runtime: save and restore fcc registers in async preempt on loong64

During the context switch of goroutine scheduling, the value of the
fcc0 register needs to be saved on the stack.

Fixs #59000.

Change-Id: Ie80dbae738f60df6c11a3fe31fc57de817d76afc
Reviewed-on: https://go-review.googlesource.com/c/go/+/475577
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: WANG Xuerui <git@xen0n.name>

diff --git a/src/runtime/mkpreempt.go b/src/runtime/mkpreempt.go
index b4915f3789aab06ec583cfc2d5274b59578ac33f..0bfbd379e03e3bca157609be72c0b259482656fa 100644 (file)
--- a/src/runtime/mkpreempt.go
+++ b/src/runtime/mkpreempt.go
@@ -481,6 +481,12 @@ func genLoong64() {
                l.add(movf, reg, regsize)
        }
 
+       // save/restore FCC0
+       l.addSpecial(
+               mov+" FCC0, R4\n"+mov+" R4, %d(R3)",
+               mov+" %d(R3), R4\n"+mov+" R4, FCC0",
+               regsize)
+
        // allocate frame, save PC of interrupted instruction (in LR)
        p(mov+" R1, -%d(R3)", l.stack)
        p(sub+" $%d, R3", l.stack)

diff --git a/src/runtime/preempt_loong64.s b/src/runtime/preempt_loong64.s
index f97a8860dc879822f3d0feb9cd4f8cd9d9a8414f..bb9c9483650147ab49986760bacb225b6e727d1e 100644 (file)
--- a/src/runtime/preempt_loong64.s
+++ b/src/runtime/preempt_loong64.s
@@ -4,8 +4,8 @@
 #include "textflag.h"
 
 TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
-       MOVV R1, -472(R3)
-       SUBV $472, R3
+       MOVV R1, -480(R3)
+       SUBV $480, R3
        MOVV R4, 8(R3)
        MOVV R5, 16(R3)
        MOVV R6, 24(R3)
@@ -64,7 +64,11 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
        MOVD F29, 448(R3)
        MOVD F30, 456(R3)
        MOVD F31, 464(R3)
+       MOVV FCC0, R4
+       MOVV R4, 472(R3)
        CALL ·asyncPreempt2(SB)
+       MOVV 472(R3), R4
+       MOVV R4, FCC0
        MOVD 464(R3), F31
        MOVD 456(R3), F30
        MOVD 448(R3), F29
@@ -123,7 +127,7 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
        MOVV 24(R3), R6
        MOVV 16(R3), R5
        MOVV 8(R3), R4
-       MOVV 472(R3), R1
+       MOVV 480(R3), R1
        MOVV (R3), R30
-       ADDV $480, R3
+       ADDV $488, R3
        JMP (R30)