| // Derived from Inferno utils/5c/swt.c |
| // http://code.google.com/p/inferno-os/source/browse/utils/5c/swt.c |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) |
| // Portions Copyright © 1997-1999 Vita Nuova Limited |
| // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) |
| // Portions Copyright © 2004,2006 Bruce Ellis |
| // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) |
| // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others |
| // Portions Copyright © 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package arm |
| |
| import ( |
| "cmd/internal/obj" |
| "encoding/binary" |
| "fmt" |
| "log" |
| "math" |
| ) |
| |
| var progedit_tlsfallback *obj.LSym |
| |
| func progedit(ctxt *obj.Link, p *obj.Prog) { |
| p.From.Class = 0 |
| p.To.Class = 0 |
| |
| // Rewrite B/BL to symbol as TYPE_BRANCH. |
| switch p.As { |
| case AB, |
| ABL, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| if p.To.Type == obj.TYPE_MEM && (p.To.Name == obj.NAME_EXTERN || p.To.Name == obj.NAME_STATIC) && p.To.Sym != nil { |
| p.To.Type = obj.TYPE_BRANCH |
| } |
| } |
| |
| // Replace TLS register fetches on older ARM procesors. |
| switch p.As { |
| // Treat MRC 15, 0, <reg>, C13, C0, 3 specially. |
| case AMRC: |
| if p.To.Offset&0xffff0fff == 0xee1d0f70 { |
| // Because the instruction might be rewriten to a BL which returns in R0 |
| // the register must be zero. |
| if p.To.Offset&0xf000 != 0 { |
| ctxt.Diag("%v: TLS MRC instruction must write to R0 as it might get translated into a BL instruction", p.Line()) |
| } |
| |
| if ctxt.Goarm < 7 { |
| // Replace it with BL runtime.read_tls_fallback(SB) for ARM CPUs that lack the tls extension. |
| if progedit_tlsfallback == nil { |
| progedit_tlsfallback = obj.Linklookup(ctxt, "runtime.read_tls_fallback", 0) |
| } |
| |
| // MOVW LR, R11 |
| p.As = AMOVW |
| |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGTMP |
| |
| // BL runtime.read_tls_fallback(SB) |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = ABL |
| p.To.Type = obj.TYPE_BRANCH |
| p.To.Sym = progedit_tlsfallback |
| p.To.Offset = 0 |
| |
| // MOVW R11, LR |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGTMP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGLINK |
| break |
| } |
| } |
| |
| // Otherwise, MRC/MCR instructions need no further treatment. |
| p.As = AWORD |
| } |
| |
| // Rewrite float constants to values stored in memory. |
| switch p.As { |
| case AMOVF: |
| if p.From.Type == obj.TYPE_FCONST && chipfloat5(ctxt, p.From.Val.(float64)) < 0 && (chipzero5(ctxt, p.From.Val.(float64)) < 0 || p.Scond&C_SCOND != C_SCOND_NONE) { |
| f32 := float32(p.From.Val.(float64)) |
| i32 := math.Float32bits(f32) |
| literal := fmt.Sprintf("$f32.%08x", i32) |
| s := obj.Linklookup(ctxt, literal, 0) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = s |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| |
| case AMOVD: |
| if p.From.Type == obj.TYPE_FCONST && chipfloat5(ctxt, p.From.Val.(float64)) < 0 && (chipzero5(ctxt, p.From.Val.(float64)) < 0 || p.Scond&C_SCOND != C_SCOND_NONE) { |
| i64 := math.Float64bits(p.From.Val.(float64)) |
