| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build ignore |
| |
| // mkpreempt generates the asyncPreempt functions for each |
| // architecture. |
| package main |
| |
| import ( |
| "flag" |
| "fmt" |
| "io" |
| "log" |
| "os" |
| "strings" |
| ) |
| |
| // Copied from cmd/compile/internal/ssa/gen/*Ops.go |
| |
| var regNames386 = []string{ |
| "AX", |
| "CX", |
| "DX", |
| "BX", |
| "SP", |
| "BP", |
| "SI", |
| "DI", |
| "X0", |
| "X1", |
| "X2", |
| "X3", |
| "X4", |
| "X5", |
| "X6", |
| "X7", |
| } |
| |
| var regNamesAMD64 = []string{ |
| "AX", |
| "CX", |
| "DX", |
| "BX", |
| "SP", |
| "BP", |
| "SI", |
| "DI", |
| "R8", |
| "R9", |
| "R10", |
| "R11", |
| "R12", |
| "R13", |
| "R14", |
| "R15", |
| "X0", |
| "X1", |
| "X2", |
| "X3", |
| "X4", |
| "X5", |
| "X6", |
| "X7", |
| "X8", |
| "X9", |
| "X10", |
| "X11", |
| "X12", |
| "X13", |
| "X14", |
| "X15", |
| } |
| |
| var out io.Writer |
| |
| var arches = map[string]func(){ |
| "386": gen386, |
| "amd64": genAMD64, |
| "arm": genARM, |
| "arm64": genARM64, |
| "mips64x": func() { genMIPS(true) }, |
| "mipsx": func() { genMIPS(false) }, |
| "ppc64x": genPPC64, |
| "riscv": genRISCV, |
| "riscv64": genRISCV64, |
| "s390x": genS390X, |
| "wasm": genWasm, |
| } |
| var beLe = map[string]bool{"mips64x": true, "mipsx": true, "ppc64x": true} |
| |
| func main() { |
| flag.Parse() |
| if flag.NArg() > 0 { |
| out = os.Stdout |
| for _, arch := range flag.Args() { |
| gen, ok := arches[arch] |
| if !ok { |
| log.Fatalf("unknown arch %s", arch) |
| } |
| header(arch) |
| gen() |
| } |
| return |
| } |
| |
| for arch, gen := range arches { |
| f, err := os.Create(fmt.Sprintf("preempt_%s.s", arch)) |
| if err != nil { |
| log.Fatal(err) |
| } |
| out = f |
| header(arch) |
| gen() |
| if err := f.Close(); err != nil { |
| log.Fatal(err) |
| } |
| } |
| } |
| |
| func header(arch string) { |
| fmt.Fprintf(out, "// Code generated by mkpreempt.go; DO NOT EDIT.\n\n") |
| if beLe[arch] { |
| base := arch[:len(arch)-1] |
| fmt.Fprintf(out, "// +build %s %sle\n\n", base, base) |
| } |
| fmt.Fprintf(out, "#include \"go_asm.h\"\n") |
| fmt.Fprintf(out, "#include \"textflag.h\"\n\n") |
| fmt.Fprintf(out, "TEXT ·asyncPreempt(SB),NOSPLIT|NOFRAME,$0-0\n") |
| } |
| |
| func p(f string, args ...interface{}) { |
| fmted := fmt.Sprintf(f, args...) |
| fmt.Fprintf(out, "\t%s\n", strings.Replace(fmted, "\n", "\n\t", -1)) |
| } |
| |
| func label(l string) { |
| fmt.Fprintf(out, "%s\n", l) |
| } |
| |
| type layout struct { |
| stack int |
| regs []regPos |
| sp string // stack pointer register |
| } |
| |
| type regPos struct { |
| pos int |
| |
| op string |
| reg string |
| |
| // If this register requires special save and restore, these |
| // give those operations with a %d placeholder for the stack |
| // offset. |
| save, restore string |
| } |
| |
| func (l *layout) add(op, reg string, size int) { |
| l.regs = append(l.regs, regPos{op: op, reg: reg, pos: l.stack}) |
| l.stack += size |
| } |
| |
| func (l *layout) addSpecial(save, restore string, size int) { |
| l.regs = append(l.regs, regPos{save: save, restore: restore, pos: l.stack}) |
