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cgcod.c
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cgcod.c
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// Copyright (C) 1985-1998 by Symantec
// Copyright (C) 2000-2009 by Digital Mars
// All Rights Reserved
// http://www.digitalmars.com
// Written by Walter Bright
/*
* This source file is made available for personal use
* only. The license is in /dmd/src/dmd/backendlicense.txt
* or /dm/src/dmd/backendlicense.txt.
* For any other uses, please contact Digital Mars.
*/
#if !SPP
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#if __sun&&__SVR4
#include <alloca.h>
#endif
#include "cc.h"
#include "el.h"
#include "oper.h"
#include "code.h"
#include "global.h"
#include "type.h"
#include "exh.h"
static char __file__[] = __FILE__; /* for tassert.h */
#include "tassert.h"
STATIC void resetEcomsub(elem *e);
STATIC code * loadcse(elem *,unsigned,regm_t);
STATIC void blcodgen(block *);
STATIC void cgcod_eh();
STATIC code * cse_save(regm_t ms);
STATIC int cse_simple(elem *e,int i);
STATIC code * comsub(elem *,regm_t *);
bool floatreg; // !=0 if floating register is required
targ_size_t Aoffset; // offset of automatics and registers
targ_size_t Toffset; // offset of temporaries
targ_size_t EEoffset; // offset of SCstack variables from ESP
int Aalign; // alignment for Aoffset
REGSAVE regsave;
CGstate cgstate; // state of code generator
/************************************
* # of bytes that SP is beyond BP.
*/
unsigned stackpush;
int stackchanged; /* set to !=0 if any use of the stack
other than accessing parameters. Used
to see if we can address parameters
with ESP rather than EBP.
*/
int refparam; // !=0 if we referenced any parameters
int reflocal; // !=0 if we referenced any locals
char anyiasm; // !=0 if any inline assembler
char calledafunc; // !=0 if we called a function
char needframe; // if TRUE, then we will need the frame
// pointer (BP for the 8088)
char usedalloca; // if TRUE, then alloca() was called
char gotref; // !=0 if the GOTsym was referenced
unsigned usednteh; // if !=0, then used NT exception handling
/* Register contents */
con_t regcon;
int pass; // PASSxxxx
static symbol *retsym; // set to symbol that should be placed in
// register AX
/****************************
* Register masks.
*/
regm_t msavereg; // Mask of registers that we would like to save.
// they are temporaries (set by scodelem())
regm_t mfuncreg; // Mask of registers preserved by a function
regm_t allregs; // ALLREGS optionally including mBP
int dfoidx; /* which block we are in */
struct CSE *csextab = NULL; /* CSE table (allocated for each function) */
unsigned cstop; /* # of entries in CSE table (csextab[]) */
unsigned csmax; /* amount of space in csextab[] */
targ_size_t funcoffset; // offset of start of function
targ_size_t startoffset; // size of function entry code
targ_size_t retoffset; /* offset from start of func to ret code */
targ_size_t retsize; /* size of function return */
static regm_t lastretregs,last2retregs,last3retregs,last4retregs,last5retregs;
/*********************************
* Generate code for a function.
* Note at the end of this routine mfuncreg will contain the mask
* of registers not affected by the function. Some minor optimization
* possibilities are here...
*/
void codgen()
{ block *b,*bn;
bool flag;
int i;
targ_size_t swoffset,coffset;
tym_t functy;
unsigned nretblocks; // number of return blocks
code *cprolog;
regm_t noparams;
#if SCPP
block *btry;
#endif
// Register usage. If a bit is on, the corresponding register is live
// in that basic block.
