| // Inferno utils/8l/pass.c |
| // http://code.google.com/p/inferno-os/source/browse/utils/8l/pass.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. |
| |
| #include <u.h> |
| #include <libc.h> |
| #include <bio.h> |
| #include <link.h> |
| #include "../cmd/8l/8.out.h" |
| #include "../pkg/runtime/stack.h" |
| |
| static Prog zprg = { |
| .back = 2, |
| .as = AGOK, |
| .from = { |
| .type = D_NONE, |
| .index = D_NONE, |
| .scale = 1, |
| }, |
| .to = { |
| .type = D_NONE, |
| .index = D_NONE, |
| .scale = 1, |
| }, |
| }; |
| |
| static int |
| symtype(Addr *a) |
| { |
| int t; |
| |
| t = a->type; |
| if(t == D_ADDR) |
| t = a->index; |
| return t; |
| } |
| |
| static int |
| isdata(Prog *p) |
| { |
| return p->as == ADATA || p->as == AGLOBL; |
| } |
| |
| static int |
| iscall(Prog *p) |
| { |
| return p->as == ACALL; |
| } |
| |
| static int |
| datasize(Prog *p) |
| { |
| return p->from.scale; |
| } |
| |
| static int |
| textflag(Prog *p) |
| { |
| return p->from.scale; |
| } |
| |
| static void |
| settextflag(Prog *p, int f) |
| { |
| p->from.scale = f; |
| } |
| |
| static int |
| canuselocaltls(Link *ctxt) |
| { |
| switch(ctxt->headtype) { |
| case Hlinux: |
| case Hnacl: |
| case Hplan9: |
| case Hwindows: |
| return 0; |
| } |
| return 1; |
| } |
| |
| static void |
| progedit(Link *ctxt, Prog *p) |
| { |
| char literal[64]; |
| LSym *s; |
| Prog *q; |
| |
| // See obj6.c for discussion of TLS. |
| if(canuselocaltls(ctxt)) { |
| // Reduce TLS initial exec model to TLS local exec model. |
| // Sequences like |
| // MOVL TLS, BX |
| // ... off(BX)(TLS*1) ... |
| // become |
| // NOP |
| // ... off(TLS) ... |
| if(p->as == AMOVL && p->from.type == D_TLS && D_AX <= p->to.type && p->to.type <= D_DI) { |
| p->as = ANOP; |
| p->from.type = D_NONE; |
| p->to.type = D_NONE; |
| } |
| if(p->from.index == D_TLS && D_INDIR+D_AX <= p->from.type && p->from.type <= D_INDIR+D_DI) { |
| p->from.type = D_INDIR+D_TLS; |
| p->from.scale = 0; |
| p->from.index = D_NONE; |
| } |
| if(p->to.index == D_TLS && D_INDIR+D_AX <= p->to.type && p->to.type <= D_INDIR+D_DI) { |
| p->to.type = D_INDIR+D_TLS; |
| p->to.scale = 0; |
| p->to.index = D_NONE; |
| } |
| } else { |
| // As a courtesy to the C compilers, rewrite TLS local exec load as TLS initial exec load. |
| // The instruction |
| // MOVL off(TLS), BX |
| // becomes the sequence |
| // MOVL TLS, BX |
| // MOVL off(BX)(TLS*1), BX |
| // This allows the C compilers to emit references to m and g using the direct off(TLS) form. |
| if(p->as == AMOVL && p->from.type == D_INDIR+D_TLS && D_AX <= p->to.type && p->to.type <= D_DI) { |
| q = appendp(ctxt, p); |
| q->as = p->as; |
| q->from = p->from; |
| q->from.type = D_INDIR + p->to.type; |
| q->from.index = D_TLS; |
| q->from.scale = 2; // TODO: use 1 |
| q->to = p->to; |
| p->from.type = D_TLS; |
| p->from.index = D_NONE; |
| p->from.offset = 0; |
| } |
| } |
| |
| // TODO: Remove. |
| if(ctxt->headtype == Hplan9) { |
| if(p->from.scale == 1 && p->from.index == D_TLS) |
| p->from.scale = 2; |
| if(p->to.scale == 1 && p->to.index == D_TLS) |
| p->to.scale = 2; |
| } |
| |
| // Rewrite CALL/JMP/RET to symbol as D_BRANCH. |
