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[PATCH v2 4/9] aarch64: Improve sysdep-cancel.h


From: Richard Henderson <rth@redhat.com>

Use a constant frame size, rather than pushing/popping for every saved
register.  Use stp, ldp, cbz.  Share code with the _nocancel path.
---
 .../unix/sysv/linux/aarch64/nptl/sysdep-cancel.h   | 181 +++++++--------------
 1 file changed, 63 insertions(+), 118 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h b/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h
index c300b2d..a78e2ad 100644
--- a/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h
+++ b/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h
@@ -26,120 +26,66 @@
 
 # undef PSEUDO
 # define PSEUDO(name, syscall_name, args)				\
-  .section ".text";							\
-  .type __##syscall_name##_nocancel,%function;				\
-  .globl __##syscall_name##_nocancel;					\
-  __##syscall_name##_nocancel:						\
-    cfi_startproc;							\
-    DO_CALL (syscall_name, args);					\
-    cmn x0, 4095;							\
-    b.cs .Lsyscall_error;						\
-    PSEUDO_RET;								\
-    cfi_endproc;							\
-    .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel;	\
-  ENTRY (name);								\
-    SINGLE_THREAD_P;							\
-    bne .Lpseudo_cancel;						\
-    DO_CALL (syscall_name, 0);						\
-    cmn x0, 4095;							\
-    b.cs .Lsyscall_error;						\
-    PSEUDO_RET;								\
-  .Lpseudo_cancel:							\
-    DOCARGS_##args;	/* save syscall args etc. around CENABLE.  */	\
-    CENABLE;								\
-    mov x16, x0;	/* put mask in safe place.  */			\
-    UNDOCARGS_##args;	/* restore syscall args.  */			\
-    mov x8, SYS_ify (syscall_name);	/* do the call.  */		\
-    svc	0;								\
-    str x0, [sp, -16]!;	/* save syscall return value.  */		\
-    cfi_adjust_cfa_offset (16);						\
-    mov x0, x16;	 /* get mask back.  */				\
-    CDISABLE;								\
-    ldr x0, [sp], 16;							\
-    cfi_adjust_cfa_offset (-16);					\
-    ldr x30, [sp], 16;							\
-    cfi_adjust_cfa_offset (-16);					\
-    cfi_restore (x30);							\
-    cmn x0, 4095;							\
-    b.cs .Lsyscall_error;
-
-# define DOCARGS_0							\
-	str x30, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x30, 0)
-
+	.section ".text";						\
+ENTRY (__##syscall_name##_nocancel);					\
+.Lpseudo_nocancel:							\
+	DO_CALL (syscall_name, args);					\
+.Lpseudo_ret:								\
+	cmn x0, 4095;							\
+	b.cs .Lsyscall_error;						\
+	.subsection 2;							\
+	.size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel; \
+ENTRY (name);								\
+	SINGLE_THREAD_P(16);						\
+	cbz	w16, .Lpseudo_nocancel;					\
+	/* Setup common stack frame no matter the number of args.  */	\
+	stp	x19, x30, [sp, -64]!;					\
+	cfi_adjust_cfa_offset (64);					\
+	cfi_rel_offset (x19, 0);					\
+	cfi_rel_offset (x30, 8);					\
+	DOCARGS_##args;		/* save syscall args around CENABLE. */	\
+	CENABLE;							\
+	mov	x19, x0;	/* save mask around syscall. */		\
+	UNDOCARGS_##args;	/* restore syscall args.  */		\
+	DO_CALL (syscall_name, args);					\
+	str	x0, [sp, 16];	/* save syscall return value.  */	\
+	mov	x0, x19;	/* pass mask to CDISABLE. */		\
+	CDISABLE;							\
+	ldr	x0, [sp, 16];						\
+	ldp	x19, x30, [sp], 64;					\
+	cfi_adjust_cfa_offset (-64);					\
+	cfi_restore (x19);						\
+	cfi_restore (x30);						\
+	b	.Lpseudo_ret;						\
+	cfi_endproc;							\
+	.size name, .-name;						\
+	.previous
+
+# undef PSEUDO_END
+# define PSEUDO_END(name)						\
+	SYSCALL_ERROR_HANDLER;						\
+	cfi_endproc
+
+# define DOCARGS_0
 # define UNDOCARGS_0
 
