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authorlemon <lsof@mailbox.org>2025-10-19 08:09:09 +0200
committerlemon <lsof@mailbox.org>2025-10-19 08:09:09 +0200
commitdea8fd171acb54b6d9685422d5e391fb55074008 (patch)
tree2c149892f35c5183c9b2a1da4ab437228dc432ef /ir/abi0.c
parent3437945692f2b87883a4f066473c9deed50f25f5 (diff)
Organize source files into directories
Diffstat (limited to 'ir/abi0.c')
-rw-r--r--ir/abi0.c393
1 files changed, 393 insertions, 0 deletions
diff --git a/ir/abi0.c b/ir/abi0.c
new file mode 100644
index 0000000..82d10a5
--- /dev/null
+++ b/ir/abi0.c
@@ -0,0 +1,393 @@
+#include "ir.h"
+
+/** This pass adds in ABI arguments/returns register mappings
+ ** and lowers aggregate params/args/returns into scalars
+ **
+ ** invariant: all `call` instructions when doing this pass shall be preceded by
+ ** exactly narg `arg` instructions with no other instructions in between
+ **/
+
+struct abiargsvec { vec_of(struct abiarg); };
+
+static int
+abiret(struct abiarg abiret[2], struct abiargsvec *abiargs, int *ni, union irtype retty)
+{
+ short r[2];
+ uchar cls[2];
+ int retreg = 0;
+ if (retty.isagg) {
+ retreg = mctarg->abiret(r, cls, ni, retty);
+ if (!retreg) {
+ vpush(abiargs, ((struct abiarg) { cls2type(KPTR), .reg = r[1] }));
+ if (r[0] == -1) {
+ memset(abiret, 0, 2*sizeof *abiret);
+ } else {
+ abiret[0].ty = cls2type(KPTR);
+ abiret[0].reg = r[0];
+ }
+ }
+ } else if (retty.cls) {
+ retreg = mctarg->abiret(r, cls, ni, retty);
+ assert(retreg == 1);
+ }
+ for (int i = 0; i < retreg; ++i) {
+ abiret[i].ty = cls2type(cls[i]);
+ abiret[i].reg = r[i];
+ }
+ return retreg;
+}
+
+static int
+abiarg(struct abiargsvec *abiargs, int *ni, int *nf, int *ns, union irtype ty)
+{
+ short r[2];
+ uchar cls[2];
+ int ret = mctarg->abiarg(r, cls, ni, nf, ns, ty);
+ if (!ret) { /* in stack */
+ vpush(abiargs, ((struct abiarg) { ty, .stk = r[0] }));
+ } else if (ret == 1 && ty.isagg && cls[0] == KPTR) { /* aggregate by pointer */
+ vpush(abiargs, ((struct abiarg) { cls2type(cls[0]), .reg = r[0] }));
+ } else { /* by regs */
+ vpush(abiargs, ((struct abiarg) { cls2type(cls[0]), .reg = r[0] }));
+ if (ret == 2)
+ vpush(abiargs, ((struct abiarg) { cls2type(cls[1]), .reg = r[1] }));
+ }
+ return ret;
+}
+
+static struct instr
+copyparam(struct function *fn, int *curi, int param, struct abiarg abi)
+{
+ struct instr par = mkinstr(Oparam, abi.ty.cls, mkref(RICON, param), mktyperef(abi.ty));
+ if (abi.reg >= 0) { /* reg */
+ assert(!abi.ty.isagg);
+ return par;
+ } else if (!abi.ty.isagg) { /* scalar in stack */
+ enum op ld;
+ par.cls = KPTR;
+ if (abi.ty.cls == KPTR) abi.ty.cls = siz2intcls[cls2siz[abi.ty.cls]];
+ switch (abi.ty.cls) {
+ default: assert(0);
+ case KI4: ld = Oloadu4; break;
+ case KI8: ld = Oloadi8; break;
+ case KF4: ld = Oloadf4; break;
+ case KF8: ld = Oloadf8; break;
+ }
+ return mkinstr(ld, abi.ty.cls, insertinstr(fn->entry, (*curi)++, par));
+ } else { /* aggregate in stack */
+ par.cls = KPTR;
+ return par;
+ }
+}
+
+static void
+patchparam(struct function *fn, int *curi, int *param, int tydat, int nabi, struct abiarg abi[2])
+{
+ struct block *blk = fn->entry;
+ assert(in_range(nabi,1,2));