| literal := fmt.Sprintf("$f64.%016x", i64) |
| s := obj.Linklookup(ctxt, literal, 0) |
| p.From.Type = obj.TYPE_MEM |
| p.From.Sym = s |
| p.From.Name = obj.NAME_EXTERN |
| p.From.Offset = 0 |
| } |
| } |
| |
| if ctxt.Flag_shared != 0 { |
| // Shared libraries use R_ARM_TLS_IE32 instead of |
| // R_ARM_TLS_LE32, replacing the link time constant TLS offset in |
| // runtime.tlsg with an address to a GOT entry containing the |
| // offset. Rewrite $runtime.tlsg(SB) to runtime.tlsg(SB) to |
| // compensate. |
| if ctxt.Tlsg == nil { |
| ctxt.Tlsg = obj.Linklookup(ctxt, "runtime.tlsg", 0) |
| } |
| |
| if p.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && p.From.Sym == ctxt.Tlsg { |
| p.From.Type = obj.TYPE_MEM |
| } |
| if p.To.Type == obj.TYPE_ADDR && p.To.Name == obj.NAME_EXTERN && p.To.Sym == ctxt.Tlsg { |
| p.To.Type = obj.TYPE_MEM |
| } |
| } |
| } |
| |
| // Prog.mark |
| const ( |
| FOLL = 1 << 0 |
| LABEL = 1 << 1 |
| LEAF = 1 << 2 |
| ) |
| |
| func linkcase(casep *obj.Prog) { |
| for p := casep; p != nil; p = p.Link { |
| if p.As == ABCASE { |
| for ; p != nil && p.As == ABCASE; p = p.Link { |
| p.Rel = casep |
| } |
| break |
| } |
| } |
| } |
| |
| func preprocess(ctxt *obj.Link, cursym *obj.LSym) { |
| autosize := int32(0) |
| |
| ctxt.Cursym = cursym |
| |
| if cursym.Text == nil || cursym.Text.Link == nil { |
| return |
| } |
| |
| softfloat(ctxt, cursym) |
| |
| p := cursym.Text |
| autoffset := int32(p.To.Offset) |
| if autoffset < 0 { |
| autoffset = 0 |
| } |
| cursym.Locals = autoffset |
| cursym.Args = p.To.Val.(int32) |
| |
| if ctxt.Debugzerostack != 0 { |
| if autoffset != 0 && p.From3.Offset&obj.NOSPLIT == 0 { |
| // MOVW $4(R13), R1 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_ADDR |
| p.From.Reg = REG_R13 |
| p.From.Offset = 4 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R1 |
| |
| // MOVW $n(R13), R2 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_ADDR |
| p.From.Reg = REG_R13 |
| p.From.Offset = 4 + int64(autoffset) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R2 |
| |
| // MOVW $0, R3 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 0 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R3 |
| |
| // L: |
| // MOVW.nil R3, 0(R1) +4 |
| // CMP R1, R2 |
| // BNE L |
| pl := obj.Appendp(ctxt, p) |
| p := pl |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R3 |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REG_R1 |
| p.To.Offset = 4 |
| p.Scond |= C_PBIT |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R1 |
| p.Reg = REG_R2 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ABNE |
| p.To.Type = obj.TYPE_BRANCH |
| p.Pcond = pl |
| } |
| } |
| |
| /* |
| * find leaf subroutines |
| * strip NOPs |
| * expand RET |
| * expand BECOME pseudo |
| */ |
| var q1 *obj.Prog |
| var q *obj.Prog |
| for p := cursym.Text; p != nil; p = p.Link { |
| switch p.As { |
| case ACASE: |
| if ctxt.Flag_shared != 0 { |
| linkcase(p) |
| } |
| |
| case obj.ATEXT: |
| p.Mark |= LEAF |
| |
| case obj.ARET: |
| break |
| |
| case ADIV, ADIVU, AMOD, AMODU: |
| q = p |
| if ctxt.Sym_div == nil { |
