[PATCH 5/5] arm-linux: Add libitm support.

[Richard Henderson <rth at redhat dot com>]

---
 libitm/Makefile.am                   |    3 +
 libitm/Makefile.in                   |   20 +++--
 libitm/config/arm/hwcap.cc           |   67 +++++++++++++++++
 libitm/config/arm/hwcap.h            |   41 ++++++++++
 libitm/config/arm/sjlj.S             |  135 ++++++++++++++++++++++++++++++++++
 libitm/config/arm/target.h           |   62 ++++++++++++++++
 libitm/config/generic/asmcfi.h       |   13 ++-
 libitm/config/linux/arm/futex_bits.h |   48 ++++++++++++
 libitm/configure                     |   18 ++++-
 libitm/configure.ac                  |    1 +
 libitm/configure.tgt                 |    2 +
 11 files changed, 395 insertions(+), 15 deletions(-)
 create mode 100644 libitm/config/arm/hwcap.cc
 create mode 100644 libitm/config/arm/hwcap.h
 create mode 100644 libitm/config/arm/sjlj.S
 create mode 100644 libitm/config/arm/target.h
 create mode 100644 libitm/config/linux/arm/futex_bits.h

diff --git a/libitm/Makefile.am b/libitm/Makefile.am
index 26e1ebc..d417026 100644
--- a/libitm/Makefile.am
+++ b/libitm/Makefile.am
@@ -62,6 +62,9 @@ libitm_la_SOURCES = \
 	query.cc retry.cc rwlock.cc useraction.cc util.cc \
 	sjlj.S tls.cc method-serial.cc method-gl.cc
 
+if ARCH_ARM
+libitm_la_SOURCES += hwcap.cc
+endif
 if ARCH_X86
 libitm_la_SOURCES += x86_sse.cc x86_avx.cc
 x86_sse.lo : XCFLAGS += -msse
diff --git a/libitm/Makefile.in b/libitm/Makefile.in
index dc77382..5305f4c 100644
--- a/libitm/Makefile.in
+++ b/libitm/Makefile.in
@@ -36,8 +36,9 @@ POST_UNINSTALL = :
 build_triplet = @build@
 host_triplet = @host@
 target_triplet = @target@
-@ARCH_X86_TRUE@am__append_1 = x86_sse.cc x86_avx.cc
-@ARCH_FUTEX_TRUE@am__append_2 = futex.cc