+
+ for (; *curi < blk->ins.n; ++*curi) {
+ struct instr *ins = &instrtab[blk->ins.p[*curi]];
+ if (ins->op != Oparam) continue;
+ assert(ins->r.t == RTYPE
+ && ins->r.i == (tydat < 0 ? abi[0].ty : (union irtype){.isagg=1, .dat=tydat}).bits);
+ if (abi[0].ty.isagg || tydat < 0) {
+ /* aggregate in stack or scalar, just copy */
+ assert(nabi == 1);
+ *ins = copyparam(fn, curi, *param, abi[0]);
+ } else { /* aggregate in registers, materialize */
+ union ref alloc, r[2];
+ struct instr st;
+ const struct typedata *td;
+ uint nalloc;
+
+ assert(tydat >= 0);
+ td = &typedata[tydat];
+ assert(td->siz <= 16 && td->align <= 16);
+ nalloc = td->align == 16 ? 1 : td->siz/8 + (td->siz%8 != 0);
+ *ins = mkinstr(Oalloca8 + (td->align==16), KPTR, mkref(RICON, nalloc));
+ alloc = mkref(RTMP, ins - instrtab);
+ r[0] = insertinstr(blk, ++*curi, copyparam(fn, NULL, *param, abi[0]));
+ if (nabi > 1)
+ r[1] = insertinstr(blk, ++*curi, copyparam(fn, NULL, ++*param, abi[1]));
+ /* transform
+ * %x = copy %p
+ * into
+ * %x = alloca...
+ * store* %x, %a
+ * store* %x + N, %b
+ */
+ st = mkinstr(Ostore1 + ilog2(cls2siz[abi[0].ty.cls]), 0, alloc, r[0]);
+ insertinstr(blk, ++*curi, st);
+ if (nabi > 1) {
+ struct instr tmp = mkinstr(Oadd, KPTR, alloc, mkref(RICON, cls2siz[abi[0].ty.cls]));
+ st = mkinstr(Ostore1 + ilog2(cls2siz[abi[1].ty.cls]), 0, insertinstr(blk, ++*curi, tmp), r[1]);
+ insertinstr(blk, ++*curi, st);
+ }
+ }
+ ++*param;
+ ++*curi;
+ break;
+ }
+}
+
+static int
+patcharg(struct block *blk, int *icall, struct call *call,
+ int argidx, int nabi, struct abiarg abi[2])
+{
+ int arginst = *icall - (call->narg - argidx);
+ struct instr *arg = &instrtab[blk->ins.p[arginst]];
+ assert(arg->op == Oarg && arg->l.t == RTYPE);
+ if (ref2type(arg->l).isagg) {
+ /* aggregate argument */
+ if (abi[0].ty.isagg /* aggregate in stack */
+ || abi[0].ty.cls == KPTR) /* aggregate by pointer */
+ {
+ return 1;
+ } else { /* aggregate in registers */
+ union ref src = arg->r;
+ /* deconstruct into
+ * %a = load* %x
+ * (%b = load* %x + N)
+ */
+ delinstr(blk, arginst);
+ for (int i = 0; i < nabi; ++i) {
+ /* XXX this can generate unaligned loads */
+ struct instr ins = {0};
+ union ref temp;
+ switch (ins.cls = abi[i].ty.cls) {
+ default: assert(0);
+ case KI4: ins.op = Oloadu4; break;
+ case KI8: ins.op = Oloadi8; break;
+ case KF4: ins.op = Oloadf4; break;
+ case KF8: ins.op = Oloadf8; break;
+ }
+ if (i == 0)
+ ins.l = src;
+ else
+ ins.l = insertinstr(blk, arginst++,
+ mkinstr(Oadd, KPTR, src,
+ mkref(RICON, cls2siz[abi[0].ty.cls])));
+ temp = insertinstr(blk, arginst++, ins);
+ insertinstr(blk, arginst++, mkarginstr(abi[i].ty, temp));
+ }
+ *icall = arginst + (call->narg - argidx - 1);
+ return nabi;
+ }
+ } else /* normal scalar argument */
+ return 1;
+}
+
+static struct abiarg abiargsbuf[32];
+
+void
+abi0_call(struct function *fn, struct instr *ins, struct block *blk, int *curi)
+{
+ union ref retmem;
+ struct abiargsvec abiargs = {VINIT(abiargsbuf, arraylength(abiargsbuf))};
+ bool sretarghidden = 0;
+ int ni, nf, ns, vararg, nret = 0;
+ struct call *call = &calltab.p[ins->r.i];
+
+ vararg = call->vararg;