| switch(p->as) { |
| case ACALL: |
| case AJMP: |
| case ARET: |
| if((p->to.type == D_EXTERN || p->to.type == D_STATIC) && p->to.sym != nil) |
| p->to.type = D_BRANCH; |
| break; |
| } |
| |
| // Rewrite float constants to values stored in memory. |
| switch(p->as) { |
| case AFMOVF: |
| case AFADDF: |
| case AFSUBF: |
| case AFSUBRF: |
| case AFMULF: |
| case AFDIVF: |
| case AFDIVRF: |
| case AFCOMF: |
| case AFCOMFP: |
| case AMOVSS: |
| case AADDSS: |
| case ASUBSS: |
| case AMULSS: |
| case ADIVSS: |
| case ACOMISS: |
| case AUCOMISS: |
| if(p->from.type == D_FCONST) { |
| int32 i32; |
| float32 f32; |
| f32 = p->from.u.dval; |
| memmove(&i32, &f32, 4); |
| sprint(literal, "$f32.%08ux", (uint32)i32); |
| s = linklookup(ctxt, literal, 0); |
| if(s->type == 0) { |
| s->type = SRODATA; |
| adduint32(ctxt, s, i32); |
| s->reachable = 0; |
| } |
| p->from.type = D_EXTERN; |
| p->from.sym = s; |
| p->from.offset = 0; |
| } |
| break; |
| |
| case AFMOVD: |
| case AFADDD: |
| case AFSUBD: |
| case AFSUBRD: |
| case AFMULD: |
| case AFDIVD: |
| case AFDIVRD: |
| case AFCOMD: |
| case AFCOMDP: |
| case AMOVSD: |
| case AADDSD: |
| case ASUBSD: |
| case AMULSD: |
| case ADIVSD: |
| case ACOMISD: |
| case AUCOMISD: |
| if(p->from.type == D_FCONST) { |
| int64 i64; |
| memmove(&i64, &p->from.u.dval, 8); |
| sprint(literal, "$f64.%016llux", (uvlong)i64); |
| s = linklookup(ctxt, literal, 0); |
| if(s->type == 0) { |
| s->type = SRODATA; |
| adduint64(ctxt, s, i64); |
| s->reachable = 0; |
| } |
| p->from.type = D_EXTERN; |
| p->from.sym = s; |
| p->from.offset = 0; |
| } |
| break; |
| } |
| } |
| |
| static Prog* |
| prg(void) |
| { |
| Prog *p; |
| |
| p = emallocz(sizeof(*p)); |
| *p = zprg; |
| return p; |
| } |
| |
| static Prog* load_g_cx(Link*, Prog*); |
| static Prog* stacksplit(Link*, Prog*, int32, int, Prog**); |
| |
| static void |
| addstacksplit(Link *ctxt, LSym *cursym) |
| { |
| Prog *p, *q; |
| int32 autoffset, deltasp; |
| int a; |
| |
| if(ctxt->symmorestack[0] == nil) { |
| ctxt->symmorestack[0] = linklookup(ctxt, "runtime.morestack", 0); |
| ctxt->symmorestack[1] = linklookup(ctxt, "runtime.morestack_noctxt", 0); |
| } |
| |
| if(ctxt->headtype == Hplan9 && ctxt->plan9tos == nil) |
| ctxt->plan9tos = linklookup(ctxt, "_tos", 0); |
| |
| ctxt->cursym = cursym; |
| |
| if(cursym->text == nil || cursym->text->link == nil) |
| return; |
| |
| p = cursym->text; |
| autoffset = p->to.offset; |
| if(autoffset < 0) |
| autoffset = 0; |
| |
| cursym->locals = autoffset; |
| cursym->args = p->to.offset2; |
| |
| q = nil; |
| |
| if(!(p->from.scale & NOSPLIT) || (p->from.scale & WRAPPER)) { |
| p = appendp(ctxt, p); |
| p = load_g_cx(ctxt, p); // load g into CX |
| } |
| if(!(cursym->text->from.scale & NOSPLIT)) |
| p = stacksplit(ctxt, p, autoffset, !(cursym->text->from.scale&NEEDCTXT), &q); // emit split check |
| |
| if(autoffset) { |
| p = appendp(ctxt, p); |
| p->as = AADJSP; |
| p->from.type = D_CONST; |
| p->from.offset = autoffset; |
| p->spadj = autoffset; |
| } else { |
| // zero-byte stack adjustment. |
| // Insert a fake non-zero adjustment so that stkcheck can |
| // recognize the end of the stack-splitting prolog. |
