58 lines
1.4 KiB
ArmAsm
58 lines
1.4 KiB
ArmAsm
// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
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// SPDX-License-Identifier: BSD-3-Clause
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#include "textflag.h"
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// The link-regression kernel for arm64, the amd64 one's sibling: stack
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// discipline (add), an intra-file branch with link (probe calling seven,
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// R_CALLARM64), an ADRP+ADD pair against static data (word<>,
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// R_ADDRARM64), a symbol-valued DATA field (entry holding seven's
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// address, R_ADDR), NOPTR data outside the GC's type scan (counter) and
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// the data section itself. The callee's result slot sits at the caller's
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// SP+8, the arm64 ABI0 frame convention.
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// func add(a, b int64) int64
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TEXT ·add(SB), NOSPLIT, $0-24
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MOVD a+0(FP), R0
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MOVD b+8(FP), R1
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ADD R1, R0, R0
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MOVD R0, ret+16(FP)
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RET
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// func seven() int64
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TEXT ·seven(SB), NOSPLIT, $0-8
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MOVD $7, R0
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MOVD R0, ret+0(FP)
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RET
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// func probe() int64 = seven() + word<>(SB)
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TEXT ·probe(SB), NOSPLIT, $8-8
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BL ·seven(SB)
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MOVD 8(RSP), R0
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MOVD $word<>(SB), R4
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MOVD (R4), R5
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ADD R5, R0, R0
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MOVD R0, ret+0(FP)
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RET
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// func entryAddr() uintptr
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TEXT ·entryAddr(SB), NOSPLIT, $0-8
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MOVD entry(SB), R4
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MOVD R4, ret+0(FP)
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RET
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// func counterVal() int64
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TEXT ·counterVal(SB), NOSPLIT, $0-8
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MOVD counter(SB), R4
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MOVD R4, ret+0(FP)
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RET
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GLOBL word<>(SB), RODATA, $8
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DATA word<>+0(SB)/8, $0x0fedcba987654321
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GLOBL entry(SB), RODATA, $8
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DATA entry+0(SB)/8, $·seven(SB)
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GLOBL counter(SB), NOPTR, $8
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DATA counter+0(SB)/8, $1234
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