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| author | Richard Sandiford <richard.sandiford@linaro.org> | 2017-10-02 09:45:40 +0000 |
|---|---|---|
| committer | Richard Sandiford <rsandifo@gcc.gnu.org> | 2017-10-02 09:45:40 +0000 |
| commit | a1488398d4abf50ff8b2ec25d6a75185aefc52c8 (patch) | |
| tree | e5cca47aca114b176833f91da6a74b6829051ce5 /gcc/c-family | |
| parent | 1a6da556c414bbbec6df82fdb342e8b84e205507 (diff) | |
| download | gcc-a1488398d4abf50ff8b2ec25d6a75185aefc52c8.zip gcc-a1488398d4abf50ff8b2ec25d6a75185aefc52c8.tar.gz gcc-a1488398d4abf50ff8b2ec25d6a75185aefc52c8.tar.bz2 | |
Fix mismatched precisions in tree arithmetic
The tree wi:: decompose routine wasn't asserting that the requested
precision matched the tree's precision. This could make a difference
for unsigned trees that are exactly N HWIs wide and that have the upper
bit set, since we then need an extra zero HWI when extending it to wider
precisions (as for wi::to_widest).
This patch adds the assert and fixes the fallout shown by the testsuite.
Go seems to be unaffected.
2017-10-02 Richard Sandiford <richard.sandiford@linaro.org>
gcc/
* tree.h (wi::int_traits <const_tree>::decompose): Assert that the
requested precision matches the type's.
* calls.c (alloc_max_size): Calculate the new candidate size as
a widest_int and use wi::to_widest when comparing it with the
current candidate size.
* gimple-ssa-warn-alloca.c (pass_walloca::execute): Compare with
zero rather than integer_zero_node.
* match.pd: Check for a no-op conversion before using wi::add
rather than after. Use tree_to_uhwi when summing small shift
counts into an unsigned int.
gcc/c-family/
* c-warn.c (warn_tautological_bitwise_comparison): Use wi::to_widest
when combining the original unconverted comparison operands.
gcc/cp/
* constexpr.c (cxx_eval_store_expression): Use wi::to_widest
when comparing the array bounds with an ARRAY_REF index.
gcc/ada/
* gcc-interface/decl.c (annotate_value): Use wi::to_widest when
handling the form (plus/mult (convert @0) @1).
From-SVN: r253341
Diffstat (limited to 'gcc/c-family')
| -rw-r--r-- | gcc/c-family/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/c-family/c-warn.c | 10 |
2 files changed, 11 insertions, 4 deletions
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog index 3c4bd05..58797f0 100644 --- a/gcc/c-family/ChangeLog +++ b/gcc/c-family/ChangeLog @@ -1,3 +1,8 @@ +2017-10-02 Richard Sandiford <richard.sandiford@linaro.org> + + * c-warn.c (warn_tautological_bitwise_comparison): Use wi::to_widest + when combining the original unconverted comparison operands. + 2017-09-29 Jakub Jelinek <jakub@redhat.com> * c-attribs.c (handle_noipa_attribute): Don't add "stack_protect" diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c index 0749d16..f86de10 100644 --- a/gcc/c-family/c-warn.c +++ b/gcc/c-family/c-warn.c @@ -355,15 +355,17 @@ warn_tautological_bitwise_comparison (location_t loc, tree_code code, else return; - wide_int res; + /* Note that the two operands are from before the usual integer + conversions, so their types might not be the same. */ + widest_int res; if (TREE_CODE (bitop) == BIT_AND_EXPR) - res = wi::bit_and (bitopcst, cst); + res = wi::to_widest (bitopcst) & wi::to_widest (cst); else - res = wi::bit_or (bitopcst, cst); + res = wi::to_widest (bitopcst) | wi::to_widest (cst); /* For BIT_AND only warn if (CST2 & CST1) != CST1, and for BIT_OR only if (CST2 | CST1) != CST1. */ - if (res == cst) + if (res == wi::to_widest (cst)) return; if (code == EQ_EXPR) |