From: Sam James <sam@gentoo.org>
Date: Fri, 22 Aug 2025 23:54:01 +0000 (+0100)
Subject: i386: wire up --with-tls to control -mtls-dialect= default
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;ds=inline;p=thirdparty%2Fgcc.git

i386: wire up --with-tls to control -mtls-dialect= default

Allow passing --with-tls= at configure-time to control the default value
of -mtls-dialect= for i386 and x86_64. The default itself (gnu) is not changed
unless --with-tls= is passed.

--with-tls= is already wired up for ARM and RISC-V.

gcc/ChangeLog:
	PR target/120933

	* config.gcc (supported_defaults): Add tls for i386, x86_64.
	* config/i386/i386.h (host_detect_local_cpu): Add tls.
	* doc/install.texi: Document --with-tls= for i386, x86_64.
---

diff --git a/gcc/config.gcc b/gcc/config.gcc
index db813a7b561..04e88cce00d 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -4658,7 +4658,7 @@ case "${target}" in
 		;;
 
 	i[34567]86-*-* | x86_64-*-*)
-		supported_defaults="abi arch arch_32 arch_64 cpu cpu_32 cpu_64 tune tune_32 tune_64"
+		supported_defaults="abi arch arch_32 arch_64 cpu cpu_32 cpu_64 tune tune_32 tune_64 tls"
 		for which in arch arch_32 arch_64 cpu cpu_32 cpu_64 tune tune_32 tune_64; do
 			eval "val=\$with_$which"
 			case " $x86_archs " in
@@ -4717,6 +4717,17 @@ case "${target}" in
 				;;
 			esac
 		done
+
+		# Handle --with-tls.
+		case "$with_tls" in
+		""|gnu|gnu2)
+			# OK
+			;;
+		*)
+			echo "Unknown TLS method used in --with-tls=$with_tls" 1>&2
+			exit 1
+			;;
+		esac
 		;;
 
 	riscv*-*-*)
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 2fbc1f6e982..2d53db68317 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -644,7 +644,8 @@ extern const char *host_detect_local_cpu (int argc, const char **argv);
   {"cpu_64", "%{" OPT_ARCH64 ":%{!mtune=*:%{!mcpu=*:%{!march=*:-mtune=%(VALUE)}}}}" }, \
   {"arch", "%{!march=*:-march=%(VALUE)}"},			   \
   {"arch_32", "%{" OPT_ARCH32 ":%{!march=*:-march=%(VALUE)}}"},	   \
-  {"arch_64", "%{" OPT_ARCH64 ":%{!march=*:-march=%(VALUE)}}"},
+  {"arch_64", "%{" OPT_ARCH64 ":%{!march=*:-march=%(VALUE)}}"},    \
+  {"tls", "%{!mtls-dialect=*:-mtls-dialect=%(VALUE)}"},
 
 /* Specs for the compiler proper */
 
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 74232247d8b..6913035b596 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1254,6 +1254,9 @@ descriptor-based dialect.
 For RISC-V targets, possible values for @var{dialect} are @code{trad} or
 @code{desc}, which select between the traditional GNU dialect and the GNU TLS
 descriptor-based dialect.
+For i386, x86-64 targets, possible values for @var{dialect} are @code{gnu} or
+@code{gnu2}, which select between the original GNU dialect and the GNU TLS
+descriptor-based dialect.
 
 @item --enable-multiarch
 Specify whether to enable or disable multiarch support.  The default is