From: Keith Randall <khr@golang.org>
Date: Wed, 18 Jun 2025 23:55:06 +0000 (-0700)
Subject: cmd/compile: move s390x over to new bounds check strategy
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=7a1679d7ae32dd8a01bd355413ee77ba517f5f43;p=gostls13.git

cmd/compile: move s390x over to new bounds check strategy

Change-Id: I86ed1a60165b729bb88a8a418da0ea1b59b3dc10
Reviewed-on: https://go-review.googlesource.com/c/go/+/682499
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Munday <mikemndy@gmail.com>
Reviewed-by: Mark Freeman <mark@golang.org>
---

diff --git a/src/cmd/compile/internal/s390x/ssa.go b/src/cmd/compile/internal/s390x/ssa.go
index ad66bfb5d8..86efde4fa0 100644
--- a/src/cmd/compile/internal/s390x/ssa.go
+++ b/src/cmd/compile/internal/s390x/ssa.go
@@ -15,6 +15,7 @@ import (
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
 	"cmd/internal/obj/s390x"
+	"internal/abi"
 )
 
 // ssaMarkMoves marks any MOVXconst ops that need to avoid clobbering flags.
@@ -573,12 +574,92 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p.To.Name = obj.NAME_EXTERN
 		// AuxInt encodes how many buffer entries we need.
 		p.To.Sym = ir.Syms.GCWriteBarrier[v.AuxInt-1]
-	case ssa.OpS390XLoweredPanicBoundsA, ssa.OpS390XLoweredPanicBoundsB, ssa.OpS390XLoweredPanicBoundsC:
-		p := s.Prog(obj.ACALL)
+
+	case ssa.OpS390XLoweredPanicBoundsRR, ssa.OpS390XLoweredPanicBoundsRC, ssa.OpS390XLoweredPanicBoundsCR, ssa.OpS390XLoweredPanicBoundsCC:
+		// 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.OpS390XLoweredPanicBoundsRR:
+			xIsReg = true
+			xVal = int(v.Args[0].Reg() - s390x.REG_R0)
+			yIsReg = true
+			yVal = int(v.Args[1].Reg() - s390x.REG_R0)
+		case ssa.OpS390XLoweredPanicBoundsRC:
+			xIsReg = true
+			xVal = int(v.Args[0].Reg() - s390x.REG_R0)
+			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(s390x.AMOVD)
+				p.From.Type = obj.TYPE_CONST
+				p.From.Offset = c
+				p.To.Type = obj.TYPE_REG
+				p.To.Reg = s390x.REG_R0 + int16(yVal)
+			}
+		case ssa.OpS390XLoweredPanicBoundsCR:
+			yIsReg = true
+			yVal := int(v.Args[0].Reg() - s390x.REG_R0)
+			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(s390x.AMOVD)
+				p.From.Type = obj.TYPE_CONST
+				p.From.Offset = c
+				p.To.Type = obj.TYPE_REG
+				p.To.Reg = s390x.REG_R0 + int16(xVal)
+			}
+		case ssa.OpS390XLoweredPanicBoundsCC:
+			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(s390x.AMOVD)
+				p.From.Type = obj.TYPE_CONST
+				p.From.Offset = c
+				p.To.Type = obj.TYPE_REG
+				p.To.Reg = s390x.REG_R0 + 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(s390x.AMOVD)
+				p.From.Type = obj.TYPE_CONST
+				p.From.Offset = c
+				p.To.Type = obj.TYPE_REG
+				p.To.Reg = s390x.REG_R0 + 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.OpS390XFLOGR, ssa.OpS390XPOPCNT,
 		ssa.OpS390XNEG, ssa.OpS390XNEGW,
 		ssa.OpS390XMOVWBR, ssa.OpS390XMOVDBR:
diff --git a/src/cmd/compile/internal/ssa/_gen/S390X.rules b/src/cmd/compile/internal/ssa/_gen/S390X.rules
index 80e12f8e29..664bf4a89c 100644
--- a/src/cmd/compile/internal/ssa/_gen/S390X.rules
+++ b/src/cmd/compile/internal/ssa/_gen/S390X.rules
@@ -458,9 +458,11 @@
 // Write barrier.
 (WB ...) => (LoweredWB ...)
 
-(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)
 
 // ***************************
 // Above: lowering rules
diff --git a/src/cmd/compile/internal/ssa/_gen/S390XOps.go b/src/cmd/compile/internal/ssa/_gen/S390XOps.go
index 38fb3cb074..c002d5bcc3 100644
--- a/src/cmd/compile/internal/ssa/_gen/S390XOps.go
+++ b/src/cmd/compile/internal/ssa/_gen/S390XOps.go
@@ -114,6 +114,7 @@ func init() {
 		sb  = buildReg("SB")
 		r0  = buildReg("R0")
 		tmp = buildReg("R11") // R11 is used as a temporary in a small number of instructions.
+		lr  = buildReg("R14")
 
 		// R10 is reserved by the assembler.
 		gp   = buildReg("R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12 R14")
@@ -518,12 +519,15 @@ func init() {
 		// Returns a pointer to a write barrier buffer in R9.
 		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ gpg) | buildReg("R14") | r1, outputs: []regMask{r9}}, clobberFlags: true, aux: "Int64"},
 