| p = appendp(ctxt, p); |
| p->as = ANOP; |
| p->spadj = -ctxt->arch->ptrsize; |
| p = appendp(ctxt, p); |
| p->as = ANOP; |
| p->spadj = ctxt->arch->ptrsize; |
| } |
| if(q != nil) |
| q->pcond = p; |
| deltasp = autoffset; |
| |
| if(cursym->text->from.scale & WRAPPER) { |
| // g->panicwrap += autoffset + ctxt->arch->ptrsize; |
| p = appendp(ctxt, p); |
| p->as = AADDL; |
| p->from.type = D_CONST; |
| p->from.offset = autoffset + ctxt->arch->ptrsize; |
| p->to.type = D_INDIR+D_CX; |
| p->to.offset = 2*ctxt->arch->ptrsize; |
| } |
| |
| if(ctxt->debugzerostack && autoffset && !(cursym->text->from.scale&NOSPLIT)) { |
| // 8l -Z means zero the stack frame on entry. |
| // This slows down function calls but can help avoid |
| // false positives in garbage collection. |
| p = appendp(ctxt, p); |
| p->as = AMOVL; |
| p->from.type = D_SP; |
| p->to.type = D_DI; |
| |
| p = appendp(ctxt, p); |
| p->as = AMOVL; |
| p->from.type = D_CONST; |
| p->from.offset = autoffset/4; |
| p->to.type = D_CX; |
| |
| p = appendp(ctxt, p); |
| p->as = AMOVL; |
| p->from.type = D_CONST; |
| p->from.offset = 0; |
| p->to.type = D_AX; |
| |
| p = appendp(ctxt, p); |
| p->as = AREP; |
| |
| p = appendp(ctxt, p); |
| p->as = ASTOSL; |
| } |
| |
| for(; p != nil; p = p->link) { |
| a = p->from.type; |
| if(a == D_AUTO) |
| p->from.offset += deltasp; |
| if(a == D_PARAM) |
| p->from.offset += deltasp + 4; |
| a = p->to.type; |
| if(a == D_AUTO) |
| p->to.offset += deltasp; |
| if(a == D_PARAM) |
| p->to.offset += deltasp + 4; |
| |
| switch(p->as) { |
| default: |
| continue; |
| case APUSHL: |
| case APUSHFL: |
| deltasp += 4; |
| p->spadj = 4; |
| continue; |
| case APUSHW: |
| case APUSHFW: |
| deltasp += 2; |
| p->spadj = 2; |
| continue; |
| case APOPL: |
| case APOPFL: |
| deltasp -= 4; |
| p->spadj = -4; |
| continue; |
| case APOPW: |
| case APOPFW: |
| deltasp -= 2; |
| p->spadj = -2; |
| continue; |
| case ARET: |
| break; |
| } |
| |
| if(autoffset != deltasp) |
| ctxt->diag("unbalanced PUSH/POP"); |
| |
| if(cursym->text->from.scale & WRAPPER) { |
| p = load_g_cx(ctxt, p); |
| p = appendp(ctxt, p); |
| // g->panicwrap -= autoffset + ctxt->arch->ptrsize; |
| p->as = ASUBL; |
| p->from.type = D_CONST; |
| p->from.offset = autoffset + ctxt->arch->ptrsize; |
| p->to.type = D_INDIR+D_CX; |
| p->to.offset = 2*ctxt->arch->ptrsize; |
| p = appendp(ctxt, p); |
| p->as = ARET; |
| } |
| |
| if(autoffset) { |
| p->as = AADJSP; |
| p->from.type = D_CONST; |
| p->from.offset = -autoffset; |
| p->spadj = -autoffset; |
| p = appendp(ctxt, p); |
| p->as = ARET; |
| // If there are instructions following |
| // this ARET, they come from a branch |
| // with the same stackframe, so undo |
| // the cleanup. |
| p->spadj = +autoffset; |
| } |
| if(p->to.sym) // retjmp |
| p->as = AJMP; |
| } |
| } |
| |
| // Append code to p to load g into cx. |
| // Overwrites p with the first instruction (no first appendp). |
| // Overwriting p is unusual but it lets use this in both the |
| // prologue (caller must call appendp first) and in the epilogue. |
| // Returns last new instruction. |
| static Prog* |
| load_g_cx(Link *ctxt, Prog *p) |
| { |
