MIPS soft-float, part 2: Add soft-float FFI support.

src/lj_ccall.c

@@ -418,6 +418,18 @@
   /* Complex values are returned in 1 or 2 FPRs. */ \
   cc->retref = 0;
 
+#if LJ_ABI_SOFTFP
+#define CCALL_HANDLE_COMPLEXRET2 \
+  if (ctr->size == 2*sizeof(float)) {  /* Copy complex float from GPRs. */ \
+    ((intptr_t *)dp)[0] = cc->gpr[0]; \
+    ((intptr_t *)dp)[1] = cc->gpr[1]; \
+  } else {  /* Copy complex double from GPRs. */ \
+    ((intptr_t *)dp)[0] = cc->gpr[0]; \
+    ((intptr_t *)dp)[1] = cc->gpr[1]; \
+    ((intptr_t *)dp)[2] = cc->gpr[2]; \
+    ((intptr_t *)dp)[3] = cc->gpr[3]; \
+  }
+#else
 #define CCALL_HANDLE_COMPLEXRET2 \
   if (ctr->size == 2*sizeof(float)) {  /* Copy complex float from FPRs. */ \
     ((float *)dp)[0] = cc->fpr[0].f; \
@@ -426,6 +438,7 @@
     ((double *)dp)[0] = cc->fpr[0].d; \
     ((double *)dp)[1] = cc->fpr[1].d; \
   }
+#endif
 
 #define CCALL_HANDLE_STRUCTARG \
   /* Pass all structs by value in registers and/or on the stack. */
@@ -433,14 +446,7 @@
 #define CCALL_HANDLE_COMPLEXARG \
   /* Pass complex by value in 2 or 4 GPRs. */
 
-#define CCALL_HANDLE_REGARG \
+#define CCALL_HANDLE_GPR \
-  if (isfp && nfpr < CCALL_NARG_FPR && !(ct->info & CTF_VARARG)) { \
-    /* Try to pass argument in FPRs. */ \
-    dp = n == 1 ? (void *)&cc->fpr[nfpr].f : (void *)&cc->fpr[nfpr].d; \
-    nfpr++; ngpr += n; \
-    goto done; \
-  } else {  /* Try to pass argument in GPRs. */ \
-    nfpr = CCALL_NARG_FPR; \
   if ((d->info & CTF_ALIGN) > CTALIGN_PTR) \
     ngpr = (ngpr + 1u) & ~1u;  /* Align to regpair. */ \
   if (ngpr < maxgpr) { \
@@ -453,12 +459,29 @@
      ngpr += n; \
     } \
     goto done; \
-    } \
   }
 
+#if !LJ_ABI_SOFTFP	/* MIPS32 hard-float */
+#define CCALL_HANDLE_REGARG \
+  if (isfp && nfpr < CCALL_NARG_FPR && !(ct->info & CTF_VARARG)) { \
+    /* Try to pass argument in FPRs. */ \
+    dp = n == 1 ? (void *)&cc->fpr[nfpr].f : (void *)&cc->fpr[nfpr].d; \
+    nfpr++; ngpr += n; \
+    goto done; \
+  } else {  /* Try to pass argument in GPRs. */ \
+    nfpr = CCALL_NARG_FPR; \
+    CCALL_HANDLE_GPR \
+  }
+#else			/* MIPS32 soft-float */
+#define CCALL_HANDLE_REGARG CCALL_HANDLE_GPR
+#endif
+
+#if !LJ_ABI_SOFTFP
+/* On MIPS64 soft-float, position of float return values is endian-dependant. */
 #define CCALL_HANDLE_RET \
   if (ctype_isfp(ctr->info) && ctr->size == sizeof(float)) \
     sp = (uint8_t *)&cc->fpr[0].f;
+#endif
 
 #else
 #error "Missing calling convention definitions for this architecture"

src/lj_ccall.h

@@ -98,9 +98,9 @@ typedef double FPRArg;
 #elif LJ_TARGET_MIPS
 
 #define CCALL_NARG_GPR		4
-#define CCALL_NARG_FPR		2
+#define CCALL_NARG_FPR		(LJ_ABI_SOFTFP ? 0 : 2)
 #define CCALL_NRET_GPR		2
-#define CCALL_NRET_FPR		2
+#define CCALL_NRET_FPR		(LJ_ABI_SOFTFP ? 0 : 2)
 #define CCALL_SPS_EXTRA		7
 #define CCALL_SPS_FREE		1
 

src/lj_ccallback.c

@@ -427,6 +427,15 @@ void lj_ccallback_mcode_free(CTState *cts)
 
 #elif LJ_TARGET_MIPS
 
+#define CALLBACK_HANDLE_GPR \
+  if (n > 1) ngpr = (ngpr + 1u) & ~1u;  /* Align to regpair. */ \
+  if (ngpr + n <= maxgpr) { \
+    sp = &cts->cb.gpr[ngpr]; \
+    ngpr += n; \
+    goto done; \
+  }
+
+#if !LJ_ABI_SOFTFP	/* MIPS32 hard-float */
 #define CALLBACK_HANDLE_REGARG \
   if (isfp && nfpr < CCALL_NARG_FPR) {  /* Try to pass argument in FPRs. */ \
     sp = (void *)((uint8_t *)&cts->cb.fpr[nfpr] + ((LJ_BE && n==1) ? 4 : 0)); \
@@ -434,13 +443,13 @@ void lj_ccallback_mcode_free(CTState *cts)
     goto done; \
   } else {  /* Try to pass argument in GPRs. */ \
     nfpr = CCALL_NARG_FPR; \
-    if (n > 1) ngpr = (ngpr + 1u) & ~1u;  /* Align to regpair. */ \
+    CALLBACK_HANDLE_GPR \
-    if (ngpr + n <= maxgpr) { \
-      sp = &cts->cb.gpr[ngpr]; \
-      ngpr += n; \
-      goto done; \
-    } \
   }
+#else			/* MIPS32 soft-float */
+#define CALLBACK_HANDLE_REGARG \
+  CALLBACK_HANDLE_GPR \
+  UNUSED(isfp);
+#endif
 
 #define CALLBACK_HANDLE_RET \
   if (ctype_isfp(ctr->info) && ctr->size == sizeof(float)) \