+@ARCH_ARM_TRUE@am__append_1 = hwcap.cc
+@ARCH_X86_TRUE@am__append_2 = x86_sse.cc x86_avx.cc
+@ARCH_FUTEX_TRUE@am__append_3 = futex.cc
 subdir = .
 DIST_COMMON = $(am__configure_deps) $(srcdir)/../config.guess \
 	$(srcdir)/../config.sub $(srcdir)/../depcomp \
@@ -99,15 +100,16 @@ libitm_la_LIBADD =
 am__libitm_la_SOURCES_DIST = aatree.cc alloc.cc alloc_c.cc \
 	alloc_cpp.cc barrier.cc beginend.cc clone.cc eh_cpp.cc \
 	local.cc query.cc retry.cc rwlock.cc useraction.cc util.cc \
-	sjlj.S tls.cc method-serial.cc method-gl.cc x86_sse.cc \
-	x86_avx.cc futex.cc
-@ARCH_X86_TRUE@am__objects_1 = x86_sse.lo x86_avx.lo
-@ARCH_FUTEX_TRUE@am__objects_2 = futex.lo
+	sjlj.S tls.cc method-serial.cc method-gl.cc hwcap.cc \
+	x86_sse.cc x86_avx.cc futex.cc
+@ARCH_ARM_TRUE@am__objects_1 = hwcap.lo
+@ARCH_X86_TRUE@am__objects_2 = x86_sse.lo x86_avx.lo
+@ARCH_FUTEX_TRUE@am__objects_3 = futex.lo
 am_libitm_la_OBJECTS = aatree.lo alloc.lo alloc_c.lo alloc_cpp.lo \
 	barrier.lo beginend.lo clone.lo eh_cpp.lo local.lo query.lo \
 	retry.lo rwlock.lo useraction.lo util.lo sjlj.lo tls.lo \
 	method-serial.lo method-gl.lo $(am__objects_1) \
-	$(am__objects_2)
+	$(am__objects_2) $(am__objects_3)
 libitm_la_OBJECTS = $(am_libitm_la_OBJECTS)
 DEFAULT_INCLUDES = -I.@am__isrc@
 depcomp = $(SHELL) $(top_srcdir)/../depcomp
@@ -376,7 +378,8 @@ libitm_la_LDFLAGS = $(libitm_version_info) $(libitm_version_script)
 libitm_la_SOURCES = aatree.cc alloc.cc alloc_c.cc alloc_cpp.cc \
 	barrier.cc beginend.cc clone.cc eh_cpp.cc local.cc query.cc \
 	retry.cc rwlock.cc useraction.cc util.cc sjlj.S tls.cc \
-	method-serial.cc method-gl.cc $(am__append_1) $(am__append_2)
+	method-serial.cc method-gl.cc $(am__append_1) $(am__append_2) \
+	$(am__append_3)
 