//printf("codgen('%s')\n",funcsym_p->Sident);
cgreg_init();
csmax = 64;
csextab = (struct CSE *) util_calloc(sizeof(struct CSE),csmax);
functy = tybasic(funcsym_p->ty());
#if TARGET_LINUX || TARGET_OSX || TARGET_FREEBSD || TARGET_OPENBSD || TARGET_SOLARIS
if (0 && config.flags3 & CFG3pic)
{
ALLREGS = ALLREGS_INIT_PIC;
BYTEREGS = BYTEREGS_INIT_PIC;
}
else
{
regm_t value = BYTEREGS_INIT;
ALLREGS = ALLREGS_INIT;
BYTEREGS = value;
}
if (I64)
{ ALLREGS = mAX|mBX|mCX|mDX|mSI|mDI| mR8|mR9|mR10|mR11|mR12|mR13|mR14|mR15;
BYTEREGS = ALLREGS;
}
#endif
allregs = ALLREGS;
if (0 && config.flags3 & CFG3pic)
allregs &= ~mBX;
pass = PASSinit;
tryagain:
#ifdef DEBUG
if (debugr)
printf("------------------ PASS%s -----------------\n",
(pass == PASSinit) ? "init" : ((pass == PASSreg) ? "reg" : "final"));
#endif
lastretregs = last2retregs = last3retregs = last4retregs = last5retregs = 0;
// if no parameters, assume we don't need a stack frame
needframe = 0;
usedalloca = 0;
gotref = 0;
stackchanged = 0;
stackpush = 0;
refparam = 0;
anyiasm = 0;
calledafunc = 0;
cgstate.stackclean = 1;
retsym = NULL;
regsave.reset();
memset(_8087elems,0,sizeof(_8087elems));
usednteh = 0;
#if (MARS) && TARGET_WINDOS
if (funcsym_p->Sfunc->Fflags3 & Fjmonitor)
usednteh |= NTEHjmonitor;
#else
if (CPP)
{
if (config.flags2 & CFG2seh &&
(funcsym_p->Stype->Tflags & TFemptyexc || funcsym_p->Stype->Texcspec))
usednteh |= NTEHexcspec;
except_reset();
}
#endif
floatreg = FALSE;
assert(stackused == 0); /* nobody in 8087 stack */
cstop = 0; /* no entries in table yet */
memset(®con,0,sizeof(regcon));
regcon.cse.mval = regcon.cse.mops = 0; // no common subs yet
#if 0 && TARGET_LINUX
if (!(allregs & mBX))
msavereg = mBX;
else
#endif
msavereg = 0;
nretblocks = 0;
mfuncreg = fregsaved; // so we can see which are used
// (bit is cleared each time
// we use one)
for (b = startblock; b; b = b->Bnext)
{ memset(&b->Bregcon,0,sizeof(b->Bregcon)); // Clear out values in registers
if (b->Belem)
resetEcomsub(b->Belem); // reset all the Ecomsubs
if (b->BC == BCasm)
anyiasm = 1; // we have inline assembler
if (b->BC == BCret || b->BC == BCretexp)
nretblocks++;
}
if (!config.fulltypes || (config.flags4 & CFG4optimized))
{
noparams = 0;
for (i = 0; i < globsym.top; i++)
{
Symbol *s = globsym.tab[i];
s->Sflags &= ~SFLread;
switch (s->Sclass)
{ case SCfastpar:
regcon.params |= mask[s->Spreg];
case SCparameter:
if (s->Sfl == FLreg)
noparams |= s->Sregm;
break;
}
}
regcon.params &= ~noparams;
}
if (config.flags4 & CFG4optimized)
{
if (nretblocks == 0 && // if no return blocks in function
!(funcsym_p->ty() & mTYnaked)) // naked functions may have hidden veys of returning
funcsym_p->Sflags |= SFLexit; // mark function as never returning
assert(dfo);
cgreg_reset();
for (dfoidx = 0; dfoidx < dfotop; dfoidx++)
{ regcon.used = msavereg | regcon.cse.mval; // registers already in use
b = dfo[dfoidx];
blcodgen(b); // gen code in depth-first order
//printf("b->Bregcon.used = x%x\n", b->Bregcon.used);
cgreg_used(dfoidx,b->Bregcon.used); // gather register used information
}
}
else
{ pass = PASSfinal;
for (b = startblock; b; b = b->Bnext)
blcodgen(b); // generate the code for each block
}
regcon.immed.mval = 0;
assert(!regcon.cse.mops); // should have all been used
// See which variables we can put into registers
if (pass != PASSfinal &&
!anyiasm) // possible LEA or LES opcodes
{
allregs |= cod3_useBP(); // see if we can use EBP
// If pic code, but EBX was never needed
if (!(allregs & mBX) && !gotref)
{ allregs |= mBX; // EBX can now be used
cgreg_assign(retsym);
pass = PASSreg;
}