| l.stack += size |
| } |
| |
| func (l *layout) save() { |
| for _, reg := range l.regs { |
| if reg.save != "" { |
| p(reg.save, reg.pos) |
| } else { |
| p("%s %s, %d(%s)", reg.op, reg.reg, reg.pos, l.sp) |
| } |
| } |
| } |
| |
| func (l *layout) restore() { |
| for i := len(l.regs) - 1; i >= 0; i-- { |
| reg := l.regs[i] |
| if reg.restore != "" { |
| p(reg.restore, reg.pos) |
| } else { |
| p("%s %d(%s), %s", reg.op, reg.pos, l.sp, reg.reg) |
| } |
| } |
| } |
| |
| func gen386() { |
| p("PUSHFL") |
| |
| // Save general purpose registers. |
| var l = layout{sp: "SP"} |
| for _, reg := range regNames386 { |
| if reg == "SP" || strings.HasPrefix(reg, "X") { |
| continue |
| } |
| l.add("MOVL", reg, 4) |
| } |
| |
| // Save the 387 state. |
| l.addSpecial( |
| "FSAVE %d(SP)\nFLDCW runtime·controlWord64(SB)", |
| "FRSTOR %d(SP)", |
| 108) |
| |
| // Save SSE state only if supported. |
| lSSE := layout{stack: l.stack, sp: "SP"} |
| for i := 0; i < 8; i++ { |
| lSSE.add("MOVUPS", fmt.Sprintf("X%d", i), 16) |
| } |
| |
| p("ADJSP $%d", lSSE.stack) |
| p("NOP SP") |
| l.save() |
| p("CMPB internal∕cpu·X86+const_offsetX86HasSSE2(SB), $1\nJNE nosse") |
| lSSE.save() |
| label("nosse:") |
| p("CALL ·asyncPreempt2(SB)") |
| p("CMPB internal∕cpu·X86+const_offsetX86HasSSE2(SB), $1\nJNE nosse2") |
| lSSE.restore() |
| label("nosse2:") |
| l.restore() |
| p("ADJSP $%d", -lSSE.stack) |
| |
| p("POPFL") |
| p("RET") |
| } |
| |
| func genAMD64() { |
| // Assign stack offsets. |
| var l = layout{sp: "SP"} |
| for _, reg := range regNamesAMD64 { |
| if reg == "SP" || reg == "BP" { |
| continue |
| } |
| if strings.HasPrefix(reg, "X") { |
| l.add("MOVUPS", reg, 16) |
| } else { |
| l.add("MOVQ", reg, 8) |
| } |
| } |
| |
| // TODO: MXCSR register? |
| |
| p("PUSHQ BP") |
| p("MOVQ SP, BP") |
| p("// Save flags before clobbering them") |
| p("PUSHFQ") |
| p("// obj doesn't understand ADD/SUB on SP, but does understand ADJSP") |
| p("ADJSP $%d", l.stack) |
| p("// But vet doesn't know ADJSP, so suppress vet stack checking") |
| p("NOP SP") |
| |
| // Apparently, the signal handling code path in darwin kernel leaves |
| // the upper bits of Y registers in a dirty state, which causes |
| // many SSE operations (128-bit and narrower) become much slower. |
| // Clear the upper bits to get to a clean state. See issue #37174. |
| // It is safe here as Go code don't use the upper bits of Y registers. |
| p("#ifdef GOOS_darwin") |
| p("CMPB internal∕cpu·X86+const_offsetX86HasAVX(SB), $0") |
| p("JE 2(PC)") |
| p("VZEROUPPER") |
| p("#endif") |
| |
| l.save() |
| p("CALL ·asyncPreempt2(SB)") |
| l.restore() |
| p("ADJSP $%d", -l.stack) |
| p("POPFQ") |
| p("POPQ BP") |
| p("RET") |
| } |
| |
| func genARM() { |
| // Add integer registers R0-R12. |
| // R13 (SP), R14 (LR), R15 (PC) are special and not saved here. |
| var l = layout{sp: "R13", stack: 4} // add LR slot |
| for i := 0; i <= 12; i++ { |
| reg := fmt.Sprintf("R%d", i) |
| if i == 10 { |
| continue // R10 is g register, no need to save/restore |
| } |
| l.add("MOVW", reg, 4) |
| } |
| // Add flag register. |
| l.addSpecial( |
