diff mbox

hppa: Fix reload error compiling nss/getXXbyYY.c on hppa

Message ID BLU436-SMTP838AA3459578989561E10597730@phx.gbl
State New
Headers show

Commit Message

John David Anglin Aug. 7, 2015, 5:37 p.m. UTC 
The attached change fixes 18787.  As noted in the bug, the asm operands need to be copied to
register variables to avoid operand reloads in the principal asm of the macro.  See the arm implementation
for reference.

Build tested on trunk with gcc-4.8.  Similar patch has been tested with 2.19 on Debian hppa-unknown-linux-gnu.

Please commit if okay.

Thanks,
Dave
--
John David Anglin	dave.anglin@bell.net
2015-08-07  John David Anglin  <danglin@gcc.gnu.org>

	[BZ 18787]
	* sysdeps/unix/sysv/linux/hppa/bits/atomic.h (_LWS_CLOBBER): Revise
	clobber registers.
	(atomic_compare_and_exchange_val_acq): Use register asms to assign
	operand registers.  Use register %r20 for EAGAIN and EDEADLOCK checks.
	Cast return to __typeof (oldval).

Comments

Mike Frysinger Aug. 8, 2015, 5:12 a.m. UTC | #1 
On 07 Aug 2015 13:37, John David Anglin wrote:
> The attached change fixes 18787.  As noted in the bug, the asm operands need to be copied to
> register variables to avoid operand reloads in the principal asm of the macro.  See the arm implementation
> for reference.
> 
> Build tested on trunk with gcc-4.8.  Similar patch has been tested with 2.19 on Debian hppa-unknown-linux-gnu.

i've pushed this now ... Gentoo has been using an older version of your
patch as well since it won't even build w/out it.
-mike
diff mbox

Patch

diff --git a/sysdeps/unix/sysv/linux/hppa/bits/atomic.h b/sysdeps/unix/sysv/linux/hppa/bits/atomic.h
index abde83e..d3a7964 100644
--- a/sysdeps/unix/sysv/linux/hppa/bits/atomic.h
+++ b/sysdeps/unix/sysv/linux/hppa/bits/atomic.h
@@ -56,42 +56,41 @@  typedef uintmax_t uatomic_max_t;
 #define _LWS "0xb0"
 #define _LWS_CAS "0"
 /* Note r31 is the link register.  */
-#define _LWS_CLOBBER "r1", "r26", "r25", "r24", "r23", "r22", "r21", "r20", "r28", "r31", "memory"
+#define _LWS_CLOBBER "r1", "r23", "r22", "r20", "r31", "memory"
 /* String constant for -EAGAIN.  */
 #define _ASM_EAGAIN "-11"
 /* String constant for -EDEADLOCK.  */
 #define _ASM_EDEADLOCK "-45"
 
 #if __ASSUME_LWS_CAS
-/* The only basic operation needed is compare and exchange.  */
+/* The only basic operation needed is compare and exchange.  The mem
+   pointer must be word aligned.  */
 # define atomic_compare_and_exchange_val_acq(mem, newval, oldval)	\
   ({									\
-     volatile int lws_errno;						\
-     __typeof__ (*mem) lws_ret;						\
-     asm volatile(							\
+     register long lws_errno asm("r21");				\
+     register unsigned long lws_ret asm("r28");				\
+     register unsigned long lws_mem asm("r26") = (unsigned long)(mem);	\
+     register unsigned long lws_old asm("r25") = (unsigned long)(oldval);\
+     register unsigned long lws_new asm("r24") = (unsigned long)(newval);\
+     __asm__ __volatile__(						\
 	"0:					\n\t"			\
-	"copy	%2, %%r26			\n\t"			\
-	"copy	%3, %%r25			\n\t"			\
-	"copy	%4, %%r24			\n\t"			\
 	"ble	" _LWS "(%%sr2, %%r0)		\n\t"			\
 	"ldi	" _LWS_CAS ", %%r20		\n\t"			\
-	"ldi	" _ASM_EAGAIN ", %%r24		\n\t"			\
-	"cmpb,=,n %%r24, %%r21, 0b		\n\t"			\
+	"ldi	" _ASM_EAGAIN ", %%r20		\n\t"			\
+	"cmpb,=,n %%r20, %%r21, 0b		\n\t"			\
 	"nop					\n\t"			\
-	"ldi	" _ASM_EDEADLOCK ", %%r25	\n\t"			\
-	"cmpb,=,n %%r25, %%r21, 0b		\n\t"			\
+	"ldi	" _ASM_EDEADLOCK ", %%r20	\n\t"			\
+	"cmpb,=,n %%r20, %%r21, 0b		\n\t"			\
 	"nop					\n\t"			\
-	"stw	%%r28, %0			\n\t"			\
-	"stw	%%r21, %1			\n\t"			\
-	: "=m" (lws_ret), "=m" (lws_errno)				\
-        : "r" (mem), "r" (oldval), "r" (newval)				\
+	: "=r" (lws_ret), "=r" (lws_errno)				\
+	: "r" (lws_mem), "r" (lws_old), "r" (lws_new)			\
 	: _LWS_CLOBBER							\
      );									\
 									\
      if(lws_errno == -EFAULT || lws_errno == -ENOSYS)			\
 	ABORT_INSTRUCTION;						\
 									\
-     lws_ret;								\
+     (__typeof (oldval)) lws_ret;					\
    })
 
 # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval)	\