When generating non-PIC code on Linux, the linker support allows us to put both
local
and global relocs in read-only data. On HP-UX, we can put local relocs in
read-only data.
We can also put constant data in read-only data on the HP-UX SOM target when
generating
PIC code.
This patch implements the above.
Tested on hppa2.0w-hp-hpux11.11, hppa64-hp-hpux11.11 and hppa-unknown-linux-gnu.
Committed to trunk and gcc-9.
Dave
--
John David Anglin dave.ang...@bell.net
2019-07-17 John David Anglin <dang...@gcc.gnu.org>
* config/pa/pa.c (pa_som_asm_init_sections): Don't force all constant
data into data section when generating PIC code.
(pa_select_section): Use pa_reloc_rw_mask() to qualify relocs.
(pa_reloc_rw_mask): Return 3 when generating PIC code and when
generating code for SOM targets earlier than HP-UX 11. Otherwise,
return 2 for SOM and 0 for other targets.
Index: config/pa/pa.c
===================================================================
--- config/pa/pa.c (revision 273480)
+++ config/pa/pa.c (working copy)
@@ -9805,20 +9805,23 @@
= get_unnamed_section (0, output_section_asm_op,
"\t.SPACE $PRIVATE$\n\t.SUBSPA $TM_CLONE_TABLE$");
- /* FIXME: HPUX ld generates incorrect GOT entries for "T" fixups
- which reference data within the $TEXT$ space (for example constant
+ /* HPUX ld generates incorrect GOT entries for "T" fixups which
+ reference data within the $TEXT$ space (for example constant
strings in the $LIT$ subspace).
The assemblers (GAS and HP as) both have problems with handling
- the difference of two symbols which is the other correct way to
+ the difference of two symbols. This is the other correct way to
reference constant data during PIC code generation.
- So, there's no way to reference constant data which is in the
- $TEXT$ space during PIC generation. Instead place all constant
- data into the $PRIVATE$ subspace (this reduces sharing, but it
- works correctly). */
- readonly_data_section = flag_pic ? data_section : som_readonly_data_section;
+ Thus, we can't put constant data needing relocation in the $TEXT$
+ space during PIC generation.
+ Previously, we placed all constant data into the $DATA$ subspace
+ when generating PIC code. This reduces sharing, but it works
+ correctly. Now we rely on pa_reloc_rw_mask() for section selection.
+ This puts constant data not needing relocation into the $TEXT$ space. */
+ readonly_data_section = som_readonly_data_section;
+
/* We must not have a reference to an external symbol defined in a
shared library in a readonly section, else the SOM linker will
complain.
@@ -9850,7 +9853,7 @@
&& DECL_INITIAL (exp)
&& (DECL_INITIAL (exp) == error_mark_node
|| TREE_CONSTANT (DECL_INITIAL (exp)))
- && !reloc)
+ && !(reloc & pa_reloc_rw_mask ()))
{
if (TARGET_SOM
&& DECL_ONE_ONLY (exp)
@@ -9859,7 +9862,8 @@
else
return readonly_data_section;
}
- else if (CONSTANT_CLASS_P (exp) && !reloc)
+ else if (CONSTANT_CLASS_P (exp)
+ && !(reloc & pa_reloc_rw_mask ()))
return readonly_data_section;
else if (TARGET_SOM
&& TREE_CODE (exp) == VAR_DECL
@@ -9875,12 +9879,11 @@
static int
pa_reloc_rw_mask (void)
{
- /* We force (const (plus (symbol) (const_int))) to memory when the
- const_int doesn't fit in a 14-bit integer. The SOM linker can't
- handle this construct in read-only memory and we want to avoid
- this for ELF. So, we always force an RTX needing relocation to
- the data section. */
- return 3;
+ if (flag_pic || (TARGET_SOM && !TARGET_HPUX_11))
+ return 3;
+
+ /* HP linker does not support global relocs in readonly memory. */
+ return TARGET_SOM ? 2 : 0;
}
static void
