Commit 70b11b47eea93bf43627588d494d0b3b0d062481
2013-02-08T16:12:19
Fix small struct passing on ppc
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diff --git a/ChangeLog b/ChangeLog
index 92e0b8b..9f7a1a4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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
diff --git a/src/powerpc/ffi.c b/src/powerpc/ffi.c
index add43e0..f3a96a1 100644
--- a/src/powerpc/ffi.c
+++ b/src/powerpc/ffi.c
@@ -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. */
diff --git a/src/powerpc/sysv.S b/src/powerpc/sysv.S
index 675ed03..5ee3a19 100644
--- a/src/powerpc/sysv.S
+++ b/src/powerpc/sysv.S
@@ -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)
diff --git a/src/sparc/ffi.c b/src/sparc/ffi.c
index 564be13..9f0fded 100644
--- a/src/sparc/ffi.c
+++ b/src/sparc/ffi.c
@@ -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