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authorwilson <wilson@138bc75d-0d04-0410-961f-82ee72b054a4>1997-11-14 00:07:27 +0000
committerwilson <wilson@138bc75d-0d04-0410-961f-82ee72b054a4>1997-11-14 00:07:27 +0000
commit62aa7862114c21c6a4f38e4113b5ce37c435d489 (patch)
tree1ed9b899bbe18e155415baaf3f9f4beafd425fb0 /gcc/real.h
parenta59e9a3a19b8ae18b9922541ebfc8cdd13858f1b (diff)
downloadgcc-62aa7862114c21c6a4f38e4113b5ce37c435d489.tar.gz
patch from paul eggert to fix -0.0/0.0 confusion that breaks glibc
* real.h (REAL_VALUES_IDENTICAL): New macro. * expr.c (is_zeros_p): Don't consider -0.0 to be all zeros. * fold-const.c (operand_equal_p): Don't consider -0.0 to be identical to 0.0. * tree.c (simple_cst_equal): Don't consider -0.0 to have the same tree structure as 0.0. * varasm.c (immed_real_const_1): Use new REAL_VALUES_IDENTICAL macro instead of doing it by hand. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@16472 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/real.h')
-rw-r--r--gcc/real.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/real.h b/gcc/real.h
index 530a88659f7..a91061ef54d 100644
--- a/gcc/real.h
+++ b/gcc/real.h
@@ -294,6 +294,13 @@ do { REAL_VALUE_TYPE in = (IN); /* Make sure it's not in a register. */\
#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(a, b) REAL_VALUE_TO_TARGET_DOUBLE (a, b)
#endif
+/* Compare two floating-point objects for bitwise identity.
+ This is not the same as comparing for equality on IEEE hosts:
+ -0.0 equals 0.0 but they are not identical, and conversely
+ two NaNs might be identical but they cannot be equal. */
+#define REAL_VALUES_IDENTICAL(x, y) \
+ (!bcmp ((char *) &(x), (char *) &(y), sizeof (REAL_VALUE_TYPE)))
+
/* Compare two floating-point values for equality. */
#ifndef REAL_VALUES_EQUAL
#define REAL_VALUES_EQUAL(x, y) ((x) == (y))