ppc32 starts using the stack for integer arg passing when we run out
of integer arg passing registers. Similarly, we start using the stack
for floating point args when we run out of floating point registers.
The decision on where an integer arg goes does not depend on number of
floating point args, nor does the decision on where a floating point
arg goes depend on number of integer args. Alignment of stack args
also simply depends on number of stack args.
This patch untangles the horrible mess we had, with intarg_count being
wrongly used to count both integer args and stack words.
* src/powerpc/ffi_sysv.c (ffi_prep_cif_sysv_core): Count fprs,
gprs, and stack words separately.
(ffi_prep_args_SYSV): Similarly.
Plus .cfi async unwind info, rearrangement of ffi_call_linux64 and
ffi_call_SYSV function params to avoid register copies, tweaks to
trampolines.
* src/powerpc/ffitarget.h (FFI_GO_CLOSURES): Define.
* src/powerpc/ffi.c (ffi_call_int): New function with extra
closure param, and args rearranged on ffi_call_linux64 and
ffi_call_SYSV calls, extracted from ..
(ffi_call): ..here.
(ffi_call_go, ffi_prep_go_closure): New functions.
* src/powerpc/ffi_linux64.c (ffi_prep_closure_loc_linux64): Make
hidden. Only flush insn part of ELFv2 trampoline. Don't shuffle
ELFv1 trampoline.
(ffi_closure_helper_LINUX64): Replace closure param with cif, fun,
user_data params.
* src/powerpc/ffi_powerpc.h (ffi_go_closure_sysv): Declare.
(ffi_go_closure_linux64): Declare.
(ffi_call_SYSV, fi_call_LINUX64): Update.
(ffi_prep_closure_loc_sysv, ffi_prep_closure_loc_linux64): Declare.
(ffi_closure_helper_SYSV, ffi_closure_helper_LINUX64): Update.
* src/powerpc/ffi_sysv.c (ASM_NEEDS_REGISTERS): Increase to 6.
(ffi_prep_closure_loc_sysv): Use bcl in trampoline, put data words
last, flush just the insn part.
(ffi_closure_helper_SYSV): Replace closure param with cif, fun and
user_data params.
* src/powerpc/linux64.S (ffi_call_LINUX64): Replace hand-written
.eh_frame with .cfi directives. Adjust for changed param order.
Pass extra "closure" param to user function in static chain. Add
.cfi directives to describe epilogue. Don't provide traceback
table for ELFv2 or _CALL_LINUX.
* src/powerpc/linux64_closure.S (ffi_closure_LINUX64): Replace
hand-written .eh_frame with .cfi directives. Adjust for changed
ffi_closure_helper_LINUX64 params. Add .cfi directives to
describe epilogue. Don't provide traceback table for ELFv2 or
_CALL_LINUX.
(ffi_go_closure_linux64): New function.
* src/powerpc/sysv.S: Remove redundant .globl ffi_prep_args_SYSV.
(ffi_call_SYSV): Make hidden. Replace hand-written .eh_frame with
.cfi directives. Adjust for changed params. Pass extra "closure"
param to user function in static chain. Add .cfi directives to
describe epilogue.
* src/powerpc/ppc_closure.S (ffi_closure_SYSV): Make hidden.
Replace hand-written .eh_frame with .cfi directives. Adjust for
changed ffi_closure_helper_SYSV params. Add .cfi directives to
describe epilogue. Don't just use nops in the dead __NO_FPRS__
epilogues.
(ffi_go_closure_sysv): New function.
code, and makes it possible to link code compiled with different
options to those used to compile libffi. For example, a
-mlong-double-128 libffi can be used with -mlong-double-64 code.
Using the return value area as a place to pass parameters wasn't such
a good idea, causing a failure of cls_ulonglong.c. I didn't see this
when running the mainline gcc libffi testsuite because that version of
the test is inferior to the upstreamm libffi test.
Using NUM_FPR_ARG_REGISTERS rather than NUM_FPR_ARG_REGISTERS64 meant
that a parameter save area could be allocated before it was strictly
necessary. Wrong but harmless. Found when splitting apart ffi.c
into 32-bit and 64-bit support.
code, and makes it possible to link code compiled with different
options to those used to compile libffi. For example, a
-mlong-double-128 libffi can be used with -mlong-double-64 code.
Using the return value area as a place to pass parameters wasn't such
a good idea, causing a failure of cls_ulonglong.c. I didn't see this
when running the mainline gcc libffi testsuite because that version of
the test is inferior to the upstreamm libffi test.
Using NUM_FPR_ARG_REGISTERS rather than NUM_FPR_ARG_REGISTERS64 meant
that a parameter save area could be allocated before it was strictly
necessary. Wrong but harmless. Found when splitting apart ffi.c
into 32-bit and 64-bit support.
linked with ELFv2 objects, so this is one case where preprocessor
tests in ffi.c are fine. Also, there is no need to define a new
FFI_ELFv2 or somesuch value in enum ffi_abi. FFI_LINUX64 will happily
serve both ABIs.
linked with ELFv2 objects, so this is one case where preprocessor
tests in ffi.c are fine. Also, there is no need to define a new
FFI_ELFv2 or somesuch value in enum ffi_abi. FFI_LINUX64 will happily
serve both ABIs.
values from 2011-11-12, but in so doing reintroduced string
instructions to sysv.S that are not supported on all powerpc variants.
This patch properly copies the bounce buffer to destination in C code
rather than in asm.
I have tested this on powerpc64-linux, powerpc-linux and
powerpc-freebsd. Well, the last on powerpc-linux by lying to
configure with
CC="gcc -m32 -msvr4-struct-return -mlong-double-64" \
CXX="g++ -m32 -msvr4-struct-return -mlong-double-64" \
/src/libffi-current/configure --build=powerpc-freebsd
and then
make && make CC="gcc -m32" CXX="g++ -m32" \
RUNTESTFLAGS=--target_board=unix/-m32/-msvr4-struct-return/-mlong-double-64\
check
gcc for quite some time. Since gcc now does the correct alignment,
libffi needs to follow suit. This ought to be made selectable via
a new abi value, and the #ifdefs removed from ffi.c along with many
other #ifdefs present there and in assembly. I'll do that with a
followup patch sometime.
This is a revised version of
https://sourceware.org/ml/libffi-discuss/2013/msg00162.html
fpr area and the parameter save area, necessary when the backend
doesn't know if a function argument corresponds to the ellipsis
arguments of a variadic function. This patch adds powerpc support for
variadic functions, and changes the code to only pass fp in the ABI
mandated area. ELFv2 needs this change since the parameter save area
may not exist there.
This also fixes two faulty tests that used a non-variadic function
cast to call a variadic function, and spuriously reasoned that this is
somehow necessary for static functions..
returned values. It would be reasonable and logical to use the actual
return argument type as passed to ffi_prep_cif, but this would mean
changing a large number of tests that use ffi_arg and all backends
that write results to an ffi_arg.
Alan Modra