runtime: save lasx and lsx registers in loong64 async preemption

This is a port of CL 669195 and CL 695916 adjusted to save loong64
lasx and lsx registers off stack.

Change-Id: Ie56787c76259a9545f5a8adcb09f588c8451bbd6
Reviewed-on: https://go-review.googlesource.com/c/go/+/711180
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Meidan Li <limeidan@loongson.cn>

src/runtime/mkpreempt.go

@@ -713,10 +713,11 @@ func genMIPS(g *gen, _64bit bool) {
 }
 
 func genLoong64(g *gen) {
-	p := g.p
+	const xReg = "R4" // *xRegState
+
+	p, label := g.p, g.label
 
 	mov := "MOVV"
-	movf := "MOVD"
 	add := "ADDV"
 	sub := "SUBV"
 	regsize := 8
@@ -732,12 +733,6 @@ func genLoong64(g *gen) {
 		l.add(mov, reg, regsize)
 	}
 
-	// Add floating point registers F0-F31.
-	for i := 0; i <= 31; i++ {
-		reg := fmt.Sprintf("F%d", i)
-		l.add(movf, reg, regsize)
-	}
-
 	// Add condition flag register fcc0-fcc7
 	sv := ""
 	rs := ""
@@ -764,12 +759,80 @@ func genLoong64(g *gen) {
 		mov+" %d(R3), R5\n"+rs,
 		regsize)
 
+	// Create layouts for lasx, lsx and fp registers.
+	lasxRegs := layout{sp: xReg}
+	lsxRegs := lasxRegs
+	fpRegs := lasxRegs
+	for i := 0; i <= 31; i++ {
+		lasxRegs.add("XVMOVQ", fmt.Sprintf("X%d", i), 256/8)
+		lsxRegs.add("VMOVQ", fmt.Sprintf("V%d", i), 128/8)
+		fpRegs.add("MOVD", fmt.Sprintf("F%d", i), 64/8)
+	}
+
+	for i := range lsxRegs.regs {
+		for j := range lsxRegs.regs[i].regs {
+			lsxRegs.regs[i].regs[j].pos = lasxRegs.regs[i].regs[j].pos
+			fpRegs.regs[i].regs[j].pos = lasxRegs.regs[i].regs[j].pos
+		}
+	}
+	writeXRegs(g.goarch, &lasxRegs)
+
 	// allocate frame, save PC of interrupted instruction (in LR)
 	p(mov+" R1, -%d(R3)", l.stack)
 	p(sub+" $%d, R3", l.stack)
 
+	p("// Save GPs")
 	l.save(g)
+
+	p("// Save extended register state to p.xRegs.scratch")
+	p("MOVV g_m(g), %s", xReg)
+	p("MOVV m_p(%s), %s", xReg, xReg)
+	p("ADDV $(p_xRegs+xRegPerP_scratch), %s, %s", xReg, xReg)
+
+	p("MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLASX(SB), R5")
+	p("BNE R5, saveLASX")
+
+	p("MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLSX(SB), R5")
+	p("BNE R5, saveLSX")
+
+	label("saveFP:")
+	fpRegs.save(g)
+	p("JMP preempt")
+
+	label("saveLSX:")
+	lsxRegs.save(g)
+	p("JMP preempt")
+
+	label("saveLASX:")
+	lasxRegs.save(g)
+
+	label("preempt:")
 	p("CALL ·asyncPreempt2(SB)")
+
+	p("// Restore non-GPs from *p.xRegs.cache")
+	p("MOVV g_m(g), %s", xReg)
+	p("MOVV m_p(%s), %s", xReg, xReg)
+	p("MOVV (p_xRegs+xRegPerP_cache)(%s), %s", xReg, xReg)
+
+	p("MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLASX(SB), R5")
+	p("BNE R5, restoreLASX")
+
+	p("MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLSX(SB), R5")
+	p("BNE R5, restoreLSX")
+
+	label("restoreFP:")
+	fpRegs.restore(g)
+	p("JMP restoreGPs")
+
+	label("restoreLSX:")
+	lsxRegs.restore(g)
+	p("JMP restoreGPs")
+
+	label("restoreLASX:")
+	lasxRegs.restore(g)
+
+	p("// Restore GPs")
+	label("restoreGPs:")
 	l.restore(g)
 