-# define DOCARGS_1							\
-	DOCARGS_0;							\
-	str x0, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x0, 0)
-
-# define UNDOCARGS_1							\
-	ldr x0, [sp], 16;						\
-	cfi_restore (x0);						\
-	cfi_adjust_cfa_offset (-16);					\
-
-# define DOCARGS_2							\
-	DOCARGS_1;							\
-	str x1, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x1, 0)
-
-# define UNDOCARGS_2							\
-	ldr x1, [sp], 16;						\
-	cfi_restore (x1);						\
-	cfi_adjust_cfa_offset (-16);					\
-	UNDOCARGS_1
-
-# define DOCARGS_3							\
-	DOCARGS_2;							\
-	str x2, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x2, 0)
-
-# define UNDOCARGS_3							\
-	ldr x2, [sp], 16;						\
-	cfi_restore (x2);						\
-	cfi_adjust_cfa_offset (-16);					\
-	UNDOCARGS_2
-
-# define DOCARGS_4							\
-	DOCARGS_3;							\
-	str x3, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x3, 0)
-
-# define UNDOCARGS_4							\
-	ldr x3, [sp], 16;						\
-	cfi_restore (x3);						\
-	cfi_adjust_cfa_offset (-16);					\
-	UNDOCARGS_3
-
-# define DOCARGS_5							\
-	DOCARGS_4;							\
-	str x4, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x4, 0)
-
-# define UNDOCARGS_5							\
-	ldr x4, [sp], 16;						\
-	cfi_restore (x4);						\
-	cfi_adjust_cfa_offset (-16);					\
-	UNDOCARGS_4
-
-# define DOCARGS_6							\
-	DOCARGS_5;							\
-	str x5, [sp, -16]!;						\
-	cfi_adjust_cfa_offset (16);					\
-	cfi_rel_offset (x5, 0)
-
-# define UNDOCARGS_6							\
-	ldr x5, [sp], 16;						\
-	cfi_restore (x5);						\
-	cfi_adjust_cfa_offset (-16);					\
-	UNDOCARGS_5
+# define DOCARGS_1	str x0, [sp, 16]
+# define UNDOCARGS_1	ldr x0, [sp, 16]
+
+# define DOCARGS_2	stp x0, x1, [sp, 16]
+# define UNDOCARGS_2	ldp x0, x1, [sp, 16]
+
+# define DOCARGS_3	DOCARGS_2;   str x2, [sp, 32]
+# define UNDOCARGS_3	UNDOCARGS_2; ldr x2, [sp, 32]
+
+# define DOCARGS_4	DOCARGS_2;   stp x2, x3, [sp, 32]
+# define UNDOCARGS_4	UNDOCARGS_2; ldp x2, x3, [sp, 32]
+
+# define DOCARGS_5	DOCARGS_4;   str x4, [sp, 48]
+# define UNDOCARGS_5	UNDOCARGS_4; ldr x4, [sp, 48]
+
+# define DOCARGS_6	DOCARGS_4;   stp x4, x5, [sp, 48]
+# define UNDOCARGS_6	UNDOCARGS_4; ldp x4, x5, [sp, 48]
 
 # ifdef IS_IN_libpthread
 #  define CENABLE	bl __pthread_enable_asynccancel
@@ -161,10 +107,9 @@
 extern int __local_multiple_threads attribute_hidden;
 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
 #  else
-#   define SINGLE_THREAD_P						\
-  adrp	x16, __local_multiple_threads;					\
-  ldr	w16, [x16, :lo12:__local_multiple_threads];			\
-  cmp	w16, 0;
+#   define SINGLE_THREAD_P(R)						\
+  adrp	x##R, __local_multiple_threads;					\
+  ldr	w##R, [x##R, :lo12:__local_multiple_threads]
 #  endif
 # else
 /*  There is no __local_multiple_threads for librt, so use the TCB.  */
@@ -173,14 +118,14 @@ extern int __local_multiple_threads attribute_hidden;
   __builtin_expect (THREAD_GETMEM (THREAD_SELF,				\
 				   header.multiple_threads) == 0, 1)
 #  else
-#   define SINGLE_THREAD_P						\
+#   define SINGLE_THREAD_P(R)						\
   stp	x0, x30, [sp, -16]!;						\
   cfi_adjust_cfa_offset (16);						\
   cfi_rel_offset (x0, 0);						\
   cfi_rel_offset (x30, 8);						\
   bl	__read_tp;							\
   sub	x0, x0, PTHREAD_SIZEOF;						\
-  ldr	w16, [x0, PTHREAD_MULTIPLE_THREADS_OFFSET];			\
+  ldr	w##R, [x0, PTHREAD_MULTIPLE_THREADS_OFFSET];			\
   ldp	x0, x30, [sp], 16;						\
   cfi_restore (x0);							\
   cfi_restore (x30);							\
-- 
1.9.0


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