| initdiv(ctxt) |
| } |
| cursym.Text.Mark &^= LEAF |
| continue |
| |
| case obj.ANOP: |
| q1 = p.Link |
| q.Link = q1 /* q is non-nop */ |
| if q1 != nil { |
| q1.Mark |= p.Mark |
| } |
| continue |
| |
| case ABL, |
| ABX, |
| obj.ADUFFZERO, |
| obj.ADUFFCOPY: |
| cursym.Text.Mark &^= LEAF |
| fallthrough |
| |
| case ABCASE, |
| AB, |
| ABEQ, |
| ABNE, |
| ABCS, |
| ABHS, |
| ABCC, |
| ABLO, |
| ABMI, |
| ABPL, |
| ABVS, |
| ABVC, |
| ABHI, |
| ABLS, |
| ABGE, |
| ABLT, |
| ABGT, |
| ABLE: |
| q1 = p.Pcond |
| if q1 != nil { |
| for q1.As == obj.ANOP { |
| q1 = q1.Link |
| p.Pcond = q1 |
| } |
| } |
| } |
| |
| q = p |
| } |
| |
| var o int |
| var p1 *obj.Prog |
| var p2 *obj.Prog |
| var q2 *obj.Prog |
| for p := cursym.Text; p != nil; p = p.Link { |
| o = int(p.As) |
| switch o { |
| case obj.ATEXT: |
| autosize = int32(p.To.Offset + 4) |
| if autosize <= 4 { |
| if cursym.Text.Mark&LEAF != 0 { |
| p.To.Offset = -4 |
| autosize = 0 |
| } |
| } |
| |
| if autosize == 0 && cursym.Text.Mark&LEAF == 0 { |
| if ctxt.Debugvlog != 0 { |
| fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name) |
| ctxt.Bso.Flush() |
| } |
| |
| cursym.Text.Mark |= LEAF |
| } |
| |
| if cursym.Text.Mark&LEAF != 0 { |
| cursym.Leaf = 1 |
| if autosize == 0 { |
| break |
| } |
| } |
| |
| if p.From3.Offset&obj.NOSPLIT == 0 { |
| p = stacksplit(ctxt, p, autosize) // emit split check |
| } |
| |
| // MOVW.W R14,$-autosize(SP) |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.Scond |= C_WBIT |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGLINK |
| p.To.Type = obj.TYPE_MEM |
| p.To.Offset = int64(-autosize) |
| p.To.Reg = REGSP |
| p.Spadj = autosize |
| |
| if cursym.Text.From3.Offset&obj.WRAPPER != 0 { |
| // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame |
| // |
| // MOVW g_panic(g), R1 |
| // CMP $0, R1 |
| // B.EQ end |
| // MOVW panic_argp(R1), R2 |
| // ADD $(autosize+4), R13, R3 |
| // CMP R2, R3 |
| // B.NE end |
| // ADD $4, R13, R4 |
| // MOVW R4, panic_argp(R1) |
| // end: |
| // NOP |
| // |
| // The NOP is needed to give the jumps somewhere to land. |
| // It is a liblink NOP, not an ARM NOP: it encodes to 0 instruction bytes. |
| |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGG |
| p.From.Offset = 4 * int64(ctxt.Arch.Ptrsize) // G.panic |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R1 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 0 |
| p.Reg = REG_R1 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ABEQ |
| p.To.Type = obj.TYPE_BRANCH |
| p1 = p |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REG_R1 |
| p.From.Offset = 0 // Panic.argp |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R2 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AADD |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(autosize) + 4 |
| p.Reg = REG_R13 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R3 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R2 |
| p.Reg = REG_R3 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ABNE |
| p.To.Type = obj.TYPE_BRANCH |
| p2 = p |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AADD |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = 4 |
