// Copyright 2023 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.
// Macros for transitioning from the host ABI to Go ABI
//
// On PPC64/ELFv2 targets, the following registers are callee
// saved when called from C. They must be preserved before
// calling into Go which does not preserve any of them.
//
// R14-R31
// CR2-4
// VR20-31
// F14-F31
//
// xcoff(aix) and ELFv1 are similar, but may only require a
// subset of these.
//
// These macros assume a 16 byte aligned stack pointer. This
// is required by ELFv1, ELFv2, and AIX PPC64.
#define SAVE_GPR_SIZE (18*8)
#define SAVE_GPR(offset) \
MOVD R14, (offset+8*0)(R1) \
MOVD R15, (offset+8*1)(R1) \
MOVD R16, (offset+8*2)(R1) \
MOVD R17, (offset+8*3)(R1) \
MOVD R18, (offset+8*4)(R1) \
MOVD R19, (offset+8*5)(R1) \
MOVD R20, (offset+8*6)(R1) \
MOVD R21, (offset+8*7)(R1) \
MOVD R22, (offset+8*8)(R1) \
MOVD R23, (offset+8*9)(R1) \
MOVD R24, (offset+8*10)(R1) \
MOVD R25, (offset+8*11)(R1) \
MOVD R26, (offset+8*12)(R1) \
MOVD R27, (offset+8*13)(R1) \
MOVD R28, (offset+8*14)(R1) \
MOVD R29, (offset+8*15)(R1) \
MOVD g, (offset+8*16)(R1) \
MOVD R31, (offset+8*17)(R1)
#define RESTORE_GPR(offset) \
MOVD (offset+8*0)(R1), R14 \
MOVD (offset+8*1)(R1), R15 \
MOVD (offset+8*2)(R1), R16 \
MOVD (offset+8*3)(R1), R17 \
MOVD (offset+8*4)(R1), R18 \
MOVD (offset+8*5)(R1), R19 \
MOVD (offset+8*6)(R1), R20 \
MOVD (offset+8*7)(R1), R21 \
MOVD (offset+8*8)(R1), R22 \
MOVD (offset+8*9)(R1), R23 \
MOVD (offset+8*10)(R1), R24 \
MOVD (offset+8*11)(R1), R25 \
MOVD (offset+8*12)(R1), R26 \
MOVD (offset+8*13)(R1), R27 \
MOVD (offset+8*14)(R1), R28 \
MOVD (offset+8*15)(R1), R29 \
MOVD (offset+8*16)(R1), g \
MOVD (offset+8*17)(R1), R31
#define SAVE_FPR_SIZE (18*8)
#define SAVE_FPR(offset) \
FMOVD F14, (offset+8*0)(R1) \
FMOVD F15, (offset+8*1)(R1) \
FMOVD F16, (offset+8*2)(R1) \
FMOVD F17, (offset+8*3)(R1) \
FMOVD F18, (offset+8*4)(R1) \
FMOVD F19, (offset+8*5)(R1) \
FMOVD F20, (offset+8*6)(R1) \
FMOVD F21, (offset+8*7)(R1) \
FMOVD F22, (offset+8*8)(R1) \
FMOVD F23, (offset+8*9)(R1) \
FMOVD F24, (offset+8*10)(R1) \
FMOVD F25, (offset+8*11)(R1) \
FMOVD F26, (offset+8*12)(R1) \
FMOVD F27, (offset+8*13)(R1) \
FMOVD F28, (offset+8*14)(R1) \
FMOVD F29, (offset+8*15)(R1) \
FMOVD F30, (offset+8*16)(R1) \
FMOVD F31, (offset+8*17)(R1)
#define RESTORE_FPR(offset) \
FMOVD (offset+8*0)(R1), F14 \
FMOVD (offset+8*1)(R1), F15 \
FMOVD (offset+8*2)(R1), F16 \
FMOVD (offset+8*3)(R1), F17 \
FMOVD (offset+8*4)(R1), F18 \
FMOVD (offset+8*5)(R1), F19 \
FMOVD (offset+8*6)(R1), F20 \
FMOVD (offset+8*7)(R1), F21 \
FMOVD (offset+8*8)(R1), F22 \
FMOVD (offset+8*9)(R1), F23 \
FMOVD (offset+8*10)(R1), F24 \
FMOVD (offset+8*11)(R1), F25 \
FMOVD (offset+8*12)(R1), F26 \
FMOVD (offset+8*13)(R1), F27 \
FMOVD (offset+8*14)(R1), F28 \
FMOVD (offset+8*15)(R1), F29 \
FMOVD (offset+8*16)(R1), F30 \
FMOVD (offset+8*17)(R1), F31
// Save and restore VR20-31 (aka VSR56-63). These
// macros must point to a 16B aligned offset.
