/* -- POSIX/x64 calling conventions --------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
- if (sz <= 16) { \
- cc->retref = 0; \
- goto err_nyi; /* NYI: crazy x64 rules for small structs. */ \
- } else { \
- cc->retref = 1; /* Return all bigger structs by reference. */ \
+ int rcl[2]; rcl[0] = rcl[1] = 0; \
+ if (ccall_classify_struct(cts, ctr, rcl, 0)) { \
+ cc->retref = 1; /* Return struct by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp; \
+ } else { \
+ cc->retref = 0; /* Return small structs in registers. */ \
}
+#define CCALL_HANDLE_STRUCTRET2 \
+ int rcl[2]; rcl[0] = rcl[1] = 0; \
+ ccall_classify_struct(cts, ctr, rcl, 0); \
+ ccall_struct_ret(cc, rcl, dp, ctr->size);
+
#define CCALL_HANDLE_COMPLEXRET \
/* Complex values are returned in one or two FPRs. */ \
cc->retref = 0;
}
#define CCALL_HANDLE_STRUCTARG \
- if (sz <= 16) { \
- goto err_nyi; /* NYI: crazy x64 rules for small structs. */ \
+ int rcl[2]; rcl[0] = rcl[1] = 0; \
+ if (!ccall_classify_struct(cts, d, rcl, 0)) { \
+ cc->nsp = nsp; cc->ngpr = ngpr; cc->nfpr = nfpr; \
+ if (ccall_struct_arg(cc, cts, d, rcl, o)) goto err_nyi; \
+ nsp = cc->nsp; ngpr = cc->ngpr; nfpr = cc->nfpr; \
+ continue; \
} /* Pass all other structs by value on stack. */
#define CCALL_HANDLE_COMPLEXARG \
#error "missing calling convention definitions for this architecture"
#endif
+#ifndef CCALL_HANDLE_STRUCTRET2
+#define CCALL_HANDLE_STRUCTRET2 \
+ memcpy(dp, sp, ctr->size); /* Copy struct return value from GPRs. */
+#endif
+
+/* -- x64 struct classification ------------------------------------------- */
+
+#if LJ_TARGET_X64 && !LJ_ABI_WIN
+
+/* Register classes for x64 struct classification. */
+#define CCALL_RCL_INT 1
+#define CCALL_RCL_SSE 2
+#define CCALL_RCL_MEM 4
+/* NYI: classify vectors. */
+
+static int ccall_classify_struct(CTState *cts, CType *ct, int *rcl, CTSize ofs);
+
+/* Classify a C type. */
+static void ccall_classify_ct(CTState *cts, CType *ct, int *rcl, CTSize ofs)
+{
+ if (ctype_isarray(ct->info)) {
+ CType *cct = ctype_rawchild(cts, ct);
+ CTSize eofs, esz = cct->size, asz = ct->size;
+ for (eofs = 0; eofs < asz; eofs += esz)
+ ccall_classify_ct(cts, cct, rcl, ofs+eofs);
+ } else if (ctype_isstruct(ct->info)) {
+ ccall_classify_struct(cts, ct, rcl, ofs);
+ } else {
+ int cl = ctype_isfp(ct->info) ? CCALL_RCL_SSE : CCALL_RCL_INT;
+ lua_assert(ctype_hassize(ct->info));
+ if ((ofs & (ct->size-1))) cl = CCALL_RCL_MEM; /* Unaligned. */
+ rcl[(ofs >= 8)] |= cl;
+ }
+}
+
+/* Recursively classify a struct based on its fields. */
+static int ccall_classify_struct(CTState *cts, CType *ct, int *rcl, CTSize ofs)
+{
+ if (ct->size > 16) return CCALL_RCL_MEM; /* Too big, gets memory class. */
+ while (ct->sib) {
+ CTSize fofs;
+ ct = ctype_get(cts, ct->sib);
+ fofs = ofs+ct->size;
+ if (ctype_isfield(ct->info))
+ ccall_classify_ct(cts, ctype_rawchild(cts, ct), rcl, fofs);
+ else if (ctype_isbitfield(ct->info))
+ rcl[(fofs >= 8)] |= CCALL_RCL_INT; /* NYI: unaligned bitfields? */
