@@ -373,6 +373,12 @@
#endif
+/* Define if your assembler supports conditional branch relaxation. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_AS_COND_BRANCH_RELAXATION
+#endif
+
+
/* Define if your assembler supports the --debug-prefix-map option. */
#ifndef USED_FOR_TARGET
#undef HAVE_AS_DEBUG_PREFIX_MAP
@@ -190,6 +190,10 @@ Target Var(TARGET_DIRECT_EXTERN_ACCESS) Init(0)
Avoid using the GOT to access external symbols.
mrelax
-Target Var(loongarch_mrelax) Init(HAVE_AS_MRELAX_OPTION)
+Target Var(loongarch_mrelax) Init(HAVE_AS_MRELAX_OPTION && HAVE_AS_COND_BRANCH_RELAXATION)
Take advantage of linker relaxations to reduce the number of instructions
required to materialize symbol addresses.
+
+mpass-mrelax-to-as
+Target Var(loongarch_pass_mrelax_to_as) Init(HAVE_AS_MRELAX_OPTION)
+Pass -mrelax or -mno-relax option to the assembler.
@@ -96,4 +96,8 @@ loongarch_config_target (struct loongarch_target *target,
#define HAVE_AS_MRELAX_OPTION 0
#endif
+#ifndef HAVE_AS_COND_BRANCH_RELAXATION
+#define HAVE_AS_COND_BRANCH_RELAXATION 0
+#endif
+
#endif /* LOONGARCH_OPTS_H */
@@ -69,8 +69,23 @@ along with GCC; see the file COPYING3. If not see
#define SUBTARGET_ASM_SPEC ""
#endif
+#if HAVE_AS_MRELAX_OPTION && HAVE_AS_COND_BRANCH_RELAXATION
+#define ASM_MRELAX_DEFAULT "%{!mrelax:%{!mno-relax:-mrelax}}"
+#else
+#define ASM_MRELAX_DEFAULT "%{!mrelax:%{!mno-relax:-mno-relax}}"
+#endif
+
+#if HAVE_AS_MRELAX_OPTION
+#define ASM_MRELAX_SPEC \
+ "%{!mno-pass-mrelax-to-as:%{mrelax} %{mno-relax} " ASM_MRELAX_DEFAULT "}"
+#else
+#define ASM_MRELAX_SPEC \
+ "%{mpass-mrelax-to-as:%{mrelax} %{mno-relax} " ASM_MRELAX_DEFAULT "}"
+#endif
+
#undef ASM_SPEC
-#define ASM_SPEC "%{mabi=*} %{subtarget_asm_spec}"
+#define ASM_SPEC \
+ "%{mabi=*} " ASM_MRELAX_SPEC " %(subtarget_asm_spec)"
/* Extra switches sometimes passed to the linker. */
@@ -197,6 +197,10 @@ Target Var(TARGET_DIRECT_EXTERN_ACCESS) Init(0)
Avoid using the GOT to access external symbols.
mrelax
-Target Var(loongarch_mrelax) Init(HAVE_AS_MRELAX_OPTION)
+Target Var(loongarch_mrelax) Init(HAVE_AS_MRELAX_OPTION && HAVE_AS_COND_BRANCH_RELAXATION)
Take advantage of linker relaxations to reduce the number of instructions
required to materialize symbol addresses.
+
+mpass-mrelax-to-as
+Target Var(loongarch_pass_mrelax_to_as) Init(HAVE_AS_MRELAX_OPTION)
+Pass -mrelax or -mno-relax option to the assembler.
@@ -29106,6 +29106,41 @@ if test $gcc_cv_as_loongarch_relax = yes; then
$as_echo "#define HAVE_AS_MRELAX_OPTION 1" >>confdefs.h
+fi
+
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for conditional branch relaxation support" >&5
+$as_echo_n "checking assembler for conditional branch relaxation support... " >&6; }
+if ${gcc_cv_as_loongarch_cond_branch_relax+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ gcc_cv_as_loongarch_cond_branch_relax=no
+ if test x$gcc_cv_as != x; then
+ $as_echo 'a:
+ .rept 32769
+ nop
+ .endr
+ beq $a0,$a1,a' > conftest.s
+ if { ac_try='$gcc_cv_as $gcc_cv_as_flags --fatal-warnings -o conftest.o conftest.s >&5'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }
+ then
+ gcc_cv_as_loongarch_cond_branch_relax=yes
+ else
+ echo "configure: failed program was" >&5
+ cat conftest.s >&5
+ fi
+ rm -f conftest.o conftest.s
+ fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_loongarch_cond_branch_relax" >&5
+$as_echo "$gcc_cv_as_loongarch_cond_branch_relax" >&6; }
+if test $gcc_cv_as_loongarch_cond_branch_relax = yes; then
+
+$as_echo "#define HAVE_AS_COND_BRANCH_RELAXATION 1" >>confdefs.h
+
fi
;;
@@ -5370,6 +5370,16 @@ x:
[-mrelax], [.text],,
[AC_DEFINE(HAVE_AS_MRELAX_OPTION, 1,
[Define if your assembler supports -mrelax option.])])
