[gcc r13-8357] LoongArch: Don't default to -mno-explicit-relocs if -mno-relax

[gcc r13-8357] LoongArch: Don't default to -mno-explicit-relocs if -mno-relax

[Xi Ruoyao]

https://gcc.gnu.org/g:befe440b8d7d49461a2746cdd0fb2c7ab2acb76b

commit r13-8357-gbefe440b8d7d49461a2746cdd0fb2c7ab2acb76b
Author: Xi Ruoyao <xry111@xry111.site>
Date:   Thu Feb 22 17:58:45 2024 +0800

    LoongArch: Don't default to -mno-explicit-relocs if -mno-relax
    
    To improve Binutils compatibility we've had to backport relaxation
    support.  But if a user just updates to GCC 13.3 and sticks with
    Binutils 2.41, there is no reason to use -mno-explicit-relocs as the
    default because we are turning off relaxation for Binutils 2.41 (it
    lacks conditional branch relaxation support) anyway.
    
    So like GCC 14, make the default of -m[no-]explicit-relocs depend on
    -m[no-]relax instead of HAVE_AS_MRELAX_OPTION.  Also update the doc to
    reflect the behavior change.
    
    gcc/ChangeLog:
    
            * config/loongarch/genopts/loongarch.opt.in
            (TARGET_EXPLICIT_RELOCS): Init to M_OPTION_NOT_SEEN.
            * config/loongarch/loongarch.opt: Regenerate.
            * config/loongarch/loongarch.cc
            (loongarch_option_override_internal): Set the default of
            TARGET_EXPLICIT_RELOCS to HAVE_AS_EXPLICIT_RELOCS
            && !loongarch_mrelax.
            * doc/invoke.texi (-m[no-]explicit-relocs): Update for
            LoongArch.

Diff:
---
 gcc/config/loongarch/genopts/loongarch.opt.in |  2 +-
 gcc/config/loongarch/loongarch.cc             |  4 ++++
 gcc/config/loongarch/loongarch.opt            |  2 +-
 gcc/doc/invoke.texi                           | 11 +++++------
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/gcc/config/loongarch/genopts/loongarch.opt.in b/gcc/config/loongarch/genopts/loongarch.opt.in
index da6fedd153ef..76acd35d39c3 100644
--- a/gcc/config/loongarch/genopts/loongarch.opt.in
+++ b/gcc/config/loongarch/genopts/loongarch.opt.in
@@ -155,7 +155,7 @@ Target Joined RejectNegative UInteger Var(loongarch_max_inline_memcpy_size) Init
 -mmax-inline-memcpy-size=SIZE	Set the max size of memcpy to inline, default is 1024.
 
 mexplicit-relocs
-Target Var(TARGET_EXPLICIT_RELOCS) Init(HAVE_AS_EXPLICIT_RELOCS & !HAVE_AS_MRELAX_OPTION)
+Target Var(TARGET_EXPLICIT_RELOCS) Init(M_OPTION_NOT_SEEN)
 Use %reloc() assembly operators.
 
 ; The code model option names for -mcmodel.
diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index 768e2427285c..e78b81cd8fcc 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -6222,6 +6222,10 @@ loongarch_option_override_internal (struct gcc_options *opts)
 	gcc_unreachable ();
     }
 
+  if (TARGET_EXPLICIT_RELOCS == M_OPTION_NOT_SEEN)
+    TARGET_EXPLICIT_RELOCS = (HAVE_AS_EXPLICIT_RELOCS
+			      && !loongarch_mrelax);
+
   /* Validate the guard size.  */
   int guard_size = param_stack_clash_protection_guard_size;
 
diff --git a/gcc/config/loongarch/loongarch.opt b/gcc/config/loongarch/loongarch.opt
index 59b1e06d3f20..e61fbaed2c1f 100644
--- a/gcc/config/loongarch/loongarch.opt
+++ b/gcc/config/loongarch/loongarch.opt
@@ -162,7 +162,7 @@ Target Joined RejectNegative UInteger Var(loongarch_max_inline_memcpy_size) Init
 -mmax-inline-memcpy-size=SIZE	Set the max size of memcpy to inline, default is 1024.
 
 mexplicit-relocs
-Target Var(TARGET_EXPLICIT_RELOCS) Init(HAVE_AS_EXPLICIT_RELOCS & !HAVE_AS_MRELAX_OPTION)
+Target Var(TARGET_EXPLICIT_RELOCS) Init(M_OPTION_NOT_SEEN)
 Use %reloc() assembly operators.
 
 ; The code model option names for -mcmodel.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 99657fb44d86..792ce283bb98 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -25830,12 +25830,11 @@ The default code model is @code{normal}.
 @itemx -mno-explicit-relocs
 Use or do not use assembler relocation operators when dealing with symbolic
 addresses.  The alternative is to use assembler macros instead, which may
-limit optimization.  The default value for the option is determined during
-GCC build-time by detecting corresponding assembler support:
-@code{-mexplicit-relocs} if said support is present,
-@code{-mno-explicit-relocs} otherwise.  This option is mostly useful for
-debugging, or interoperation with assemblers different from the build-time
-one.
+limit instruction scheduling but allow linker relaxation.  The default
+value for the option is determined with the assembler capability detected
+during GCC build-time and the setting of @code{-mrelax}:
+@code{-mexplicit-relocs} if the assembler supports relocation operators
+but @code{-mrelax} is not enabled, @code{-mno-explicit-relocs} otherwise.
 
 @opindex mdirect-extern-access
 @item -mdirect-extern-access