diff options
Diffstat (limited to 'src/cmd/6l/pass.c')
-rw-r--r-- | src/cmd/6l/pass.c | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/src/cmd/6l/pass.c b/src/cmd/6l/pass.c new file mode 100644 index 000000000..d9e0b2fc1 --- /dev/null +++ b/src/cmd/6l/pass.c @@ -0,0 +1,722 @@ +// Inferno utils/6l/pass.c +// http://code.google.com/p/inferno-os/source/browse/utils/6l/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. + +// Code and data passes. + +#include "l.h" +#include "../ld/lib.h" +#include "../../pkg/runtime/stack.h" + +static void xfol(Prog*, Prog**); + +Prog* +brchain(Prog *p) +{ + int i; + + for(i=0; i<20; i++) { + if(p == P || p->as != AJMP) + return p; + p = p->pcond; + } + return P; +} + +void +follow(void) +{ + Prog *firstp, *lastp; + + if(debug['v']) + Bprint(&bso, "%5.2f follow\n", cputime()); + Bflush(&bso); + + for(cursym = textp; cursym != nil; cursym = cursym->next) { + firstp = prg(); + lastp = firstp; + xfol(cursym->text, &lastp); + lastp->link = nil; + cursym->text = firstp->link; + } +} + +static int +nofollow(int a) +{ + switch(a) { + case AJMP: + case ARET: + case AIRETL: + case AIRETQ: + case AIRETW: + case ARETFL: + case ARETFQ: + case ARETFW: + return 1; + } + return 0; +} + +static int +pushpop(int a) +{ + switch(a) { + case APUSHL: + case APUSHFL: + case APUSHQ: + case APUSHFQ: + case APUSHW: + case APUSHFW: + case APOPL: + case APOPFL: + case APOPQ: + case APOPFQ: + case APOPW: + case APOPFW: + return 1; + } + return 0; +} + +static void +xfol(Prog *p, Prog **last) +{ + Prog *q; + int i; + enum as a; + +loop: + if(p == P) + return; + if(p->as == AJMP) + if((q = p->pcond) != P && 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 == P) + 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 == P || q->pcond->mark) + continue; + if(a == ACALL || a == ALOOP) + continue; + for(;;) { + if(p->as == ANOP) { + p = p->link; + continue; + } + q = copyp(p); + p = p->link; + q->mark = 1; + (*last)->link = q; + *last = q; + if(q->as != a || q->pcond == P || q->pcond->mark) + continue; + + q->as = relinv(q->as); + p = q->pcond; + q->pcond = q->link; + q->link = p; + xfol(q->link, last); + p = q->link; + if(p->mark) + return; + goto loop; + } + } /* */ + q = prg(); + q->as = AJMP; + q->line = p->line; + 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 != P && a != ACALL) { + /* + * some kind of conditional branch. + * recurse to follow one path. + * continue loop on the other. + */ + q = brchain(p->link); + if(q != P && q->mark) + if(a != ALOOP) { + p->as = relinv(a); + p->link = p->pcond; + p->pcond = q; + } + xfol(p->link, last); + q = brchain(p->pcond); + if(q->mark) { + p->pcond = q; + return; + } + p = q; + goto loop; + } + p = p->link; + goto loop; +} + +Prog* +byteq(int v) +{ + Prog *p; + + p = prg(); + p->as = ABYTE; + p->from.type = D_CONST; + p->from.offset = v&0xff; + return p; +} + +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; + } + diag("unknown relation: %s in %s", anames[a], TNAME); + errorexit(); + return a; +} + +void +patch(void) +{ + int32 c; + Prog *p, *q; + Sym *s; + int32 