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-rw-r--r--src/cmd/6l/pass.c991
1 files changed, 0 insertions, 991 deletions
diff --git a/src/cmd/6l/pass.c b/src/cmd/6l/pass.c
deleted file mode 100644
index 1be3c18fe..000000000
--- a/src/cmd/6l/pass.c
+++ /dev/null
@@ -1,991 +0,0 @@
-// 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:
- case AUNDEF:
- 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.
- */
- if((q = brchain(p->pcond)) != P)
- p->pcond = q;
- if((q = brchain(p->link)) != P)
- 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(p->link, last);
- if(p->pcond->mark)
- return;
- p = p->pcond;
- 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;
- Sym *gmsym;
-
- 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);
-
- if(flag_shared) {
- s = lookup("init_array", 0);
- s->type = SINITARR;
- s->reachable = 1;
- s->hide = 1;
- addaddr(s, lookup(INITENTRY, 0));
- }
-
- gmsym = lookup("runtime.tlsgm", 0);
- if(linkmode != LinkExternal)
- gmsym->reachable = 0;
- 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 0x28(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 = 0x28;
- }
- }
- if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd
- || HEADTYPE == Hopenbsd || HEADTYPE == Hnetbsd
- || HEADTYPE == Hplan9x64 || HEADTYPE == Hdragonfly) {
- // 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->from.index == D_GS)
- p->from.index = D_FS;
- if(p->to.index == D_GS)
- p->to.index = D_FS;
- }
- if(!flag_shared) {
- // Convert g() or m() accesses of the form
- // op n(reg)(GS*1), reg
- // to
- // op n(GS*1), reg
- if(p->from.index == D_FS || p->from.index == D_GS) {
- p->from.type = D_INDIR + p->from.index;
- p->from.index = D_NONE;
- }
- // Convert g() or m() accesses of the form
- // op reg, n(reg)(GS*1)
- // to
- // op reg, n(GS*1)
- if(p->to.index == D_FS || p->to.index == D_GS) {
- p->to.type = D_INDIR + p->to.index;
- p->to.index = D_NONE;
- }
- // Convert get_tls access of the form
- // op runtime.tlsgm(SB), reg
- // to
- // NOP
- if(gmsym != S && p->from.sym == gmsym) {
- p->as = ANOP;
- p->from.type = D_NONE;
- p->to.type = D_NONE;
- p->from.sym = nil;
- p->to.sym = nil;
- continue;
- }
- } else {
- // Convert TLS reads of the form
- // op n(GS), reg
- // to
- // MOVQ $runtime.tlsgm(SB), reg
- // op n(reg)(GS*1), reg
- if((p->from.type == D_INDIR+D_FS || p->from.type == D_INDIR + D_GS) && p->to.type >= D_AX && p->to.type <= D_DI) {
- q = appendp(p);
- q->to = p->to;
- q->as = p->as;
- q->from.type = D_INDIR+p->to.type;
- q->from.index = p->from.type - D_INDIR;
- q->from.scale = 1;
- q->from.offset = p->from.offset;
- p->as = AMOVQ;
- p->from.type = D_EXTERN;
- p->from.sym = gmsym;
- p->from.offset = 0;
- }
- }
- if(p->as == ACALL || (p->as == AJMP && p->to.type != D_BRANCH) || (p->as == ARET && p->to.sym != nil)) {
- s = p->to.sym;
- if(s) {
- if(debug['c'])
- Bprint(&bso, "%s calls %s\n", TNAME, s->name);
- if((s->type&SMASK) != 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)];
-Sym* gmsym;
-
-static Prog* load_g_cx(Prog*);
-static Prog* stacksplit(Prog*, int32, Prog**);
-
-void
-dostkoff(void)
-{
- Prog *p, *q, *q1;
- int32 autoffset, deltasp;
- int a, pcsize;
- uint32 i;
-
- gmsym = lookup("runtime.tlsgm", 0);
- 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;
-
- if(autoffset < StackSmall && !(p->from.scale & NOSPLIT)) {
- for(q = p; q != P; q = q->link)
- if(q->as == ACALL)
- goto noleaf;
- p->from.scale |= NOSPLIT;
- noleaf:;
- }
-
- if((p->from.scale & NOSPLIT) && autoffset >= StackSmall)
- diag("nosplit func likely to overflow stack");
-
- q = P;
- if(!(p->from.scale & NOSPLIT) || (p->from.scale & WRAPPER)) {
- p = appendp(p);
- p = load_g_cx(p); // load g into CX
- }
- if(!(cursym->text->from.scale & NOSPLIT))
- p = stacksplit(p, autoffset, &q); // emit split check
-
- if(autoffset) {
- p = appendp(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(p);
- p->as = ANOP;
- p->spadj = -PtrSize;
- p = appendp(p);
- p->as = ANOP;
- p->spadj = PtrSize;
- }
- if(q != P)
- q->pcond = p;
- deltasp = autoffset;
-
- if(cursym->text->from.scale & WRAPPER) {
- // g->panicwrap += autoffset + PtrSize;
- p = appendp(p);
- p->as = AADDL;
- p->from.type = D_CONST;
- p->from.offset = autoffset + PtrSize;
- p->to.type = D_INDIR+D_CX;
- p->to.offset = 2*PtrSize;
- }
-
- 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;
- }
-
- if(debug['Z'] && autoffset && !(cursym->text->from.scale&NOSPLIT)) {
- // 6l -Z means zero the stack frame on entry.
