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[PATCH 16/26] arm: Commonize BX conditionals
- From: Richard Henderson <rth at twiddle dot net>
- To: libc-ports at sourceware dot org
- Cc: Joseph Myers <joseph at codesourcery dot com>
- Date: Tue, 26 Feb 2013 19:16:16 -0800
- Subject: [PATCH 16/26] arm: Commonize BX conditionals
- References: <1361934986-17018-1-git-send-email-rth@twiddle.net>
Add BLX macro in addition and use it where appropriate.
---
* sysdeps/arm/sysdep.h (BX, BXC, BLX): New macros.
(DO_RET): Use BX.
(RETINSTR): Use BXC.
* sysdeps/arm/dl-tlsdesc.S (BX): Remove.
* sysdeps/arm/dl-trampoline.S (BX): Remove.
(_dl_runtime_profile): Use BLX.
---
ports/sysdeps/arm/dl-tlsdesc.S | 6 ------
ports/sysdeps/arm/dl-trampoline.S | 9 +--------
ports/sysdeps/arm/sysdep.h | 29 +++++++++++++----------------
3 files changed, 14 insertions(+), 30 deletions(-)
diff --git a/ports/sysdeps/arm/dl-tlsdesc.S b/ports/sysdeps/arm/dl-tlsdesc.S
index 15a0c21..417b8b3 100644
--- a/ports/sysdeps/arm/dl-tlsdesc.S
+++ b/ports/sysdeps/arm/dl-tlsdesc.S
@@ -20,12 +20,6 @@
#include <tls.h>
#include "tlsdesc.h"
-#ifdef __USE_BX__
- #define BX(x) bx x
-#else
- #define BX(x) mov pc, x
-#endif
-
.text
@ emit debug information with cfi
@ use arm-specific pseudos for unwinding itself
diff --git a/ports/sysdeps/arm/dl-trampoline.S b/ports/sysdeps/arm/dl-trampoline.S
index a13a4c3..c34c61e 100644
--- a/ports/sysdeps/arm/dl-trampoline.S
+++ b/ports/sysdeps/arm/dl-trampoline.S
@@ -21,12 +21,6 @@
#include <sysdep.h>
#include <libc-symbols.h>
-#if defined(__USE_BX__)
-#define BX(x) bx x
-#else
-#define BX(x) mov pc, x
-#endif
-
.text
.globl _dl_runtime_resolve
.type _dl_runtime_resolve, #function
@@ -192,8 +186,7 @@ _dl_runtime_profile:
add ip, r7, #72
ldmia ip, {r0-r3}
ldr ip, [r7, #264]
- mov lr, pc
- BX(ip)
+ BLX(ip)
stmia r7, {r0-r3}
@ Call pltexit.
diff --git a/ports/sysdeps/arm/sysdep.h b/ports/sysdeps/arm/sysdep.h
index bfdba27..71abb7a 100644
--- a/ports/sysdeps/arm/sysdep.h
+++ b/ports/sysdeps/arm/sysdep.h
@@ -33,26 +33,23 @@
#define PLTJMP(_x) _x##(PLT)
-/* APCS-32 doesn't preserve the condition codes across function call. */
-#ifdef __APCS_32__
#ifdef __USE_BX__
-#define RETINSTR(cond, reg) \
- bx##cond reg
-#define DO_RET(_reg) \
- bx _reg
+# define BX(R) bx R
+# define BXC(C, R) bx##C R
+# ifdef __ARM_ARCH_4T__
+# define BLX(R) mov lr, pc; bx R
+# else
+# define BLX(R) blx R
+# endif
#else
-#define RETINSTR(cond, reg) \
- mov##cond pc, reg
-#define DO_RET(_reg) \
- mov pc, _reg
-#endif
-#else /* APCS-26 */
-#define RETINSTR(cond, reg) \
- mov##cond##s pc, reg
-#define DO_RET(_reg) \
- movs pc, _reg
+# define BX(R) mov pc, R
+# define BXC(C, R) mov##C pc, R
+# define BLX(R) mov lr, pc; mov pc, R
#endif
+#define DO_RET(R) BX(R)
+#define RETINSTR(C, R) BXC(C, R)
+
/* Define an entry point visible from C. */
#define ENTRY(name) \
.globl C_SYMBOL_NAME(name); \
--
1.8.1.2