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| author | Roger Sayle <roger@eyesopen.com> | 2005-02-03 06:44:35 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2005-02-03 06:44:35 +0000 |
| commit | 762297d941e94600c6b81d5ccdd464872d9a9692 (patch) | |
| tree | fb250b8935df7ba966a9aeae4f38b4eca4fc2969 /gcc | |
| parent | 666158b9cecdc55cc2f2cf0c77f571220b5a10c3 (diff) | |
| download | gcc-762297d941e94600c6b81d5ccdd464872d9a9692.zip gcc-762297d941e94600c6b81d5ccdd464872d9a9692.tar.gz gcc-762297d941e94600c6b81d5ccdd464872d9a9692.tar.bz2 | |
re PR middle-end/19405 (18_support/numeric_limits.cc fails on ppc-darwin (long doubles))
PR middle-end/19405
* real.h (REAL_MODE_FORMAT_COMPOSITE_P): New macro.
* fold-const.c (const_binop): Avoid constant folding floating
point operations in modes that use composite representations.
* simplify-rtx.c (simplify_binary_operation): Likewise.
From-SVN: r94653
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/fold-const.c | 7 | ||||
| -rw-r--r-- | gcc/real.h | 6 | ||||
| -rw-r--r-- | gcc/simplify-rtx.c | 8 |
4 files changed, 25 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 70370e2..b9a6395 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2005-02-02 Roger Sayle <roger@eyesopen.com> + + PR middle-end/19405 + * real.h (REAL_MODE_FORMAT_COMPOSITE_P): New macro. + * fold-const.c (const_binop): Avoid constant folding floating + point operations in modes that use composite representations. + * simplify-rtx.c (simplify_binary_operation): Likewise. + 2005-02-02 Geoffrey Keating <geoffk@apple.com> * config/rs6000/altivec.md (altivec_dst): Make the first operand diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 2285742..1d2efbd 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -1517,9 +1517,12 @@ const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc) /* Don't constant fold this floating point operation if the result may dependent upon the run-time rounding mode and - flag_rounding_math is set. */ + flag_rounding_math is set, or if GCC's software emulation + is unable to accurately represent the result. */ - if (flag_rounding_math + if ((flag_rounding_math + || (REAL_MODE_FORMAT_COMPOSITE_P (mode) + && !flag_unsafe_math_optimizations)) && (inexact || !real_identical (&result, &value))) return NULL_TREE; @@ -157,6 +157,12 @@ extern const struct real_format * #define REAL_MODE_FORMAT(MODE) (real_format_for_mode[(MODE) - MIN_MODE_FLOAT]) +/* The following macro determines whether the floating point format is + composite, i.e. may contain non-consecutive mantissa bits, in which + case compile-time FP overflow may not model run-time overflow. */ +#define REAL_MODE_FORMAT_COMPOSITE_P(MODE) \ + ((REAL_MODE_FORMAT(MODE))->pnan < (REAL_MODE_FORMAT (MODE))->p) + /* Declare functions in real.c. */ /* Binary or unary arithmetic on tree_code. */ diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 92567fe..a1a7747 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -1346,8 +1346,12 @@ simplify_binary_operation (enum rtx_code code, enum machine_mode mode, /* Don't constant fold this floating point operation if the result may dependent upon the run-time rounding mode and - flag_rounding_math is set. */ - if (flag_rounding_math + flag_rounding_math is set, or if GCC's software emulation + is unable to accurately represent the result. */ + + if ((flag_rounding_math + || (REAL_MODE_FORMAT_COMPOSITE_P (mode) + && !flag_unsafe_math_optimizations)) && (inexact || !real_identical (&result, &value))) return NULL_RTX; |