| "MOVW CPSR, R0\nMOVW R0, %d(R13)", |
| "MOVW %d(R13), R0\nMOVW R0, CPSR", |
| 4) |
| |
| // Add floating point registers F0-F15 and flag register. |
| var lfp = layout{stack: l.stack, sp: "R13"} |
| lfp.addSpecial( |
| "MOVW FPCR, R0\nMOVW R0, %d(R13)", |
| "MOVW %d(R13), R0\nMOVW R0, FPCR", |
| 4) |
| for i := 0; i <= 15; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| lfp.add("MOVD", reg, 8) |
| } |
| |
| p("MOVW.W R14, -%d(R13)", lfp.stack) // allocate frame, save LR |
| l.save() |
| p("MOVB ·goarm(SB), R0\nCMP $6, R0\nBLT nofp") // test goarm, and skip FP registers if goarm=5. |
| lfp.save() |
| label("nofp:") |
| p("CALL ·asyncPreempt2(SB)") |
| p("MOVB ·goarm(SB), R0\nCMP $6, R0\nBLT nofp2") // test goarm, and skip FP registers if goarm=5. |
| lfp.restore() |
| label("nofp2:") |
| l.restore() |
| |
| p("MOVW %d(R13), R14", lfp.stack) // sigctxt.pushCall pushes LR on stack, restore it |
| p("MOVW.P %d(R13), R15", lfp.stack+4) // load PC, pop frame (including the space pushed by sigctxt.pushCall) |
| p("UNDEF") // shouldn't get here |
| } |
| |
| func genARM64() { |
| // Add integer registers R0-R26 |
| // R27 (REGTMP), R28 (g), R29 (FP), R30 (LR), R31 (SP) are special |
| // and not saved here. |
| var l = layout{sp: "RSP", stack: 8} // add slot to save PC of interrupted instruction |
| for i := 0; i <= 26; i++ { |
| if i == 18 { |
| continue // R18 is not used, skip |
| } |
| reg := fmt.Sprintf("R%d", i) |
| l.add("MOVD", reg, 8) |
| } |
| // Add flag registers. |
| l.addSpecial( |
| "MOVD NZCV, R0\nMOVD R0, %d(RSP)", |
| "MOVD %d(RSP), R0\nMOVD R0, NZCV", |
| 8) |
| l.addSpecial( |
| "MOVD FPSR, R0\nMOVD R0, %d(RSP)", |
| "MOVD %d(RSP), R0\nMOVD R0, FPSR", |
| 8) |
| // TODO: FPCR? I don't think we'll change it, so no need to save. |
| // Add floating point registers F0-F31. |
| for i := 0; i <= 31; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| l.add("FMOVD", reg, 8) |
| } |
| if l.stack%16 != 0 { |
| l.stack += 8 // SP needs 16-byte alignment |
| } |
| |
| // allocate frame, save PC of interrupted instruction (in LR) |
| p("MOVD R30, %d(RSP)", -l.stack) |
| p("SUB $%d, RSP", l.stack) |
| p("#ifdef GOOS_linux") |
| p("MOVD R29, -8(RSP)") // save frame pointer (only used on Linux) |
| p("SUB $8, RSP, R29") // set up new frame pointer |
| p("#endif") |
| // On darwin, save the LR again after decrementing SP. We run the |
| // signal handler on the G stack (as it doesn't support SA_ONSTACK), |
| // so any writes below SP may be clobbered. |
| p("#ifdef GOOS_darwin") |
| p("MOVD R30, (RSP)") |
| p("#endif") |
| |
| l.save() |
| p("CALL ·asyncPreempt2(SB)") |
| l.restore() |
| |
| p("MOVD %d(RSP), R30", l.stack) // sigctxt.pushCall has pushed LR (at interrupt) on stack, restore it |
| p("#ifdef GOOS_linux") |
| p("MOVD -8(RSP), R29") // restore frame pointer |
| p("#endif") |
| p("MOVD (RSP), R27") // load PC to REGTMP |
| p("ADD $%d, RSP", l.stack+16) // pop frame (including the space pushed by sigctxt.pushCall) |
| p("JMP (R27)") |
| } |
| |
| func genMIPS(_64bit bool) { |
| mov := "MOVW" |
| movf := "MOVF" |
| add := "ADD" |
| sub := "SUB" |
| r28 := "R28" |
| regsize := 4 |
