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| author | Andrew Pinski <apinski@marvell.com> | 2023-06-30 19:22:48 -0700 |
|---|---|---|
| committer | Andrew Pinski <apinski@marvell.com> | 2023-07-04 10:19:50 -0700 |
| commit | 71b68cc559b5d30d07e6b507df7cc6d008f56aad (patch) | |
| tree | 2b2a8246c6cf28eb2888c174c5e221a2d092eaa3 | |
| parent | 2e5c1b123d5bc4b7eca91f1eb2dab88d0bcdfcfa (diff) | |
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PR 110487: `(a !=/== CST1 ? CST2 : CST3)` pattern for type safety
The problem here is we might produce some values out of the type's
min/max (and/or valid values, e.g. signed booleans). The fix is to
use an integer type which has the same precision and signedness
as the original type.
Note two_value_replacement in phiopt had the same issue in previous
versions; though I don't know if a problem will show up there.
OK? Bootstrapped and tested on x86_64-linux-gnu.
gcc/ChangeLog:
PR tree-optimization/110487
* match.pd (a !=/== CST1 ? CST2 : CST3): Always
build a nonstandard integer and use that.
| -rw-r--r-- | gcc/match.pd | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 637d22c..8543f77 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -4799,24 +4799,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) tree type1; if ((eqne == EQ_EXPR) ^ (wi::to_wide (@1) == min)) std::swap (arg0, arg1); - if (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type)) - { - /* Avoid performing the arithmetics in bool type which has different - semantics, otherwise prefer unsigned types from the two with - the same precision. */ - if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE - || !TYPE_UNSIGNED (type)) - type1 = TREE_TYPE (@0); - else - type1 = TREE_TYPE (arg0); - } - else if (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type)) + if (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type)) type1 = TREE_TYPE (@0); else type1 = type; - min = wide_int::from (min, TYPE_PRECISION (type1), + auto prec = TYPE_PRECISION (type1); + auto unsign = TYPE_UNSIGNED (type1); + type1 = build_nonstandard_integer_type (prec, unsign); + min = wide_int::from (min, prec, TYPE_SIGN (TREE_TYPE (@0))); - wide_int a = wide_int::from (wi::to_wide (arg0), TYPE_PRECISION (type1), + wide_int a = wide_int::from (wi::to_wide (arg0), prec, TYPE_SIGN (type)); enum tree_code code; wi::overflow_type ovf; @@ -4824,7 +4816,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) { code = PLUS_EXPR; a -= min; - if (!TYPE_UNSIGNED (type1)) + if (!unsign) { /* lhs is known to be in range [min, min+1] and we want to add a to it. Check if that operation can overflow for those 2 values @@ -4838,7 +4830,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) { code = MINUS_EXPR; a += min; - if (!TYPE_UNSIGNED (type1)) + if (!unsign) { /* lhs is known to be in range [min, min+1] and we want to subtract it from a. Check if that operation can overflow for those 2 |