reflect, runtime: add reflect support for regabi on s390x

This adds the regabi support needed for reflect calls
makeFuncSub and methodValueCall. Also, It add's archFloat32FromReg
and archFloat32ToReg.

Update #40724

Change-Id: Ic4b9e30c82f292a24fd2c2b9796cd80a58cecf77
Reviewed-on: https://go-review.googlesource.com/c/go/+/719480
Reviewed-by: Vishwanatha HD <vishwanatha.hd@ibm.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This commit is contained in:
Srinivas Pokala 2025-11-11 05:07:49 +01:00 committed by Keith Randall
parent e92d2964fa
commit 2a185fae7e
5 changed files with 104 additions and 16 deletions

View file

@ -5,34 +5,82 @@
#include "textflag.h"
#include "funcdata.h"
// The frames of each of the two functions below contain two locals, at offsets
// that are known to the runtime.
//
// The first local is a bool called retValid with a whole pointer-word reserved
// for it on the stack. The purpose of this word is so that the runtime knows
// whether the stack-allocated return space contains valid values for stack
// scanning.
//
// The second local is an abi.RegArgs value whose offset is also known to the
// runtime, so that a stack map for it can be constructed, since it contains
// pointers visible to the GC.
#define LOCAL_RETVALID 40
#define LOCAL_REGARGS 48
// The frame size of the functions below is
// 32 (args of callReflect/callMethod) + 8 (bool + padding) + 264 (abi.RegArgs) = 304.
// makeFuncStub is the code half of the function returned by MakeFunc.
// See the comment on the declaration of makeFuncStub in makefunc.go
// for more details.
// No arg size here, runtime pulls arg map out of the func value.
TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$40
TEXT ·makeFuncStub(SB),(NOSPLIT|WRAPPER),$304
NO_LOCAL_POINTERS
ADD $LOCAL_REGARGS, R15, R10 // spillArgs using R10
BL runtime·spillArgs(SB)
MOVD R12, 32(R15) // save context reg R12 > args of moveMakeFuncArgPtrs < LOCAL_REGARGS
#ifdef GOEXPERIMENT_regabiargs
MOVD R12, R2
MOVD R10, R3
#else
MOVD R12, 8(R15)
MOVD $argframe+0(FP), R3
MOVD R3, 16(R15)
MOVB $0, 40(R15)
ADD $40, R15, R3
MOVD R3, 24(R15)
MOVD $0, 32(R15)
MOVD R10, 16(R15)
#endif
BL ·moveMakeFuncArgPtrs<ABIInternal>(SB)
MOVD 32(R15), R12 // restore context reg R12
MOVD R12, 8(R15)
MOVD $argframe+0(FP), R1
MOVD R1, 16(R15)
MOVB $0, LOCAL_RETVALID(R15)
ADD $LOCAL_RETVALID, R15, R1
MOVD R1, 24(R15)
ADD $LOCAL_REGARGS, R15, R1
MOVD R1, 32(R15)
BL ·callReflect(SB)
ADD $LOCAL_REGARGS, R15, R10 // unspillArgs using R10
BL runtime·unspillArgs(SB)
RET
// methodValueCall is the code half of the function returned by makeMethodValue.
// See the comment on the declaration of methodValueCall in makefunc.go
// for more details.
// No arg size here; runtime pulls arg map out of the func value.
TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$40
TEXT ·methodValueCall(SB),(NOSPLIT|WRAPPER),$304
NO_LOCAL_POINTERS
ADD $LOCAL_REGARGS, R15, R10 // spillArgs using R10
BL runtime·spillArgs(SB)
MOVD R12, 32(R15) // save context reg R12 > args of moveMakeFuncArgPtrs < LOCAL_REGARGS
#ifdef GOEXPERIMENT_regabiargs
MOVD R12, R2
MOVD R10, R3
#else
MOVD R12, 8(R15)
MOVD $argframe+0(FP), R3
MOVD R3, 16(R15)
MOVB $0, 40(R15)
ADD $40, R15, R3
MOVD R3, 24(R15)
MOVD $0, 32(R15)
MOVD R10, 16(R15)
#endif
BL ·moveMakeFuncArgPtrs<ABIInternal>(SB)
MOVD 32(R15), R12 // restore context reg R12
MOVD R12, 8(R15)
MOVD $argframe+0(FP), R1
MOVD R1, 16(R15)
MOVB $0, LOCAL_RETVALID(R15)
ADD $LOCAL_RETVALID, R15, R1
MOVD R1, 24(R15)
ADD $LOCAL_REGARGS, R15, R1
MOVD R1, 32(R15)
BL ·callMethod(SB)
ADD $LOCAL_REGARGS, R15, R10 // unspillArgs using R10
BL runtime·unspillArgs(SB)
RET

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@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !ppc64 && !ppc64le && !riscv64
//go:build !ppc64 && !ppc64le && !riscv64 && !s390x
package reflect

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@ -0,0 +1,30 @@
// Copyright 2025 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build s390x
#include "textflag.h"
// On s390x, the float32 becomes a float64
// when loaded in a register, different from
// other platforms. These functions are
// needed to ensure correct conversions on s390x.
// Convert float32->uint64
TEXT ·archFloat32ToReg(SB),NOSPLIT,$0-16
FMOVS val+0(FP), F1
FMOVD F1, ret+8(FP)
RET
// Convert uint64->float32
TEXT ·archFloat32FromReg(SB),NOSPLIT,$0-12
FMOVD reg+0(FP), F1
// Normally a float64->float32 conversion
// would need rounding, but that is not needed
// here since the uint64 was originally converted
// from float32, and should be avoided to
// preserve SNaN values.
FMOVS F1, ret+8(FP)
RET

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@ -0,0 +1,10 @@
// Copyright 2025 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build s390x
package reflect
func archFloat32FromReg(reg uint64) float32
func archFloat32ToReg(val float32) uint64

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@ -234,7 +234,7 @@ func (frame *stkframe) getStackMap(debug bool) (locals, args bitvector, objs []s
}
// stack objects.
if (GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "loong64" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64") &&
if (GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "loong64" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64" || GOARCH == "s390x") &&
unsafe.Sizeof(abi.RegArgs{}) > 0 && isReflect {
// For reflect.makeFuncStub and reflect.methodValueCall,
// we need to fake the stack object record.