soft-fp: Support conditional zero-initialization in declarations.

In the Linux kernel, some architectures have a single function that
uses different kinds of unpacking and packing depending on the
instruction being emulated, meaning it is not readily visible to the
compiler that variables from _FP_DECL and _FP_FRAC_DECL_* macros are
only used in cases where they were initialized.  The existing copy of
soft-fp in the Linux kernel uses zero-initialization to avoid warnings
in this case, so while frowned upon as a warning suppression mechanism
in code built for glibc it seems appropriate to have such
zero-initialization conditional on __KERNEL__.  This patch duly adds
it, via a macro _FP_ZERO_INIT that expands to empty for non-kernel
compilations.

Tested for powerpc-nofpu that installed stripped shared libraries are
unchanged by this patch.

	* soft-fp/soft-fp.h (_FP_ZERO_INIT): New macro.  Define depending
	on [__KERNEL__].
	* soft-fp/op-1.h (_FP_FRAC_DECL_1): Use _FP_ZERO_INIT.
	* soft-fp/op-2.h (_FP_FRAC_DECL_2): Likewise.
	* soft-fp/op-common.h (_FP_DECL): Likewise.

1 files changed, 11 insertions, 0 deletions

diff --git a/soft-fp/soft-fp.h b/soft-fp/soft-fp.h
index 1eafcb433d..f93a94182b 100644
--- a/soft-fp/soft-fp.h
+++ b/soft-fp/soft-fp.h
@@ -51,6 +51,17 @@
 # endif
 #endif
 
+/* In the Linux kernel, some architectures have a single function that
+   uses different kinds of unpacking and packing depending on the
+   instruction being emulated, meaning it is not readily visible to
+   the compiler that variables from _FP_DECL and _FP_FRAC_DECL_*
+   macros are only used in cases where they were initialized.  */
+#ifdef __KERNEL__
+# define _FP_ZERO_INIT		= 0
+#else
+# define _FP_ZERO_INIT
+#endif
+
 #define _FP_WORKBITS		3
 #define _FP_WORK_LSB		((_FP_W_TYPE) 1 << 3)
 #define _FP_WORK_ROUND		((_FP_W_TYPE) 1 << 2)