| softfloat := "GOMIPS_softfloat" |
| if _64bit { |
| mov = "MOVV" |
| movf = "MOVD" |
| add = "ADDV" |
| sub = "SUBV" |
| r28 = "RSB" |
| regsize = 8 |
| softfloat = "GOMIPS64_softfloat" |
| } |
| |
| // Add integer registers R1-R22, R24-R25, R28 |
| // R0 (zero), R23 (REGTMP), R29 (SP), R30 (g), R31 (LR) are special, |
| // and not saved here. R26 and R27 are reserved by kernel and not used. |
| var l = layout{sp: "R29", stack: regsize} // add slot to save PC of interrupted instruction (in LR) |
| for i := 1; i <= 25; i++ { |
| if i == 23 { |
| continue // R23 is REGTMP |
| } |
| reg := fmt.Sprintf("R%d", i) |
| l.add(mov, reg, regsize) |
| } |
| l.add(mov, r28, regsize) |
| l.addSpecial( |
| mov+" HI, R1\n"+mov+" R1, %d(R29)", |
| mov+" %d(R29), R1\n"+mov+" R1, HI", |
| regsize) |
| l.addSpecial( |
| mov+" LO, R1\n"+mov+" R1, %d(R29)", |
| mov+" %d(R29), R1\n"+mov+" R1, LO", |
| regsize) |
| |
| // Add floating point control/status register FCR31 (FCR0-FCR30 are irrelevant) |
| var lfp = layout{sp: "R29", stack: l.stack} |
| lfp.addSpecial( |
| mov+" FCR31, R1\n"+mov+" R1, %d(R29)", |
| mov+" %d(R29), R1\n"+mov+" R1, FCR31", |
| regsize) |
| // Add floating point registers F0-F31. |
| for i := 0; i <= 31; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| lfp.add(movf, reg, regsize) |
| } |
| |
| // allocate frame, save PC of interrupted instruction (in LR) |
| p(mov+" R31, -%d(R29)", lfp.stack) |
| p(sub+" $%d, R29", lfp.stack) |
| |
| l.save() |
| p("#ifndef %s", softfloat) |
| lfp.save() |
| p("#endif") |
| p("CALL ·asyncPreempt2(SB)") |
| p("#ifndef %s", softfloat) |
| lfp.restore() |
| p("#endif") |
| l.restore() |
| |
| p(mov+" %d(R29), R31", lfp.stack) // sigctxt.pushCall has pushed LR (at interrupt) on stack, restore it |
| p(mov + " (R29), R23") // load PC to REGTMP |
| p(add+" $%d, R29", lfp.stack+regsize) // pop frame (including the space pushed by sigctxt.pushCall) |
| p("JMP (R23)") |
| } |
| |
| func genPPC64() { |
| // Add integer registers R3-R29 |
| // R0 (zero), R1 (SP), R30 (g) are special and not saved here. |
| // R2 (TOC pointer in PIC mode), R12 (function entry address in PIC mode) have been saved in sigctxt.pushCall. |
| // R31 (REGTMP) will be saved manually. |
| var l = layout{sp: "R1", stack: 32 + 8} // MinFrameSize on PPC64, plus one word for saving R31 |
| for i := 3; i <= 29; i++ { |
| if i == 12 || i == 13 { |
| // R12 has been saved in sigctxt.pushCall. |
| // R13 is TLS pointer, not used by Go code. we must NOT |
| // restore it, otherwise if we parked and resumed on a |
| // different thread we'll mess up TLS addresses. |
| continue |
| } |
| reg := fmt.Sprintf("R%d", i) |
| l.add("MOVD", reg, 8) |
| } |
| l.addSpecial( |
| "MOVW CR, R31\nMOVW R31, %d(R1)", |
| "MOVW %d(R1), R31\nMOVFL R31, $0xff", // this is MOVW R31, CR |
| 8) // CR is 4-byte wide, but just keep the alignment |
| l.addSpecial( |
| "MOVD XER, R31\nMOVD R31, %d(R1)", |
| "MOVD %d(R1), R31\nMOVD R31, XER", |
| 8) |
| // Add floating point registers F0-F31. |
| for i := 0; i <= 31; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| l.add("FMOVD", reg, 8) |
| } |