+ gcc_GAS_CHECK_FEATURE([conditional branch relaxation support],
+ gcc_cv_as_loongarch_cond_branch_relax,
+ [--fatal-warnings],
+ [a:
+ .rept 32769
+ nop
+ .endr
+ beq $a0,$a1,a],,
+ [AC_DEFINE(HAVE_AS_COND_BRANCH_RELAXATION, 1,
+ [Define if your assembler supports conditional branch relaxation.])])
;;
s390*-*-*)
gcc_GAS_CHECK_FEATURE([.gnu_attribute support],
@@ -1030,7 +1030,7 @@ Objective-C and Objective-C++ Dialects}.
-mmax-inline-memcpy-size=@var{n}
-mexplicit-relocs -mno-explicit-relocs
-mdirect-extern-access -mno-direct-extern-access
--mcmodel=@var{code-model}}
+-mcmodel=@var{code-model} -mrelax -mpass-mrelax-to-as}
@emph{M32R/D Options}
@gccoptlist{-m32r2 -m32rx -m32r
@@ -25850,6 +25850,28 @@ environments where no dynamic link is performed, like firmwares, OS
kernels, executables linked with @option{-static} or @option{-static-pie}.
@option{-mdirect-extern-access} is not compatible with @option{-fPIC} or
@option{-fpic}.
+
+@item -mrelax
+@itemx -mno-relax
+Take (do not take) advantage of linker relaxations. If
+@option{-mpass-mrelax-to-as} is enabled, this option is also passed to
+the assembler. The default is determined during GCC build-time by
+detecting corresponding assembler support:
+@option{-mrelax} if the assembler supports both the @option{-mrelax}
+option and the conditional branch relaxation (it's required or the
+@code{.align} directives and conditional branch instructions in the
+assembly code outputted by GCC may be rejected by the assembler because
+of a relocation overflow), @option{-mno-relax} otherwise.
+
+@item -mpass-mrelax-to-as
+@itemx -mno-pass-mrelax-to-as
+Pass (do not pass) the @option{-mrelax} or @option{-mno-relax} option
+to the assembler. The default is determined during GCC build-time by
+detecting corresponding assembler support:
+@option{-mpass-mrelax-to-as} if the assembler supports the
+@option{-mrelax} option, @option{-mno-pass-mrelax-to-as} otherwise.
+This option is mostly useful for debugging, or interoperation with
+assemblers different from the build-time one.
@end table
@node M32C Options
From: Xi Ruoyao <xry111@xry111.site> As the commit message of r14-4674 has indicated, if the assembler does not support conditional branch relaxation, a relocation overflow may happen on conditional branches when relaxation is enabled because the number of NOP instructions inserted by the assembler will be more than the number estimated by GCC. To work around this issue, disable relaxation by default if the assembler is detected incapable to perform conditional branch relaxation at GCC build time. We also need to pass -mno-relax to the assembler to really disable relaxation. But, if the assembler does not support -mrelax option at all, we should not pass -mno-relax to the assembler or it will immediately error out. Also handle this with the build time assembler capability probing, and add a pair of options -m[no-]pass-mrelax-to-as to allow using a different assembler from the build-time one. With this change, if GCC is built with GAS 2.41, relaxation will be disabled by default. So the default value of -mexplicit-relocs= is also changed to 'always' if -mno-relax is specified or implied by the build-time default, because using assembler macros for symbol addresses produces no benefit when relaxation is disabled. gcc/ChangeLog: PR target/112330 * config/loongarch/genopts/loongarch.opt.in: Add -m[no]-pass-relax-to-as. Change the default of -m[no]-relax to account conditional branch relaxation support status. * config/loongarch/loongarch.opt: Regenerate. * configure.ac (gcc_cv_as_loongarch_cond_branch_relax): Check if the assembler supports conditional branch relaxation. * configure: Regenerate. * config.in: Regenerate. Note that there are some unrelated changes introduced by r14-5424 (which does not contain a config.in regeneration). * config/loongarch/loongarch-opts.h (HAVE_AS_COND_BRANCH_RELAXATION): Define to 0 if not defined. * config/loongarch/loongarch-driver.h (ASM_MRELAX_DEFAULT): Define. (ASM_MRELAX_SPEC): Define. (ASM_SPEC): Use ASM_MRELAX_SPEC instead of "%{mno-relax}". * config/loongarch/loongarch.cc: Take the setting of -m[no-]relax into account when determining the default of -mexplicit-relocs=. * doc/invoke.texi: Document -m[no-]relax and -m[no-]pass-mrelax-to-as for LoongArch. Update the default value of -mexplicit-relocs=. (cherry picked from commit fe23a2ff1f5072559552be0e41ab55bf72f5c79f) --- gcc/config.in | 6 ++++ gcc/config/loongarch/genopts/loongarch.opt.in | 6 +++- gcc/config/loongarch/loongarch-opts.h | 4 +++ gcc/config/loongarch/loongarch.h | 17 ++++++++- gcc/config/loongarch/loongarch.opt | 6 +++- gcc/configure | 35 +++++++++++++++++++ gcc/configure.ac | 10 ++++++ gcc/doc/invoke.texi | 24 ++++++++++++- 8 files changed, 104 insertions(+), 4 deletions(-)