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[RS6000] Correct powerpc sysv stack argument accounting 

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.

From-SVN: r228307
This commit is contained in:
Alan Modra 2015-10-01 06:59:00 +09:30 committed by Alan Modra
parent d64f8dd280
commit c57173b69a
2 changed files with 104 additions and 109 deletions
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6
libffi/ChangeLog
View File

@ -1,3 +1,9 @@
2015-10-01 Alan Modra <amodra@gmail.com>
* src/powerpc/ffi_sysv.c (ffi_prep_cif_sysv_core): Count fprs,
gprs, and stack words separately.
(ffi_prep_args_SYSV): Similarly.
2015-05-13 Michael Haubenwallner <michael.haubenwallner@ssi-schaefer.com>
* Makefile.in: Regenerated with automake-1.11.6.

207
libffi/src/powerpc/ffi_sysv.c
View File

@ -93,7 +93,7 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
{
ffi_type **ptr;
unsigned bytes;
unsigned i, fparg_count = 0, intarg_count = 0;
unsigned i, fpr_count = 0, gpr_count = 0, stack_count = 0;
unsigned flags = cif->flags;
unsigned struct_copy_size = 0;
unsigned type = cif->rtype->type;
@ -155,7 +155,7 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
flags |= FLAG_RETURNS_SMST;
break;
}
intarg_count++;
gpr_count++;
flags |= FLAG_RETVAL_REFERENCE;
/* Fall through. */
case FFI_TYPE_VOID:
@ -182,24 +182,41 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
{
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
case FFI_TYPE_LONGDOUBLE:
fparg_count++;
/* Fall thru */
if (fpr_count >= NUM_FPR_ARG_REGISTERS - 1)
{
fpr_count = NUM_FPR_ARG_REGISTERS;
/* 8-byte align long doubles. */
stack_count += stack_count & 1;
stack_count += 4;
}
else
fpr_count += 2;
#ifdef __NO_FPRS__
return FFI_BAD_ABI;
#endif
break;
#endif
case FFI_TYPE_DOUBLE:
fparg_count++;
/* If this FP arg is going on the stack, it must be
8-byte-aligned. */
if (fparg_count > NUM_FPR_ARG_REGISTERS
&& intarg_count >= NUM_GPR_ARG_REGISTERS
&& intarg_count % 2 != 0)
intarg_count++;
if (fpr_count >= NUM_FPR_ARG_REGISTERS)
{
/* 8-byte align doubles. */
stack_count += stack_count & 1;
stack_count += 2;
}
else
fpr_count += 1;
#ifdef __NO_FPRS__
return FFI_BAD_ABI;
#endif
break;
case FFI_TYPE_FLOAT:
fparg_count++;
if (fpr_count >= NUM_FPR_ARG_REGISTERS)
/* Yes, we don't follow the ABI, but neither does gcc. */
stack_count += 1;
else
fpr_count += 1;
#ifdef __NO_FPRS__
return FFI_BAD_ABI;
#endif
@ -208,11 +225,13 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
case FFI_TYPE_UINT128:
/* A long double in FFI_LINUX_SOFT_FLOAT can use only a set
of four consecutive gprs. If we do not have enough, we
have to adjust the intarg_count value. */
if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3
&& intarg_count < NUM_GPR_ARG_REGISTERS)
intarg_count = NUM_GPR_ARG_REGISTERS;
intarg_count += 4;
have to adjust the gpr_count value. */
if (gpr_count >= NUM_GPR_ARG_REGISTERS - 3)
gpr_count = NUM_GPR_ARG_REGISTERS;
if (gpr_count >= NUM_GPR_ARG_REGISTERS)
stack_count += 4;
else
gpr_count += 4;
break;
case FFI_TYPE_UINT64:
@ -225,10 +244,14 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
Also, only certain register pairs can be used for
passing long long int -- specifically (r3,r4), (r5,r6),
(r7,r8), (r9,r10). */
if (intarg_count == NUM_GPR_ARG_REGISTERS-1
|| intarg_count % 2 != 0)
intarg_count++;
intarg_count += 2;
gpr_count += gpr_count & 1;
if (gpr_count >= NUM_GPR_ARG_REGISTERS)