+ vinit(&abiargs, abiargsbuf, arraylength(abiargsbuf));
+ ni = nf = ns = 0;
+ assert(!ins->cls == !call->ret.bits);
+ nret = abiret(call->abiret, &abiargs, &ni, call->ret);
+ if (call->ret.isagg) { /* adjust struct return */
+ union irtype retty = call->ret;
+ struct typedata *td = &typedata[retty.dat];
+ struct instr alloca = mkalloca(td->siz, td->align);
+ int ialloca;
+
+ sretarghidden = ni == 0;
+ /* swap alloca and call temps so users of original call point to alloca */
+ retmem = insertinstr(blk, ialloca = (*curi)++ - call->narg, *ins);
+ *ins = alloca;
+ blk->ins.p[ialloca] = ins - instrtab;
+ blk->ins.p[*curi] = retmem.i;
+ ins = &instrtab[retmem.i];
+ retmem.i = blk->ins.p[ialloca];
+
+ if (!nret) /* hidden pointer argument */
+ insertinstr(blk, (*curi)++ - call->narg,
+ mkinstr(Oarg, 0, mktyperef((union irtype){.cls=KPTR}), retmem));
+ }
+
+ /* adjust args */
+ for (int i = 0, i2 = ni + sretarghidden; i < call->narg; ++i) {
+ int arginst = *curi - (call->narg - i);
+ struct instr *arg = &instrtab[blk->ins.p[arginst]];
+ union irtype pty = ref2type(arg->l);
+ int first = abiargs.n;
+ int ret = abiarg(&abiargs, &ni, &nf, &ns, pty);
+ ret = patcharg(blk, curi, call, i, ret, &abiargs.p[first]);
+ if (call->vararg == i) vararg = i2;
+ i2 += ret;
+ }
+ /* adjust return */
+ if (call->ret.isagg) {
+ ins->cls = 0;
+ if (!nret) { /* hidden pointer argument */
+ ins->cls = 0;
+ if (call->abiret[0].reg >= 0) {
+ /* the result location pointer is also returned by the callee, e.g. in x86 */
+ ins->cls = KPTR;
+ ++nret;
+ /* even if this is not used, the register copy
+ * must be emitted for the register allocator to know */
+ }
+ } else { /* aggregate returned in regs */
+ union ref r[2];
+ struct instr ret2;
+ assert(in_range(nret, 1, 2));
+ ins->cls = call->abiret[0].ty.cls;
+ r[0] = mkref(RTMP, ins - instrtab);
+ if (nret == 2) {
+ ret2 = mkinstr(Ocall2r, call->abiret[1].ty.cls, r[0]);
+ r[1] = insertinstr(blk, ++*curi, ret2);
+ }
+ for (int i = 0; i < nret; ++i) {
+ struct instr store = {0};
+ /* XXX this can generate unaligned stores */
+ switch (call->abiret[i].ty.cls) {
+ default: assert(0);
+ case KF4: case KI4: store.op = Ostore4; break;
+ case KI8: case KF8: store.op = Ostore8; break;
+ }
+ if (i == 0) {
+ store.l = retmem;
+ } else {
+ union ref off = mkref(RICON, cls2siz[call->abiret[0].ty.cls]);
+ struct instr addr = mkinstr(Oadd, KPTR, retmem, off);
+ store.l = insertinstr(blk, ++*curi, addr);
+ }
+ store.r = r[i];
+ insertinstr(blk, ++*curi, store);
+ }
+ }
+ }
+
+ if (call->ret.isagg) call->ret = (union irtype){0};
+ call->vararg = vararg;
+ call->abiarg = alloccopy(fn->arena, abiargs.p, abiargs.n * sizeof(struct abiarg), 0);
+ call->narg = abiargs.n;
+ vfree(&abiargs);
+}
+
+void
+abi0(struct function *fn)
+{
+ uint nparam = typedata[fn->fnty.dat].nmemb;
+ const union type *paramty = typedata[fn->fnty.dat].param;
+ struct abiargsvec abiargs = {VINIT(abiargsbuf, arraylength(abiargsbuf))};
+ int rvovar = -1;
+ int ni = 0, nf = 0, ns = 0, istart = 0;
+ struct block *blk;
+ union ref sret = {0};
+
+ if (fn->retty.t == TYVOID) {
+ fn->nabiret = 0;
+ } else {
+ fn->nabiret = abiret(fn->abiret, &abiargs, &ni, mkirtype(fn->retty));
