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From: Richard Henderson <rth@twiddle.net>
To: libc-ports@sourceware.org
Cc: Joseph Myers <joseph@codesourcery.com>
Subject: [PATCH 11/26] arm: Introduce and use NEGOFF series of macros
Date: Wed, 27 Feb 2013 03:17:00 -0000	[thread overview]
Message-ID: <1361934986-17018-12-git-send-email-rth@twiddle.net> (raw)
In-Reply-To: <1361934986-17018-1-git-send-email-rth@twiddle.net>

There are several places in which we access negative offsets from
the thread-pointer, but thumb2 only supports positive offsets in
memory references.

Avoid duplicating the rather large macros in which these references
are embedded by abstracting out the operation.
---
	* sysdeps/arm/sysdep.h (NEGOFF_ADJ_BASE): New macro.
	(NEGOFF_ADJ_BASE2, NEGOFF_OFF1, NEGOFF_OFF2): New macros.
	* sysdeps/unix/sysv/linux/arm/clone.S (__clone): Use them.
	* sysdeps/unix/sysv/linux/arm/nptl/vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S: Likewise.
	* sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h (SINGLE_THREAD_P):
	Likewise.
---
 ports/sysdeps/arm/sysdep.h                            | 16 ++++++++++++++++
 ports/sysdeps/unix/sysv/linux/arm/clone.S             |  5 +++--
 ports/sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S     | 11 ++++++-----
 .../sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h  | 19 ++++++++++---------
 ports/sysdeps/unix/sysv/linux/arm/nptl/vfork.S        | 14 ++++++++------
 5 files changed, 43 insertions(+), 22 deletions(-)

diff --git a/ports/sysdeps/arm/sysdep.h b/ports/sysdeps/arm/sysdep.h
index b7ba9b1..2d40823 100644
--- a/ports/sysdeps/arm/sysdep.h
+++ b/ports/sysdeps/arm/sysdep.h
@@ -147,4 +147,20 @@
 99:	OP	R, [pc, T]
 #endif
 
+/* Cope with negative memory offsets, which thumb can't encode.
+   Use NEGOFF_ADJ_BASE to (conditionally) alter the base register,
+   and then NEGOFF_OFF1 to use 0 for thumb and the offset for arm,
+   or NEGOFF_OFF2 to use A-B for thumb and A for arm.  */
+#ifdef __thumb2__
+# define NEGOFF_ADJ_BASE(R, OFF)	add R, R, $OFF
+# define NEGOFF_ADJ_BASE2(D, S, OFF)	add D, S, $OFF
+# define NEGOFF_OFF1(R, OFF)		[R]
+# define NEGOFF_OFF2(R, OFFA, OFFB)	[R, $((OFFA) - (OFFB))]
+#else
+# define NEGOFF_ADJ_BASE(R, OFF)
+# define NEGOFF_ADJ_BASE2(D, S, OFF)	mov D, S
+# define NEGOFF_OFF1(R, OFF)		[R, $OFF]
+# define NEGOFF_OFF2(R, OFFA, OFFB)	[R, $OFFA]
+#endif
+
 #endif	/* __ASSEMBLER__ */
diff --git a/ports/sysdeps/unix/sysv/linux/arm/clone.S b/ports/sysdeps/unix/sysv/linux/arm/clone.S
index 9de37f2..58ee7b4 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/clone.S
+++ b/ports/sysdeps/unix/sysv/linux/arm/clone.S
@@ -81,8 +81,9 @@ PSEUDO_END (__clone)
 	ite	ne
 	movne	r0, #-1
 	swieq	0x0
-	str	r0, [r1, #PID_OFFSET]
-	str	r0, [r1, #TID_OFFSET]
+	NEGOFF_ADJ_BASE(r1, TID_OFFSET)
+	str	r0, NEGOFF_OFF1(r1, TID_OFFSET)
+	str	r0, NEGOFF_OFF2(r1, PID_OFFSET, TID_OFFSET)
 3:
 #endif
 	@ pick the function arg and call address off the stack and execute
diff --git a/ports/sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S b/ports/sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S
index 749aaab..bc0a771 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S
+++ b/ports/sysdeps/unix/sysv/linux/arm/nptl/pt-vfork.S
@@ -26,14 +26,15 @@
 	ldr	lr, [sp], #4;		/* Restore LR.  */		\
 	cfi_adjust_cfa_offset (-4);					\
 	cfi_restore (lr);						\
-	mov	r2, r0;			/* Save the TLS addr in r2.  */	\
-	ldr	r3, [r2, #PID_OFFSET];	/* Load the saved PID.  */	\
-	rsb	r0, r3, #0;		/* Negate it.  */		\
-	str	r0, [r2, #PID_OFFSET]	/* Store the temporary PID.  */
+	NEGOFF_ADJ_BASE2(r2, r0, PID_OFFSET); /* Save the TLS addr in r2. */ \
+	ldr	r3, NEGOFF_OFF1(r2, PID_OFFSET); /* Load the saved PID.  */  \
+	rsb	r0, r3, #0;		/* Negate it.  */		     \
+	str	r0, NEGOFF_OFF1(r2, PID_OFFSET); /* Store the temp PID.  */
 