else if (cgreg_assign(retsym)) // if we found some registers
pass = PASSreg;
else
pass = PASSfinal;
for (b = startblock; b; b = b->Bnext)
{ code_free(b->Bcode);
b->Bcode = NULL;
}
goto tryagain;
}
cgreg_term();
#if SCPP
if (CPP)
cgcod_eh();
#endif
stackoffsets(1); // compute addresses of stack variables
cod5_prol_epi(); // see where to place prolog/epilog
// Get rid of unused cse temporaries
while (cstop != 0 && (csextab[cstop - 1].flags & CSEload) == 0)
cstop--;
if (configv.addlinenumbers)
objlinnum(funcsym_p->Sfunc->Fstartline,Coffset);
// Otherwise, jmp's to startblock will execute the prolog again
assert(!startblock->Bpred);
cprolog = prolog(); // gen function start code
if (cprolog)
pinholeopt(cprolog,NULL); // optimize
funcoffset = Coffset;
coffset = Coffset;
if (eecontext.EEelem)
{ regm_t retregs;
code *c;
eecontext.EEin++;
regcon.immed.mval = 0;
retregs = 0; //regmask(eecontext.EEelem->Ety);
assert(EEoffset >= REGSIZE);
c = genc2(NULL,0x81,modregrm(3,5,SP),EEoffset - REGSIZE); // SUB ESP,EEoffset
gen1(c,0x50 + SI); // PUSH ESI
genadjesp(c,EEoffset);
c = gencodelem(c,eecontext.EEelem,&retregs, FALSE);
assignaddrc(c);
pinholeopt(c,NULL);
jmpaddr(c);
eecontext.EEcode = gen1(c,0xCC); // INT 3
eecontext.EEin--;
}
for (b = startblock; b; b = b->Bnext)
{
// We couldn't do this before because localsize was unknown
switch (b->BC)
{ case BCret:
if (configv.addlinenumbers && b->Bsrcpos.Slinnum && !(funcsym_p->ty() & mTYnaked))
cgen_linnum(&b->Bcode,b->Bsrcpos);
case BCretexp:
epilog(b);
break;
default:
if (b->Bflags & BFLepilog)
epilog(b);
break;
}
assignaddr(b); // assign addresses
pinholeopt(b->Bcode,b); // do pinhole optimization
if (b->Bflags & BFLprolog) // do function prolog
{
startoffset = coffset + calcblksize(cprolog) - funcoffset;
b->Bcode = cat(cprolog,b->Bcode);
}
if (config.flags4 & CFG4speed &&
config.target_cpu >= TARGET_Pentium &&
b->BC != BCasm
)
{ regm_t scratch;
scratch = allregs & ~(b->Bregcon.used | b->Bregcon.params | mfuncreg);
scratch &= ~(b->Bregcon.immed.mval | b->Bregcon.cse.mval);
cgsched_pentium(&b->Bcode,scratch);
//printf("after schedule:\n"); WRcodlst(b->Bcode);
}
b->Bsize = calcblksize(b->Bcode); // calculate block size
if (b->Balign)
{ targ_size_t u = b->Balign - 1;
coffset = (coffset + u) & ~u;
}
b->Boffset = coffset; /* offset of this block */
coffset += b->Bsize; /* offset of following block */
}
#ifdef DEBUG
debugw && printf("code addr complete\n");
#endif
// Do jump optimization
do
{ flag = FALSE;
for (b = startblock; b; b = b->Bnext)
{ if (b->Bflags & BFLjmpoptdone) /* if no more jmp opts for this blk */
continue;
i = branch(b,0); // see if jmp => jmp short
if (i) /* if any bytes saved */
{ targ_size_t offset;
b->Bsize -= i;
offset = b->Boffset + b->Bsize;
for (bn = b->Bnext; bn; bn = bn->Bnext)
{
if (bn->Balign)
{ targ_size_t u = bn->Balign - 1;
offset = (offset + u) & ~u;
}
bn->Boffset = offset;
offset += bn->Bsize;
}
coffset = offset;
flag = TRUE;
}
}
if (!I16 && !(config.flags4 & CFG4optimized))
break; // use the long conditional jmps
} while (flag); // loop till no more bytes saved
#ifdef DEBUG
debugw && printf("code jump optimization complete\n");
#endif
#if MARS
if (usednteh & NTEH_try)
{
// Do this before code is emitted because we patch some instructions
nteh_filltables();
}
#endif
// Compute starting offset for switch tables
#if ELFOBJ || MACHOBJ
swoffset = (config.flags & CFGromable) ? coffset : CDoffset;
#else
swoffset = (config.flags & CFGromable) ? coffset : Doffset;
#endif
swoffset = align(0,swoffset);
// Emit the generated code
if (eecontext.EEcompile == 1)
{
codout(eecontext.EEcode);