+ else if (ctype_isxattrib(ct->info, CTA_SUBTYPE))
+ ccall_classify_struct(cts, ctype_child(cts, ct), rcl, fofs);
+ }
+ return ((rcl[0]|rcl[1]) & CCALL_RCL_MEM); /* Memory class? */
+}
+
+/* Try to split up a small struct into registers. */
+static int ccall_struct_reg(CCallState *cc, GPRArg *dp, int *rcl)
+{
+ MSize ngpr = cc->ngpr, nfpr = cc->nfpr;
+ uint32_t i;
+ for (i = 0; i < 2; i++) {
+ lua_assert(!(rcl[i] & CCALL_RCL_MEM));
+ if ((rcl[i] & CCALL_RCL_INT)) { /* Integer class takes precedence. */
+ if (ngpr >= CCALL_NARG_GPR) return 1; /* Register overflow. */
+ cc->gpr[ngpr++] = dp[i];
+ } else if ((rcl[i] & CCALL_RCL_SSE)) {
+ if (nfpr >= CCALL_NARG_FPR) return 1; /* Register overflow. */
+ cc->fpr[nfpr++].l[0] = dp[i];
+ }
+ }
+ cc->ngpr = ngpr; cc->nfpr = nfpr;
+ return 0; /* Ok. */
+}
+
+/* Pass a small struct argument. */
+static int ccall_struct_arg(CCallState *cc, CTState *cts, CType *d, int *rcl,
+ TValue *o)
+{
+ GPRArg dp[2];
+ dp[0] = dp[1] = 0;
+ lj_cconv_ct_tv(cts, d, (uint8_t *)dp, o, 0); /* Convert to temp. struct. */
+ if (!ccall_struct_reg(cc, dp, rcl)) { /* Register overflow? Pass on stack. */
+ MSize nsp = cc->nsp, n = rcl[1] ? 2 : 1;
+ if (nsp + n > CCALL_MAXSTACK) return 1; /* Too many arguments. */
+ cc->nsp = nsp + n;
+ memcpy(&cc->stack[nsp], dp, n*CTSIZE_PTR);
+ }
+ return 0; /* Ok. */
+}
+
+/* Combine returned small struct. */
+static void ccall_struct_ret(CCallState *cc, int *rcl, uint8_t *dp, CTSize sz)
+{
+ GPRArg sp[2];
+ MSize ngpr = 0, nfpr = 0;
+ uint32_t i;
+ for (i = 0; i < 2; i++) {
+ if ((rcl[i] & CCALL_RCL_INT)) { /* Integer class takes precedence. */
+ sp[i] = cc->gpr[ngpr++];
+ } else if ((rcl[i] & CCALL_RCL_SSE)) {
+ sp[i] = cc->fpr[nfpr++].l[0];
+ }
+ }
+ memcpy(dp, sp, sz);
+}
+#endif
+
+/* -- Common C call handling ---------------------------------------------- */
+
/* Infer the destination CTypeID for a vararg argument. */
static CTypeID ccall_ctid_vararg(CTState *cts, cTValue *o)
{
return lj_ctype_intern(cts,
CTINFO(CT_PTR, CTALIGN_PTR|ctype_cid(s->info)), CTSIZE_PTR);
} else if (ctype_isstruct(s->info) || ctype_isfunc(s->info)) {
+ /* NYI: how to pass a struct by value in a vararg argument? */
return lj_ctype_intern(cts, CTINFO(CT_PTR, CTALIGN_PTR|id), CTSIZE_PTR);
} if (ctype_isfp(s->info) && s->size == sizeof(float)) {
return CTID_DOUBLE;
MSize align = (1u << ctype_align(d->info-CTALIGN_PTR)) -1;
nsp = (nsp + align) & ~align; /* Align argument on stack. */
}
- if (nsp + n >= CCALL_MAXSTACK) { /* Too many arguments. */
+ if (nsp + n > CCALL_MAXSTACK) { /* Too many arguments. */
err_nyi:
lj_err_caller(L, LJ_ERR_FFI_NYICALL);
}
/* Return cdata object which is already on top of stack. */
if (!cc->retref) {
void *dp = cdataptr(cdataV(L->top-1)); /* Use preallocated object. */
- memcpy(dp, sp, ctr->size); /* Copy struct return value from GPRs. */
+ CCALL_HANDLE_STRUCTRET2
}
return 1; /* One GC step. */
}
projects / thirdparty / LuaJIT.git / commitdiff
