diff options
| author | Austin Clements <austin@google.com> | 2017-11-15 14:54:24 -0800 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2018-02-13 16:34:20 +0000 |
| commit | a39de964385fb32d13d8fac3991a669de962f0bd (patch) | |
| tree | 9548b43b134f7311a1307641d7fe7024b09f3e92 /src/runtime/asm_mips64x.s | |
| parent | 79594ee95a4b91c894f00e2562ba12e7f803191b (diff) | |
| download | go-a39de964385fb32d13d8fac3991a669de962f0bd.tar.gz go-a39de964385fb32d13d8fac3991a669de962f0bd.zip | |
runtime: buffered write barrier for mips64
Updates #22460.
Change-Id: I9718bff3a346e765601cfd1890417bdfa0f7b9d8
Reviewed-on: https://go-review.googlesource.com/92700
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_mips64x.s')
| -rw-r--r-- | src/runtime/asm_mips64x.s | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/runtime/asm_mips64x.s b/src/runtime/asm_mips64x.s index 7d8d97d17a..f59421fbf6 100644 --- a/src/runtime/asm_mips64x.s +++ b/src/runtime/asm_mips64x.s @@ -776,3 +776,101 @@ TEXT ·checkASM(SB),NOSPLIT,$0-1 MOVW $1, R1 MOVB R1, 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: +// - R20 is the destination of the write +// - R21 is the value being written at R20. +// It clobbers R23 (the linker temp register). +// The act of CALLing gcWriteBarrier will clobber R31 (LR). +// It does not clobber any other general-purpose registers, +// but may clobber others (e.g., floating point registers). +TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$192 + // Save the registers clobbered by the fast path. + MOVV R1, 184(R29) + MOVV R2, 192(R29) + MOVV g_m(g), R1 + MOVV m_p(R1), R1 + MOVV (p_wbBuf+wbBuf_next)(R1), R2 + // Increment wbBuf.next position. + ADDV $16, R2 + MOVV R2, (p_wbBuf+wbBuf_next)(R1) + MOVV (p_wbBuf+wbBuf_end)(R1), R1 + MOVV R1, R23 // R23 is linker temp register + // Record the write. + MOVV R21, -16(R2) // Record value + MOVV (R20), R1 // TODO: This turns bad writes into bad reads. + MOVV R1, -8(R2) // Record *slot + // Is the buffer full? + BEQ R2, R23, flush +ret: + MOVV 184(R29), R1 + MOVV 192(R29), R2 + // Do the write. + MOVV R21, (R20) + RET + +flush: + // Save all general purpose registers since these could be + // clobbered by wbBufFlush and were not saved by the caller. + MOVV R20, 8(R29) // Also first argument to wbBufFlush + MOVV R21, 16(R29) // Also second argument to wbBufFlush + // R1 already saved + // R2 already saved + MOVV R3, 24(R29) + MOVV R4, 32(R29) + MOVV R5, 40(R29) + MOVV R6, 48(R29) + MOVV R7, 56(R29) + MOVV R8, 64(R29) + MOVV R9, 72(R29) + MOVV R10, 80(R29) + MOVV R11, 88(R29) + MOVV R12, 96(R29) + MOVV R13, 104(R29) + MOVV R14, 112(R29) + MOVV R15, 120(R29) + MOVV R16, 128(R29) + MOVV R17, 136(R29) + MOVV R18, 144(R29) + MOVV R19, 152(R29) + // R20 already saved + // R21 already saved. + MOVV R22, 160(R29) + // R23 is tmp register. + MOVV R24, 168(R29) + MOVV R25, 176(R29) + // R26 is reserved by kernel. + // R27 is reserved by kernel. + // R28 is REGSB (not modified by Go code). + // R29 is SP. + // R30 is g. + // R31 is LR, which was saved by the prologue. + + // This takes arguments R20 and R21. + CALL runtime·wbBufFlush(SB) + + MOVV 8(R29), R20 + MOVV 16(R29), R21 + MOVV 24(R29), R3 + MOVV 32(R29), R4 + MOVV 40(R29), R5 + MOVV 48(R29), R6 + MOVV 56(R29), R7 + MOVV 64(R29), R8 + MOVV 72(R29), R9 + MOVV 80(R29), R10 + MOVV 88(R29), R11 + MOVV 96(R29), R12 + MOVV 104(R29), R13 + MOVV 112(R29), R14 + MOVV 120(R29), R15 + MOVV 128(R29), R16 + MOVV 136(R29), R17 + MOVV 144(R29), R18 + MOVV 152(R29), R19 + MOVV 160(R29), R22 + MOVV 168(R29), R24 + MOVV 176(R29), R25 + JMP ret |