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author | jsm28 <jsm28@138bc75d-0d04-0410-961f-82ee72b054a4> | 2008-10-29 17:05:42 +0000 |
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committer | jsm28 <jsm28@138bc75d-0d04-0410-961f-82ee72b054a4> | 2008-10-29 17:05:42 +0000 |
commit | 02c52e944f67987d3e2a506e9e3e9c60282db7ae (patch) | |
tree | f0bc48b745fe374d4990579d0ef02a2d88bb7799 /gcc/real.c | |
parent | b43b7954e03f8578e48822cd9b5753feae3ec616 (diff) | |
download | gcc-02c52e944f67987d3e2a506e9e3e9c60282db7ae.tar.gz |
PR middle-end/36578
* convert.c (convert_to_real): Do not optimize conversions of
binary arithmetic operations between binary and decimal
floating-point types. Consider mode of target type in determining
decimal type for arithmetic. Unless
flag_unsafe_math_optimizations, do not optimize binary conversions
where this may change rounding behavior.
* real.c (real_can_shorten_arithmetic): New.
* real.h (real_can_shorten_arithmetic): Declare.
testsuite:
* gcc.dg/dfp/convert-bfp-13.c, gcc.dg/dfp/convert-bfp-14.c,
gcc.dg/dfp/convert-dfp-fold-2.c, gcc.target/i386/pr36578-1.c,
gcc.target/i386/pr36578-2.c: New tests.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@141432 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/real.c')
-rw-r--r-- | gcc/real.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/real.c b/gcc/real.c index dc6d7483e99..c5a16a867e1 100644 --- a/gcc/real.c +++ b/gcc/real.c @@ -1266,6 +1266,35 @@ exact_real_inverse (enum machine_mode mode, REAL_VALUE_TYPE *r) *r = u; return true; } + +/* Return true if arithmetic on values in IMODE that were promoted + from values in TMODE is equivalent to direct arithmetic on values + in TMODE. */ + +bool +real_can_shorten_arithmetic (enum machine_mode imode, enum machine_mode tmode) +{ + const struct real_format *tfmt, *ifmt; + tfmt = REAL_MODE_FORMAT (tmode); + ifmt = REAL_MODE_FORMAT (imode); + /* These conditions are conservative rather than trying to catch the + exact boundary conditions; the main case to allow is IEEE float + and double. */ + return (ifmt->b == tfmt->b + && ifmt->p > 2 * tfmt->p + && ifmt->emin < 2 * tfmt->emin - tfmt->p - 2 + && ifmt->emin < tfmt->emin - tfmt->emax - tfmt->p - 2 + && ifmt->emax > 2 * tfmt->emax + 2 + && ifmt->emax > tfmt->emax - tfmt->emin + tfmt->p + 2 + && ifmt->round_towards_zero == tfmt->round_towards_zero + && (ifmt->has_sign_dependent_rounding + == tfmt->has_sign_dependent_rounding) + && ifmt->has_nans >= tfmt->has_nans + && ifmt->has_inf >= tfmt->has_inf + && ifmt->has_signed_zero >= tfmt->has_signed_zero + && !MODE_COMPOSITE_P (tmode) + && !MODE_COMPOSITE_P (imode)); +} /* Render R as an integer. */ |