| Prog *next; |
| |
| p->as = AMOVL; |
| p->from.type = D_INDIR+D_TLS; |
| p->from.offset = 0; |
| p->to.type = D_CX; |
| |
| next = p->link; |
| progedit(ctxt, p); |
| while(p->link != next) |
| p = p->link; |
| |
| if(p->from.index == D_TLS) |
| p->from.scale = 2; |
| |
| return p; |
| } |
| |
| // Append code to p to check for stack split. |
| // Appends to (does not overwrite) p. |
| // Assumes g is in CX. |
| // Returns last new instruction. |
| // On return, *jmpok is the instruction that should jump |
| // to the stack frame allocation if no split is needed. |
| static Prog* |
| stacksplit(Link *ctxt, Prog *p, int32 framesize, int noctxt, Prog **jmpok) |
| { |
| Prog *q, *q1; |
| int arg; |
| |
| if(ctxt->debugstack) { |
| // 8l -K means check not only for stack |
| // overflow but stack underflow. |
| // On underflow, INT 3 (breakpoint). |
| // Underflow itself is rare but this also |
| // catches out-of-sync stack guard info. |
| p = appendp(ctxt, p); |
| p->as = ACMPL; |
| p->from.type = D_INDIR+D_CX; |
| p->from.offset = 4; |
| p->to.type = D_SP; |
| |
| p = appendp(ctxt, p); |
| p->as = AJCC; |
| p->to.type = D_BRANCH; |
| p->to.offset = 4; |
| q1 = p; |
| |
| p = appendp(ctxt, p); |
| p->as = AINT; |
| p->from.type = D_CONST; |
| p->from.offset = 3; |
| |
| p = appendp(ctxt, p); |
| p->as = ANOP; |
| q1->pcond = p; |
| } |
| q1 = nil; |
| |
| if(framesize <= StackSmall) { |
| // small stack: SP <= stackguard |
| // CMPL SP, stackguard |
| p = appendp(ctxt, p); |
| p->as = ACMPL; |
| p->from.type = D_SP; |
| p->to.type = D_INDIR+D_CX; |
| } else if(framesize <= StackBig) { |
| // large stack: SP-framesize <= stackguard-StackSmall |
| // LEAL -(framesize-StackSmall)(SP), AX |
| // CMPL AX, stackguard |
| p = appendp(ctxt, p); |
| p->as = ALEAL; |
| p->from.type = D_INDIR+D_SP; |
| p->from.offset = -(framesize-StackSmall); |
| p->to.type = D_AX; |
| |
| p = appendp(ctxt, p); |
| p->as = ACMPL; |
| p->from.type = D_AX; |
| p->to.type = D_INDIR+D_CX; |
| } 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. |
| // |
| // Preemption sets stackguard to StackPreempt, a very large value. |
| // That breaks the math above, so we have to check for that explicitly. |
| // MOVL stackguard, CX |
| // CMPL CX, $StackPreempt |
| // JEQ label-of-call-to-morestack |
| // LEAL StackGuard(SP), AX |
| // SUBL stackguard, AX |
| // CMPL AX, $(framesize+(StackGuard-StackSmall)) |
| p = appendp(ctxt, p); |
| p->as = AMOVL; |
| p->from.type = D_INDIR+D_CX; |
| p->from.offset = 0; |
| p->to.type = D_SI; |
| |
| p = appendp(ctxt, p); |
| p->as = ACMPL; |
| p->from.type = D_SI; |
| p->to.type = D_CONST; |
| p->to.offset = (uint32)StackPreempt; |
| |
| p = appendp(ctxt, p); |
| p->as = AJEQ; |
| p->to.type = D_BRANCH; |
| q1 = p; |
| |
| p = appendp(ctxt, p); |
| p->as = ALEAL; |
| p->from.type = D_INDIR+D_SP; |
| p->from.offset = StackGuard; |
| p->to.type = D_AX; |
| |
| p = appendp(ctxt, p); |
| p->as = ASUBL; |
| p->from.type = D_SI; |
| p->from.offset = 0; |
| p->to.type = D_AX; |
| |
| p = appendp(ctxt, p); |
| p->as = ACMPL; |
| p->from.type = D_AX; |
| p->to.type = D_CONST; |
| p->to.offset = framesize+(StackGuard-StackSmall); |