| // Add floating point control/status register FPSCR. |
| l.addSpecial( |
| "MOVFL FPSCR, F0\nFMOVD F0, %d(R1)", |
| "FMOVD %d(R1), F0\nMOVFL F0, FPSCR", |
| 8) |
| |
| p("MOVD R31, -%d(R1)", l.stack-32) // save R31 first, we'll use R31 for saving LR |
| p("MOVD LR, R31") |
| p("MOVDU R31, -%d(R1)", l.stack) // allocate frame, save PC of interrupted instruction (in LR) |
| |
| l.save() |
| p("CALL ·asyncPreempt2(SB)") |
| l.restore() |
| |
| p("MOVD %d(R1), R31", l.stack) // sigctxt.pushCall has pushed LR, R2, R12 (at interrupt) on stack, restore them |
| p("MOVD R31, LR") |
| p("MOVD %d(R1), R2", l.stack+8) |
| p("MOVD %d(R1), R12", l.stack+16) |
| p("MOVD (R1), R31") // load PC to CTR |
| p("MOVD R31, CTR") |
| p("MOVD 32(R1), R31") // restore R31 |
| p("ADD $%d, R1", l.stack+32) // pop frame (including the space pushed by sigctxt.pushCall) |
| p("JMP (CTR)") |
| } |
| |
| func genRISCV() { |
| p("// No async preemption on riscv - see issue 36711") |
| p("UNDEF") |
| } |
| |
| func genRISCV64() { |
| // X0 (zero), X1 (LR), X2 (SP), X4 (g), X31 (TMP) are special. |
| var l = layout{sp: "X2", stack: 8} |
| |
| // Add integer registers (X3, X5-X30). |
| for i := 3; i < 31; i++ { |
| if i == 4 { |
| continue |
| } |
| reg := fmt.Sprintf("X%d", i) |
| l.add("MOV", reg, 8) |
| } |
| |
| // Add floating point registers (F0-F31). |
| for i := 0; i <= 31; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| l.add("MOVD", reg, 8) |
| } |
| |
| p("MOV X1, -%d(X2)", l.stack) |
| p("ADD $-%d, X2", l.stack) |
| l.save() |
| p("CALL ·asyncPreempt2(SB)") |
| l.restore() |
| p("MOV %d(X2), X1", l.stack) |
| p("MOV (X2), X31") |
| p("ADD $%d, X2", l.stack+8) |
| p("JMP (X31)") |
| } |
| |
| func genS390X() { |
| // Add integer registers R0-R12 |
| // R13 (g), R14 (LR), R15 (SP) are special, and not saved here. |
| // Saving R10 (REGTMP) is not necessary, but it is saved anyway. |
| var l = layout{sp: "R15", stack: 16} // add slot to save PC of interrupted instruction and flags |
| l.addSpecial( |
| "STMG R0, R12, %d(R15)", |
| "LMG %d(R15), R0, R12", |
| 13*8) |
| // Add floating point registers F0-F31. |
| for i := 0; i <= 15; i++ { |
| reg := fmt.Sprintf("F%d", i) |
| l.add("FMOVD", reg, 8) |
| } |
| |
| // allocate frame, save PC of interrupted instruction (in LR) and flags (condition code) |
| p("IPM R10") // save flags upfront, as ADD will clobber flags |
| p("MOVD R14, -%d(R15)", l.stack) |
| p("ADD $-%d, R15", l.stack) |
| p("MOVW R10, 8(R15)") // save flags |
| |
| l.save() |
| p("CALL ·asyncPreempt2(SB)") |
| l.restore() |
| |
| p("MOVD %d(R15), R14", l.stack) // sigctxt.pushCall has pushed LR (at interrupt) on stack, restore it |
| p("ADD $%d, R15", l.stack+8) // pop frame (including the space pushed by sigctxt.pushCall) |
| p("MOVWZ -%d(R15), R10", l.stack) // load flags to REGTMP |
| p("TMLH R10, $(3<<12)") // restore flags |
| p("MOVD -%d(R15), R10", l.stack+8) // load PC to REGTMP |
| p("JMP (R10)") |
| } |
| |
| func genWasm() { |
| p("// No async preemption on wasm") |
| p("UNDEF") |
| } |
| |
| func notImplemented() { |
| p("// Not implemented yet") |
| p("JMP ·abort(SB)") |
| } |
