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| author | Richard Biener <rguenther@suse.de> | 2021-10-28 11:38:32 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-10-28 15:45:22 +0200 |
| commit | 81342e95827f77c0917dd7a9fd54ac9729439c8e (patch) | |
| tree | 2e1dd82b395637f69ac307d1e0414a778aaef6d0 /gcc/fold-const.c | |
| parent | 113dab2b9d511f3aadc30a6a921fc30bd5f93706 (diff) | |
| download | gcc-81342e95827f77c0917dd7a9fd54ac9729439c8e.zip gcc-81342e95827f77c0917dd7a9fd54ac9729439c8e.tar.gz gcc-81342e95827f77c0917dd7a9fd54ac9729439c8e.tar.bz2 | |
middle-end/84407 - honor -frounding-math for int to float conversion
This makes us honor -frounding-math for integer to float conversions
and avoid constant folding when such conversion is not exact.
2021-10-28 Richard Biener <rguenther@suse.de>
PR middle-end/84407
* fold-const.c (fold_convert_const): Avoid int to float
constant folding with -frounding-math and inexact result.
* simplify-rtx.c (simplify_const_unary_operation): Likewise
for both float and unsigned_float.
* gcc.dg/torture/fp-uint64-convert-double-1.c: New testcase.
* gcc.dg/torture/fp-uint64-convert-double-2.c: Likewise.
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 18950ae..c7daf871 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2290,7 +2290,20 @@ fold_convert_const (enum tree_code code, tree type, tree arg1) else if (TREE_CODE (type) == REAL_TYPE) { if (TREE_CODE (arg1) == INTEGER_CST) - return build_real_from_int_cst (type, arg1); + { + tree res = build_real_from_int_cst (type, arg1); + /* Avoid the folding if flag_rounding_math is on and the + conversion is not exact. */ + if (HONOR_SIGN_DEPENDENT_ROUNDING (type)) + { + bool fail = false; + wide_int w = real_to_integer (&TREE_REAL_CST (res), &fail, + TYPE_PRECISION (TREE_TYPE (arg1))); + if (fail || wi::ne_p (w, wi::to_wide (arg1))) + return NULL_TREE; + } + return res; + } else if (TREE_CODE (arg1) == REAL_CST) return fold_convert_const_real_from_real (type, arg1); else if (TREE_CODE (arg1) == FIXED_CST) |