+ if (!fn->nabiret && isagg(fn->retty)) { /* ret agg by hidden pointer */
+ struct instr param = copyparam(fn, NULL, 0, abiargs.p[0]);
+ sret = insertinstr(fn->entry, 0, param);
+ ++istart;
+ /* increment real param ordinals */
+ for (int i = 1; i < fn->entry->ins.n; ++i) {
+ struct instr *ins = &instrtab[fn->entry->ins.p[i]];
+ if (ins->op == Oparam) ++ins->l.i;
+ }
+ }
+ }
+
+ /* adjust params */
+ for (int i = 0, param = abiargs.n; i < nparam; ++i) {
+ union irtype pty = mkirtype(paramty[i]);
+ int first = abiargs.n;
+ int ret = abiarg(&abiargs, &ni, &nf, &ns, pty);
+ patchparam(fn, &istart, &param, pty.isagg ? pty.dat : -1, ret+!ret, &abiargs.p[first]);
+ }
+ fn->abiarg = alloccopy(fn->arena, abiargs.p, abiargs.n * sizeof *abiargs.p, 0);
+ fn->nabiarg = abiargs.n;
+ vfree(&abiargs);
+
+ if (!fn->nabiret && isagg(fn->retty)) {
+ /* for structures returned by hidden pointer argument,
+ * if all return instrs return local var X, make X point to the result location,
+ * (return value optimization (RVO)) */
+ blk = fn->entry;
+ do {
+ union ref arg = blk->jmp.arg[0];
+ if (blk->jmp.t != Jret) continue;
+ if (!arg.bits) continue;
+ if (arg.t != RTMP || !oisalloca(instrtab[arg.i].op)) {
+ rvovar = -1;
+ break;
+ }
+ if (rvovar == -1) {
+ rvovar = arg.i;
+ } else if (arg.i != rvovar) {
+ rvovar = -1;
+ break;
+ }
+ } while ((blk = blk->lnext) != fn->entry);
+ if (rvovar != -1)
+ instrtab[rvovar] = mkinstr(Ocopy, KPTR, sret);
+ }
+
+ blk = fn->entry->lnext;
+ do {
+ /* adjust calls */
+ for (int iinstr = 0; iinstr < blk->ins.n; ++iinstr) {
+ struct instr *ins = &instrtab[blk->ins.p[iinstr]];
+ if (ins->op != Ocall) continue;
+ abi0_call(fn, ins, blk, &iinstr);
+ }
+
+ /* adjust returns */
+ if (isagg(fn->retty) && blk->jmp.t == Jret && blk->jmp.arg[0].bits) {
+ assert(!blk->jmp.arg[1].bits);
+ if (fn->nabiret) { /* aggregate return in register(s) */
+ union ref src = blk->jmp.arg[0];
+ for (int i = 0; i < fn->nabiret; ++i) {
+ /* XXX this can generate unaligned loads */
+ struct instr ins = {0};
+ switch (ins.cls = fn->abiret[i].ty.cls) {
+ default: assert(0);
+ case KI4: ins.op = Oloadu4; break;
+ case KI8: ins.op = Oloadi8; break;
+ case KF4: ins.op = Oloadf4; break;
+ case KF8: ins.op = Oloadf8; break;
+ }
+ if (i == 0)
+ ins.l = src;
+ else
+ ins.l = insertinstr(blk, blk->ins.n,
+ mkinstr(Oadd, KPTR, src,
+ mkref(RICON, cls2siz[fn->abiret[0].ty.cls])));
+ blk->jmp.arg[i] = insertinstr(blk, blk->ins.n, ins);
+ }
+ } else {
+ /* aggregate return (arg[0] is pointer to return value) */
+ if (rvovar == -1) {
+ /* blit %sret, %arg */
+ union irtype typ = mkirtype(fn->retty);
+ insertinstr(blk, blk->ins.n, mkarginstr(typ, sret));
+ insertinstr(blk, blk->ins.n, mkarginstr(typ, blk->jmp.arg[0]));
+ insertinstr(blk, blk->ins.n, mkintrin(INstructcopy, 0, 2));
+ } else assert(blk->jmp.arg[0].bits == mkref(RTMP, rvovar).bits);
+ if (fn->abiret[0].ty.cls) blk->jmp.arg[0] = rvovar == -1 ? sret : mkref(RTMP, rvovar);
+ else memset(blk->jmp.arg, 0, sizeof blk->jmp.arg);
+ }
+ }
+ } while ((blk = blk->lnext) != fn->entry);
+
+ if (ccopt.dbg.a) {
+ efmt("<< After abi0 >>\n");
+ irdump(fn);
+ }
+}
+
+/* vim:set ts=3 sw=3 expandtab: */