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| author | Austin Clements <austin@google.com> | 2017-11-15 14:54:24 -0800 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2018-02-13 16:34:19 +0000 |
| commit | 79594ee95a4b91c894f00e2562ba12e7f803191b (patch) | |
| tree | 7ce1f344287b43ce76ecfd09396d45c8e0203459 /src/runtime/asm_arm64.s | |
| parent | 1de1f316df84569c449d6d709b0d711921ea6116 (diff) | |
| download | go-79594ee95a4b91c894f00e2562ba12e7f803191b.tar.gz go-79594ee95a4b91c894f00e2562ba12e7f803191b.zip | |
runtime: buffered write barrier for arm64
Updates #22460.
Change-Id: I5f8fbece9545840f5fc4c9834e2050b0920776f0
Reviewed-on: https://go-review.googlesource.com/92699
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Diffstat (limited to 'src/runtime/asm_arm64.s')
| -rw-r--r-- | src/runtime/asm_arm64.s | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/runtime/asm_arm64.s b/src/runtime/asm_arm64.s index e41ee7004d..2e08013097 100644 --- a/src/runtime/asm_arm64.s +++ b/src/runtime/asm_arm64.s @@ -1055,3 +1055,102 @@ TEXT ·checkASM(SB),NOSPLIT,$0-1 MOVW $1, R3 MOVB R3, ret+0(FP) RET + +// gcWriteBarrier performs a heap pointer write and informs the GC. +// +// gcWriteBarrier does NOT follow the Go ABI. It takes two arguments: +// - R2 is the destination of the write +// - R3 is the value being written at R2 +// It clobbers condition codes. +// It does not clobber any general-purpose registers, +// but may clobber others (e.g., floating point registers) +// The act of CALLing gcWriteBarrier will clobber R30 (LR). +TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$216 + // Save the registers clobbered by the fast path. + MOVD R0, 200(RSP) + MOVD R1, 208(RSP) + MOVD g_m(g), R0 + MOVD m_p(R0), R0 + MOVD (p_wbBuf+wbBuf_next)(R0), R1 + // Increment wbBuf.next position. + ADD $16, R1 + MOVD R1, (p_wbBuf+wbBuf_next)(R0) + MOVD (p_wbBuf+wbBuf_end)(R0), R0 + CMP R1, R0 + // Record the write. + MOVD R3, -16(R1) // Record value + MOVD (R2), R0 // TODO: This turns bad writes into bad reads. + MOVD R0, -8(R1) // Record *slot + // Is the buffer full? (flags set in CMP above) + BEQ flush +ret: + MOVD 200(RSP), R0 + MOVD 208(RSP), R1 + // Do the write. + MOVD R3, (R2) + RET + +flush: + // Save all general purpose registers since these could be + // clobbered by wbBufFlush and were not saved by the caller. + MOVD R2, 8(RSP) // Also first argument to wbBufFlush + MOVD R3, 16(RSP) // Also second argument to wbBufFlush + // R0 already saved + // R1 already saved + MOVD R4, 24(RSP) + MOVD R5, 32(RSP) + MOVD R6, 40(RSP) + MOVD R7, 48(RSP) + MOVD R8, 56(RSP) + MOVD R9, 64(RSP) + MOVD R10, 72(RSP) + MOVD R11, 80(RSP) + MOVD R12, 88(RSP) + MOVD R13, 96(RSP) + MOVD R14, 104(RSP) + MOVD R15, 112(RSP) + MOVD R16, 120(RSP) + MOVD R17, 128(RSP) + // R18 is unused. + MOVD R19, 136(RSP) + MOVD R20, 144(RSP) + MOVD R21, 152(RSP) + MOVD R22, 160(RSP) + MOVD R23, 168(RSP) + MOVD R24, 176(RSP) + MOVD R25, 184(RSP) + MOVD R26, 192(RSP) + // R27 is temp register. + // R28 is g. + // R29 is frame pointer (unused). + // R30 is LR, which was saved by the prologue. + // R31 is SP. + + // This takes arguments R2 and R3. + CALL runtime·wbBufFlush(SB) + + MOVD 8(RSP), R2 + MOVD 16(RSP), R3 + MOVD 24(RSP), R4 + MOVD 32(RSP), R5 + MOVD 40(RSP), R6 + MOVD 48(RSP), R7 + MOVD 56(RSP), R8 + MOVD 64(RSP), R9 + MOVD 72(RSP), R10 + MOVD 80(RSP), R11 + MOVD 88(RSP), R12 + MOVD 96(RSP), R13 + MOVD 104(RSP), R14 + MOVD 112(RSP), R15 + MOVD 120(RSP), R16 + MOVD 128(RSP), R17 + MOVD 136(RSP), R19 + MOVD 144(RSP), R20 + MOVD 152(RSP), R21 + MOVD 160(RSP), R22 + MOVD 168(RSP), R23 + MOVD 176(RSP), R24 + MOVD 184(RSP), R25 + MOVD 192(RSP), R26 + JMP ret |