{
stack_count += stack_count & 1;
stack_count += 2;
}
else
gpr_count += 2;
break;
case FFI_TYPE_STRUCT:
@ -249,7 +272,10 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
case FFI_TYPE_SINT8:
/* Everything else is passed as a 4-byte word in a GPR, either
the object itself or a pointer to it. */
intarg_count++;
if (gpr_count >= NUM_GPR_ARG_REGISTERS)
stack_count += 1;
else
gpr_count += 1;
break;
default:
@ -257,22 +283,19 @@ ffi_prep_cif_sysv_core (ffi_cif *cif)
}
}
if (fparg_count != 0)
if (fpr_count != 0)
flags |= FLAG_FP_ARGUMENTS;
if (intarg_count > 4)
if (gpr_count > 4)
flags |= FLAG_4_GPR_ARGUMENTS;
if (struct_copy_size != 0)
flags |= FLAG_ARG_NEEDS_COPY;
/* Space for the FPR registers, if needed. */
if (fparg_count != 0)
if (fpr_count != 0)
bytes += NUM_FPR_ARG_REGISTERS * sizeof (double);
/* Stack space. */
if (intarg_count > NUM_GPR_ARG_REGISTERS)
bytes += (intarg_count - NUM_GPR_ARG_REGISTERS) * sizeof (int);
if (fparg_count > NUM_FPR_ARG_REGISTERS)
bytes += (fparg_count - NUM_FPR_ARG_REGISTERS) * sizeof (double);
bytes += stack_count * sizeof (int);
/* The stack space allocated needs to be a multiple of 16 bytes. */
bytes = (bytes + 15) & ~0xF;
@ -367,13 +390,13 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
/* 'gpr_base' points at the space for gpr3, and grows upwards as
we use GPR registers. */
valp gpr_base;
int intarg_count;
valp gpr_end;
#ifndef __NO_FPRS__
/* 'fpr_base' points at the space for fpr1, and grows upwards as
we use FPR registers. */
valp fpr_base;
int fparg_count;
valp fpr_end;
#endif
/* 'copy_space' grows down as we put structures in it. It should
@ -405,11 +428,11 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
unsigned gprvalue;
stacktop.c = (char *) stack + bytes;
gpr_base.u = stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS;
intarg_count = 0;
gpr_end.u = stacktop.u - ASM_NEEDS_REGISTERS;
gpr_base.u = gpr_end.u - NUM_GPR_ARG_REGISTERS;
#ifndef __NO_FPRS__
fpr_base.d = gpr_base.d - NUM_FPR_ARG_REGISTERS;
fparg_count = 0;
fpr_end.d = gpr_base.d;
fpr_base.d = fpr_end.d - NUM_FPR_ARG_REGISTERS;
copy_space.c = ((flags & FLAG_FP_ARGUMENTS) ? fpr_base.c : gpr_base.c);
#else
copy_space.c = gpr_base.c;
@ -425,10 +448,7 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
/* Deal with return values that are actually pass-by-reference. */
if (flags & FLAG_RETVAL_REFERENCE)
{
*gpr_base.u++ = (unsigned long) (char *) ecif->rvalue;
intarg_count++;
}
*gpr_base.u++ = (unsigned) (char *) ecif->rvalue;
/* Now for the arguments. */
p_argv.v = ecif->avalue;
@ -448,14 +468,11 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
case FFI_TYPE_LONGDOUBLE:
double_tmp = (*p_argv.d)[0];
if (fparg_count >= NUM_FPR_ARG_REGISTERS - 1)
if (fpr_base.d >= fpr_end.d - 1)
{
if (intarg_count >= NUM_GPR_ARG_REGISTERS
&& intarg_count % 2 != 0)
{
intarg_count++;
next_arg.u++;
}
fpr_base.d = fpr_end.d;
if (((next_arg.u - stack) & 1) != 0)
next_arg.u += 1;
*next_arg.d = double_tmp;
next_arg.u += 2;
double_tmp = (*p_argv.d)[1];
@ -468,42 +485,33 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
double_tmp = (*p_argv.d)[1];
*fpr_base.d++ = double_tmp;
}
fparg_count += 2;
FFI_ASSERT (flags & FLAG_FP_ARGUMENTS);
break;
# endif
case FFI_TYPE_DOUBLE:
double_tmp = **p_argv.d;
if (fparg_count >= NUM_FPR_ARG_REGISTERS)
if (fpr_base.d >= fpr_end.d)
{
if (intarg_count >= NUM_GPR_ARG_REGISTERS
&& intarg_count % 2 != 0)
