After discussing the -mtp= option with Arm's LLVM developers we'd like to extend
the functionality of the option somewhat.
There are actually 3 system registers that can be accessed for the thread pointer
in aarch32: tpidrurw, tpidruro, tpidrprw. They are all read through the CP15 co-processor
mechanism. The current -mtp=cp15 option reads the tpidruro register.
This patch extends -mtp to allow for the above three explicit tpidr names and
keeps -mtp=cp15 as an alias of -mtp=tpidruro for backwards compatibility.
Bootstrapped and tested on arm-none-linux-gnueabihf.
gcc/ChangeLog:
* config/arm/arm-opts.h (enum arm_tp_type): Remove TP_CP15.
Add TP_TPIDRURW, TP_TPIDRURO, TP_TPIDRPRW values.
* config/arm/arm-protos.h (arm_output_load_tpidr): Declare prototype.
* config/arm/arm.cc (arm_option_reconfigure_globals): Replace TP_CP15
with TP_TPIDRURO.
(arm_output_load_tpidr): Define.
* config/arm/arm.h (TARGET_HARD_TP): Define in terms of TARGET_SOFT_TP.
* config/arm/arm.md (load_tp_hard): Call arm_output_load_tpidr to output
assembly.
(reload_tp_hard): Likewise.
* config/arm/arm.opt (tpidrurw, tpidruro, tpidrprw): New values for
arm_tp_type.
* doc/invoke.texi (Arm Options, mtp): Document new values.
gcc/testsuite/ChangeLog:
* gcc.target/arm/mtp.c: New test.
* gcc.target/arm/mtp_1.c: New test.
* gcc.target/arm/mtp_2.c: New test.
* gcc.target/arm/mtp_3.c: New test.
* gcc.target/arm/mtp_4.c: New test.
enum arm_tp_type {
TP_AUTO,
TP_SOFT,
- TP_CP15
+ TP_TPIDRURW,
+ TP_TPIDRURO,
+ TP_TPIDRPRW
};
/* Which TLS scheme to use. */
extern int arm_emit_vector_const (FILE *, rtx);
extern void arm_emit_fp16_const (rtx c);
extern const char * arm_output_load_gr (rtx *);
+extern const char * arm_output_load_tpidr (rtx, bool);
extern const char *vfp_output_vstmd (rtx *);
extern void arm_output_multireg_pop (rtx *, bool, rtx, bool, bool);
extern void arm_set_return_address (rtx, rtx);
if (target_thread_pointer == TP_AUTO)
{
if (arm_arch6k && !TARGET_THUMB1)
- target_thread_pointer = TP_CP15;
+ target_thread_pointer = TP_TPIDRURO;
else
target_thread_pointer = TP_SOFT;
}
return default_get_mask_mode (mode);
}
+/* Output assembly to read the thread pointer from the appropriate TPIDR
+ register into DEST. If PRED_P also emit the %? that can be used to
+ output the predication code. */
+
+const char *
+arm_output_load_tpidr (rtx dst, bool pred_p)
+{
+ char buf[64];
+ int tpidr_coproc_num = -1;
+ switch (target_thread_pointer)
+ {
+ case TP_TPIDRURW:
+ tpidr_coproc_num = 2;
+ break;
+ case TP_TPIDRURO:
+ tpidr_coproc_num = 3;
+ break;
+ case TP_TPIDRPRW:
+ tpidr_coproc_num = 4;
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ snprintf (buf, sizeof (buf),
+ "mrc%s\tp15, 0, %%0, c13, c0, %d\t@ load_tp_hard",
+ pred_p ? "%?" : "", tpidr_coproc_num);
+ output_asm_insn (buf, &dst);
+ return "";
+}
+
#include "gt-arm.h"
#define TARGET_AAPCS_BASED \
(arm_abi != ARM_ABI_APCS && arm_abi != ARM_ABI_ATPCS)
-#define TARGET_HARD_TP (target_thread_pointer == TP_CP15)
#define TARGET_SOFT_TP (target_thread_pointer == TP_SOFT)
