arm: Introduce and use LDST_PCREL

Macro-ising the few instances where we need to distinguish between
arm and thumb pc-relative memory operations.

ports/ChangeLog.arm

@@ -1,3 +1,15 @@
+2013-03-06  Richard Henderson <rth@redhat.com>
+
+	* sysdeps/arm/sysdep.h (LDST_PCREL): New macro.
+	* sysdeps/unix/arm/sysdep.S (__syscall_error): Use LDST_PCREL.
+	Fix up gottpoff load of errno for thumb2.
+	* sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h
+	(SINGLE_THREAD_P): Use LDST_PCREL.
+	(PSEUDO_PROLOGUE): Remove.
+	(PSEUDO): Don't use it.
+	* sysdeps/unix/sysv/linux/arm/sysdep.h (SYSCALL_ERROR_HANDLER):
+	Use LDST_PCREL.
+
 2013-03-06  Andreas Jaeger  <aj@suse.de>
 
 	* sysdeps/unix/sysv/linux/arm/bits/mman.h: Remove all defines

ports/sysdeps/arm/sysdep.h

@@ -117,6 +117,23 @@
    the caller.  */
 	.eabi_attribute 24, 1
 
+/* Load or store to/from a pc-relative EXPR into/from R, using T.  */
+# ifdef __thumb2__
+#  define LDST_PCREL(OP, R, T, EXPR) \
+	ldr	T, 98f;					\
+	.subsection 2;					\
+98:	.word	EXPR - 99f - PC_OFS;			\
+	.previous;					\
+99:	add	T, T, pc;				\
+	OP	R, [T]
+# else
+#  define LDST_PCREL(OP, R, T, EXPR) \
+	ldr	T, 98f;					\
+	.subsection 2;					\
+98:	.word	EXPR - 99f - PC_OFS;			\
+	.previous;					\
+99:	OP	R, [pc, T]
+# endif
 #endif	/* __ASSEMBLER__ */
 
 /* This number is the offset from the pc at the current location.  */

ports/sysdeps/unix/arm/sysdep.S

@@ -45,20 +45,22 @@ __syscall_error:
 	mov lr, pc
 	sub pc, r0, #31
 
-	ldr r2, 1f
+	ldr	r2, 1f
-2:	ldr r2, [pc, r2]
+#ifdef __thumb__
-	str r1, [r0, r2]
+2:	add	r2, r2, pc
-	mvn r0, #0
+	ldr	r2, [r2]
-	RETINSTR (, ip)
+#else
+2:	ldr	r2, [pc, r2]
+#endif
+	str	r1, [r0, r2]
+	mvn	r0, #0
+	DO_RET(ip)
 
 1:	.word errno(gottpoff) + (. - 2b - PC_OFS)
 #elif RTLD_PRIVATE_ERRNO
-	ldr r1, 1f
+	LDST_PCREL(str, r0, r1, C_SYMBOL_NAME(rtld_errno))
-0:	str r0, [pc, r1]
+	mvn	r0, #0
-	mvn r0, $0
 	DO_RET(r14)
-
-1:	.word C_SYMBOL_NAME(rtld_errno) - 0b - PC_OFS
 #else
 #error "Unsupported non-TLS case"
 #endif

ports/sysdeps/unix/sysv/linux/arm/nptl/sysdep-cancel.h

@@ -31,7 +31,6 @@
 # undef PSEUDO
 # define PSEUDO(name, syscall_name, args)				\
 	.text;								\
-	PSEUDO_PROLOGUE;						\
   ENTRY (__##syscall_name##_nocancel);					\
 	CFI_SECTIONS;							\
 	DO_CALL (syscall_name, args);					\
@@ -203,12 +202,8 @@ extern int __local_multiple_threads attribute_hidden;
 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
 #  else
 #   define SINGLE_THREAD_P						\
-	ldr	ip, 1b;							\
+	LDST_PCREL(ldr, ip, ip, __local_multiple_threads);		\
-  2:									\
+	teq ip, #0
-	ldr ip, [pc, ip];						\
-	teq ip, #0;
-#   define PSEUDO_PROLOGUE						\
-  1:	.word	__local_multiple_threads - 2f - PC_OFS;
 #  endif
 # else
 /*  There is no __local_multiple_threads for librt, so use the TCB.  */
@@ -217,7 +212,6 @@ extern int __local_multiple_threads attribute_hidden;
   __builtin_expect (THREAD_GETMEM (THREAD_SELF,				\
 				   header.multiple_threads) == 0, 1)
 #  else
-#   define PSEUDO_PROLOGUE
 #   define SINGLE_THREAD_P						\
 	stmfd	sp!, {r0, lr};						\
 	cfi_adjust_cfa_offset (8);					\

ports/sysdeps/unix/sysv/linux/arm/sysdep.h

@@ -110,12 +110,10 @@
 # if RTLD_PRIVATE_ERRNO
 #  define SYSCALL_ERROR_HANDLER					\
 __local_syscall_error:						\
-       ldr     r1, 1f;						\
+	rsb	r0, r0, #0;					\
-       rsb     r0, r0, #0;					\
+	LDST_PCREL(str, r0, r1, C_SYMBOL_NAME(rtld_errno));	\
-0:     str     r0, [pc, r1];					\
+	mvn	r0, #0;						\
-       mvn     r0, #0;						\
+	DO_RET(lr)
-       DO_RET(lr);						\
-1:     .word C_SYMBOL_NAME(rtld_errno) - 0b - PC_OFS;
 # else
 #  if defined(__ARM_ARCH_4T__) && defined(__THUMB_INTERWORK__)
 #   define POP_PC \