 /* Restore the old PID value in the parent.  */
 #define RESTORE_PID \
 	cmp	r0, #0;			/* If we are the parent... */	\
-	strne	r3, [r2, #PID_OFFSET]	/* ... restore the saved PID.  */
+	it	ne;							\
+	strne	r3, NEGOFF_OFF1(r2, PID_OFFSET); /* restore the saved PID.  */
 
 #include "../vfork.S"
diff --git a/ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h b/ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h
index b6dc3e0..0c9e780 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h
+++ b/ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h
@@ -217,15 +217,16 @@ extern int __local_multiple_threads attribute_hidden;
 				   header.multiple_threads) == 0, 1)
 #  else
 #   define SINGLE_THREAD_P						\
-  stmfd	sp!, {r0, lr};							\
-  cfi_adjust_cfa_offset (8);						\
-  cfi_rel_offset (lr, 4);						\
-  bl	__aeabi_read_tp;						\
-  ldr	ip, [r0, #MULTIPLE_THREADS_OFFSET];				\
-  ldmfd	sp!, {r0, lr};							\
-  cfi_adjust_cfa_offset (-8);						\
-  cfi_restore (lr);							\
-  teq	ip, #0
+	stmfd	sp!, {r0, lr};						\
+	cfi_adjust_cfa_offset (8);					\
+	cfi_rel_offset (lr, 4);						\
+	bl	__aeabi_read_tp;					\
+	NEGOFF_ADJ_BASE(r0, MULTIPLE_THREADS_OFFSET);			\
+	ldr	ip, NEGOFF_OFF1(r0, MULTIPLE_THREADS_OFFSET);		\
+	ldmfd	sp!, {r0, lr};						\
+	cfi_adjust_cfa_offset (-8);					\
+	cfi_restore (lr);						\
+	teq	ip, #0
 #   define SINGLE_THREAD_P_PIC(x) SINGLE_THREAD_P
 #  endif
 # endif
diff --git a/ports/sysdeps/unix/sysv/linux/arm/nptl/vfork.S b/ports/sysdeps/unix/sysv/linux/arm/nptl/vfork.S
index 1bbe5c6..3c0ef78 100644
--- a/ports/sysdeps/unix/sysv/linux/arm/nptl/vfork.S
+++ b/ports/sysdeps/unix/sysv/linux/arm/nptl/vfork.S
@@ -26,15 +26,17 @@
 	ldr	lr, [sp], #4;		/* Restore LR.  */		\
 	cfi_adjust_cfa_offset (-4);					\
 	cfi_restore (lr);						\
-	mov	r2, r0;			/* Save the TLS addr in r2.  */	\
-	ldr	r3, [r2, #PID_OFFSET];	/* Load the saved PID.  */	\
-	rsbs	r0, r3, #0;		/* Negate it.  */		\
-	moveq	r0, #0x80000000;	/* Use 0x80000000 if it was 0.  */ \
-	str	r0, [r2, #PID_OFFSET]	/* Store the temporary PID.  */
+	NEGOFF_ADJ_BASE2(r2, r0, PID_OFFSET); /* Save the TLS addr in r2.  */ \
+	ldr	r3, NEGOFF_OFF1(r2, PID_OFFSET); /* Load the saved PID.  */   \
+	rsbs	r0, r3, #0;		/* Negate it.  */		      \
+	it	eq;							      \
+	moveq	r0, #0x80000000;	/* Use 0x80000000 if it was 0.  */    \
+	str	r0, NEGOFF_OFF1(r2, PID_OFFSET); /* Store the temp PID.  */
 
 /* Restore the old PID value in the parent.  */
 #define RESTORE_PID \
 	cmp	r0, #0;		/* If we are the parent... */		\
-	strne	r3, [r2, #PID_OFFSET]	/* ... restore the saved PID.  */
+	it	ne;							\
+	strne	r3, NEGOFF_OFF1(r2, PID_OFFSET); /* restore the saved PID.  */
 
