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pa.c (pa_output_addr_vec): Align address table.

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* config/pa/pa.c (pa_output_addr_vec): Align address table.
	* config/pa/pa.h (JUMP_TABLES_IN_TEXT_SECTION): Revise comment.
	* config/pa/pa32-linux.h (JUMP_TABLES_IN_TEXT_SECTION): Define.

From-SVN: r263051
This commit is contained in:
John David Anglin 2018-07-29 15:50:13 +00:00
parent d3d94f7a7a
commit 3605ba0d1b
4 changed files with 29 additions and 10 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2018-07-29 John David Anglin <danglin@gcc.gnu.org>
* config/pa/pa.c (pa_output_addr_vec): Align address table.
* config/pa/pa.h (JUMP_TABLES_IN_TEXT_SECTION): Revise comment.
* config/pa/pa32-linux.h (JUMP_TABLES_IN_TEXT_SECTION): Define.
2018-07-27 Michael Meissner <meissner@linux.ibm.com>
* config/rs6000/constraints.md (wG constraint): Delete, no longer

2
gcc/config/pa/pa.c
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@ -10680,6 +10680,8 @@ pa_output_addr_vec (rtx lab, rtx body)
{
int idx, vlen = XVECLEN (body, 0);
if (!TARGET_SOM)
fputs ("\t.align 4\n", asm_out_file);
targetm.asm_out.internal_label (asm_out_file, "L", CODE_LABEL_NUMBER (lab));
if (TARGET_GAS)
fputs ("\t.begin_brtab\n", asm_out_file);

22
gcc/config/pa/pa.h
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@ -1143,21 +1143,23 @@ do { \
#define ASM_OUTPUT_ASCII(FILE, P, SIZE) \
pa_output_ascii ((FILE), (P), (SIZE))
/* Jump tables are always placed in the text section. Technically, it
is possible to put them in the readonly data section. This has the
benefit of getting the table out of .text and reducing branch lengths
as a result.
/* Jump tables are always placed in the text section. We have to do
this for the HP-UX SOM target as we can't switch sections in the
middle of a function.
The downside is that an additional insn (addil) is needed to access
On ELF targets, it is possible to put them in the readonly-data section.
This would get the table out of .text and reduce branch lengths.
A downside is that an additional insn (addil) is needed to access
the table when generating PIC code. The address difference table
also has to use 32-bit pc-relative relocations. Currently, GAS does
not support these relocations, although it is easily modified to do
this operation.
also has to use 32-bit pc-relative relocations.
The table entries need to look like "$L1+(.+8-$L0)-$PIC_pcrel$0"
when using ELF GAS. A simple difference can be used when using
SOM GAS or the HP assembler. The final downside is GDB complains
about the nesting of the label for the table when debugging. */
the HP assembler.
The final downside is GDB complains about the nesting of the label
for the table. */
#define JUMP_TABLES_IN_TEXT_SECTION 1

9
gcc/config/pa/pa32-linux.h
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@ -67,3 +67,12 @@ call_ ## FUNC (void) \
layout compatibility with the original linux thread implementation. */
#undef MALLOC_ABI_ALIGNMENT
#define MALLOC_ABI_ALIGNMENT 128
/* Place jump tables in the text section except when generating non-PIC
code. When generating non-PIC code, the relocations needed to load the
address of the jump table result in a text label in the final executable
if the jump table is placed in the text section. This breaks the unwind
data for the function. Thus, the jump table needs to be placed in
rodata when generating non-PIC code. */
#undef JUMP_TABLES_IN_TEXT_SECTION
#define JUMP_TABLES_IN_TEXT_SECTION (flag_pic)