I'm just shuffling the FP self tests here, with no change to existing functionality.
If we agree that explicit NANs in the source code with !HONOR_NANS should behave any differently, I'm happy to address whatever needs fixing, but for now I'd like to unblock the !HONOR_NANS build systems. I have added an adaptation of a test Jakub suggested we handle in the PR: void funk(int cond) { float x; if (cond) x = __builtin_nan (""); else x = 1.24; bar(x); } For !HONOR_NANS, the range for the PHI of x_1 is the union of 1.24 and NAN which is really 1.24 with a maybe NAN. This reflects the IL-- the presence of the actual NAN. However, VRP will propagate this because it sees the 1.24 and ignores the possibility of a NAN, per !HONOR_NANS. IMO, this is correct. OTOH, for HONOR_NANS the unknown NAN property keeps us from propagating the value. Is there a reason we don't warn for calls to __builtin_nan when !HONOR_NANS? That makes no sense to me. PR tree-optimization/106785 gcc/ChangeLog: * value-range.cc (range_tests_nan): Adjust tests for !HONOR_NANS. (range_tests_floats): Same. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/vrp-float-nan-1.c: New test. --- .../gcc.dg/tree-ssa/vrp-float-nan-1.c | 18 +++++++++++++++ gcc/value-range.cc | 23 +++++++++++-------- 2 files changed, 32 insertions(+), 9 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp-float-nan-1.c diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-nan-1.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-nan-1.c new file mode 100644 index 00000000000..126949b2b4c --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp-float-nan-1.c @@ -0,0 +1,18 @@ +// { dg-do compile } +// { dg-options "-O2 -ffinite-math-only -fdump-tree-evrp" } + +void bar(float); + +void funk(int cond) +{ + float x; + + if (cond) + x = __builtin_nan (""); + else + x = 1.24; + + bar(x); +} + +// { dg-final { scan-tree-dump-times "bar \\(1.24" 1 "evrp" } } diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 473139c6dbd..3c7d4cb84b9 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -3535,13 +3535,16 @@ range_tests_nan () REAL_VALUE_TYPE q, r; // Equal ranges but with differing NAN bits are not equal. - r1 = frange_float ("10", "12"); - r0 = r1; - ASSERT_EQ (r0, r1); - r0.set_nan (fp_prop::NO); - ASSERT_NE (r0, r1); - r0.set_nan (fp_prop::YES); - ASSERT_NE (r0, r1); + if (HONOR_NANS (float_type_node)) + { + r1 = frange_float ("10", "12"); + r0 = r1; + ASSERT_EQ (r0, r1); + r0.set_nan (fp_prop::NO); + ASSERT_NE (r0, r1); + r0.set_nan (fp_prop::YES); + ASSERT_NE (r0, r1); + } // NAN ranges are not equal to each other. r0 = frange_nan (float_type_node); @@ -3624,9 +3627,11 @@ range_tests_floats () if (HONOR_SIGNED_ZEROS (float_type_node)) range_tests_signed_zeros (); - // A range of [-INF,+INF] is actually VARYING... + // A range of [-INF,+INF] is actually VARYING if no other properties + // are set. r0 = frange_float ("-Inf", "+Inf"); - ASSERT_TRUE (r0.varying_p ()); + if (r0.get_nan ().varying_p ()) + ASSERT_TRUE (r0.varying_p ()); // ...unless it has some special property... r0.set_nan (fp_prop::NO); ASSERT_FALSE (r0.varying_p ()); -- 2.37.1