Extend this attribute to cover long double ABIs, for 64-bit too. The
idea is that the linker should warn if you are linking object files
with incompatible ABIs, for example IEEE128 long double with IBM long
double. It's only a warning, and doesn't catch everything. In
particular, global data mismatches. ie. initialised global variables
in one format can be used by code that expects a different format
without warning. Also, a function returning "sizeof (long double)"
or similar won't cause an object file to be tagged. Oh, and you need
a new linker to see long double warnings.
The patch also corrects an error that crept in to code setting
rs6000_passes_float. See the added comment. Passing IEEE128 values
in vsx regs ought to set both Tag_GNU_Power_ABI_FP and
Tag_GNU_Power_ABI_Vector.
I've also added a new option, default on, that disables output of
.gnu_attribute tags. That's needed because this patch alone
introduces libstdc++ testsuite regressions, fixed by the next patch.
Bootstrapped and regression tested powerpc64le-linux and
powerpc64-linux biarch. OK to apply?
* config/rs6000/sysv4.opt (mgnu-attr): New option.
* config/rs6000/rs6000.c (HAVE_LD_PPC_GNU_ATTR): Define.
(rs6000_passes_float): Comment.
(rs6000_passes_long_double): New static var.
(call_ABI_of_interest): Return false unless rs6000_gnu_attr is set.
(init_cumulative_args): Set up to emit fp .gnu.attribute for
ELF 64-bit ABIs as well as 32-bit ELF. Correct rs6000_passes_float
to include fp values returned in vectors.
Set rs6000_passes_long_double.
(rs6000_function_arg_advance_1): Likewise for function args.
(rs6000_elf_file_end): Emit fp .gnu.attribute for ELF 64-bit ABIs,
and SPE. Emit long double tag value too.
(rs6000_opt_vars): Add gnu-attr.
* configure.ac (HAVE_LD_PPC_GNU_ATTR): New ppc32 test.
* configure: Regenerate.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 4d3706c..49f662a 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -183,8 +183,16 @@ unsigned rs6000_pmode;
unsigned rs6000_pointer_size;
#ifdef HAVE_AS_GNU_ATTRIBUTE
-/* Flag whether floating point values have been passed/returned. */
+# ifndef HAVE_LD_PPC_GNU_ATTR
+# define HAVE_LD_PPC_GNU_ATTR 0
+# endif
+/* Flag whether floating point values have been passed/returned.
+ Note that this doesn't say whether fprs are used, since the
+ Tag_GNU_Power_ABI_FP .gnu.attributes value this flag controls
+ should be set for soft-float values passed in gprs and ieee128
+ values passed in vsx registers. */
static bool rs6000_passes_float;
+static bool rs6000_passes_long_double;
/* Flag whether vector values have been passed/returned. */
static bool rs6000_passes_vector;
/* Flag whether small (<= 8 byte) structures have been returned. */
@@ -10920,7 +10928,7 @@ rs6000_return_in_msb (const_tree valtype)
static bool
call_ABI_of_interest (tree fndecl)
{
- if (symtab->state == EXPANSION)
+ if (rs6000_gnu_attr && symtab->state == EXPANSION)
{
struct cgraph_node *c_node;
@@ -10997,7 +11005,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype,
}
#ifdef HAVE_AS_GNU_ATTRIBUTE
- if (DEFAULT_ABI == ABI_V4)
+ if (TARGET_ELF && (TARGET_64BIT || DEFAULT_ABI == ABI_V4))
{
cum->escapes = call_ABI_of_interest (fndecl);
if (cum->escapes)
@@ -11025,10 +11033,19 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree
fntype,
<= 8))
rs6000_returns_struct = true;
}
- if (SCALAR_FLOAT_MODE_NOT_VECTOR_P (return_mode))
- rs6000_passes_float = true;
- else if (ALTIVEC_OR_VSX_VECTOR_MODE (return_mode)
- || SPE_VECTOR_MODE (return_mode))
+ if (SCALAR_FLOAT_MODE_P (return_mode))
+ {
+ rs6000_passes_float = true;
+ if ((HAVE_LD_PPC_GNU_ATTR || TARGET_64BIT)
+ && (FLOAT128_IBM_P (return_mode)
+ || FLOAT128_IEEE_P (return_mode)
+ || (return_type != NULL
+ && (TYPE_MAIN_VARIANT (return_type)
+ == long_double_type_node))))
+ rs6000_passes_long_double = true;
+ }
+ if (ALTIVEC_OR_VSX_VECTOR_MODE (return_mode)
+ || SPE_VECTOR_MODE (return_mode))
rs6000_passes_vector = true;
}
}
@@ -11475,16 +11492,23 @@ rs6000_function_arg_advance_1 (CUMULATIVE_ARGS *cum,
machine_mode mode,
cum->nargs_prototype--;
#ifdef HAVE_AS_GNU_ATTRIBUTE
- if (DEFAULT_ABI == ABI_V4
+ if (TARGET_ELF && (TARGET_64BIT || DEFAULT_ABI == ABI_V4)
&& cum->escapes)
{
- if (SCALAR_FLOAT_MODE_NOT_VECTOR_P (mode))
- rs6000_passes_float = true;
- else if (named && ALTIVEC_OR_VSX_VECTOR_MODE (mode))
- rs6000_passes_vector = true;
- else if (SPE_VECTOR_MODE (mode)
- && !cum->stdarg
- && cum->sysv_gregno <= GP_ARG_MAX_REG)
+ if (SCALAR_FLOAT_MODE_P (mode))
+ {
+ rs6000_passes_float = true;
+ if ((HAVE_LD_PPC_GNU_ATTR || TARGET_64BIT)
+ && (FLOAT128_IBM_P (mode)
+ || FLOAT128_IEEE_P (mode)
+ || (type != NULL
+ && TYPE_MAIN_VARIANT (type) == long_double_type_node)))
+ rs6000_passes_long_double = true;
+ }
+ if ((named && ALTIVEC_OR_VSX_VECTOR_MODE (mode))
+ || (SPE_VECTOR_MODE (mode)
+ && !cum->stdarg
+ && cum->sysv_gregno <= GP_ARG_MAX_REG))
rs6000_passes_vector = true;
}
#endif
@@ -34292,13 +34316,21 @@ static void
rs6000_elf_file_end (void)
{
#ifdef HAVE_AS_GNU_ATTRIBUTE
+ /* ??? The value emitted depends on options active at file end.