 # Automake Documentation:
 # If your package has Texinfo files in many directories, you can use the
@@ -505,6 +508,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/clone.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/eh_cpp.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/futex.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/hwcap.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/local.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/method-gl.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/method-serial.Plo@am__quote@
diff --git a/libitm/config/arm/hwcap.cc b/libitm/config/arm/hwcap.cc
new file mode 100644
index 0000000..007c10e
--- /dev/null
+++ b/libitm/config/arm/hwcap.cc
@@ -0,0 +1,67 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU Transactional Memory Library (libitm).
+
+   Libitm is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This file initializes GTM_hwcap in some os-specific way to indicate
+   what ISA extensions are present for ARM.  */
+
+#include "libitm_i.h"
+#include "hwcap.h"
+
+/* Begin by defaulting to whatever options were given to the compiler.  */
+int GTM_hwcap HIDDEN = 0
+#ifdef __VFP_FP__
+  | HWCAP_ARM_VFP
+#endif
+#ifdef __IWMMXT__
+  | HWCAP_ARM_IWMMXT
+#endif
+  ;
+
+#ifdef __linux__
+#include <unistd.h>
+#include <sys/fcntl.h>
+#include <elf.h>
+
+static void __attribute__((constructor))
+init_gtm_hwcap(void)
+{
+  int fd = open ("/proc/self/auxv", O_RDONLY);
+  if (fd < 0)
+    return;
+
+  Elf32_auxv_t pairs[512];
+  ssize_t rlen = read (fd, pairs, sizeof(pairs));
+  close (fd);
+  if (rlen < 0)
+    return;
+
+  size_t n = (size_t)rlen / sizeof(pairs[0]);
+  for (size_t i = 0; i < n; ++i)
+    if (pairs[i].a_type == AT_HWCAP)
+      {
+	GTM_hwcap = pairs[i].a_un.a_val;
+	return;
+      }
+}
+#endif
diff --git a/libitm/config/arm/hwcap.h b/libitm/config/arm/hwcap.h
new file mode 100644
index 0000000..16e4034
--- /dev/null
+++ b/libitm/config/arm/hwcap.h
@@ -0,0 +1,41 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU Transactional Memory Library (libitm).
+
+   Libitm is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* The following must match the kernel's <asm/procinfo.h>.  */
+#define HWCAP_ARM_SWP           1
+#define HWCAP_ARM_HALF          2
+#define HWCAP_ARM_THUMB         4
+#define HWCAP_ARM_26BIT         8
+#define HWCAP_ARM_FAST_MULT     16
+#define HWCAP_ARM_FPA           32
+#define HWCAP_ARM_VFP           64
+#define HWCAP_ARM_EDSP          128
+#define HWCAP_ARM_JAVA          256
+#define HWCAP_ARM_IWMMXT        512
+#define HWCAP_ARM_CRUNCH        1024
+#define HWCAP_ARM_THUMBEE       2048
+#define HWCAP_ARM_NEON          4096
+#define HWCAP_ARM_VFPv3         8192
+#define HWCAP_ARM_VFPv3D16      16384
+
diff --git a/libitm/config/arm/sjlj.S b/libitm/config/arm/sjlj.S
new file mode 100644
index 0000000..cf2ae4b
--- /dev/null
+++ b/libitm/config/arm/sjlj.S
@@ -0,0 +1,135 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU Transactional Memory Library (libitm).
+
+   Libitm is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "hwcap.h"
+#include "asmcfi.h"
+
+	.syntax	unified
+
+#if defined(__thumb__)
+        .thumb
+        .thumb_func
+#endif
+
+/* ??? Use movw/movt when possible.  */
+#if defined(PIC)
+.macro ldaddr reg, addr
+	ldr	\reg, 99f
+	ldr	\reg, [\reg]
+98:	add	\reg, \reg, pc
+.subsection 1
