Index: libffi/ChangeLog =================================================================== --- libffi.orig/ChangeLog +++ libffi/ChangeLog @@ -17,6 +17,12 @@ * configure: Regenerate. +2011-11-12 Kyle Moffett + Anthony Green + + * src/ppc/sysv.S, src/ppc/ffi.c: Remove use of ppc string + instructions (not available on some cores, like the PPC440). + 2011-11-12 Kimura Wataru * m4/ax_enable_builddir: Change from string comparison to numeric Index: libffi/src/powerpc/ffi.c =================================================================== --- libffi.orig/src/powerpc/ffi.c +++ libffi/src/powerpc/ffi.c @@ -1,5 +1,6 @@ /* ----------------------------------------------------------------------- ffi.c - Copyright (C) 2011 Anthony Green + Copyright (C) 2011 Kyle Moffett Copyright (C) 2008 Red Hat, Inc Copyright (C) 2007, 2008 Free Software Foundation, Inc Copyright (c) 1998 Geoffrey Keating @@ -44,11 +45,6 @@ enum { FLAG_RETURNS_64BITS = 1 << (31-28), 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. */ - /* Bits (31-24) through (31-19) store shift value for SMST */ FLAG_ARG_NEEDS_COPY = 1 << (31- 7), FLAG_FP_ARGUMENTS = 1 << (31- 6), /* cr1.eq; specified by ABI */ @@ -672,34 +668,19 @@ ffi_prep_cif_machdep (ffi_cif *cif) break; case FFI_TYPE_STRUCT: - 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; - } - } - } + /* + * 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 FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE byref: #endif @@ -887,21 +868,32 @@ extern void FFI_HIDDEN ffi_call_LINUX64( void ffi_call(ffi_cif *cif, void (*fn)(void), void *rvalue, void **avalue) { + /* + * 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. + * + * Just to keep things simple for the assembly code, we will always + * bounce-buffer struct return values less than or equal to 8 bytes. + * This allows the ASM to handle SYSV small structures by directly + * writing r3 and r4 to memory without worrying about struct size. + */ + unsigned int smst_buffer[2]; extended_cif ecif; + unsigned int rsize; ecif.cif = cif; ecif.avalue = avalue; - /* If the return value is a struct and we don't have a return */ - /* value address then we need to make one */ - - if ((rvalue == NULL) && (cif->rtype->type == FFI_TYPE_STRUCT)) - { - ecif.rvalue = alloca(cif->rtype->size); - } - else - ecif.rvalue = rvalue; - + /* Ensure that we have a valid struct return value */ + ecif.rvalue = rvalue; + if (cif->rtype->type == FFI_TYPE_STRUCT) { + rsize = cif->rtype->size; + if (rsize <= 8) + ecif.rvalue = smst_buffer; + else if (!rvalue) + ecif.rvalue = alloca(rsize); + } switch (cif->abi) { @@ -921,6 +913,10 @@ ffi_call(ffi_cif *cif, void (*fn)(void), FFI_ASSERT (0); break; } + + /* Check for a bounce-buffered return value */ + if (rvalue && ecif.rvalue == smst_buffer) + memcpy(rvalue, smst_buffer, rsize); } Index: libffi/src/powerpc/sysv.S =================================================================== --- libffi.orig/src/powerpc/sysv.S +++ libffi/src/powerpc/sysv.S @@ -136,19 +136,14 @@ L(float_return_value): b L(done_return_value) L(small_struct_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) + /* + * 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) .LFE1: END(ffi_call_SYSV)