 	p(mov+" %d(R3), R1", l.stack)      // sigctxt.pushCall has pushed LR (at interrupt) on stack, restore it

src/runtime/preempt_loong64.go

@@ -0,0 +1,38 @@
+// Code generated by mkpreempt.go; DO NOT EDIT.
+
+package runtime
+
+type xRegs struct {
+	X0  [32]byte
+	X1  [32]byte
+	X2  [32]byte
+	X3  [32]byte
+	X4  [32]byte
+	X5  [32]byte
+	X6  [32]byte
+	X7  [32]byte
+	X8  [32]byte
+	X9  [32]byte
+	X10 [32]byte
+	X11 [32]byte
+	X12 [32]byte
+	X13 [32]byte
+	X14 [32]byte
+	X15 [32]byte
+	X16 [32]byte
+	X17 [32]byte
+	X18 [32]byte
+	X19 [32]byte
+	X20 [32]byte
+	X21 [32]byte
+	X22 [32]byte
+	X23 [32]byte
+	X24 [32]byte
+	X25 [32]byte
+	X26 [32]byte
+	X27 [32]byte
+	X28 [32]byte
+	X29 [32]byte
+	X30 [32]byte
+	X31 [32]byte
+}

src/runtime/preempt_loong64.s

@@ -4,8 +4,9 @@
 #include "textflag.h"
 
 TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
-	MOVV R1, -480(R3)
-	SUBV $480, R3
+	MOVV R1, -224(R3)
+	SUBV $224, R3
+	// Save GPs
 	MOVV R4, 8(R3)
 	MOVV R5, 16(R3)
 	MOVV R6, 24(R3)
@@ -32,38 +33,6 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVV R28, 192(R3)
 	MOVV R29, 200(R3)
 	MOVV R31, 208(R3)
-	MOVD F0, 216(R3)
-	MOVD F1, 224(R3)
-	MOVD F2, 232(R3)
-	MOVD F3, 240(R3)
-	MOVD F4, 248(R3)
-	MOVD F5, 256(R3)
-	MOVD F6, 264(R3)
-	MOVD F7, 272(R3)
-	MOVD F8, 280(R3)
-	MOVD F9, 288(R3)
-	MOVD F10, 296(R3)
-	MOVD F11, 304(R3)
-	MOVD F12, 312(R3)
-	MOVD F13, 320(R3)
-	MOVD F14, 328(R3)
-	MOVD F15, 336(R3)
-	MOVD F16, 344(R3)
-	MOVD F17, 352(R3)
-	MOVD F18, 360(R3)
-	MOVD F19, 368(R3)
-	MOVD F20, 376(R3)
-	MOVD F21, 384(R3)
-	MOVD F22, 392(R3)
-	MOVD F23, 400(R3)
-	MOVD F24, 408(R3)
-	MOVD F25, 416(R3)
-	MOVD F26, 424(R3)
-	MOVD F27, 432(R3)
-	MOVD F28, 440(R3)
-	MOVD F29, 448(R3)
-	MOVD F30, 456(R3)
-	MOVD F31, 464(R3)
 	MOVV FCC0, R4
 	BSTRINSV $7, R4, $0, R5
 	MOVV FCC1, R4
@@ -80,9 +49,230 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	BSTRINSV $55, R4, $48, R5
 	MOVV FCC7, R4
 	BSTRINSV $63, R4, $56, R5
-	MOVV R5, 472(R3)
+	MOVV R5, 216(R3)
+	// Save extended register state to p.xRegs.scratch
+	MOVV g_m(g), R4
+	MOVV m_p(R4), R4
+	ADDV $(p_xRegs+xRegPerP_scratch), R4, R4
+	MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLASX(SB), R5
+	BNE R5, saveLASX
+	MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLSX(SB), R5
+	BNE R5, saveLSX
+saveFP:
+	MOVD F0, 0(R4)
+	MOVD F1, 32(R4)
+	MOVD F2, 64(R4)
+	MOVD F3, 96(R4)
+	MOVD F4, 128(R4)
+	MOVD F5, 160(R4)
+	MOVD F6, 192(R4)
+	MOVD F7, 224(R4)
+	MOVD F8, 256(R4)
+	MOVD F9, 288(R4)
+	MOVD F10, 320(R4)
+	MOVD F11, 352(R4)
+	MOVD F12, 384(R4)
+	MOVD F13, 416(R4)
+	MOVD F14, 448(R4)
+	MOVD F15, 480(R4)
+	MOVD F16, 512(R4)
+	MOVD F17, 544(R4)
+	MOVD F18, 576(R4)
+	MOVD F19, 608(R4)
+	MOVD F20, 640(R4)
+	MOVD F21, 672(R4)
+	MOVD F22, 704(R4)
+	MOVD F23, 736(R4)
+	MOVD F24, 768(R4)
+	MOVD F25, 800(R4)
+	MOVD F26, 832(R4)
+	MOVD F27, 864(R4)
+	MOVD F28, 896(R4)
+	MOVD F29, 928(R4)
+	MOVD F30, 960(R4)
+	MOVD F31, 992(R4)
+	JMP preempt
+saveLSX:
+	VMOVQ V0, 0(R4)
+	VMOVQ V1, 32(R4)
+	VMOVQ V2, 64(R4)
+	VMOVQ V3, 96(R4)
+	VMOVQ V4, 128(R4)
+	VMOVQ V5, 160(R4)
+	VMOVQ V6, 192(R4)
+	VMOVQ V7, 224(R4)
+	VMOVQ V8, 256(R4)
+	VMOVQ V9, 288(R4)
+	VMOVQ V10, 320(R4)
+	VMOVQ V11, 352(R4)
+	VMOVQ V12, 384(R4)
+	VMOVQ V13, 416(R4)
+	VMOVQ V14, 448(R4)
+	VMOVQ V15, 480(R4)
+	VMOVQ V16, 512(R4)
+	VMOVQ V17, 544(R4)
+	VMOVQ V18, 576(R4)