code_free(eecontext.EEcode);
#if SCPP
el_free(eecontext.EEelem);
#endif
}
else
{
for (b = startblock; b; b = b->Bnext)
{
if (b->BC == BCjmptab || b->BC == BCswitch)
{ b->Btableoffset = swoffset; /* offset of sw tab */
swoffset += b->Btablesize;
}
jmpaddr(b->Bcode); /* assign jump addresses */
#ifdef DEBUG
if (debugc)
{ printf("Boffset = x%lx, Bsize = x%lx, Coffset = x%lx\n",
(long)b->Boffset,(long)b->Bsize,(long)Coffset);
if (b->Bcode)
printf( "First opcode of block is: %0x\n", b->Bcode->Iop );
}
#endif
if (b->Balign)
{ unsigned u = b->Balign;
unsigned nalign = (u - (unsigned)Coffset) & (u - 1);
while (nalign--)
obj_byte(cseg,Coffset++,0x90); // XCHG AX,AX
}
assert(b->Boffset == Coffset);
#if SCPP
if (CPP &&
!(config.flags2 & CFG2seh))
{
//printf("b = %p, index = %d\n",b,b->Bindex);
//except_index_set(b->Bindex);
if (btry != b->Btry)
{
btry = b->Btry;
except_pair_setoffset(b,Coffset - funcoffset);
}
if (b->BC == BCtry)
{
btry = b;
except_pair_setoffset(b,Coffset - funcoffset);
}
}
#endif
codout(b->Bcode); // output code
}
if (coffset != Coffset)
{
#ifdef DEBUG
printf("coffset = %ld, Coffset = %ld\n",(long)coffset,(long)Coffset);
#endif
assert(0);
}
funcsym_p->Ssize = Coffset - funcoffset; // size of function
#if NTEXCEPTIONS || MARS
#if (SCPP && NTEXCEPTIONS)
if (usednteh & NTEHcpp)
#elif MARS
if (usednteh & NTEH_try)
#endif
{ assert(!(config.flags & CFGromable));
//printf("framehandleroffset = x%x, coffset = x%x\n",framehandleroffset,coffset);
reftocodseg(cseg,framehandleroffset,coffset);
}
#endif
// Write out switch tables
flag = FALSE; // TRUE if last active block was a ret
for (b = startblock; b; b = b->Bnext)
{
switch (b->BC)
{ case BCjmptab: /* if jump table */
outjmptab(b); /* write out jump table */
break;
case BCswitch:
outswitab(b); /* write out switch table */
break;
case BCret:
case BCretexp:
/* Compute offset to return code from start of function */
retoffset = b->Boffset + b->Bsize - retsize - funcoffset;
#if MARS
/* Add 3 bytes to retoffset in case we have an exception
* handler. THIS PROBABLY NEEDS TO BE IN ANOTHER SPOT BUT
* IT FIXES THE PROBLEM HERE AS WELL.
*/
if (usednteh & NTEH_try)
retoffset += 3;
#endif
flag = TRUE;
break;
case BCexit:
// Fake it to keep debugger happy
retoffset = b->Boffset + b->Bsize - funcoffset;
break;
}
}
if (flag && configv.addlinenumbers && !(funcsym_p->ty() & mTYnaked))
/* put line number at end of function on the
start of the last instruction
*/
/* Instead, try offset to cleanup code */
objlinnum(funcsym_p->Sfunc->Fendline,funcoffset + retoffset);
#if MARS
if (usednteh & NTEH_try)
{
// Do this before code is emitted because we patch some instructions
nteh_gentables();
}
if (usednteh & EHtry)
{
except_gentables();
}
#endif
#if SCPP
#if NTEXCEPTIONS
// Write out frame handler
if (usednteh & NTEHcpp)
nteh_framehandler(except_gentables());
else
#endif
{
#if NTEXCEPTIONS
if (usednteh & NTEH_try)
nteh_gentables();
else
#endif
{
if (CPP)
except_gentables();
}
;
}
#endif
for (b = startblock; b; b = b->Bnext)
{
code_free(b->Bcode);
b->Bcode = NULL;
}
}
// Mask of regs saved
// BUG: do interrupt functions save BP?
funcsym_p->Sregsaved = (functy == TYifunc) ? mBP : (mfuncreg | fregsaved);
util_free(csextab);
csextab = NULL;
#ifdef DEBUG
if (stackused != 0)
printf("stackused = %d\n",stackused);
#endif
assert(stackused == 0); /* nobody in 8087 stack */
/* Clean up ndp save array */
mem_free(NDP::save);
NDP::save = NULL;
NDP::savetop = 0;
NDP::savemax = 0;
}
/******************************
* Compute offsets for remaining tmp, automatic and register variables
* that did not make it into registers.