+ Assume anyone using #pragma or attributes that might change
+ options knows what they are doing. */
+ if ((TARGET_64BIT || DEFAULT_ABI == ABI_V4)
+ && rs6000_passes_float)
+ fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
+ ((TARGET_DF_FPR | TARGET_DF_SPE ? 1
+ : TARGET_SF_FPR | TARGET_SF_SPE ? 3
+ : 2)
+ | (!rs6000_passes_long_double ? 0
+ : !TARGET_LONG_DOUBLE_128 ? 2 * 4
+ : TARGET_IEEEQUAD ? 3 * 4
+ : 1 * 4)));
if (TARGET_32BIT && DEFAULT_ABI == ABI_V4)
{
- if (rs6000_passes_float)
- fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
- ((TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_DOUBLE_FLOAT) ? 1
- : (TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_SINGLE_FLOAT) ?
3
- : 2));
if (rs6000_passes_vector)
fprintf (asm_out_file, "\t.gnu_attribute 8, %d\n",
(TARGET_ALTIVEC_ABI ? 2
@@ -37085,6 +37117,9 @@ static struct rs6000_opt_var const rs6000_opt_vars[] =
{ "warn-cell-microcode",
offsetof (struct gcc_options, x_rs6000_warn_cell_microcode),
offsetof (struct cl_target_option, x_rs6000_warn_cell_microcode), },
+ { "gnu-attr",
+ offsetof (struct gcc_options, x_rs6000_gnu_attr),
+ offsetof (struct cl_target_option, x_rs6000_gnu_attr), },
};
/* Inner function to handle attribute((target("..."))) and #pragma GCC target
diff --git a/gcc/config/rs6000/sysv4.opt b/gcc/config/rs6000/sysv4.opt
index 581fcde..d5b27cc 100644
--- a/gcc/config/rs6000/sysv4.opt
+++ b/gcc/config/rs6000/sysv4.opt
@@ -155,3 +155,7 @@ Generate code to use a non-exec PLT and GOT.
mbss-plt
Target Report RejectNegative Var(secure_plt, 0) Save
Generate code for old exec BSS PLT.
+
+mgnu-attr
+Target Report Var(rs6000_gnu_attr) Init(-1) Save
+Emit .gnu_attribute tags.
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 534f22e..94912a0 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -5322,6 +5322,49 @@ if test "x$gcc_cv_ld_clearcap" = xyes; then
fi
AC_MSG_RESULT($gcc_cv_ld_clearcap)
+case "$target" in
+ powerpc*-*-*)
+ case "$target" in
+ *le-*-linux*)
+ emul_name="-melf32lppc"
+ ;;
+ *)
+ emul_name="-melf32ppc"
+ ;;
+ esac
+ AC_CACHE_CHECK(linker .gnu_attribute long double support,
+ gcc_cv_ld_ppc_attr,
+ [gcc_cv_ld_ppc_attr=no
+ if test x"$ld_is_gold" = xyes; then
+ gcc_cv_ld_ppc_attr=yes
+ elif test $in_tree_ld = yes ; then
+ if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version"
-ge 28 -o "$gcc_cv_gld_major_version" -gt 2; then
+ gcc_cv_ld_ppc_attr=yes
+ fi
+ elif test x$gcc_cv_as != x -a x$gcc_cv_ld != x ; then
+ # check that merging the long double .gnu_attribute doesn't warn
+ cat > conftest1.s <<EOF
+ .gnu_attribute 4,1
+EOF
+ cat > conftest2.s <<EOF
+ .gnu_attribute 4,9
+EOF
+ if $gcc_cv_as -a32 -o conftest1.o conftest1.s > /dev/null 2>&1 \
+ && $gcc_cv_as -a32 -o conftest2.o conftest2.s > /dev/null 2>&1 \
+ && $gcc_cv_ld $emul_name -r -o conftest.o conftest1.o conftest2.o >
/dev/null 2> conftest.err \
+ && test ! -s conftest.err; then
+ gcc_cv_ld_ppc_attr=yes
+ fi
+ rm -f conftest.err conftest.o conftest1.o conftest2.o conftest1.s
conftest2.s
+ fi
+ ])
+ if test x$gcc_cv_ld_ppc_attr = xyes; then
+ AC_DEFINE(HAVE_LD_PPC_GNU_ATTR, 1,
+ [Define if your PowerPC linker has .gnu_attribute long double support.])
+ fi
+ ;;
+esac
+
case "$target:$tm_file" in
powerpc64-*-freebsd* | powerpc64*-*-linux* |
powerpc*-*-linux*rs6000/biarch64.h*)
case "$target" in
--
Alan Modra
Australia Development Lab, IBM