+	VMOVQ V19, 608(R4)
+	VMOVQ V20, 640(R4)
+	VMOVQ V21, 672(R4)
+	VMOVQ V22, 704(R4)
+	VMOVQ V23, 736(R4)
+	VMOVQ V24, 768(R4)
+	VMOVQ V25, 800(R4)
+	VMOVQ V26, 832(R4)
+	VMOVQ V27, 864(R4)
+	VMOVQ V28, 896(R4)
+	VMOVQ V29, 928(R4)
+	VMOVQ V30, 960(R4)
+	VMOVQ V31, 992(R4)
+	JMP preempt
+saveLASX:
+	XVMOVQ X0, 0(R4)
+	XVMOVQ X1, 32(R4)
+	XVMOVQ X2, 64(R4)
+	XVMOVQ X3, 96(R4)
+	XVMOVQ X4, 128(R4)
+	XVMOVQ X5, 160(R4)
+	XVMOVQ X6, 192(R4)
+	XVMOVQ X7, 224(R4)
+	XVMOVQ X8, 256(R4)
+	XVMOVQ X9, 288(R4)
+	XVMOVQ X10, 320(R4)
+	XVMOVQ X11, 352(R4)
+	XVMOVQ X12, 384(R4)
+	XVMOVQ X13, 416(R4)
+	XVMOVQ X14, 448(R4)
+	XVMOVQ X15, 480(R4)
+	XVMOVQ X16, 512(R4)
+	XVMOVQ X17, 544(R4)
+	XVMOVQ X18, 576(R4)
+	XVMOVQ X19, 608(R4)
+	XVMOVQ X20, 640(R4)
+	XVMOVQ X21, 672(R4)
+	XVMOVQ X22, 704(R4)
+	XVMOVQ X23, 736(R4)
+	XVMOVQ X24, 768(R4)
+	XVMOVQ X25, 800(R4)
+	XVMOVQ X26, 832(R4)
+	XVMOVQ X27, 864(R4)
+	XVMOVQ X28, 896(R4)
+	XVMOVQ X29, 928(R4)
+	XVMOVQ X30, 960(R4)
+	XVMOVQ X31, 992(R4)
+preempt:
 	CALL ·asyncPreempt2(SB)
-	MOVV 472(R3), R5
+	// Restore non-GPs from *p.xRegs.cache
+	MOVV g_m(g), R4
+	MOVV m_p(R4), R4
+	MOVV (p_xRegs+xRegPerP_cache)(R4), R4
+	MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLASX(SB), R5
+	BNE R5, restoreLASX
+	MOVBU internal∕cpu·Loong64+const_offsetLOONG64HasLSX(SB), R5
+	BNE R5, restoreLSX
+restoreFP:
+	MOVD 992(R4), F31
+	MOVD 960(R4), F30
+	MOVD 928(R4), F29
+	MOVD 896(R4), F28
+	MOVD 864(R4), F27
+	MOVD 832(R4), F26
+	MOVD 800(R4), F25
+	MOVD 768(R4), F24
+	MOVD 736(R4), F23
+	MOVD 704(R4), F22
+	MOVD 672(R4), F21
+	MOVD 640(R4), F20
+	MOVD 608(R4), F19
+	MOVD 576(R4), F18
+	MOVD 544(R4), F17
+	MOVD 512(R4), F16
+	MOVD 480(R4), F15
+	MOVD 448(R4), F14
+	MOVD 416(R4), F13
+	MOVD 384(R4), F12
+	MOVD 352(R4), F11
+	MOVD 320(R4), F10
+	MOVD 288(R4), F9
+	MOVD 256(R4), F8
+	MOVD 224(R4), F7
+	MOVD 192(R4), F6
+	MOVD 160(R4), F5
+	MOVD 128(R4), F4
+	MOVD 96(R4), F3
+	MOVD 64(R4), F2
+	MOVD 32(R4), F1
+	MOVD 0(R4), F0
+	JMP restoreGPs
+restoreLSX:
+	VMOVQ 992(R4), V31
+	VMOVQ 960(R4), V30
+	VMOVQ 928(R4), V29
+	VMOVQ 896(R4), V28
+	VMOVQ 864(R4), V27
+	VMOVQ 832(R4), V26
+	VMOVQ 800(R4), V25
+	VMOVQ 768(R4), V24
+	VMOVQ 736(R4), V23
+	VMOVQ 704(R4), V22
+	VMOVQ 672(R4), V21
+	VMOVQ 640(R4), V20
+	VMOVQ 608(R4), V19
+	VMOVQ 576(R4), V18
+	VMOVQ 544(R4), V17
+	VMOVQ 512(R4), V16
+	VMOVQ 480(R4), V15
+	VMOVQ 448(R4), V14
+	VMOVQ 416(R4), V13
+	VMOVQ 384(R4), V12
+	VMOVQ 352(R4), V11
+	VMOVQ 320(R4), V10
+	VMOVQ 288(R4), V9
+	VMOVQ 256(R4), V8
+	VMOVQ 224(R4), V7