| } |
| |
| // common |
| p = appendp(ctxt, p); |
| p->as = AJHI; |
| p->to.type = D_BRANCH; |
| p->to.offset = 4; |
| q = p; |
| |
| p = appendp(ctxt, p); // save frame size in DI |
| p->as = AMOVL; |
| p->to.type = D_DI; |
| p->from.type = D_CONST; |
| |
| // If we ask for more stack, we'll get a minimum of StackMin bytes. |
| // We need a stack frame large enough to hold the top-of-stack data, |
| // the function arguments+results, our caller's PC, our frame, |
| // a word for the return PC of the next call, and then the StackLimit bytes |
| // that must be available on entry to any function called from a function |
| // that did a stack check. If StackMin is enough, don't ask for a specific |
| // amount: then we can use the custom functions and save a few |
| // instructions. |
| if(StackTop + ctxt->cursym->text->to.offset2 + ctxt->arch->ptrsize + framesize + ctxt->arch->ptrsize + StackLimit >= StackMin) |
| p->from.offset = (framesize+7) & ~7LL; |
| |
| arg = ctxt->cursym->text->to.offset2; |
| if(arg == 1) // special marker for known 0 |
| arg = 0; |
| if(arg&3) |
| ctxt->diag("misaligned argument size in stack split"); |
| p = appendp(ctxt, p); // save arg size in AX |
| p->as = AMOVL; |
| p->to.type = D_AX; |
| p->from.type = D_CONST; |
| p->from.offset = arg; |
| |
| p = appendp(ctxt, p); |
| p->as = ACALL; |
| p->to.type = D_BRANCH; |
| p->to.sym = ctxt->symmorestack[noctxt]; |
| |
| p = appendp(ctxt, p); |
| p->as = AJMP; |
| p->to.type = D_BRANCH; |
| p->pcond = ctxt->cursym->text->link; |
| |
| if(q != nil) |
| q->pcond = p->link; |
| if(q1 != nil) |
| q1->pcond = q->link; |
| |
| *jmpok = q; |
| return p; |
| } |
| |
| static void xfol(Link*, Prog*, Prog**); |
| |
| static void |
| follow(Link *ctxt, LSym *s) |
| { |
| Prog *firstp, *lastp; |
| |
| ctxt->cursym = s; |
| |
| firstp = ctxt->arch->prg(); |
| lastp = firstp; |
| xfol(ctxt, s->text, &lastp); |
| lastp->link = nil; |
| s->text = firstp->link; |
| } |
| |
| static int |
| nofollow(int a) |
| { |
| switch(a) { |
| case AJMP: |
| case ARET: |
| case AIRETL: |
| case AIRETW: |
| case AUNDEF: |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int |
| pushpop(int a) |
| { |
| switch(a) { |
| case APUSHL: |
| case APUSHFL: |
| case APUSHW: |
| case APUSHFW: |
| case APOPL: |
| case APOPFL: |
| case APOPW: |
| case APOPFW: |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int |
| relinv(int a) |
| { |
| |
| switch(a) { |
| case AJEQ: return AJNE; |
| case AJNE: return AJEQ; |
| case AJLE: return AJGT; |
| case AJLS: return AJHI; |
| case AJLT: return AJGE; |
| case AJMI: return AJPL; |
| case AJGE: return AJLT; |
| case AJPL: return AJMI; |
| case AJGT: return AJLE; |
| case AJHI: return AJLS; |
| case AJCS: return AJCC; |
| case AJCC: return AJCS; |
| case AJPS: return AJPC; |
| case AJPC: return AJPS; |
| case AJOS: return AJOC; |
| case AJOC: return AJOS; |
| } |
| sysfatal("unknown relation: %s", anames8[a]); |
| return 0; |
| } |
| |
| static void |
| xfol(Link *ctxt, Prog *p, Prog **last) |
| { |
| Prog *q; |
| int i; |
| enum as a; |
| |
| loop: |
| if(p == nil) |
| return; |
| if(p->as == AJMP) |