vexit; + + if(debug['v']) + Bprint(&bso, "%5.2f mkfwd\n", cputime()); + Bflush(&bso); + mkfwd(); + if(debug['v']) + Bprint(&bso, "%5.2f patch\n", cputime()); + Bflush(&bso); + + s = lookup("exit", 0); + vexit = s->value; + for(cursym = textp; cursym != nil; cursym = cursym->next) + for(p = cursym->text; p != P; p = p->link) { + if(HEADTYPE == Hwindows) { + // Windows + // Convert + // op n(GS), reg + // to + // MOVL 0x58(GS), reg + // op n(reg), reg + // The purpose of this patch is to fix some accesses + // to extern register variables (TLS) on Windows, as + // a different method is used to access them. + if(p->from.type == D_INDIR+D_GS + && p->to.type >= D_AX && p->to.type <= D_DI + && p->from.offset <= 8) { + q = appendp(p); + q->from = p->from; + q->from.type = D_INDIR + p->to.type; + q->to = p->to; + q->as = p->as; + p->as = AMOVQ; + p->from.type = D_INDIR+D_GS; + p->from.offset = 0x58; + } + } + if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd + || HEADTYPE == Hopenbsd) { + // ELF uses FS instead of GS. + if(p->from.type == D_INDIR+D_GS) + p->from.type = D_INDIR+D_FS; + if(p->to.type == D_INDIR+D_GS) + p->to.type = D_INDIR+D_FS; + } + if(p->as == ACALL || (p->as == AJMP && p->to.type != D_BRANCH)) { + s = p->to.sym; + if(s) { + if(debug['c']) + Bprint(&bso, "%s calls %s\n", TNAME, s->name); + if((s->type&~SSUB) != STEXT) { + /* diag prints TNAME first */ + diag("undefined: %s", s->name); + s->type = STEXT; + s->value = vexit; + continue; // avoid more error messages + } + if(s->text == nil) + continue; + p->to.type = D_BRANCH; + p->to.offset = s->text->pc; + p->pcond = s->text; + continue; + } + } + if(p->to.type != D_BRANCH) + continue; + c = p->to.offset; + for(q = cursym->text; q != P;) { + if(c == q->pc) + break; + if(q->forwd != P && c >= q->forwd->pc) + q = q->forwd; + else + q = q->link; + } + if(q == P) { + diag("branch out of range in %s (%#ux)\n%P [%s]", + TNAME, c, p, p->to.sym ? p->to.sym->name : "<nil>"); + p->to.type = D_NONE; + } + p->pcond = q; + } + + for(cursym = textp; cursym != nil; cursym = cursym->next) + for(p = cursym->text; p != P; p = p->link) { + p->mark = 0; /* initialization for follow */ + if(p->pcond != P) { + p->pcond = brloop(p->pcond); + if(p->pcond != P) + if(p->to.type == D_BRANCH) + p->to.offset = p->pcond->pc; + } + } +} + +Prog* +brloop(Prog *p) +{ + int c; + Prog *q; + + c = 0; + for(q = p; q != P; q = q->pcond) { + if(q->as != AJMP) + break; + c++; + if(c >= 5000) + return P; + } + return q; +} + +static char* +morename[] = +{ + "runtime.morestack00", + "runtime.morestack10", + "runtime.morestack01", + "runtime.morestack11", + + "runtime.morestack8", + "runtime.morestack16", + "runtime.morestack24", + "runtime.morestack32", + "runtime.morestack40", + "runtime.morestack48", +}; +Prog* pmorestack[nelem(morename)]; +Sym* symmorestack[nelem(morename)]; + +void +dostkoff(void) +{ + Prog *p, *q, *q1; + int32 autoffset, deltasp; + int a, pcsize; + uint32 moreconst1, moreconst2, i; + + for(i=0; i<nelem(morename); i++) { + symmorestack[i] = lookup(morename[i], 0); + if(symmorestack[i]->type != STEXT) + diag("morestack trampoline not defined - %s", morename[i]); + pmorestack[i] = symmorestack[i]->text; + } + + for(cursym = textp; cursym != nil; cursym = cursym->next) { + if(cursym->text == nil || cursym->text->link == nil) + continue; + + p = cursym->text; + parsetextconst(p->to.offset); + autoffset = textstksiz; + if(autoffset < 0) + autoffset = 0; + + q = P; + if((p->from.scale & NOSPLIT) && autoffset >= StackSmall) + diag("nosplit func likely to overflow stack"); + + if(!(p->from.scale & NOSPLIT)) { + p = appendp(p); // load g into CX + p->as = AMOVQ; + if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd + || HEADTYPE == Hopenbsd) // ELF uses FS + p->from.type = D_INDIR+D_FS; + else + p->from.type = D_INDIR+D_GS; + p->from.offset = tlsoffset+0; + p->to.type = D_CX; + if(HEADTYPE == Hwindows) { + // movq %gs:0x58, %rcx + // movq (%rcx), %rcx + p->as = AMOVQ; + p->from.type = D_INDIR+D_GS; + p->from.offset = 0x58; + p->to.type = D_CX; + + + p = appendp(p); + p->as = AMOVQ; + p->from.type = D_INDIR+D_CX; + p->from.offset = 0; + p->to.type = D_CX; + } + + if(debug['K']) { + // 6l -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(p); + p->as = ACMPQ; + p->from.type = D_INDIR+D_CX; + p->from.offset = 8; + p->to.type = D_SP; + + p = appendp(p); + p->as = AJHI; + p->to.type = D_BRANCH; + p->to.offset = 4; + q1 = p; + + p = appendp(p); + p->as = AINT; + p->from.type = D_CONST; + p->from.offset = 3; + + p = appendp(p); + p->as = ANOP; + q1->pcond = p; + } + + if(autoffset < StackBig) { // do we need to call morestack? + if(autoffset <= StackSmall) { + // small stack + p = appendp(p); + p->as = ACMPQ; + p->from.type = D_SP; + p->to.type = D_INDIR+D_CX; + } else { + // large stack + p = appendp(p); + p->as = ALEAQ; + p->from.type = D_INDIR+D_SP; + p->from.offset = -(autoffset-StackSmall); + p->to.type = D_AX; + + p = appendp(p); + p->as = ACMPQ; + p->from.type = D_AX; + p->to.type = D_INDIR+D_CX; + } + + // common + p = appendp(p); + p->as = AJHI; + p->to.type = D_BRANCH; + p->to.offset = 4; + q = p; + } + + /* 160 comes from 3 calls (3*8) 4 safes (4*8) and 104 guard */ + moreconst1 = 0; + if(autoffset+160+textarg > 4096) + moreconst1 = (autoffset+160) & ~7LL; + moreconst2 = textarg; + + // 4 varieties varieties (const1==0 cross const2==0) + // and 6 subvarieties of (const1==0 and const2!=0) + p = appendp(p); + if(moreconst1 == 0 && moreconst2 == 0) { + p->as = ACALL; + p->to.type = D_BRANCH; + p->pcond = pmorestack[0]; + p->to.sym = symmorestack[0]; + } else + if(moreconst1 != 0 && moreconst2 == 0) { + p->as = AMOVL; + p->from.type = D_CONST; + p->from.offset = moreconst1; + p->to.type = D_AX; + + p = appendp(p); + p->as = ACALL; + p->to.type = D_BRANCH; + p->pcond = pmorestack[1]; + p->to.sym = symmorestack[1]; + } else + if(moreconst1 == 0 && moreconst2 <= 48 && moreconst2%8 == 0) { + i = moreconst2/8 + 3; + p->as = ACALL; + p->to.type = D_BRANCH; + p->pcond = pmorestack[i]; + p->to.sym = symmorestack[i]; + } else + if(moreconst1 == 0 && moreconst2 != 0) { + p->as = AMOVL; + p->from.type = D_CONST; + p->from.offset = moreconst2; + p->to.type = D_AX; + + p = appendp(p); + p->as = ACALL; + p->to.type = D_BRANCH; + p->pcond = pmorestack[2]; + p->to.sym = symmorestack[2]; + } else { + p->as = AMOVQ; + p->from.type = D_CONST; + p->from.offset = (uint64)moreconst2 << 32; + p->from.offset |= moreconst1; + p->to.type = D_AX; + + p = appendp(p); + p->as = ACALL; + p->to.type = D_BRANCH; + p->pcond = pmorestack[3]; + p->to.sym = symmorestack[3]; + } + } + + if(q != P) + q->pcond = p->link; + + if(autoffset) { + p = appendp(p); + p->as = AADJSP; + p->from.type = D_CONST; + p->from.offset = autoffset; + p->spadj = autoffset; + if(q != P) + q->pcond = p; + } + deltasp = autoffset; + + if(debug['K'] > 1 && autoffset) { + // 6l -KK means double-check for stack overflow + // even after calling morestack and even if the + // function is marked as nosplit. + p = appendp(p); + p->as = AMOVQ; + p->from.type = D_INDIR+D_CX; + p->from.offset = 0; + p->to.type = D_BX; + + p = appendp(p); + p->as = ASUBQ; + p->from.type = D_CONST; + p->from.offset = StackSmall+32; + p->to.type = D_BX; + + p = appendp(p); + p->as = ACMPQ; + p->from.type = D_SP; + p->to.type = D_BX; + + p = appendp(p); + p->as = AJHI; + p->to.type = D_BRANCH; + q1 = p; + + p = appendp(p); + p->as = AINT; + p->from.type = D_CONST; + p->from.offset = 3; + + p = appendp(p); + p->as = ANOP; + q1->pcond = p; + } + + for(; p != P; p = p->link) { + pcsize = p->mode/8; + a = p->from.type; + if(a == D_AUTO) + p->from.offset += deltasp; + if(a == D_PARAM) + p->from.offset += deltasp + pcsize; + a = p->to.type; + if(a == D_AUTO) + p->to.offset += deltasp; + if(a == D_PARAM) + p->to.offset += deltasp + pcsize; + + switch(p->as) { + default: + continue; + case APUSHL: + case APUSHFL: + deltasp += 4; + p->spadj = 4; + continue; + case APUSHQ: + case APUSHFQ: + deltasp += 8; + p->spadj = 8; + continue; + case APUSHW: + case APUSHFW: + deltasp += 2; + p->spadj = 2; + continue; + case APOPL: + case APOPFL: + deltasp -= 4; + p->spadj = -4; + continue; + case APOPQ: + case APOPFQ: + deltasp -= 8; + p->spadj = -8; + continue; + case APOPW: + case APOPFW: + deltasp -= 2; + p->spadj = -2; + continue; + case ARET: + break; + } + + if(autoffset != deltasp) + diag("unbalanced PUSH/POP"); + + if(autoffset) { + p->as = AADJSP; + p->from.type = D_CONST; + p->from.offset = -autoffset; + p->spadj = -autoffset; + p = appendp(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; + } + } + } +} + +vlong +atolwhex(char *s) +{ + vlong n; + int f; + + n = 0; + f = 0; + while(*s == ' ' || *s == '\t') + s++; + if(*s == '-' || *s == '+') { + if(*s++ == '-') + f = 1; + while(*s == ' ' || *s == '\t') + s++; + } + if(s[0]=='0' && s[1]){ + if(s[1]=='x' || s[1]=='X'){ + s += 2; + for(;;){ + if(*s >= '0' && *s <= '9') + n = n*16 + *s++ - '0'; + else if(*s >= 'a' && *s <= 'f') + n = n*16 + *s++ - 'a' + 10; + else if(*s >= 'A' && *s <= 'F') + n = n*16 + *s++ - 'A' + 10; + else + break; + } + } else + while(*s >= '0' && *s <= '7') + n = n*8 + *s++ - '0'; + } else + while(*s >= '0' && *s <= '9') + n = n*10 + *s++ - '0'; + if(f) + n = -n; + return n; +} |