| p.Reg = REG_R13 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R4 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R4 |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REG_R1 |
| p.To.Offset = 0 // Panic.argp |
| |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = obj.ANOP |
| p1.Pcond = p |
| p2.Pcond = p |
| } |
| |
| case obj.ARET: |
| obj.Nocache(p) |
| if cursym.Text.Mark&LEAF != 0 { |
| if autosize == 0 { |
| p.As = AB |
| p.From = obj.Addr{} |
| if p.To.Sym != nil { // retjmp |
| p.To.Type = obj.TYPE_BRANCH |
| } else { |
| p.To.Type = obj.TYPE_MEM |
| p.To.Offset = 0 |
| p.To.Reg = REGLINK |
| } |
| |
| break |
| } |
| } |
| |
| p.As = AMOVW |
| p.Scond |= C_PBIT |
| p.From.Type = obj.TYPE_MEM |
| p.From.Offset = int64(autosize) |
| p.From.Reg = REGSP |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGPC |
| |
| // If there are instructions following |
| // this ARET, they come from a branch |
| // with the same stackframe, so no spadj. |
| if p.To.Sym != nil { // retjmp |
| p.To.Reg = REGLINK |
| q2 = obj.Appendp(ctxt, p) |
| q2.As = AB |
| q2.To.Type = obj.TYPE_BRANCH |
| q2.To.Sym = p.To.Sym |
| p.To.Sym = nil |
| p = q2 |
| } |
| |
| case AADD: |
| if p.From.Type == obj.TYPE_CONST && p.From.Reg == 0 && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP { |
| p.Spadj = int32(-p.From.Offset) |
| } |
| |
| case ASUB: |
| if p.From.Type == obj.TYPE_CONST && p.From.Reg == 0 && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP { |
| p.Spadj = int32(p.From.Offset) |
| } |
| |
| case ADIV, ADIVU, AMOD, AMODU: |
| if cursym.Text.From3.Offset&obj.NOSPLIT != 0 { |
| ctxt.Diag("cannot divide in NOSPLIT function") |
| } |
| if ctxt.Debugdivmod != 0 { |
| break |
| } |
| if p.From.Type != obj.TYPE_REG { |
| break |
| } |
| if p.To.Type != obj.TYPE_REG { |
| break |
| } |
| |
| // Make copy because we overwrite p below. |
| q1 := *p |
| if q1.Reg == REGTMP || q1.Reg == 0 && q1.To.Reg == REGTMP { |
| ctxt.Diag("div already using REGTMP: %v", p) |
| } |
| |
| /* MOV m(g),REGTMP */ |
| p.As = AMOVW |
| p.Lineno = q1.Lineno |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGG |
| p.From.Offset = 6 * 4 // offset of g.m |
| p.Reg = 0 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGTMP |
| |
| /* MOV a,m_divmod(REGTMP) */ |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.Lineno = q1.Lineno |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = q1.From.Reg |
| p.To.Type = obj.TYPE_MEM |
| p.To.Reg = REGTMP |
| p.To.Offset = 8 * 4 // offset of m.divmod |
| |
| /* MOV b,REGTMP */ |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.Lineno = q1.Lineno |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = q1.Reg |
| if q1.Reg == 0 { |
| p.From.Reg = q1.To.Reg |
| } |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REGTMP |
| p.To.Offset = 0 |
| |
| /* CALL appropriate */ |
| p = obj.Appendp(ctxt, p) |
| p.As = ABL |
| p.Lineno = q1.Lineno |
| p.To.Type = obj.TYPE_BRANCH |
| switch o { |
| case ADIV: |
| p.To.Sym = ctxt.Sym_div |
| |
| case ADIVU: |
| p.To.Sym = ctxt.Sym_divu |
