Commit 3c1608613ab3c2184222b98c5482cddedd6b559b
2013-03-26T19:24:47
extend ffi_prepare_args for FFI_VFP (hard-float ABI), fixing an issue with passing VFP arguments in VFP registers and the stack, while at the same time not using all core registers.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
diff --git a/src/arm/ffi.c b/src/arm/ffi.c
index d3dba9c..cce24d8 100644
--- a/src/arm/ffi.c
+++ b/src/arm/ffi.c
@@ -153,6 +153,76 @@ int ffi_prep_args_VFP(char *stack, extended_cif *ecif, float *vfp_space)
{
// make sure we are using FFI_VFP
FFI_ASSERT(ecif->cif->abi == FFI_VFP);
+
+ register unsigned int i, vi = 0;
+ register void **p_argv;
+ register char *argp, *regp, *eo_regp;
+ register ffi_type **p_arg;
+ char stack_used = 0;
+ char done_with_regs = 0;
+ char is_vfp_type;
+
+ /* the first 4 words on the stack are used for values passed in core
+ * registers. */
+ regp = stack;
+ eo_regp = argp = regp + 16;
+
+
+ /* if the function returns an FFI_TYPE_STRUCT in memory, that address is
+ * passed in r0 to the function */
+ if ( ecif->cif->flags == FFI_TYPE_STRUCT ) {
+ *(void **) regp = ecif->rvalue;
+ regp += 4;
+ }
+
+ p_argv = ecif->avalue;
+
+ for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
+ (i != 0);
+ i--, p_arg++, p_argv++)
+ {
+ is_vfp_type = vfp_type_p (*p_arg);
+
+ /* Allocated in VFP registers. */
+ if(vi < ecif->cif->vfp_nargs && is_vfp_type)
+ {
+ char *vfp_slot = (char *)(vfp_space + ecif->cif->vfp_args[vi++]);
+ ffi_put_arg(p_arg, p_argv, vfp_slot);
+ continue;
+ }
+ /* Try allocating in core registers. */
+ else if (!done_with_regs && !is_vfp_type)
+ {
+ char *tregp = ffi_align(p_arg, regp);
+ size_t size = (*p_arg)->size;
+ size = (size < 4)? 4 : size; // pad
+ /* Check if there is space left in the aligned register area to place
+ * the argument */
+ if(tregp + size <= eo_regp)
+ {
+ regp = tregp + ffi_put_arg(p_arg, p_argv, tregp);
+ done_with_regs = (regp == argp);
+ // ensure we did not write into the stack area
+ FFI_ASSERT(regp <= argp);
+ continue;
+ }
+ /* In case there are no arguments in the stack area yet,
+ the argument is passed in the remaining core registers and on the
+ stack. */
+ else if (!stack_used)
+ {
+ stack_used = 1;
+ done_with_regs = 1;
+ argp = tregp + ffi_put_arg(p_arg, p_argv, tregp);
+ FFI_ASSERT(eo_regp < argp);
+ continue;
+ }
+ }
+ /* Base case, arguments are passed on the stack */
+ stack_used = 1;
+ argp = ffi_align(p_arg, argp);
+ argp += ffi_put_arg(p_arg, p_argv, argp);
+ }
/* Indicate the VFP registers used. */
return ecif->cif->vfp_used;
}