- // This slows down function calls but can help avoid
- // false positives in garbage collection.
- p = appendp(p);
- p->as = AMOVQ;
- p->from.type = D_SP;
- p->to.type = D_DI;
-
- p = appendp(p);
- p->as = AMOVQ;
- p->from.type = D_CONST;
- p->from.offset = autoffset/8;
- p->to.type = D_CX;
-
- p = appendp(p);
- p->as = AMOVQ;
- p->from.type = D_CONST;
- p->from.offset = 0;
- p->to.type = D_AX;
-
- p = appendp(p);
- p->as = AREP;
-
- p = appendp(p);
- p->as = ASTOSQ;
- }
-
- 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(cursym->text->from.scale & WRAPPER) {
- p = load_g_cx(p);
- p = appendp(p);
- // g->panicwrap -= autoffset + PtrSize;
- p->as = ASUBL;
- p->from.type = D_CONST;
- p->from.offset = autoffset + PtrSize;
- p->to.type = D_INDIR+D_CX;
- p->to.offset = 2*PtrSize;
- p = appendp(p);
- p->as = ARET;
- }
-
- 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;
- }
- 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(Prog *p)
-{
- if(flag_shared) {
- // Load TLS offset with MOVQ $runtime.tlsgm(SB), CX
- p->as = AMOVQ;
- p->from.type = D_EXTERN;
- p->from.sym = gmsym;
- p->to.type = D_CX;
- p = appendp(p);
- }
- p->as = AMOVQ;
- if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd
- || HEADTYPE == Hopenbsd || HEADTYPE == Hnetbsd
- || HEADTYPE == Hplan9x64 || HEADTYPE == Hdragonfly)
- // ELF uses FS
- p->from.type = D_INDIR+D_FS;
- else
- p->from.type = D_INDIR+D_GS;
- if(flag_shared) {
- // Add TLS offset stored in CX
- p->from.index = p->from.type - D_INDIR;
- p->from.type = D_INDIR + D_CX;
- }
- p->from.offset = tlsoffset+0;
- p->to.type = D_CX;
- if(HEADTYPE == Hwindows) {
- // movq %gs:0x28, %rcx
- // movq (%rcx), %rcx
- p->as = AMOVQ;
- p->from.type = D_INDIR+D_GS;
- p->from.offset = 0x28;
- 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;
- }
- 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(Prog *p, int32 framesize, Prog **jmpok)
-{
- Prog *q, *q1;
- uint32 moreconst1, moreconst2, i;
-
- 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;
- }
-
- q = P;
- q1 = P;
- if(framesize <= StackSmall) {
- // small stack: SP <= stackguard
- // CMPQ SP, stackguard
- p = appendp(p);
- p->as = ACMPQ;
- p->from.type = D_SP;
- p->to.type = D_INDIR+D_CX;
- } else if(framesize <= StackBig) {
- // large stack: SP-framesize <= stackguard-StackSmall
- // LEAQ -xxx(SP), AX
- // CMPQ AX, stackguard
- p = appendp(p);
- p->as = ALEAQ;
- p->from.type = D_INDIR+D_SP;
- p->from.offset = -(framesize-StackSmall);
- p->to.type = D_AX;
-
- p = appendp(p);
- p->as = ACMPQ;
- 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.
- // MOVQ stackguard, CX
- // CMPQ CX, $StackPreempt
- // JEQ label-of-call-to-morestack
- // LEAQ StackGuard(SP), AX
- // SUBQ CX, AX
- // CMPQ AX, $(framesize+(StackGuard-StackSmall))
-
- p = appendp(p);
- p->as = AMOVQ;
- p->from.type = D_INDIR+D_CX;
- p->from.offset = 0;
- p->to.type = D_SI;
-
- p = appendp(p);
- p->as = ACMPQ;
- p->from.type = D_SI;
- p->to.type = D_CONST;
- p->to.offset = StackPreempt;
-
- p = appendp(p);
- p->as = AJEQ;
- p->to.type = D_BRANCH;
- q1 = p;
-
- p = appendp(p);
- p->as = ALEAQ;
- p->from.type = D_INDIR+D_SP;
- p->from.offset = StackGuard;
- p->to.type = D_AX;
-
- p = appendp(p);
- p->as = ASUBQ;
- p->from.type = D_SI;
- p->to.type = D_AX;
-
- p = appendp(p);
- p->as = ACMPQ;
- p->from.type = D_AX;
- p->to.type = D_CONST;
- p->to.offset = framesize+(StackGuard-StackSmall);
- }
-
- // common
- p = appendp(p);
- p->as = AJHI;
- p->to.type = D_BRANCH;
- q = p;
-
- // 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.
- moreconst1 = 0;
- if(StackTop + textarg + PtrSize + framesize + PtrSize + StackLimit >= StackMin)
- moreconst1 = framesize;
- moreconst2 = textarg;
- if(moreconst2 == 1) // special marker
- moreconst2 = 0;
- if((moreconst2&7) != 0)
- diag("misaligned argument size in stack split");
- // 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];
- }
-
- p = appendp(p);
- p->as = AJMP;
- p->to.type = D_BRANCH;
- p->pcond = cursym->text->link;
-
- if(q != P)
- q->pcond = p->link;
- if(q1 != P)
- q1->pcond = q->link;
-
- *jmpok = q;
- return p;
-}
-
-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;
-}