 #include "../vfork.S"
-- 
1.8.1.2

  parent reply	other threads:[~2013-02-27  3:17 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-27  3:16 [PATCH 00/26] ARM improvements Richard Henderson
2013-02-27  3:16 ` [PATCH 03/26] arm: Handle armv6 in preconfigure Richard Henderson
2013-02-27 18:02   ` Joseph S. Myers
2013-02-27 18:04     ` Roland McGrath
2013-02-27 18:08       ` Richard Henderson
2013-02-27 18:34     ` Richard Henderson
2013-02-27 19:57       ` Joseph S. Myers
2013-02-27  3:16 ` [PATCH 01/26] Sync config.guess and config.sub with upstream Richard Henderson
2013-02-27 17:03   ` Joseph S. Myers
2013-02-27  3:16 ` [PATCH 05/26] arm: Introduce thumb helpers s and pc_ofs Richard Henderson
2013-02-28  0:20   ` Joseph S. Myers
2013-02-28  0:36     ` Richard Henderson
2013-02-28  1:45       ` Måns Rullgård
2013-02-27  3:16 ` [PATCH 09/26] arm: Mark assembly files that will not use thumb mode Richard Henderson
2013-02-28  0:58   ` Joseph S. Myers
2013-02-27  3:16 ` [PATCH 04/26] arm: Include libc-do-syscall in sysdep-rtld-routines Richard Henderson
2013-02-28  0:15   ` Joseph S. Myers
2013-02-27  3:17 ` Richard Henderson [this message]
2013-02-27  3:17 ` [PATCH 19/26] arm: Add optimized ffs for armv6t2 Richard Henderson
2013-02-27 15:51   ` Måns Rullgård
2013-02-27 16:34     ` Richard Henderson
2013-02-27 17:49   ` Roland McGrath
2013-02-27  3:17 ` [PATCH 18/26] arm: Use GET_TLS more often Richard Henderson
2013-02-28 21:59   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 13/26] arm: Store lr in r2 around GET_TLS Richard Henderson
2013-02-27  3:17 ` [PATCH 20/26] arm: Implement armv6t2 optimized strlen Richard Henderson
2013-02-27 17:12   ` Måns Rullgård
2013-02-27 17:44     ` Richard Henderson
2013-02-27  3:17 ` [PATCH 14/26] arm: Use push/pop mnemonics Richard Henderson
2013-02-28  1:03   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 07/26] arm: Introduce and use GET_TLS Richard Henderson
2013-02-28  0:34   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 23/26] arm: Rewrite armv6t2 memchr with uqadd8 Richard Henderson
2013-02-27  7:04   ` Richard Henderson
2013-02-27  3:17 ` [PATCH 17/26] arm: Unless arm4t, pop return address directly into pc Richard Henderson
2013-02-28 21:57   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 22/26] arm: Implement armv6t2 optimized strchr, strrchr, rawmemchr Richard Henderson
2013-02-28  1:31   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 24/26] arm: Add optimized addmul_1 Richard Henderson
2013-02-28 13:58   ` Måns Rullgård
2013-02-28 18:19     ` Richard Henderson
2013-02-28 19:37       ` Måns Rullgård
2013-02-27  3:17 ` [PATCH 21/26] arm: Implement armv6t2 optimized strcpy Richard Henderson
2013-02-27  3:17 ` [PATCH 02/26] arm: Update preconfigure fragment for gcc 4.8 Richard Henderson
2013-02-27 17:54   ` Joseph S. Myers
2013-02-27 18:11     ` Richard Henderson
2013-02-27  3:17 ` [PATCH 06/26] arm: Use pc_ofs Richard Henderson
2013-02-28  0:21   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 26/26] arm: Add optimized add_n and sub_n Richard Henderson
2013-02-27  3:17 ` [PATCH 10/26] arm: Introduce and use LDST_PCREL Richard Henderson
2013-02-28  1:00   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 25/26] arm: Add optimized submul_1 Richard Henderson
2013-02-27  3:17 ` [PATCH 12/26] arm: Enable thumb2 mode in assembly files Richard Henderson
2013-02-27  3:17 ` [PATCH 15/26] arm: Delete LOADREGS macro Richard Henderson
2013-02-28  1:24   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 08/26] arm: Add IT insns for thumb mode Richard Henderson
2013-02-28  0:41   ` Joseph S. Myers
2013-02-27  3:17 ` [PATCH 16/26] arm: Commonize BX conditionals Richard Henderson
2013-02-28 21:51   ` Joseph S. Myers
2013-02-27 15:41 ` [PATCH 00/26] ARM improvements Måns Rullgård
2013-02-27 16:59 ` Joseph S. Myers
2013-02-27 17:34   ` Richard Henderson
2013-02-28 22:05 ` Joseph S. Myers

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