#define SAVE_VR_SIZE (12*16)
#define SAVE_VR(offset, rtmp) \
MOVD $(offset+16*0), rtmp \
STVX V20, (rtmp)(R1) \
MOVD $(offset+16*1), rtmp \
STVX V21, (rtmp)(R1) \
MOVD $(offset+16*2), rtmp \
STVX V22, (rtmp)(R1) \
MOVD $(offset+16*3), rtmp \
STVX V23, (rtmp)(R1) \
MOVD $(offset+16*4), rtmp \
STVX V24, (rtmp)(R1) \
MOVD $(offset+16*5), rtmp \
STVX V25, (rtmp)(R1) \
MOVD $(offset+16*6), rtmp \
STVX V26, (rtmp)(R1) \
MOVD $(offset+16*7), rtmp \
STVX V27, (rtmp)(R1) \
MOVD $(offset+16*8), rtmp \
STVX V28, (rtmp)(R1) \
MOVD $(offset+16*9), rtmp \
STVX V29, (rtmp)(R1) \
MOVD $(offset+16*10), rtmp \
STVX V30, (rtmp)(R1) \
MOVD $(offset+16*11), rtmp \
STVX V31, (rtmp)(R1)
#define RESTORE_VR(offset, rtmp) \
MOVD $(offset+16*0), rtmp \
LVX (rtmp)(R1), V20 \
MOVD $(offset+16*1), rtmp \
LVX (rtmp)(R1), V21 \
MOVD $(offset+16*2), rtmp \
LVX (rtmp)(R1), V22 \
MOVD $(offset+16*3), rtmp \
LVX (rtmp)(R1), V23 \
MOVD $(offset+16*4), rtmp \
LVX (rtmp)(R1), V24 \
MOVD $(offset+16*5), rtmp \
LVX (rtmp)(R1), V25 \
MOVD $(offset+16*6), rtmp \
LVX (rtmp)(R1), V26 \
MOVD $(offset+16*7), rtmp \
LVX (rtmp)(R1), V27 \
MOVD $(offset+16*8), rtmp \
LVX (rtmp)(R1), V28 \
MOVD $(offset+16*9), rtmp \
LVX (rtmp)(R1), V29 \
MOVD $(offset+16*10), rtmp \
LVX (rtmp)(R1), V30 \
MOVD $(offset+16*11), rtmp \
LVX (rtmp)(R1), V31
// LR and CR are saved in the caller's frame. The callee must
// make space for all other callee-save registers.
#define SAVE_ALL_REG_SIZE (SAVE_GPR_SIZE+SAVE_FPR_SIZE+SAVE_VR_SIZE)
// Stack a frame and save all callee-save registers following the
// host OS's ABI. Fortunately, this is identical for AIX, ELFv1, and
// ELFv2. All host ABIs require the stack pointer to maintain 16 byte
// alignment, and save the callee-save registers in the same places.
//
// To restate, R1 is assumed to be aligned when this macro is used.
// This assumes the caller's frame is compliant with the host ABI.
// CR and LR are saved into the caller's frame per the host ABI.
// R0 is initialized to $0 as expected by Go.
#define STACK_AND_SAVE_HOST_TO_GO_ABI(extra) \
MOVD LR, R0 \
MOVD R0, 16(R1) \
MOVW CR, R0 \
MOVD R0, 8(R1) \
MOVDU R1, -(extra)-FIXED_FRAME-SAVE_ALL_REG_SIZE(R1) \
SAVE_GPR(extra+FIXED_FRAME) \
SAVE_FPR(extra+FIXED_FRAME+SAVE_GPR_SIZE) \
SAVE_VR(extra+FIXED_FRAME+SAVE_GPR_SIZE+SAVE_FPR_SIZE, R0) \
MOVD $0, R0
// This unstacks the frame, restoring all callee-save registers
// as saved by STACK_AND_SAVE_HOST_TO_GO_ABI.
//
// R0 is not guaranteed to contain $0 after this macro.
#define UNSTACK_AND_RESTORE_GO_TO_HOST_ABI(extra) \
RESTORE_GPR(extra+FIXED_FRAME) \
RESTORE_FPR(extra+FIXED_FRAME+SAVE_GPR_SIZE) \
RESTORE_VR(extra+FIXED_FRAME+SAVE_GPR_SIZE+SAVE_FPR_SIZE, R0) \
ADD $(extra+FIXED_FRAME+SAVE_ALL_REG_SIZE), R1 \
MOVD 16(R1), R0 \
MOVD R0, LR \
MOVD 8(R1), R0 \
MOVW R0, CR
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