| |
| case AMOD: |
| p.To.Sym = ctxt.Sym_mod |
| |
| case AMODU: |
| p.To.Sym = ctxt.Sym_modu |
| } |
| |
| /* MOV REGTMP, b */ |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.Lineno = q1.Lineno |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REGTMP |
| p.From.Offset = 0 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = q1.To.Reg |
| |
| case AMOVW: |
| if (p.Scond&C_WBIT != 0) && p.To.Type == obj.TYPE_MEM && p.To.Reg == REGSP { |
| p.Spadj = int32(-p.To.Offset) |
| } |
| if (p.Scond&C_PBIT != 0) && p.From.Type == obj.TYPE_MEM && p.From.Reg == REGSP && p.To.Reg != REGPC { |
| p.Spadj = int32(-p.From.Offset) |
| } |
| if p.From.Type == obj.TYPE_ADDR && p.From.Reg == REGSP && p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP { |
| p.Spadj = int32(-p.From.Offset) |
| } |
| } |
| } |
| } |
| |
| func isfloatreg(a *obj.Addr) bool { |
| return a.Type == obj.TYPE_REG && REG_F0 <= a.Reg && a.Reg <= REG_F15 |
| } |
| |
| func softfloat(ctxt *obj.Link, cursym *obj.LSym) { |
| if ctxt.Goarm > 5 { |
| return |
| } |
| |
| symsfloat := obj.Linklookup(ctxt, "_sfloat", 0) |
| |
| wasfloat := 0 |
| for p := cursym.Text; p != nil; p = p.Link { |
| if p.Pcond != nil { |
| p.Pcond.Mark |= LABEL |
| } |
| } |
| var next *obj.Prog |
| for p := cursym.Text; p != nil; p = p.Link { |
| switch p.As { |
| case AMOVW: |
| if isfloatreg(&p.To) || isfloatreg(&p.From) { |
| goto soft |
| } |
| goto notsoft |
| |
| case AMOVWD, |
| AMOVWF, |
| AMOVDW, |
| AMOVFW, |
| AMOVFD, |
| AMOVDF, |
| AMOVF, |
| AMOVD, |
| ACMPF, |
| ACMPD, |
| AADDF, |
| AADDD, |
| ASUBF, |
| ASUBD, |
| AMULF, |
| AMULD, |
| ADIVF, |
| ADIVD, |
| ASQRTF, |
| ASQRTD, |
| AABSF, |
| AABSD: |
| goto soft |
| |
| default: |
| goto notsoft |
| } |
| |
| soft: |
| if wasfloat == 0 || (p.Mark&LABEL != 0) { |
| next = ctxt.NewProg() |
| *next = *p |
| |
| // BL _sfloat(SB) |
| *p = obj.Prog{} |
| p.Ctxt = ctxt |
| p.Link = next |
| p.As = ABL |
| p.To.Type = obj.TYPE_BRANCH |
| p.To.Sym = symsfloat |
| p.Lineno = next.Lineno |
| |
| p = next |
| wasfloat = 1 |
| } |
| |
| continue |
| |
| notsoft: |
| wasfloat = 0 |
| } |
| } |
| |
| func stacksplit(ctxt *obj.Link, p *obj.Prog, framesize int32) *obj.Prog { |
| // MOVW g_stackguard(g), R1 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_MEM |
| p.From.Reg = REGG |
| p.From.Offset = 2 * int64(ctxt.Arch.Ptrsize) // G.stackguard0 |
| if ctxt.Cursym.Cfunc != 0 { |
| p.From.Offset = 3 * int64(ctxt.Arch.Ptrsize) // G.stackguard1 |
| } |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R1 |
| |
| if framesize <= obj.StackSmall { |
| // small stack: SP < stackguard |
| // CMP stackguard, SP |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R1 |
| p.Reg = REGSP |
| } else if framesize <= obj.StackBig { |
| // large stack: SP-framesize < stackguard-StackSmall |
| // MOVW $-framesize(SP), R2 |
| // CMP stackguard, R2 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_ADDR |
| p.From.Reg = REGSP |
| p.From.Offset = int64(-framesize) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R2 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R1 |
| p.Reg = REG_R2 |