+#define TARGET_HARD_TP !TARGET_SOFT_TP
#define TARGET_GNU2_TLS (target_tls_dialect == TLS_GNU2)
/* Only 16-bit thumb code. */
[(set (match_operand:SI 0 "register_operand" "=r")
(unspec:SI [(const_int 0)] UNSPEC_TLS))]
"TARGET_HARD_TP"
- "mrc%?\\tp15, 0, %0, c13, c0, 3\\t@ load_tp_hard"
+ "* return arm_output_load_tpidr (operands[0], true);"
[(set_attr "predicable" "yes")
(set_attr "type" "mrs")]
)
[(set (match_operand:SI 0 "register_operand" "=r")
(unspec_volatile:SI [(const_int 0)] VUNSPEC_MRC))]
"TARGET_HARD_TP"
- "mrc\\tp15, 0, %0, c13, c0, 3\\t@ reload_tp_hard"
+ "* return arm_output_load_tpidr (operands[0], false);"
[(set_attr "type" "mrs")]
)
Enum(arm_tp_type) String(auto) Value(TP_AUTO)
EnumValue
-Enum(arm_tp_type) String(cp15) Value(TP_CP15)
+Enum(arm_tp_type) String(tpidrurw) Value(TP_TPIDRURW)
+
+EnumValue
+Enum(arm_tp_type) String(cp15) Value(TP_TPIDRURO)
+
+EnumValue
+Enum(arm_tp_type) String(tpidruro) Value(TP_TPIDRURO)
+
+EnumValue
+Enum(arm_tp_type) String(tpidrprw) Value(TP_TPIDRPRW)
mtpcs-frame
Target Mask(TPCS_FRAME)
@opindex mtp
@item -mtp=@var{name}
-Specify the access model for the thread local storage pointer. The valid
-models are @samp{soft}, which generates calls to @code{__aeabi_read_tp},
-@samp{cp15}, which fetches the thread pointer from @code{cp15} directly
-(supported in the arm6k architecture), and @samp{auto}, which uses the
-best available method for the selected processor. The default setting is
-@samp{auto}.
+Specify the access model for the thread local storage pointer. The model
+@samp{soft} generates calls to @code{__aeabi_read_tp}. Other accepted
+models are @samp{tpidrurw}, @samp{tpidruro} and @samp{tpidrprw} which fetch
+the thread pointer from the corresponding system register directly
+(supported from the arm6k architecture and later). These system registers
+are accessed through the CP15 co-processor interface and the argument
+@samp{cp15} is also accepted as a convenience alias of @samp{tpidruro}.
+The argument @samp{auto} uses the best available method for the selected
+processor. The default setting is @samp{auto}.
@opindex mtls-dialect
@item -mtls-dialect=@var{dialect}
--- /dev/null
+__thread int i;
+
+int
+foo (void)
+{
+ return i;
+}
+
--- /dev/null
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-options "-O -mtp=cp15" } */
+
+#include "mtp.c"
+
+/* { dg-final { scan-assembler-times {mrc\tp15, 0, r3, c13, c0, 3} 1 } } */
--- /dev/null
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-options "-O -mtp=tpidrprw" } */
+
+#include "mtp.c"
+
+/* { dg-final { scan-assembler-times {mrc\tp15, 0, r3, c13, c0, 4} 1 } } */
--- /dev/null
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-options "-O -mtp=tpidruro" } */
+
+#include "mtp.c"
+
+/* { dg-final { scan-assembler-times {mrc\tp15, 0, r3, c13, c0, 3} 1 } } */
--- /dev/null
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-options "-O -mtp=tpidrurw" } */
+
+#include "mtp.c"
+
+/* { dg-final { scan-assembler-times {mrc\tp15, 0, r3, c13, c0, 2} 1 } } */