diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 15 | ||||
| -rw-r--r-- | gcc/expr.c | 2 | ||||
| -rw-r--r-- | gcc/fold-const.c | 4 | ||||
| -rw-r--r-- | gcc/real.h | 7 | ||||
| -rw-r--r-- | gcc/tree.c | 2 | ||||
| -rw-r--r-- | gcc/varasm.c | 3 |
6 files changed, 27 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 79a5a8bbebc..12cac79d33c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,18 @@ +1997-11-13 Paul Eggert <eggert@twinsun.com> + + Fix some confusion with IEEE minus zero. + + * 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. + Thu Nov 13 16:56:14 1997 Jeffrey A Law (law@cygnus.com) * v850/lib1funcs.asm: Minor whitespace changes. diff --git a/gcc/expr.c b/gcc/expr.c index 2f28be5a3e4..a18b09e9aba 100644 --- a/gcc/expr.c +++ b/gcc/expr.c @@ -3476,7 +3476,7 @@ is_zeros_p (exp) is_zeros_p (TREE_REALPART (exp)) && is_zeros_p (TREE_IMAGPART (exp)); case REAL_CST: - return REAL_VALUES_EQUAL (TREE_REAL_CST (exp), dconst0); + return REAL_VALUES_IDENTICAL (TREE_REAL_CST (exp), dconst0); case CONSTRUCTOR: if (TREE_TYPE (exp) && TREE_CODE (TREE_TYPE (exp)) == SET_TYPE) diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 9b342528f8a..4b4c5e184b4 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -1796,8 +1796,8 @@ operand_equal_p (arg0, arg1, only_const) case REAL_CST: return (! TREE_CONSTANT_OVERFLOW (arg0) && ! TREE_CONSTANT_OVERFLOW (arg1) - && REAL_VALUES_EQUAL (TREE_REAL_CST (arg0), - TREE_REAL_CST (arg1))); + && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0), + TREE_REAL_CST (arg1))); case COMPLEX_CST: return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1), 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)) diff --git a/gcc/tree.c b/gcc/tree.c index 2129f8491e1..ecd6961daf6 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -3840,7 +3840,7 @@ simple_cst_equal (t1, t2) && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2); case REAL_CST: - return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); + return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); case STRING_CST: return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) diff --git a/gcc/varasm.c b/gcc/varasm.c index 1161837cec3..ab88bebb46f 100644 --- a/gcc/varasm.c +++ b/gcc/varasm.c @@ -2245,8 +2245,7 @@ immed_real_const_1 (d, mode) /* Detect special cases. */ - /* Avoid REAL_VALUES_EQUAL here in order to distinguish minus zero. */ - if (!bcmp ((char *) &dconst0, (char *) &d, sizeof d)) + if (REAL_VALUES_IDENTICAL (dconst0, d)) return CONST0_RTX (mode); /* Check for NaN first, because some ports (specifically the i386) do not emit correct ieee-fp code by default, and thus will generate a core |