+	VMOVQ 192(R4), V6
+	VMOVQ 160(R4), V5
+	VMOVQ 128(R4), V4
+	VMOVQ 96(R4), V3
+	VMOVQ 64(R4), V2
+	VMOVQ 32(R4), V1
+	VMOVQ 0(R4), V0
+	JMP restoreGPs
+restoreLASX:
+	XVMOVQ 992(R4), X31
+	XVMOVQ 960(R4), X30
+	XVMOVQ 928(R4), X29
+	XVMOVQ 896(R4), X28
+	XVMOVQ 864(R4), X27
+	XVMOVQ 832(R4), X26
+	XVMOVQ 800(R4), X25
+	XVMOVQ 768(R4), X24
+	XVMOVQ 736(R4), X23
+	XVMOVQ 704(R4), X22
+	XVMOVQ 672(R4), X21
+	XVMOVQ 640(R4), X20
+	XVMOVQ 608(R4), X19
+	XVMOVQ 576(R4), X18
+	XVMOVQ 544(R4), X17
+	XVMOVQ 512(R4), X16
+	XVMOVQ 480(R4), X15
+	XVMOVQ 448(R4), X14
+	XVMOVQ 416(R4), X13
+	XVMOVQ 384(R4), X12
+	XVMOVQ 352(R4), X11
+	XVMOVQ 320(R4), X10
+	XVMOVQ 288(R4), X9
+	XVMOVQ 256(R4), X8
+	XVMOVQ 224(R4), X7
+	XVMOVQ 192(R4), X6
+	XVMOVQ 160(R4), X5
+	XVMOVQ 128(R4), X4
+	XVMOVQ 96(R4), X3
+	XVMOVQ 64(R4), X2
+	XVMOVQ 32(R4), X1
+	XVMOVQ 0(R4), X0
+	// Restore GPs
+restoreGPs:
+	MOVV 216(R3), R5
 	BSTRPICKV $7, R5, $0, R4
 	MOVV R4, FCC0
 	BSTRPICKV $15, R5, $8, R4
@@ -99,38 +289,6 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVV R4, FCC6
 	BSTRPICKV $63, R5, $56, R4
 	MOVV R4, FCC7
-	MOVD 464(R3), F31
-	MOVD 456(R3), F30
-	MOVD 448(R3), F29
-	MOVD 440(R3), F28
-	MOVD 432(R3), F27
-	MOVD 424(R3), F26
-	MOVD 416(R3), F25
-	MOVD 408(R3), F24
-	MOVD 400(R3), F23
-	MOVD 392(R3), F22
-	MOVD 384(R3), F21
-	MOVD 376(R3), F20
-	MOVD 368(R3), F19
-	MOVD 360(R3), F18
-	MOVD 352(R3), F17
-	MOVD 344(R3), F16
-	MOVD 336(R3), F15
-	MOVD 328(R3), F14
-	MOVD 320(R3), F13
-	MOVD 312(R3), F12
-	MOVD 304(R3), F11
-	MOVD 296(R3), F10
-	MOVD 288(R3), F9
-	MOVD 280(R3), F8
-	MOVD 272(R3), F7
-	MOVD 264(R3), F6
-	MOVD 256(R3), F5
-	MOVD 248(R3), F4
-	MOVD 240(R3), F3
-	MOVD 232(R3), F2
-	MOVD 224(R3), F1
-	MOVD 216(R3), F0
 	MOVV 208(R3), R31
 	MOVV 200(R3), R29
 	MOVV 192(R3), R28
@@ -157,7 +315,7 @@ TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0
 	MOVV 24(R3), R6
 	MOVV 16(R3), R5
 	MOVV 8(R3), R4
-	MOVV 480(R3), R1
+	MOVV 224(R3), R1
 	MOVV (R3), R30
-	ADDV $488, R3
+	ADDV $232, R3
 	JMP (R30)

src/runtime/preempt_noxreg.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !amd64 && !arm64
+//go:build !amd64 && !arm64 && !loong64
 
 // This provides common support for architectures that DO NOT use extended
 // register state in asynchronous preemption.

src/runtime/preempt_xreg.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64
+//go:build amd64 || arm64 || loong64
 
 // This provides common support for architectures that use extended register
 // state in asynchronous preemption.