+99:	.word	\addr - (98b + 8)
+.subsection 0
+.endm
+#else
+.macro ldaddr reg, addr
+	ldr	\reg, =\addr
+.endm
+#endif
+
+	.text
+	.align	2
+	.global	_ITM_beginTransaction
+	.type	_ITM_beginTransaction, %function
+
+_ITM_beginTransaction:
+	.fnstart
+	cfi_startproc
+#ifdef __thumb__
+	mov	ip, sp
+	push	{ r4-r11, ip, lr }
+#else
+	push	{ r4-r11, sp, lr }
+#endif
+	.save	{ lr }
+	.pad	#(9*4)
+	cfi_adjust_cfa_offset(40)
+	cfi_rel_offset(lr, 36)
+	sub	sp, sp, #(14*8)
+	.pad	#(14*8)
+	cfi_adjust_cfa_offset(14*8)
+
+	ldaddr	r2, GTM_hwcap
+
+	/* Store the VFP registers.  Don't use VFP instructions directly
+	   because this code is used in non-VFP multilibs.  */
+	tst	r2, #HWCAP_ARM_VFP
+	it	ne
+	stcne	p11, cr8, [sp], {16}	/* vstmne sp, {d8-d15} */
+
+	/* Save the call-preserved iWMMXt registers.  */
+	tst	r2, #HWCAP_ARM_IWMMXT
+	beq	1f
+	stcl	p1, cr10, [sp, #64]	/* wstrd wr10, [sp, #64] */
+	stcl	p1, cr11, [sp, #72]
+	stcl	p1, cr12, [sp, #80]
+	stcl	p1, cr13, [sp, #88]
+	stcl	p1, cr14, [sp, #96]
+	stcl	p1, cr15, [sp, #104]
+1:
+	/* Invoke GTM_begin_transaction with the struct we just built.  */
+	mov	r1, sp
+	bl	GTM_begin_transaction
+
+	/* Return; we don't need to restore any of the call-saved regs.  */
+	add     sp, sp, #(14*8 + 9*4)
+	cfi_adjust_cfa_offset(-(14*8 + 9*4))
+	pop	{ pc }
+	.fnend
+	cfi_endproc
+	.size	_ITM_beginTransaction, . - _ITM_beginTransaction
+
+	.global	GTM_longjmp
+	.hidden	GTM_longjmp
+	.type	GTM_longjmp, %function
+
+GTM_longjmp:
+	ldaddr	r2, GTM_hwcap
+
+	tst	r2, #HWCAP_ARM_VFP
+	it	ne
+	ldcne	p11, cr8, [r1], {16}	/* vldmiane r1, {d8-d15} */
+
+	tst	r2, #HWCAP_ARM_IWMMXT
+	beq	1f
+	ldcl	p1, cr10, [r1, #64]	/* wldrd wr10, [r1, #64] */
+	ldcl	p1, cr11, [r1, #72]
+	ldcl	p1, cr12, [r1, #80]
+	ldcl	p1, cr13, [r1, #88]
+	ldcl	p1, cr14, [r1, #96]
+	ldcl	p1, cr15, [r1, #104]
+1:
+	add	r1, r1, #(14*8)		/* Skip both VFP and iWMMXt blocks */
+#ifdef __thumb__
+	ldm	r1, { r4-r11, ip, lr }
+	mov	sp, ip
+	bx	lr
+#else
+	ldm	r1, { r4-r11, sp, pc }
+#endif
+	.size	GTM_longjmp, . - GTM_longjmp
+
+#ifdef __linux__
+.section .note.GNU-stack, "", %progbits
+#endif
diff --git a/libitm/config/arm/target.h b/libitm/config/arm/target.h
new file mode 100644
index 0000000..99dd99a
--- /dev/null
+++ b/libitm/config/arm/target.h
@@ -0,0 +1,62 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU Transactional Memory Library (libitm).
+
+   Libitm is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+namespace GTM HIDDEN {
+
+typedef struct gtm_jmpbuf
+{
+  unsigned long long vfp[8];	/* d8-d15 */
+  unsigned long long iwmmxt[6];	/* cr10-cr15 */
+  unsigned long gr[8];		/* r4-r11 */
+  void *cfa;
+  unsigned long pc;
+} gtm_jmpbuf;
+
+/* ARM generally uses a fixed page size of 4K.  */
+#define PAGE_SIZE	4096
+#define FIXED_PAGE_SIZE	1
+
+/* ??? The size of one line in hardware caches (in bytes). */
+#define HW_CACHELINE_SIZE 64
+
+static inline void
+cpu_relax (void)
+{
+  /* ??? Maybe use WFE.  */
+  __asm volatile ("" : : : "memory");
+}
+
+static inline void
+atomic_read_barrier (void)
+{
+  __sync_synchronize ();
+}
+
+static inline void
+atomic_write_barrier (void)
+{
+  __sync_synchronize ();
+}
+
+} // namespace GTM
diff --git a/libitm/config/generic/asmcfi.h b/libitm/config/generic/asmcfi.h
index 4344d6f..bb7f98f 100644
--- a/libitm/config/generic/asmcfi.h
+++ b/libitm/config/generic/asmcfi.h
@@ -27,16 +27,19 @@
 
