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authorJoseph Myers <joseph@codesourcery.com>2015-03-11 01:14:15 +0000
committerJoseph Myers <joseph@codesourcery.com>2015-03-11 01:14:34 +0000
commit068a6274556f9f362443648f4fd47525c8cf2dba (patch)
treeabf011f3003985f34b109d3dbfdb96c934336a17 /soft-fp/soft-fp.h
parent44a6213c8eebf3f69712a5fba9a33bbb90a79023 (diff)
downloadglibc-068a6274556f9f362443648f4fd47525c8cf2dba.tar.gz
soft-fp: Add _FP_UNREACHABLE.
This patch makes soft-fp use a new macro _FP_UNREACHABLE in place of calling abort in unreachable default cases of switch statements. _FP_UNREACHABLE expands to call __builtin_unreachable for GCC 4.5 and later; the fallback to abort is thus only for kernel use. Tested for powerpc-nofpu that installed stripped shared libraries are unchanged by this patch. Also tested with the math/ tests for mips64 (in the case of fma there *was* previously an abort call generated, unlike for the other operations - one switch only deals with a subset of classes for one operand based on what could have been generated in the earlier part of fma, whereas the other switches deal with all combinations of two classes - and this is apparently too complicated for the default case to have been optimized away). * soft-fp/soft-fp.h (_FP_UNREACHABLE): New macro. * soft-fp/op-common.h (_FP_MUL): Use _FP_UNREACHABLE instead of abort. (_FP_FMA): Likewise. (_FP_DIV): Likewise.
Diffstat (limited to 'soft-fp/soft-fp.h')
-rw-r--r--soft-fp/soft-fp.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/soft-fp/soft-fp.h b/soft-fp/soft-fp.h
index bb68df9160..b247125a39 100644
--- a/soft-fp/soft-fp.h
+++ b/soft-fp/soft-fp.h
@@ -51,6 +51,15 @@
# endif
#endif
+/* For unreachable default cases in switch statements over bitwise OR
+ of FP_CLS_* values. */
+#if (defined __GNUC__ \
+ && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
+# define _FP_UNREACHABLE __builtin_unreachable ()
+#else
+# define _FP_UNREACHABLE abort ()
+#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