+TEXT runtime·panicBounds<ABIInternal>(SB),NOSPLIT,$104-0
+       // Note: frame size is 16 bytes larger than necessary
+       // in order to pacify vet. Vet doesn't understand ppc64
+       // layout properly.
+       NO_LOCAL_POINTERS
+       // Save all 8 int registers that could have an index in them.
+       // They may be pointers, but if they are they are dead.
+       // Skip R0 aka ZERO, R1 aka SP, R2 aka SB
+       MOVD    R3, 48(R1)
+       MOVD    R4, 56(R1)
+       MOVD    R5, 64(R1)
+       MOVD    R6, 72(R1)
+       MOVD    R7, 80(R1)
+       MOVD    R8, 88(R1)
+       MOVD    R9, 96(R1)
+       MOVD    R10, 104(R1)
+       // Note: we only save 8 reigsters to keep under nosplit stack limit
+       // Also, R11 is clobbered in dynamic linking situations
+
+       MOVD    LR, R3          // PC immediately after call to panicBounds
+       ADD     $48, R1, R4     // pointer to save area
+       CALL    runtime·panicBounds64<ABIInternal>(SB)
+       RET
 
 // These functions are used when internal linking cgo with external
 // objects compiled with the -Os on gcc. They reduce prologue/epilogue