diff options
| author | Joel Sing <joel@sing.id.au> | 2020-10-27 23:30:14 +1100 |
|---|---|---|
| committer | Joel Sing <joel@sing.id.au> | 2020-10-29 08:00:23 +0000 |
| commit | ae82ee4016c44e558b002f0c7ffbb40d698d411e (patch) | |
| tree | 3b29df058948547e92799165bf01a67147038b09 /src/runtime/asm_riscv64.s | |
| parent | 15131caeaa83e57fd8bdf87dde2801443f5602db (diff) | |
| download | go-ae82ee4016c44e558b002f0c7ffbb40d698d411e.tar.gz go-ae82ee4016c44e558b002f0c7ffbb40d698d411e.zip | |
runtime: optimise gcWriteBarrier for riscv64
Avoid saving unnecessary registers in gcWriteBarrier on riscv64, which also
removes references to X4 and X27 (TP and g registers).
Change-Id: I2854161dcdf0c6047a45347165371827dcf8c1cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/265518
Trust: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Diffstat (limited to 'src/runtime/asm_riscv64.s')
| -rw-r--r-- | src/runtime/asm_riscv64.s | 134 |
1 files changed, 59 insertions, 75 deletions
diff --git a/src/runtime/asm_riscv64.s b/src/runtime/asm_riscv64.s index fd01fd6f07..caaf42a7d0 100644 --- a/src/runtime/asm_riscv64.s +++ b/src/runtime/asm_riscv64.s @@ -488,10 +488,10 @@ TEXT ·checkASM(SB),NOSPLIT,$0-1 // The act of CALLing gcWriteBarrier will clobber RA (LR). // It does not clobber any other general-purpose registers, // but may clobber others (e.g., floating point registers). -TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$296 +TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$216 // Save the registers clobbered by the fast path. - MOV A0, 280(X2) - MOV A1, 288(X2) + MOV A0, 25*8(X2) + MOV A1, 26*8(X2) MOV g_m(g), A0 MOV m_p(A0), A0 MOV (p_wbBuf+wbBuf_next)(A0), A1 @@ -507,8 +507,8 @@ TEXT runtime·gcWriteBarrier(SB),NOSPLIT,$296 // Is the buffer full? BEQ A1, T6, flush ret: - MOV 280(X2), A0 - MOV 288(X2), A1 + MOV 25*8(X2), A0 + MOV 26*8(X2), A1 // Do the write. MOV T1, (T0) RET @@ -516,84 +516,68 @@ ret: flush: // Save all general purpose registers since these could be // clobbered by wbBufFlush and were not saved by the caller. - MOV T0, 8(X2) // Also first argument to wbBufFlush - MOV T1, 16(X2) // Also second argument to wbBufFlush - - // TODO: Optimise - // X5 already saved (T0) - // X6 already saved (T1) + MOV T0, 1*8(X2) // Also first argument to wbBufFlush + MOV T1, 2*8(X2) // Also second argument to wbBufFlush + // X0 is zero register + // X1 is LR, saved by prologue + // X2 is SP + MOV X3, 3*8(X2) + // X4 is TP + // X5 is first arg to wbBufFlush (T0) + // X6 is second arg to wbBufFlush (T1) + MOV X7, 4*8(X2) + MOV X8, 5*8(X2) + MOV X9, 6*8(X2) // X10 already saved (A0) // X11 already saved (A1) + MOV X12, 7*8(X2) + MOV X13, 8*8(X2) + MOV X14, 9*8(X2) + MOV X15, 10*8(X2) + MOV X16, 11*8(X2) + MOV X17, 12*8(X2) + MOV X18, 13*8(X2) + MOV X19, 14*8(X2) + MOV X20, 15*8(X2) + MOV X21, 16*8(X2) + MOV X22, 17*8(X2) + MOV X23, 18*8(X2) + MOV X24, 19*8(X2) + MOV X25, 20*8(X2) + MOV X26, 21*8(X2) // X27 is g. + MOV X28, 22*8(X2) + MOV X29, 23*8(X2) + MOV X30, 24*8(X2) // X31 is tmp register. - MOV X0, 24(X2) - MOV X1, 32(X2) - MOV X2, 40(X2) - MOV X3, 48(X2) - MOV X4, 56(X2) - MOV X5, 64(X2) - MOV X6, 72(X2) - MOV X7, 80(X2) - MOV X8, 88(X2) - MOV X9, 96(X2) - MOV X10, 104(X2) - MOV X11, 112(X2) - MOV X12, 120(X2) - MOV X13, 128(X2) - MOV X14, 136(X2) - MOV X15, 144(X2) - MOV X16, 152(X2) - MOV X17, 160(X2) - MOV X18, 168(X2) - MOV X19, 176(X2) - MOV X20, 184(X2) - MOV X21, 192(X2) - MOV X22, 200(X2) - MOV X23, 208(X2) - MOV X24, 216(X2) - MOV X25, 224(X2) - MOV X26, 232(X2) - MOV X27, 240(X2) - MOV X28, 248(X2) - MOV X29, 256(X2) - MOV X30, 264(X2) - MOV X31, 272(X2) // This takes arguments T0 and T1. CALL runtime·wbBufFlush(SB) - MOV 24(X2), X0 - MOV 32(X2), X1 - MOV 40(X2), X2 - MOV 48(X2), X3 - MOV 56(X2), X4 - MOV 64(X2), X5 - MOV 72(X2), X6 - MOV 80(X2), X7 - MOV 88(X2), X8 - MOV 96(X2), X9 - MOV 104(X2), X10 - MOV 112(X2), X11 - MOV 120(X2), X12 - MOV 128(X2), X13 - MOV 136(X2), X14 - MOV 144(X2), X15 - MOV 152(X2), X16 - MOV 160(X2), X17 - MOV 168(X2), X18 - MOV 176(X2), X19 - MOV 184(X2), X20 - MOV 192(X2), X21 - MOV 200(X2), X22 - MOV 208(X2), X23 - MOV 216(X2), X24 - MOV 224(X2), X25 - MOV 232(X2), X26 - MOV 240(X2), X27 - MOV 248(X2), X28 - MOV 256(X2), X29 - MOV 264(X2), X30 - MOV 272(X2), X31 + MOV 1*8(X2), T0 + MOV 2*8(X2), T1 + MOV 3*8(X2), X3 + MOV 4*8(X2), X7 + MOV 5*8(X2), X8 + MOV 6*8(X2), X9 + MOV 7*8(X2), X12 + MOV 8*8(X2), X13 + MOV 9*8(X2), X14 + MOV 10*8(X2), X15 + MOV 11*8(X2), X16 + MOV 12*8(X2), X17 + MOV 13*8(X2), X18 + MOV 14*8(X2), X19 + MOV 15*8(X2), X20 + MOV 16*8(X2), X21 + MOV 17*8(X2), X22 + MOV 18*8(X2), X23 + MOV 19*8(X2), X24 + MOV 20*8(X2), X25 + MOV 21*8(X2), X26 + MOV 22*8(X2), X28 + MOV 23*8(X2), X29 + MOV 24*8(X2), X30 JMP ret |