*/
void stackoffsets(int flags)
{
symbol *s;
targ_size_t Amax,sz;
unsigned alignsize;
int offi;
#if AUTONEST
targ_size_t offstack[20];
int offi = 0; // index into offstack[]
#endif
vec_t tbl = NULL;
//printf("stackoffsets()\n");
if (config.flags4 & CFG4optimized)
{
tbl = vec_calloc(globsym.top);
}
Aoffset = 0; // automatic & register offset
Toffset = 0; // temporary offset
Poffset = 0; // parameter offset
EEoffset = 0; // for SCstack's
Amax = 0;
Aalign = REGSIZE;
for (int pass = 0; pass < 2; pass++)
{
for (int si = 0; si < globsym.top; si++)
{ s = globsym.tab[si];
if (s->Sflags & SFLdead ||
(!anyiasm && !(s->Sflags & SFLread) && s->Sflags & SFLunambig &&
#if MARS
/* mTYvolatile was set if s has been reference by a nested function
* meaning we'd better allocate space for it
*/
!(s->Stype->Tty & mTYvolatile) &&
#endif
(config.flags4 & CFG4optimized || !config.fulltypes))
)
sz = 0;
else
{ sz = type_size(s->Stype);
if (sz == 0)
sz++; // can't handle 0 length structs
}
alignsize = type_alignsize(s->Stype);
//printf("symbol '%s', size = x%lx, align = %d, read = %x\n",s->Sident,(long)sz, (int)type_alignsize(s->Stype), s->Sflags & SFLread);
assert((int)sz >= 0);
if (pass == 1)
{
if (s->Sclass == SCfastpar) // if parameter s is passed in a register
{
/* Allocate in second pass in order to get these
* right next to the stack frame pointer, EBP.
* Needed so we can call nested contract functions
* frequire and fensure.
*/
if (s->Sfl == FLreg) // if allocated in register
continue;
/* Needed because storing fastpar's on the stack in prolog()
* does the entire register
*/
if (sz < REGSIZE)
sz = REGSIZE;
Aoffset = align(sz,Aoffset);
s->Soffset = Aoffset;
Aoffset += sz;
if (Aoffset > Amax)
Amax = Aoffset;
//printf("fastpar '%s' sz = %d, auto offset = x%lx\n",s->Sident,sz,(long)s->Soffset);
// Align doubles to 8 byte boundary
if (!I16 && alignsize > REGSIZE)
Aalign = alignsize;
}
continue;
}
/* Can't do this for CPP because the inline function expander
adds new symbols on the end.
*/
#if AUTONEST
/*printf("symbol '%s', push = %d, pop = %d\n",
s->Sident,s->Spush,s->Spop);*/
/* Can't do this for optimizer if any code motion occurred.
Code motion changes the live range, so variables that
occupy the same space could have live ranges that overlap!
*/
if (config.flags4 & CFG4optimized)
s->Spop = 0;
else
while (s->Spush != 0)
{ s->Spush--;
assert(offi < arraysize(offstack));
/*printf("Pushing offset x%x\n",Aoffset);*/
offstack[offi++] = Aoffset;
}
#endif
switch (s->Sclass)
{
case SCfastpar:
break; // ignore on pass 0
case SCregister:
case SCauto:
if (s->Sfl == FLreg) // if allocated in register
break;
// See if we can share storage with another variable
if (config.flags4 & CFG4optimized &&
// Don't share because could stomp on variables
// used in finally blocks
!(usednteh & ~NTEHjmonitor) &&
s->Srange && sz && flags && !(s->Sflags & SFLspill))
{
for (int i = 0; i < si; i++)
{
if (!vec_testbit(i,tbl))
continue;
symbol *sp = globsym.tab[i];
//printf("auto s = '%s', sp = '%s', %d, %d, %d\n",s->Sident,sp->Sident,dfotop,vec_numbits(s->Srange),vec_numbits(sp->Srange));
if (vec_disjoint(s->Srange,sp->Srange) &&
sz <= type_size(sp->Stype))
{
vec_or(sp->Srange,sp->Srange,s->Srange);
//printf("sharing space - '%s' onto '%s'\n",s->Sident,sp->Sident);
s->Soffset = sp->Soffset;
goto L2;
}
}
}
Aoffset = align(sz,Aoffset);
s->Soffset = Aoffset;
//printf("auto '%s' sz = %d, auto offset = x%lx\n",s->Sident,sz,(long)s->Soffset);
Aoffset += sz;
if (Aoffset > Amax)
Amax = Aoffset;
if (s->Srange && sz && !(s->Sflags & SFLspill))
vec_setbit(si,tbl);
// Align doubles to 8 byte boundary
if (!I16 && type_alignsize(s->Stype) > REGSIZE)
Aalign = type_alignsize(s->Stype);
L2:
break;
case SCtmp:
// Allocated separately from SCauto to avoid storage
// overlapping problems.