-		// 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{r2, r3}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in generic.go).
-		{name: "LoweredPanicBoundsB", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r1, r2}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in generic.go).
-		{name: "LoweredPanicBoundsC", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r0, r1}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in generic.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{gp &^ lr, gp &^ lr}}, typ: "Mem", call: true}, // arg0=x, arg1=y, arg2=mem, returns memory.
+		{name: "LoweredPanicBoundsRC", argLength: 2, aux: "PanicBoundsC", reg: regInfo{inputs: []regMask{gp &^ lr}}, typ: "Mem", call: true},    // arg0=x, arg1=mem, returns memory.
+		{name: "LoweredPanicBoundsCR", argLength: 2, aux: "PanicBoundsC", reg: regInfo{inputs: []regMask{gp &^ lr}}, 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.
 
 		// Constant condition code values. The condition code can be 0, 1, 2 or 3.
 		{name: "FlagEQ"}, // CC=0 (equal)
diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
index 38fd3f6a79..b9c5b1f77c 100644
--- a/src/cmd/compile/internal/ssa/opGen.go
+++ b/src/cmd/compile/internal/ssa/opGen.go
@@ -2843,9 +2843,10 @@ const (
 	OpS390XLoweredRound32F
 	OpS390XLoweredRound64F
 	OpS390XLoweredWB
-	OpS390XLoweredPanicBoundsA
-	OpS390XLoweredPanicBoundsB
-	OpS390XLoweredPanicBoundsC
+	OpS390XLoweredPanicBoundsRR
+	OpS390XLoweredPanicBoundsRC
+	OpS390XLoweredPanicBoundsCR
+	OpS390XLoweredPanicBoundsCC
 	OpS390XFlagEQ
 	OpS390XFlagLT
 	OpS390XFlagGT
@@ -38525,41 +38526,46 @@ var opcodeTable = [...]opInfo{
 		},
 	},
 	{
-		name:    "LoweredPanicBoundsA",
+		name:    "LoweredPanicBoundsRR",
 		auxType: auxInt64,
 		argLen:  3,
 		call:    true,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 4}, // R2
-				{1, 8}, // R3
+				{0, 7167}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12
+				{1, 7167}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12
 			},
 		},
 	},
 	{
-		name:    "LoweredPanicBoundsB",
-		auxType: auxInt64,
-		argLen:  3,
+		name:    "LoweredPanicBoundsRC",
+		auxType: auxPanicBoundsC,
+		argLen:  2,
 		call:    true,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 2}, // R1
-				{1, 4}, // R2
+				{0, 7167}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12
 			},
 		},
 	},
 	{
-		name:    "LoweredPanicBoundsC",
-		auxType: auxInt64,
-		argLen:  3,
+		name:    "LoweredPanicBoundsCR",
+		auxType: auxPanicBoundsC,
+		argLen:  2,
 		call:    true,
 		reg: regInfo{
 			inputs: []inputInfo{
-				{0, 1}, // R0
-				{1, 2}, // R1
+				{0, 7167}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12
 			},
 		},
 	},
+	{
+		name:    "LoweredPanicBoundsCC",
+		auxType: auxPanicBoundsCC,
+		argLen:  1,
+		call:    true,
+		reg:     regInfo{},
+	},
 	{
 		name:   "FlagEQ",
 		argLen: 0,
diff --git a/src/cmd/compile/internal/ssa/rewriteS390X.go b/src/cmd/compile/internal/ssa/rewriteS390X.go
index a7fde81c47..07dbe7bf7a 100644
--- a/src/cmd/compile/internal/ssa/rewriteS390X.go
+++ b/src/cmd/compile/internal/ssa/rewriteS390X.go
@@ -477,7 +477,8 @@ func rewriteValueS390X(v *Value) bool {
 		v.Op = OpS390XORW
 		return true
 	case OpPanicBounds:
-		return rewriteValueS390X_OpPanicBounds(v)
+		v.Op = OpS390XLoweredPanicBoundsRR
+		return true
 	case OpPopCount16:
 		return rewriteValueS390X_OpPopCount16(v)
 	case OpPopCount32:
@@ -644,6 +645,12 @@ func rewriteValueS390X(v *Value) bool {
 		return rewriteValueS390X_OpS390XLTDBR(v)
 	case OpS390XLTEBR:
 		return rewriteValueS390X_OpS390XLTEBR(v)
+	case OpS390XLoweredPanicBoundsCR:
+		return rewriteValueS390X_OpS390XLoweredPanicBoundsCR(v)
+	case OpS390XLoweredPanicBoundsRC:
+		return rewriteValueS390X_OpS390XLoweredPanicBoundsRC(v)
+	case OpS390XLoweredPanicBoundsRR:
+		return rewriteValueS390X_OpS390XLoweredPanicBoundsRR(v)
 	case OpS390XLoweredRound32F:
 		return rewriteValueS390X_OpS390XLoweredRound32F(v)
 	case OpS390XLoweredRound64F:
@@ -3971,60 +3978,6 @@ func rewriteValueS390X_OpOffPtr(v *Value) bool {
 		return true
 	}
 }
-func rewriteValueS390X_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(OpS390XLoweredPanicBoundsA)
-		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(OpS390XLoweredPanicBoundsB)
-		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(OpS390XLoweredPanicBoundsC)
-		v.AuxInt = int64ToAuxInt(kind)
-		v.AddArg3(x, y, mem)
-		return true
-	}
-	return false
-}
 func rewriteValueS390X_OpPopCount16(v *Value) bool {
 	v_0 := v.Args[0]
 	b := v.Block
@@ -8147,6 +8100,86 @@ func rewriteValueS390X_OpS390XLTEBR(v *Value) bool {
 	}
 	return false
 }
+func rewriteValueS390X_OpS390XLoweredPanicBoundsCR(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 != OpS390XMOVDconst {
+			break
+		}
+		c := auxIntToInt64(v_0.AuxInt)
+		mem := v_1
+		v.reset(OpS390XLoweredPanicBoundsCC)
+		v.AuxInt = int64ToAuxInt(kind)
+		v.Aux = panicBoundsCCToAux(PanicBoundsCC{Cx: p.C, Cy: c})
+		v.AddArg(mem)
+		return true
+	}
+	return false
+}
+func rewriteValueS390X_OpS390XLoweredPanicBoundsRC(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 != OpS390XMOVDconst {
+			break
+		}
+		c := auxIntToInt64(v_0.AuxInt)
+		mem := v_1
+		v.reset(OpS390XLoweredPanicBoundsCC)
+		v.AuxInt = int64ToAuxInt(kind)
+		v.Aux = panicBoundsCCToAux(PanicBoundsCC{Cx: c, Cy: p.C})
+		v.AddArg(mem)
+		return true
+	}
+	return false
+}
+func rewriteValueS390X_OpS390XLoweredPanicBoundsRR(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 != OpS390XMOVDconst {
+			break
+		}
+		c := auxIntToInt64(v_1.AuxInt)
+		mem := v_2
+		v.reset(OpS390XLoweredPanicBoundsRC)
+		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 != OpS390XMOVDconst {
+			break
+		}
+		c := auxIntToInt64(v_0.AuxInt)
+		y := v_1
+		mem := v_2
+		v.reset(OpS390XLoweredPanicBoundsCR)
+		v.AuxInt = int64ToAuxInt(kind)
+		v.Aux = panicBoundsCToAux(PanicBoundsC{C: c})
+		v.AddArg2(y, mem)
+		return true
+	}
+	return false
+}
 func rewriteValueS390X_OpS390XLoweredRound32F(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (LoweredRound32F x:(FMOVSconst))
diff --git a/src/runtime/asm_s390x.s b/src/runtime/asm_s390x.s
index 7fc88009e8..4cc1c0eb10 100644
--- a/src/runtime/asm_s390x.s
+++ b/src/runtime/asm_s390x.s
@@ -892,76 +892,18 @@ TEXT runtime·gcWriteBarrier8<ABIInternal>(SB),NOSPLIT,$0
 	MOVD	$64, R9
 	JMP	gcWriteBarrier<>(SB)
 
