range_true_and_false() returns a range of [0,1], which for a 1-bit signed integer gets passed to the irange setter as [0, -1]. These endpoints are out of order and cause an ICE. Through some dumb luck, the legacy code swaps out of order endpoints, because old VRP would sometimes pass endpoints reversed, depending on the setter to fix them. This swapping does not happen for non-legacy, hence the ICE.
The right thing to do (apart from killing legacy and 1-bit signed integers ;-)), is to avoid passing out of order endpoints for 1-bit signed integers. For that matter, a range of [-1, 0] (signed) or [0, 1] (unsigned) is just varying. PR tree-optimization/107312 gcc/ChangeLog: * range.h (range_true_and_false): Special case 1-bit signed types. * value-range.cc (range_tests_misc): New test. gcc/testsuite/ChangeLog: * gcc.target/i386/pr107312.c: New test. --- gcc/range.h | 2 ++ gcc/testsuite/gcc.target/i386/pr107312.c | 11 +++++++++++ gcc/value-range.cc | 2 ++ 3 files changed, 15 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/pr107312.c diff --git a/gcc/range.h b/gcc/range.h index 8138d6f5515..ba3a6b2516f 100644 --- a/gcc/range.h +++ b/gcc/range.h @@ -50,6 +50,8 @@ static inline int_range<1> range_true_and_false (tree type) { unsigned prec = TYPE_PRECISION (type); + if (prec == 1) + return int_range<2> (type); return int_range<2> (type, wi::zero (prec), wi::one (prec)); } diff --git a/gcc/testsuite/gcc.target/i386/pr107312.c b/gcc/testsuite/gcc.target/i386/pr107312.c new file mode 100644 index 00000000000..b4180e3bd7d --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr107312.c @@ -0,0 +1,11 @@ +// { dg-do compile } +// { dg-options "-mavx512vbmi -O1 -ftree-loop-vectorize" } + +void +foo (_Float16 *r, short int *a) +{ + int i; + + for (i = 0; i < 32; ++i) + r[i] = !!a[i]; +} diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 90d5e660684..511cd0ad767 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -3437,6 +3437,8 @@ range_tests_misc () max.union_ (min); ASSERT_TRUE (max.varying_p ()); } + // Test that we can set a range of true+false for a 1-bit signed int. + r0 = range_true_and_false (one_bit_type); // Test inversion of 1-bit signed integers. { -- 2.37.3