Toffset = align(sz,Toffset);
s->Soffset = Toffset;
//printf("tmp offset = x%lx\n",(long)s->Soffset);
Toffset += sz;
break;
case SCstack:
EEoffset = align(sz,EEoffset);
s->Soffset = EEoffset;
//printf("EEoffset = x%lx\n",(long)s->Soffset);
EEoffset += sz;
break;
case SCparameter:
Poffset = align(REGSIZE,Poffset); /* align on word stack boundary */
if (I64 && alignsize == 16 && Poffset & 8)
Poffset += 8;
s->Soffset = Poffset;
//printf("%s param offset = x%lx, alignsize = %d\n",s->Sident,(long)s->Soffset, (int)alignsize);
Poffset += (s->Sflags & SFLdouble)
? type_size(tsdouble) // float passed as double
: type_size(s->Stype);
break;
case SCpseudo:
case SCstatic:
case SCbprel:
break;
default:
#ifdef DEBUG
symbol_print(s);
#endif
assert(0);
}
#if AUTONEST
while (s->Spop != 0)
{ s->Spop--;
assert(offi > 0);
Aoffset = offstack[--offi];
/*printf("Popping offset x%x\n",Aoffset);*/
}
#endif
}
}
Aoffset = Amax;
Aoffset = align(0,Aoffset);
if (Aalign > REGSIZE)
Aoffset = (Aoffset + Aalign - 1) & ~(Aalign - 1);
//printf("Aligned Aoffset = x%lx, Toffset = x%lx\n", (long)Aoffset,(long)Toffset);
Toffset = align(0,Toffset);
if (config.flags4 & CFG4optimized)
{
vec_free(tbl);
}
}
/****************************
* Generate code for a block.
*/
STATIC void blcodgen(block *bl)
{ regm_t retregs;
bool jcond;
elem *e;
code *c;
block *nextb;
block *bs1,*bs2;
list_t bpl;
int refparamsave;
regm_t mfuncregsave = mfuncreg;
char *sflsave = NULL;
int anyspill;
//dbg_printf("blcodgen(%p)\n",bl);
/* Determine existing immediate values in registers by ANDing
together the values from all the predecessors of b.