| if((q = p->pcond) != nil && q->as != ATEXT) { |
| /* mark instruction as done and continue layout at target of jump */ |
| p->mark = 1; |
| p = q; |
| if(p->mark == 0) |
| goto loop; |
| } |
| if(p->mark) { |
| /* |
| * p goes here, but already used it elsewhere. |
| * copy up to 4 instructions or else branch to other copy. |
| */ |
| for(i=0,q=p; i<4; i++,q=q->link) { |
| if(q == nil) |
| break; |
| if(q == *last) |
| break; |
| a = q->as; |
| if(a == ANOP) { |
| i--; |
| continue; |
| } |
| if(nofollow(a) || pushpop(a)) |
| break; // NOTE(rsc): arm does goto copy |
| if(q->pcond == nil || q->pcond->mark) |
| continue; |
| if(a == ACALL || a == ALOOP) |
| continue; |
| for(;;) { |
| if(p->as == ANOP) { |
| p = p->link; |
| continue; |
| } |
| q = copyp(ctxt, p); |
| p = p->link; |
| q->mark = 1; |
| (*last)->link = q; |
| *last = q; |
| if(q->as != a || q->pcond == nil || q->pcond->mark) |
| continue; |
| |
| q->as = relinv(q->as); |
| p = q->pcond; |
| q->pcond = q->link; |
| q->link = p; |
| xfol(ctxt, q->link, last); |
| p = q->link; |
| if(p->mark) |
| return; |
| goto loop; |
| } |
| } /* */ |
| q = ctxt->arch->prg(); |
| q->as = AJMP; |
| q->lineno = p->lineno; |
| q->to.type = D_BRANCH; |
| q->to.offset = p->pc; |
| q->pcond = p; |
| p = q; |
| } |
| |
| /* emit p */ |
| p->mark = 1; |
| (*last)->link = p; |
| *last = p; |
| a = p->as; |
| |
| /* continue loop with what comes after p */ |
| if(nofollow(a)) |
| return; |
| if(p->pcond != nil && a != ACALL) { |
| /* |
| * some kind of conditional branch. |
| * recurse to follow one path. |
| * continue loop on the other. |
| */ |
| if((q = brchain(ctxt, p->pcond)) != nil) |
| p->pcond = q; |
| if((q = brchain(ctxt, p->link)) != nil) |
| p->link = q; |
| if(p->from.type == D_CONST) { |
| if(p->from.offset == 1) { |
| /* |
| * expect conditional jump to be taken. |
| * rewrite so that's the fall-through case. |
| */ |
| p->as = relinv(a); |
| q = p->link; |
| p->link = p->pcond; |
| p->pcond = q; |
| } |
| } else { |
| q = p->link; |
| if(q->mark) |
| if(a != ALOOP) { |
| p->as = relinv(a); |
| p->link = p->pcond; |
| p->pcond = q; |
| } |
| } |
| xfol(ctxt, p->link, last); |
| if(p->pcond->mark) |
| return; |
| p = p->pcond; |
| goto loop; |
| } |
| p = p->link; |
| goto loop; |
| } |
| |
| LinkArch link386 = { |
| .name = "386", |
| .thechar = '8', |
| |
| .addstacksplit = addstacksplit, |
| .assemble = span8, |
| .datasize = datasize, |
| .follow = follow, |
| .iscall = iscall, |
| .isdata = isdata, |
| .prg = prg, |
| .progedit = progedit, |
| .settextflag = settextflag, |
| .symtype = symtype, |
| .textflag = textflag, |
| |
| .minlc = 1, |
| .ptrsize = 4, |
| .regsize = 4, |
| |
| .D_ADDR = D_ADDR, |
| .D_AUTO = D_AUTO, |
| .D_BRANCH = D_BRANCH, |
| .D_CONST = D_CONST, |
| .D_EXTERN = D_EXTERN, |
| .D_FCONST = D_FCONST, |
| .D_NONE = D_NONE, |
| .D_PARAM = D_PARAM, |
| .D_SCONST = D_SCONST, |
| .D_STATIC = D_STATIC, |
| |
| .ACALL = ACALL, |
| .ADATA = ADATA, |
| .AEND = AEND, |
| .AFUNCDATA = AFUNCDATA, |
| .AGLOBL = AGLOBL, |
| .AJMP = AJMP, |
| .ANOP = ANOP, |
| .APCDATA = APCDATA, |
| .ARET = ARET, |
| .ATEXT = ATEXT, |
| .ATYPE = ATYPE, |
| .AUSEFIELD = AUSEFIELD, |
| }; |