 #ifdef HAVE_AS_CFI_PSEUDO_OP
 
-#define cfi_startproc		.cfi_startproc
-#define cfi_endproc		.cfi_endproc
-#define cfi_def_cfa_offset(n)	.cfi_def_cfa_offset n
-#define cfi_def_cfa(r,n)	.cfi_def_cfa r, n
-#define cfi_register(o,n)	.cfi_register o, n
+#define cfi_startproc			.cfi_startproc
+#define cfi_endproc			.cfi_endproc
+#define cfi_adjust_cfa_offset(n)	.cfi_adjust_cfa_offset n
+#define cfi_def_cfa_offset(n)		.cfi_def_cfa_offset n
+#define cfi_def_cfa(r,n)		.cfi_def_cfa r, n
+#define cfi_rel_offset(r,o)		.cfi_rel_offset r, o
+#define cfi_register(o,n)		.cfi_register o, n
 
 #else
 
 #define cfi_startproc
 #define cfi_endproc
+#define cfi_adjust_cfa_offset(n)
 #define cfi_def_cfa_offset(n)
 #define cfi_def_cfa(r,n)
 #define cfi_register(o,n)
diff --git a/libitm/config/linux/arm/futex_bits.h b/libitm/config/linux/arm/futex_bits.h
new file mode 100644
index 0000000..7e1b52f
--- /dev/null
+++ b/libitm/config/linux/arm/futex_bits.h
@@ -0,0 +1,48 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU Transactional Memory Library (libitm).
+
+   Libitm is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Provide target-specific access to the futex system call.  */
+
+#include <sys/syscall.h>
+
+static inline long
+sys_futex0 (int *addr, long op, long val)
+{
+  register long sc_0 __asm__("r0");
+  register long sc_1 __asm__("r1");
+  register long sc_2 __asm__("r2");
+  register long sc_3 __asm__("r3");
+
+  sc_0 = (long) addr;
+  sc_1 = op;
+  sc_2 = val;
+  sc_3 = 0;
+
+  __asm volatile ("swi %1"
+		  : "+r"(sc_0)
+		  : "i"(SYS_futex), "r"(sc_1), "r"(sc_2), "r"(sc_3)
+		  : "memory");
+
+  return sc_0;
+}
diff --git a/libitm/configure b/libitm/configure
index 9b06359..3abc793 100644
--- a/libitm/configure
+++ b/libitm/configure
@@ -607,6 +607,8 @@ ARCH_X86_AVX_FALSE
 ARCH_X86_AVX_TRUE
 ARCH_X86_FALSE
 ARCH_X86_TRUE
+ARCH_ARM_FALSE
+ARCH_ARM_TRUE
 link_itm
 XLDFLAGS
 XCFLAGS
@@ -11720,7 +11722,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11723 "configure"
+#line 11725 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11826,7 +11828,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11829 "configure"
+#line 11831 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -17369,6 +17371,14 @@ else
 fi
 
 
+ if test "$ARCH" = arm; then
+  ARCH_ARM_TRUE=
+  ARCH_ARM_FALSE='#'
+else
+  ARCH_ARM_TRUE='#'
+  ARCH_ARM_FALSE=
+fi
+
  if test "$ARCH" = x86; then
   ARCH_X86_TRUE=
   ARCH_X86_FALSE='#'
@@ -17542,6 +17552,10 @@ if test -z "${LIBITM_BUILD_VERSIONED_SHLIB_SUN_TRUE}" && test -z "${LIBITM_BUILD
   as_fn_error "conditional \"LIBITM_BUILD_VERSIONED_SHLIB_SUN\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${ARCH_ARM_TRUE}" && test -z "${ARCH_ARM_FALSE}"; then
+  as_fn_error "conditional \"ARCH_ARM\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${ARCH_X86_TRUE}" && test -z "${ARCH_X86_FALSE}"; then
   as_fn_error "conditional \"ARCH_X86\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
diff --git a/libitm/configure.ac b/libitm/configure.ac
index 45ee870..ab2a90b 100644
--- a/libitm/configure.ac
+++ b/libitm/configure.ac
@@ -273,6 +273,7 @@ else
 fi
 AC_SUBST(link_itm)
 
+AM_CONDITIONAL([ARCH_ARM], [test "$ARCH" = arm])
 AM_CONDITIONAL([ARCH_X86], [test "$ARCH" = x86])
 AM_CONDITIONAL([ARCH_X86_AVX], [test "$libitm_cv_as_avx" = yes])
 AM_CONDITIONAL([ARCH_FUTEX], [test $enable_linux_futex = yes])
diff --git a/libitm/configure.tgt b/libitm/configure.tgt
index eac6f50..a17f3fc 100644
--- a/libitm/configure.tgt
+++ b/libitm/configure.tgt
@@ -48,6 +48,8 @@ fi
 case "${target_cpu}" in
   alpha*)	ARCH=alpha ;;
 
+  arm*)		ARCH=arm ;;
+
   i[3456]86)
 	case " ${CC} ${CFLAGS} " in
 	  *" -m64 "*)
-- 
1.7.6.4