{
intarg_count++;
next_arg.u++;
}
if (((next_arg.u - stack) & 1) != 0)
next_arg.u += 1;
*next_arg.d = double_tmp;
next_arg.u += 2;
}
else
*fpr_base.d++ = double_tmp;
fparg_count++;
FFI_ASSERT (flags & FLAG_FP_ARGUMENTS);
break;
case FFI_TYPE_FLOAT:
double_tmp = **p_argv.f;
if (fparg_count >= NUM_FPR_ARG_REGISTERS)
if (fpr_base.d >= fpr_end.d)
{
*next_arg.f = (float) double_tmp;
next_arg.u += 1;
intarg_count++;
}
else
*fpr_base.d++ = double_tmp;
fparg_count++;
FFI_ASSERT (flags & FLAG_FP_ARGUMENTS);
break;
#endif /* have FPRs */
@ -513,42 +521,34 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
is passed in four consecutive GPRs if available. A maximum of 2
long doubles can be passed in gprs. If we do not have 4 GPRs
left, the long double is passed on the stack, 4-byte aligned. */
{
unsigned int int_tmp;
unsigned int ii;
if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3)
{
if (intarg_count < NUM_GPR_ARG_REGISTERS)
intarg_count = NUM_GPR_ARG_REGISTERS;
for (ii = 0; ii < 4; ii++)
{
int_tmp = (*p_argv.ui)[ii];
*next_arg.u++ = int_tmp;
}
}
else
{
for (ii = 0; ii < 4; ii++)
{
int_tmp = (*p_argv.ui)[ii];
*gpr_base.u++ = int_tmp;
}
}
intarg_count += 4;
break;
}
if (gpr_base.u >= gpr_end.u - 3)
{
unsigned int ii;
gpr_base.u = gpr_end.u;
for (ii = 0; ii < 4; ii++)
{
unsigned int int_tmp = (*p_argv.ui)[ii];
*next_arg.u++ = int_tmp;
}
}
else
{
unsigned int ii;
for (ii = 0; ii < 4; ii++)
{
unsigned int int_tmp = (*p_argv.ui)[ii];
*gpr_base.u++ = int_tmp;
}
}
break;
case FFI_TYPE_UINT64:
case FFI_TYPE_SINT64:
if (intarg_count == NUM_GPR_ARG_REGISTERS-1)
intarg_count++;
if (intarg_count >= NUM_GPR_ARG_REGISTERS)
if (gpr_base.u >= gpr_end.u - 1)
{
if (intarg_count % 2 != 0)
{
intarg_count++;
next_arg.u++;
}
gpr_base.u = gpr_end.u;
if (((next_arg.u - stack) & 1) != 0)
next_arg.u++;
*next_arg.ll = **p_argv.ll;
next_arg.u += 2;
}
@ -559,14 +559,10 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
(r5,r6), (r7,r8), (r9,r10). If next arg is long long
but not correct starting register of pair then skip
until the proper starting register. */
if (intarg_count % 2 != 0)
{
intarg_count ++;
gpr_base.u++;
}
if (((gpr_end.u - gpr_base.u) & 1) != 0)
gpr_base.u++;
*gpr_base.ll++ = **p_argv.ll;
}
intarg_count += 2;
break;
case FFI_TYPE_STRUCT:
@ -601,29 +597,22 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack)
gprvalue = **p_argv.ui;
putgpr:
if (intarg_count >= NUM_GPR_ARG_REGISTERS)
if (gpr_base.u >= gpr_end.u)
*next_arg.u++ = gprvalue;
else
*gpr_base.u++ = gprvalue;
intarg_count++;
break;
}
}
/* Check that we didn't overrun the stack... */
FFI_ASSERT (copy_space.c >= next_arg.c);
FFI_ASSERT (gpr_base.u <= stacktop.u - ASM_NEEDS_REGISTERS);
/* The assert below is testing that the number of integer arguments agrees
with the number found in ffi_prep_cif_machdep(). However, intarg_count
is incremented whenever we place an FP arg on the stack, so account for
that before our assert test. */
FFI_ASSERT (gpr_base.u <= gpr_end.u);
#ifndef __NO_FPRS__
if (fparg_count > NUM_FPR_ARG_REGISTERS)
intarg_count -= fparg_count - NUM_FPR_ARG_REGISTERS;
FFI_ASSERT (fpr_base.u
<= stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS);
FFI_ASSERT (fpr_base.u <= fpr_end.u);
#endif
FFI_ASSERT (flags & FLAG_4_GPR_ARGUMENTS || intarg_count <= 4);
FFI_ASSERT (((flags & FLAG_4_GPR_ARGUMENTS) != 0)
== (gpr_end.u - gpr_base.u < 4));
}
#define MIN_CACHE_LINE_SIZE 8