| } else { |
| // Such a large stack we need to protect against wraparound |
| // if SP is close to zero. |
| // SP-stackguard+StackGuard < framesize + (StackGuard-StackSmall) |
| // The +StackGuard on both sides is required to keep the left side positive: |
| // SP is allowed to be slightly below stackguard. See stack.h. |
| // CMP $StackPreempt, R1 |
| // MOVW.NE $StackGuard(SP), R2 |
| // SUB.NE R1, R2 |
| // MOVW.NE $(framesize+(StackGuard-StackSmall)), R3 |
| // CMP.NE R3, R2 |
| p = obj.Appendp(ctxt, p) |
| |
| p.As = ACMP |
| p.From.Type = obj.TYPE_CONST |
| p.From.Offset = int64(uint32(obj.StackPreempt & (1<<32 - 1))) |
| p.Reg = REG_R1 |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_ADDR |
| p.From.Reg = REGSP |
| p.From.Offset = obj.StackGuard |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R2 |
| p.Scond = C_SCOND_NE |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ASUB |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R1 |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R2 |
| p.Scond = C_SCOND_NE |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = AMOVW |
| p.From.Type = obj.TYPE_ADDR |
| p.From.Offset = int64(framesize) + (obj.StackGuard - obj.StackSmall) |
| p.To.Type = obj.TYPE_REG |
| p.To.Reg = REG_R3 |
| p.Scond = C_SCOND_NE |
| |
| p = obj.Appendp(ctxt, p) |
| p.As = ACMP |
| p.From.Type = obj.TYPE_REG |
| p.From.Reg = REG_R3 |
| p.Reg = REG_R2 |
| p.Scond = C_SCOND_NE |
| } |
| |
| // BLS call-to-morestack |
| bls := obj.Appendp(ctxt, p) |
| bls.As = ABLS |
| bls.To.Type = obj.TYPE_BRANCH |
| |
| var last *obj.Prog |
| for last = ctxt.Cursym.Text; last.Link != nil; last = last.Link { |
| } |
| |
| // MOVW LR, R3 |
| movw := obj.Appendp(ctxt, last) |
| movw.As = AMOVW |
| movw.From.Type = obj.TYPE_REG |
| movw.From.Reg = REGLINK |
| movw.To.Type = obj.TYPE_REG |
| movw.To.Reg = REG_R3 |
| |
| bls.Pcond = movw |
| |
| // BL runtime.morestack |
| call := obj.Appendp(ctxt, movw) |
| call.As = obj.ACALL |
| call.To.Type = obj.TYPE_BRANCH |
| morestack := "runtime.morestack" |
| switch { |
| case ctxt.Cursym.Cfunc != 0: |
| morestack = "runtime.morestackc" |
| case ctxt.Cursym.Text.From3.Offset&obj.NEEDCTXT == 0: |
| morestack = "runtime.morestack_noctxt" |
| } |
| call.To.Sym = obj.Linklookup(ctxt, morestack, 0) |
| |
| // B start |
| b := obj.Appendp(ctxt, call) |
| b.As = obj.AJMP |
| b.To.Type = obj.TYPE_BRANCH |
| b.Pcond = ctxt.Cursym.Text.Link |
| |
| return bls |
| } |
| |
| func initdiv(ctxt *obj.Link) { |
| if ctxt.Sym_div != nil { |
| return |
| } |
| ctxt.Sym_div = obj.Linklookup(ctxt, "_div", 0) |
| ctxt.Sym_divu = obj.Linklookup(ctxt, "_divu", 0) |
| ctxt.Sym_mod = obj.Linklookup(ctxt, "_mod", 0) |
| ctxt.Sym_modu = obj.Linklookup(ctxt, "_modu", 0) |
| } |
| |
| func follow(ctxt *obj.Link, s *obj.LSym) { |
| ctxt.Cursym = s |
| |
| firstp := ctxt.NewProg() |
| lastp := firstp |
| xfol(ctxt, s.Text, &lastp) |
| lastp.Link = nil |
| s.Text = firstp.Link |
| } |
| |
| func relinv(a int) int { |
| switch a { |
| case ABEQ: |
| return ABNE |
| case ABNE: |
| return ABEQ |
| case ABCS: |
| return ABCC |
