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From 6d852ffb43b111a39162135c95249e749c4e285b Mon Sep 17 00:00:00 2001

From: Max Filippov <jcmvbkbc@gmail.com>

Date: Thu, 6 Aug 2015 01:16:02 +0300

Subject: [PATCH] xtensa: add -mauto-litpools option

​

With support from assembler this option allows compiling huge functions,

where single literal pool at the beginning of a function may not be

reachable by L32R instructions at its end.

​

Currently assembler --auto-litpools option cannot deal with literals

used from multiple locations separated by more than 256 KBytes of code.

Don't turn constants into literals, instead use MOVI instruction to load

them into registers and let the assembler turn them into literals as

necessary.

​

2015-08-12  Max Filippov  <jcmvbkbc@gmail.com>

gcc/

    * config/xtensa/constraints.md (define_constraint "Y"): New

    constraint.

    * config/xtensa/elf.h (ASM_SPEC): Add m(no-)auto-litpools.

    * config/xtensa/linux.h (ASM_SPEC): Likewise.

    * config/xtensa/predicates.md (move_operand): Match constants

    and symbols in the presence of TARGET_AUTO_LITPOOLS.

    * config/xtensa/xtensa.c (xtensa_valid_move): Don't allow

    immediate references to TLS data.

    (xtensa_emit_move_sequence): Don't force constants to memory in

    the presence of TARGET_AUTO_LITPOOLS.

    (print_operand): Add 'y' format, same as default, but capable of

    printing SF mode constants as well.

    * config/xtensa/xtensa.md (movsi_internal, movhi_internal)

    (movsf_internal): Add movi pattern that loads literal.

    (movsf, movdf): Don't force constants to memory in the presence

    of TARGET_AUTO_LITPOOLS.

    (movdf_internal): Add 'Y' constraint.

    * config/xtensa/xtensa.opt (mauto-litpools): New option.

​

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

---

Backported from: r226828

Changes to ChangeLogs and documentation are dropped.

​

 gcc/config/xtensa/constraints.md |  5 +++++

 gcc/config/xtensa/elf.h          |  4 +++-

 gcc/config/xtensa/linux.h        |  4 +++-

 gcc/config/xtensa/predicates.md  |  3 ++-

 gcc/config/xtensa/xtensa.c       | 19 ++++++++++++++++++-

 gcc/config/xtensa/xtensa.md      | 35 +++++++++++++++++++----------------

 gcc/config/xtensa/xtensa.opt     |  4 ++++

 7 files changed, 54 insertions(+), 20 deletions(-)

​

diff --git a/gcc/config/xtensa/constraints.md b/gcc/config/xtensa/constraints.md

index 30f4c1f..773d4f9 100644

--- a/gcc/config/xtensa/constraints.md

+++ b/gcc/config/xtensa/constraints.md

@@ -111,6 +111,11 @@

  (and (match_code "const_int")

       (match_test "xtensa_mask_immediate (ival)")))

+(define_constraint "Y"

+ "A constant that can be used in relaxed MOVI instructions."

+ (and (match_code "const_int,const_double,const,symbol_ref,label_ref")

+      (match_test "TARGET_AUTO_LITPOOLS")))

+