-// 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(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicIndex(SB)
-TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicIndexU(SB)
-TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAlen(SB)
-TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAlenU(SB)
-TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAcap(SB)
-TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSliceAcapU(SB)
-TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSliceB(SB)
-TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSliceBU(SB)
-TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16
-	MOVD	R2, x+0(FP)
-	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3Alen(SB)
-TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16
-	MOVD	R2, x+0(FP)
-	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3AlenU(SB)
-TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16
-	MOVD	R2, x+0(FP)
-	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3Acap(SB)
-TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16
-	MOVD	R2, x+0(FP)
-	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSlice3AcapU(SB)
-TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSlice3B(SB)
-TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16
-	MOVD	R1, x+0(FP)
-	MOVD	R2, y+8(FP)
-	JMP	runtime·goPanicSlice3BU(SB)
-TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSlice3C(SB)
-TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16
-	MOVD	R0, x+0(FP)
-	MOVD	R1, y+8(FP)
-	JMP	runtime·goPanicSlice3CU(SB)
-TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16
-	MOVD	R2, x+0(FP)
-	MOVD	R3, y+8(FP)
-	JMP	runtime·goPanicSliceConvert(SB)
+TEXT runtime·panicBounds<ABIInternal>(SB),NOSPLIT,$144-0
+	NO_LOCAL_POINTERS
+	// Save all 16 int registers that could have an index in them.
+	// They may be pointers, but if they are they are dead.
+	STMG	R0, R12, 24(R15)
+	// Note that R10 @ 104 is not needed, it is an assembler temp
+	// skip R13 aka G @ 128
+	// skip R14 aka LR @ 136
+	// skip R15 aka SP @ 144
+
+	MOVD	R14, 8(R15)	// PC immediately after call to panicBounds
+	ADD	$24, R15, R0	// pointer to save area
+	MOVD	R0, 16(R15)
+	CALL	runtime·panicBounds64<ABIInternal>(SB)
+	RET