[3/5,ARC] Disable TP register when building for bare metal.

Submitted by Claudiu Zissulescu on March 20, 2017, 11:43 a.m.

Details

Message ID 1490010210-9489-4-git-send-email-claziss@synopsys.com
State New
Headers show

Commit Message

Claudiu Zissulescu March 20, 2017, 11:43 a.m.
No need for thread pointer in bare metal toolchain. Use TP register normally.

gcc/
2016-09-29  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/elf.h (ARGET_ARC_TP_REGNO_DEFAULT): Define.
	* config/arc/linux.h (ARGET_ARC_TP_REGNO_DEFAULT): Likewise.
	* config/arc/arc.opt (mtp-regno): Use ARGET_ARC_TP_REGNO_DEFAULT.
---
 gcc/config/arc/arc.opt | 2 +-
 gcc/config/arc/elf.h   | 5 +++++
 gcc/config/arc/linux.h | 4 ++++
 3 files changed, 10 insertions(+), 1 deletion(-)

Comments

Andrew Burgess March 24, 2017, 5:53 p.m.
* Claudiu Zissulescu <Claudiu.Zissulescu@synopsys.com> [2017-03-20 12:43:28 +0100]:

> No need for thread pointer in bare metal toolchain. Use TP register normally.
> 
> gcc/
> 2016-09-29  Claudiu Zissulescu  <claziss@synopsys.com>
> 
> 	* config/arc/elf.h (ARGET_ARC_TP_REGNO_DEFAULT): Define.
> 	* config/arc/linux.h (ARGET_ARC_TP_REGNO_DEFAULT): Likewise.
> 	* config/arc/arc.opt (mtp-regno): Use
> 	* ARGET_ARC_TP_REGNO_DEFAULT.

Looks fine.  I've suggested some alternative phrasing for the comments
to make them read a little easier.

Thanks,
Andrew



> ---
>  gcc/config/arc/arc.opt | 2 +-
>  gcc/config/arc/elf.h   | 5 +++++
>  gcc/config/arc/linux.h | 4 ++++
>  3 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/gcc/config/arc/arc.opt b/gcc/config/arc/arc.opt
> index 17af736..6060ded 100644
> --- a/gcc/config/arc/arc.opt
> +++ b/gcc/config/arc/arc.opt
> @@ -469,7 +469,7 @@ EnumValue
>  Enum(arc_fpu) String(fpud_all) Value(FPU_FPUD_ALL)
>  
>  mtp-regno=
> -Target RejectNegative Joined UInteger Var(arc_tp_regno) Init(25)
> +Target RejectNegative Joined UInteger Var(arc_tp_regno) Init(TARGET_ARC_TP_REGNO_DEFAULT)
>  Specify thread pointer register number.
>  
>  mtp-regno=none
> diff --git a/gcc/config/arc/elf.h b/gcc/config/arc/elf.h
> index d2106c5..a6d6c05 100644
> --- a/gcc/config/arc/elf.h
> +++ b/gcc/config/arc/elf.h
> @@ -53,3 +53,8 @@ along with GCC; see the file COPYING3.  If not see
>  #  define MULTILIB_DEFAULTS { "mcpu=" ARC_MULTILIB_CPU_DEFAULT }
>  # endif
>  #endif
> +
> +/* Bare-metal toolchains are not having a thread pointer register
> +   set.  */

/* Bare-metal toolchains do not need a thread pointer register.  */

> +#undef TARGET_ARC_TP_REGNO_DEFAULT
> +#define TARGET_ARC_TP_REGNO_DEFAULT -1
> diff --git a/gcc/config/arc/linux.h b/gcc/config/arc/linux.h
> index 10c291c..1d10357 100644
> --- a/gcc/config/arc/linux.h
> +++ b/gcc/config/arc/linux.h
> @@ -74,3 +74,7 @@ along with GCC; see the file COPYING3.  If not see
>  /* We do not have any MULTILIB_OPTIONS specified, so there are no
>     MULTILIB_DEFAULTS.  */
>  #undef  MULTILIB_DEFAULTS
> +
> +/* Linux toolchains are using r25 as TLS register.  */

/* Linux toolchains use r25 as the thread pointer register.  */

> +#undef TARGET_ARC_TP_REGNO_DEFAULT
> +#define TARGET_ARC_TP_REGNO_DEFAULT 25
> -- 
> 1.9.1
>

Patch hide | download patch | download mbox

diff --git a/gcc/config/arc/arc.opt b/gcc/config/arc/arc.opt
index 17af736..6060ded 100644
--- a/gcc/config/arc/arc.opt
+++ b/gcc/config/arc/arc.opt
@@ -469,7 +469,7 @@  EnumValue
 Enum(arc_fpu) String(fpud_all) Value(FPU_FPUD_ALL)
 
 mtp-regno=
-Target RejectNegative Joined UInteger Var(arc_tp_regno) Init(25)
+Target RejectNegative Joined UInteger Var(arc_tp_regno) Init(TARGET_ARC_TP_REGNO_DEFAULT)
 Specify thread pointer register number.
 
 mtp-regno=none
diff --git a/gcc/config/arc/elf.h b/gcc/config/arc/elf.h
index d2106c5..a6d6c05 100644
--- a/gcc/config/arc/elf.h
+++ b/gcc/config/arc/elf.h
@@ -53,3 +53,8 @@  along with GCC; see the file COPYING3.  If not see
 #  define MULTILIB_DEFAULTS { "mcpu=" ARC_MULTILIB_CPU_DEFAULT }
 # endif
 #endif
+
+/* Bare-metal toolchains are not having a thread pointer register
+   set.  */
+#undef TARGET_ARC_TP_REGNO_DEFAULT
+#define TARGET_ARC_TP_REGNO_DEFAULT -1
diff --git a/gcc/config/arc/linux.h b/gcc/config/arc/linux.h
index 10c291c..1d10357 100644
--- a/gcc/config/arc/linux.h
+++ b/gcc/config/arc/linux.h
@@ -74,3 +74,7 @@  along with GCC; see the file COPYING3.  If not see
 /* We do not have any MULTILIB_OPTIONS specified, so there are no
    MULTILIB_DEFAULTS.  */
 #undef  MULTILIB_DEFAULTS
+
+/* Linux toolchains are using r25 as TLS register.  */
+#undef TARGET_ARC_TP_REGNO_DEFAULT
+#define TARGET_ARC_TP_REGNO_DEFAULT 25