| case ABHS: |
| return ABLO |
| case ABCC: |
| return ABCS |
| case ABLO: |
| return ABHS |
| case ABMI: |
| return ABPL |
| case ABPL: |
| return ABMI |
| case ABVS: |
| return ABVC |
| case ABVC: |
| return ABVS |
| case ABHI: |
| return ABLS |
| case ABLS: |
| return ABHI |
| case ABGE: |
| return ABLT |
| case ABLT: |
| return ABGE |
| case ABGT: |
| return ABLE |
| case ABLE: |
| return ABGT |
| } |
| |
| log.Fatalf("unknown relation: %s", Anames[a]) |
| return 0 |
| } |
| |
| func xfol(ctxt *obj.Link, p *obj.Prog, last **obj.Prog) { |
| var q *obj.Prog |
| var r *obj.Prog |
| var a int |
| var i int |
| |
| loop: |
| if p == nil { |
| return |
| } |
| a = int(p.As) |
| if a == AB { |
| q = p.Pcond |
| if q != nil && q.As != obj.ATEXT { |
| p.Mark |= FOLL |
| p = q |
| if p.Mark&FOLL == 0 { |
| goto loop |
| } |
| } |
| } |
| |
| if p.Mark&FOLL != 0 { |
| i = 0 |
| q = p |
| for ; i < 4; i, q = i+1, q.Link { |
| if q == *last || q == nil { |
| break |
| } |
| a = int(q.As) |
| if a == obj.ANOP { |
| i-- |
| continue |
| } |
| |
| if a == AB || (a == obj.ARET && q.Scond == C_SCOND_NONE) || a == ARFE || a == obj.AUNDEF { |
| goto copy |
| } |
| if q.Pcond == nil || (q.Pcond.Mark&FOLL != 0) { |
| continue |
| } |
| if a != ABEQ && a != ABNE { |
| continue |
| } |
| |
| copy: |
| for { |
| r = ctxt.NewProg() |
| *r = *p |
| if r.Mark&FOLL == 0 { |
| fmt.Printf("can't happen 1\n") |
| } |
| r.Mark |= FOLL |
| if p != q { |
| p = p.Link |
| (*last).Link = r |
| *last = r |
| continue |
| } |
| |
| (*last).Link = r |
| *last = r |
| if a == AB || (a == obj.ARET && q.Scond == C_SCOND_NONE) || a == ARFE || a == obj.AUNDEF { |
| return |
| } |
| r.As = ABNE |
| if a == ABNE { |
| r.As = ABEQ |
| } |
| r.Pcond = p.Link |
| r.Link = p.Pcond |
| if r.Link.Mark&FOLL == 0 { |
| xfol(ctxt, r.Link, last) |
| } |
| if r.Pcond.Mark&FOLL == 0 { |
| fmt.Printf("can't happen 2\n") |
| } |
| return |
| } |
| } |
| |
| a = AB |
| q = ctxt.NewProg() |
| q.As = int16(a) |
| q.Lineno = p.Lineno |
| q.To.Type = obj.TYPE_BRANCH |
| q.To.Offset = p.Pc |
| q.Pcond = p |
| p = q |
| } |
| |
| p.Mark |= FOLL |
| (*last).Link = p |
| *last = p |
| if a == AB || (a == obj.ARET && p.Scond == C_SCOND_NONE) || a == ARFE || a == obj.AUNDEF { |
| return |
| } |
| |
| if p.Pcond != nil { |
| if a != ABL && a != ABX && p.Link != nil { |
| q = obj.Brchain(ctxt, p.Link) |
| if a != obj.ATEXT && a != ABCASE { |
| if q != nil && (q.Mark&FOLL != 0) { |
| p.As = int16(relinv(a)) |
| p.Link = p.Pcond |
| p.Pcond = q |
| } |
| } |
| |
| xfol(ctxt, p.Link, last) |
| q = obj.Brchain(ctxt, p.Pcond) |
| if q == nil { |
| q = p.Pcond |
| } |
| if q.Mark&FOLL != 0 { |
| p.Pcond = q |
| return |
| } |
| |
| p = q |
| goto loop |
| } |
| } |
| |
| p = p.Link |
| goto loop |
| } |
| |
| var unaryDst = map[int]bool{ |
| ASWI: true, |
| AWORD: true, |
| } |
| |
| var Linkarm = obj.LinkArch{ |
| ByteOrder: binary.LittleEndian, |
| Name: "arm", |
| Thechar: '5', |
| Preprocess: preprocess, |
| Assemble: span5, |
| Follow: follow, |
| Progedit: progedit, |
| UnaryDst: unaryDst, |
| Minlc: 4, |
| Ptrsize: 4, |
| Regsize: 4, |
| } |