*/
assert(bl->Bregcon.immed.mval == 0);
regcon.immed.mval = 0; // assume no previous contents in registers
// regcon.cse.mval = 0;
for (bpl = bl->Bpred; bpl; bpl = list_next(bpl))
{ block *bp = list_block(bpl);
if (bpl == bl->Bpred)
{ regcon.immed = bp->Bregcon.immed;
regcon.params = bp->Bregcon.params;
// regcon.cse = bp->Bregcon.cse;
}
else
{ int i;
regcon.params &= bp->Bregcon.params;
if ((regcon.immed.mval &= bp->Bregcon.immed.mval) != 0)
// Actual values must match, too
for (i = 0; i < REGMAX; i++)
{
if (regcon.immed.value[i] != bp->Bregcon.immed.value[i])
regcon.immed.mval &= ~mask[i];
}
#if 0
if ((regcon.cse.mval &= bp->Bregcon.cse.mval) != 0)
// Actual values must match, too
for (i = 0; i < REGMAX; i++)
{
if (regcon.cse.value[i] != bp->Bregcon.cse.value[i])
regcon.cse.mval &= ~mask[i];
}
#endif
}
}
regcon.cse.mops &= regcon.cse.mval;
// Set regcon.mvar according to what variables are in registers for this block
c = NULL;
regcon.mvar = 0;
regcon.mpvar = 0;
regcon.indexregs = 1;
anyspill = 0;
if (config.flags4 & CFG4optimized)
{ SYMIDX i;
code *cload = NULL;
code *cstore = NULL;
sflsave = (char *) alloca(globsym.top * sizeof(char));
for (i = 0; i < globsym.top; i++)
{ symbol *s = globsym.tab[i];
sflsave[i] = s->Sfl;
if (s->Sclass & SCfastpar &&
regcon.params & mask[s->Spreg] &&
vec_testbit(dfoidx,s->Srange))
{
regcon.used |= mask[s->Spreg];
}
if (s->Sfl == FLreg)
{ if (vec_testbit(dfoidx,s->Srange))
{ regcon.mvar |= s->Sregm;
if (s->Sclass == SCfastpar)
regcon.mpvar |= s->Sregm;
}
}
else if (s->Sflags & SFLspill)
{ if (vec_testbit(dfoidx,s->Srange))
{
anyspill = i + 1;
cgreg_spillreg_prolog(bl,s,&cstore,&cload);
if (vec_testbit(dfoidx,s->Slvreg))
{ s->Sfl = FLreg;
regcon.mvar |= s->Sregm;
regcon.cse.mval &= ~s->Sregm;
regcon.immed.mval &= ~s->Sregm;
if (s->Sclass == SCfastpar)
regcon.mpvar |= s->Sregm;
}
}
}
}
if ((regcon.cse.mops & regcon.cse.mval) != regcon.cse.mops)
{ code *cx;
cx = cse_save(regcon.cse.mops & ~regcon.cse.mval);
cstore = cat(cx, cstore);
}
c = cat(cstore,cload);
mfuncreg &= ~regcon.mvar; // use these registers
regcon.used |= regcon.mvar;
// Determine if we have more than 1 uncommitted index register
regcon.indexregs = IDXREGS & ~regcon.mvar;
regcon.indexregs &= regcon.indexregs - 1;
}
e = bl->Belem;
regsave.idx = 0;
retregs = 0;
reflocal = 0;
refparamsave = refparam;
refparam = 0;
assert((regcon.cse.mops & regcon.cse.mval) == regcon.cse.mops);
switch (bl->BC) /* block exit condition */
{
case BCiftrue:
jcond = TRUE;
bs1 = list_block(bl->Bsucc);
bs2 = list_block(list_next(bl->Bsucc));
if (bs1 == bl->Bnext)
{ // Swap bs1 and bs2
block *btmp;
jcond ^= 1;
btmp = bs1;
bs1 = bs2;
bs2 = btmp;
}
c = cat(c,logexp(e,jcond,FLblock,(code *) bs1));
nextb = bs2;
bl->Bcode = NULL;
L2:
if (nextb != bl->Bnext)
{ if (configv.addlinenumbers && bl->Bsrcpos.Slinnum &&
!(funcsym_p->ty() & mTYnaked))
cgen_linnum(&c,bl->Bsrcpos);
assert(!(bl->Bflags & BFLepilog));
c = cat(c,genjmp(CNIL,JMP,FLblock,nextb));
}
bl->Bcode = cat(bl->Bcode,c);
break;
case BCjmptab:
case BCifthen:
case BCswitch:
assert(!(bl->Bflags & BFLepilog));
doswitch(bl); /* hide messy details */
bl->Bcode = cat(c,bl->Bcode);
break;
#if MARS
case BCjcatch:
// Mark all registers as destroyed. This will prevent
// register assignments to variables used in catch blocks.
c = cat(c,getregs((I32 | I64) ? allregs : (ALLREGS | mES)));
#if 0 && TARGET_LINUX
if (config.flags3 & CFG3pic && !(allregs & mBX))
{
c = cat(c, cod3_load_got());
}
#endif
goto case_goto;
#endif
#if SCPP
case BCcatch:
// Mark all registers as destroyed. This will prevent
// register assignments to variables used in catch blocks.
c = cat(c,getregs(allregs | mES));
#if 0 && TARGET_LINUX
if (config.flags3 & CFG3pic && !(allregs & mBX))
{
c = cat(c, cod3_load_got());
}
#endif
goto case_goto;
case BCtry:
usednteh |= EHtry;
if (config.flags2 & CFG2seh)