From: Richard Henderson <rth@twiddle.net>
Date: Thu, 11 Jul 2013 16:47:45 +0000 (-0700)
Subject: alpha: Eliminate compiler warning from memset macro
X-Git-Tag: accepted/tizen/common/20141203.182822~1057^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a47e5bb5764f029f989a182b0dd2d4cce69f8b14;p=platform%2Fkernel%2Flinux-arm64.git

alpha: Eliminate compiler warning from memset macro

Compiling with GCC 4.8 yields several instances of

crypto/vmac.c: In function ‘vmac_final’:
crypto/vmac.c:616:9: warning: value computed is not used [-Wunused-value]
  memset(&mac, 0, sizeof(vmac_t));
         ^
arch/alpha/include/asm/string.h:31:25: note: in definition of macro ‘memset’
     ? __builtin_memset((s),0,(n))          \
                         ^
Converting the macro to an inline function eliminates this problem.

However, doing only that causes problems with the GCC 3.x series.  The
inline function cannot be named "memset", as otherwise we wind up with
recursion via __builtin_memset.  Solve this by adjusting the symbols
such that __memset is the inline, and ___memset is the real function.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---

diff --git a/arch/alpha/include/asm/string.h b/arch/alpha/include/asm/string.h
index b02b8a2..c2911f5 100644
--- a/arch/alpha/include/asm/string.h
+++ b/arch/alpha/include/asm/string.h
@@ -22,15 +22,27 @@ extern void * __memcpy(void *, const void *, size_t);
 
 #define __HAVE_ARCH_MEMSET
 extern void * __constant_c_memset(void *, unsigned long, size_t);
+extern void * ___memset(void *, int, size_t);
 extern void * __memset(void *, int, size_t);
 extern void * memset(void *, int, size_t);
 
-#define memset(s, c, n)							    \
-(__builtin_constant_p(c)						    \
- ? (__builtin_constant_p(n) && (c) == 0					    \
-    ? __builtin_memset((s),0,(n)) 					    \
-    : __constant_c_memset((s),0x0101010101010101UL*(unsigned char)(c),(n))) \
- : __memset((s),(c),(n)))
+/* For gcc 3.x, we cannot have the inline function named "memset" because
+   the __builtin_memset will attempt to resolve to the inline as well,
+   leading to a "sorry" about unimplemented recursive inlining.  */
+extern inline void *__memset(void *s, int c, size_t n)
+{
+	if (__builtin_constant_p(c)) {
+		if (__builtin_constant_p(n)) {
+			return __builtin_memset(s, c, n);
+		} else {
+			unsigned long c8 = (c & 0xff) * 0x0101010101010101UL;
+			return __constant_c_memset(s, c8, n);
+		}
+	}
+	return ___memset(s, c, n);
+}
+
+#define memset __memset
 
 #define __HAVE_ARCH_STRCPY
 extern char * strcpy(char *,const char *);
diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
index 89566b3..f4c7ab6 100644
--- a/arch/alpha/kernel/alpha_ksyms.c
+++ b/arch/alpha/kernel/alpha_ksyms.c
@@ -40,6 +40,7 @@ EXPORT_SYMBOL(strrchr);
 EXPORT_SYMBOL(memmove);
 EXPORT_SYMBOL(__memcpy);
 EXPORT_SYMBOL(__memset);
+EXPORT_SYMBOL(___memset);
 EXPORT_SYMBOL(__memsetw);
 EXPORT_SYMBOL(__constant_c_memset);
 EXPORT_SYMBOL(copy_page);
diff --git a/arch/alpha/lib/ev6-memset.S b/arch/alpha/lib/ev6-memset.S
index d8b94e1..356bb2f 100644
--- a/arch/alpha/lib/ev6-memset.S
+++ b/arch/alpha/lib/ev6-memset.S
@@ -30,14 +30,15 @@
 	.set noat
 	.set noreorder
 .text
+	.globl memset
 	.globl __memset
+	.globl ___memset
 	.globl __memsetw
 	.globl __constant_c_memset
-	.globl memset
 
-	.ent __memset
+	.ent ___memset
 .align 5
-__memset:
+___memset:
 	.frame $30,0,$26,0
 	.prologue 0
 
@@ -227,7 +228,7 @@ end_b:
 	nop
 	nop
 	ret $31,($26),1		# L0 :
-	.end __memset
+	.end ___memset
 
 	/*
 	 * This is the original body of code, prior to replication and
@@ -594,4 +595,5 @@ end_w:
 
 	.end __memsetw
 
-memset = __memset
+memset = ___memset
+__memset = ___memset
diff --git a/arch/alpha/lib/memset.S b/arch/alpha/lib/memset.S
index 311b8cf..76ccc6d 100644
--- a/arch/alpha/lib/memset.S
+++ b/arch/alpha/lib/memset.S
@@ -19,11 +19,13 @@
 .text
 	.globl memset
 	.globl __memset
+	.globl ___memset
 	.globl __memsetw
 	.globl __constant_c_memset
-	.ent __memset
+
+	.ent ___memset
 .align 5
-__memset:
+___memset:
 	.frame $30,0,$26,0
 	.prologue 0
 
@@ -103,7 +105,7 @@ within_one_quad:
 
 end:
 	ret $31,($26),1		/* E1 */
-	.end __memset
+	.end ___memset
 
 	.align 5
 	.ent __memsetw
@@ -121,4 +123,5 @@ __memsetw:
 
 	.end __memsetw
 
-memset = __memset
+memset = ___memset
+__memset = ___memset