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| author | Aldy Hernandez <aldyh@redhat.com> | 2022-09-03 15:41:06 +0200 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@redhat.com> | 2022-09-03 17:37:29 +0200 |
| commit | dae8b9e2bbb6017bf90d68c7b720c500125c8295 (patch) | |
| tree | 7f82ff761e84280258ffc14750b36f84cba718f0 | |
| parent | 08de065293f8b08158e1089fbacce9dbaba95077 (diff) | |
| download | gcc-dae8b9e2bbb6017bf90d68c7b720c500125c8295.zip gcc-dae8b9e2bbb6017bf90d68c7b720c500125c8295.tar.gz gcc-dae8b9e2bbb6017bf90d68c7b720c500125c8295.tar.bz2 | |
[PR/middle-end 106819] NANs can never be a singleton
Possible NANs can never be a singleton, so they will never be
propagated. This was the intent, and then the signed zero code crept
in, and was mistakenly checked before the NAN.
PR/middle-end 106819
gcc/ChangeLog:
* value-range.cc (frange::singleton_p): Move NAN check to the top.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr106819.c: New test.
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr106819.c | 24 | ||||
| -rw-r--r-- | gcc/value-range.cc | 9 |
2 files changed, 28 insertions, 5 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr106819.c b/gcc/testsuite/gcc.dg/tree-ssa/pr106819.c new file mode 100644 index 0000000..1272d4b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr106819.c @@ -0,0 +1,24 @@ +// { dg-do compile } +// { dg-options "-O2 -fdump-tree-evrp-details" } + +static int isNaN(double x) +{ + return x != x; +} + +static double opCmpProper(int lhs, double rhs) +{ + return lhs < rhs ? -1.0 + : lhs > rhs ? 1.0 + : lhs == rhs ? 0.0 + : __builtin_nan(""); +} + +int main() +{ + if (!isNaN(opCmpProper(41, __builtin_nan("")))) + __builtin_abort(); + return 0; +} + +// { dg-final {scan-tree-dump-not "Folds to: 0.0" "evrp" } } diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 6fd6e3b..a1c29f7 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -632,6 +632,10 @@ frange::singleton_p (tree *result) const { if (m_kind == VR_RANGE && real_identical (&m_min, &m_max)) { + // Return false for any singleton that may be a NAN. + if (HONOR_NANS (m_type) && !get_nan ().no_p ()) + return false; + // Return the appropriate zero if known. if (HONOR_SIGNED_ZEROS (m_type) && zero_p ()) { @@ -649,11 +653,6 @@ frange::singleton_p (tree *result) const } return false; } - - // Return false for any singleton that may be a NAN. - if (HONOR_NANS (m_type) && !get_nan ().no_p ()) - return false; - if (result) *result = build_real (m_type, m_min); return true; |