Fix small struct passing on ppc

This commit is contained in:
Anthony Green
2013-02-08 16:12:19 -05:00
parent 63ba1fa79f
commit 70b11b47ee
4 changed files with 54 additions and 20 deletions

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@@ -1,3 +1,9 @@
2013-02-08 Andreas Tobler <andreast@fgznet.ch>
* src/powerpc/ffi.c (ffi_prep_cif_machdep): Fix small struct
support.
* src/powerpc/sysv.S: Ditto.
2013-02-08 Anthony Green <green@moxielogic.com>
* testsuite/libffi.call/cls_longdouble.c: Remove xfail for

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@@ -48,6 +48,11 @@ enum {
FLAG_RETURNS_128BITS = 1 << (31-27), /* cr6 */
FLAG_SYSV_SMST_R4 = 1 << (31-26), /* use r4 for FFI_SYSV 8 byte
structs. */
FLAG_SYSV_SMST_R3 = 1 << (31-25), /* use r3 for FFI_SYSV 4 byte
structs. */
FLAG_ARG_NEEDS_COPY = 1 << (31- 7),
#ifndef __NO_FPRS__
FLAG_FP_ARGUMENTS = 1 << (31- 6), /* cr1.eq; specified by ABI */
@@ -692,18 +697,35 @@ ffi_prep_cif_machdep (ffi_cif *cif)
break;
case FFI_TYPE_STRUCT:
/*
* The final SYSV ABI says that structures smaller or equal 8 bytes
* are returned in r3/r4. The FFI_GCC_SYSV ABI instead returns them
* in memory.
*
* NOTE: The assembly code can safely assume that it just needs to
* store both r3 and r4 into a 8-byte word-aligned buffer, as
* we allocate a temporary buffer in ffi_call() if this flag is
* set.
*/
if (cif->abi == FFI_SYSV && size <= 8)
flags |= FLAG_RETURNS_SMST;
if (cif->abi == FFI_SYSV)
{
/* The final SYSV ABI says that structures smaller or equal 8 bytes
are returned in r3/r4. The FFI_GCC_SYSV ABI instead returns them
in memory. */
/* Treat structs with size <= 8 bytes. */
if (size <= 8)
{
flags |= FLAG_RETURNS_SMST;
/* These structs are returned in r3. We pack the type and the
precalculated shift value (needed in the sysv.S) into flags.
The same applies for the structs returned in r3/r4. */
if (size <= 4)
{
flags |= FLAG_SYSV_SMST_R3;
flags |= 8 * (4 - size) << 8;
break;
}
/* These structs are returned in r3 and r4. See above. */
if (size <= 8)
{
flags |= FLAG_SYSV_SMST_R3 | FLAG_SYSV_SMST_R4;
flags |= 8 * (8 - size) << 8;
break;
}
}
}
intarg_count++;
flags |= FLAG_RETVAL_REFERENCE;
/* Fall through. */

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@@ -142,14 +142,19 @@ L(float_return_value):
#endif
L(small_struct_return_value):
/*
* The C code always allocates a properly-aligned 8-byte bounce
* buffer to make this assembly code very simple. Just write out
* r3 and r4 to the buffer to allow the C code to handle the rest.
*/
stw %r3, 0(%r30)
stw %r4, 4(%r30)
b L(done_return_value)
extrwi %r6,%r31,2,19 /* number of bytes padding = shift/8 */
mtcrf 0x02,%r31 /* copy flags to cr[24:27] (cr6) */
extrwi %r5,%r31,5,19 /* r5 <- number of bits of padding */
subfic %r6,%r6,4 /* r6 <- number of useful bytes in r3 */
bf- 25,L(done_return_value) /* struct in r3 ? if not, done. */
/* smst_one_register: */
slw %r3,%r3,%r5 /* Left-justify value in r3 */
mtxer %r6 /* move byte count to XER ... */
stswx %r3,0,%r30 /* ... and store that many bytes */
bf+ 26,L(done_return_value) /* struct in r3:r4 ? */
add %r6,%r6,%r30 /* adjust pointer */
stswi %r4,%r6,4 /* store last four bytes */
b L(done_return_value)
.LFE1:
END(ffi_call_SYSV)

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@@ -529,6 +529,7 @@ ffi_prep_closure_loc (ffi_closure* closure,
/* SPARC v8 requires 5 instructions for flush to be visible */
asm volatile ("nop; nop; nop; nop; nop");
#endif
#else
ffi_flush_icache (closure, 16);
#endif