On Fri, 12 Jan 2024, Jakub Jelinek wrote: > Hi! > > For INTEGER_CST operands, the code decides if it should emit the whole > INTEGER_CST into memory, or if there are enough upper bits either all 0s > or all 1s to warrant an optimization, where we use memory for lower limbs > or even just an INTEGER_CST for least significant limb and fill in the > rest of limbs with 0s or 1s. Unfortunately when not using > bitint_min_cst_precision, the code was using tree_int_cst_sgn (op) < 0 > to determine whether to fill in the upper bits with 1s or 0s. That is > incorrect for TYPE_UNSIGNED INTEGER_CSTs which have higher limbs full of > ones, we really want to check here whether the most significant bit is > set or clear. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for > trunk?
OK. > 2024-01-12 Jakub Jelinek <ja...@redhat.com> > > PR tree-optimization/113334 > * gimple-lower-bitint.cc (bitint_large_huge::handle_operand): Use > wi::neg_p (wi::to_wide (op)) instead of tree_int_cst_sgn (op) < 0 > to determine if number should be extended by all ones rather than zero > extended. > > * gcc.dg/torture/bitint-46.c: New test. > > --- gcc/gimple-lower-bitint.cc.jj 2024-01-11 14:27:26.000000000 +0100 > +++ gcc/gimple-lower-bitint.cc 2024-01-11 17:35:07.484557476 +0100 > @@ -997,7 +997,7 @@ bitint_large_huge::handle_operand (tree > { > unsigned int prec = TYPE_PRECISION (TREE_TYPE (op)); > unsigned rem = prec % (2 * limb_prec); > - int ext = tree_int_cst_sgn (op) < 0 ? -1 : 0; > + int ext = wi::neg_p (wi::to_wide (op)) ? -1 : 0; > tree c = m_data[m_data_cnt]; > unsigned min_prec = TYPE_PRECISION (TREE_TYPE (c)); > g = gimple_build_cond (LT_EXPR, idx, > --- gcc/testsuite/gcc.dg/torture/bitint-46.c.jj 2024-01-11 > 17:44:42.360409112 +0100 > +++ gcc/testsuite/gcc.dg/torture/bitint-46.c 2024-01-11 17:44:31.471564635 > +0100 > @@ -0,0 +1,32 @@ > +/* PR tree-optimization/113334 */ > +/* { dg-do run { target bitint } } */ > +/* { dg-options "-std=c23 -pedantic-errors" } */ > +/* { dg-skip-if "" { ! run_expensive_tests } { "*" } { "-O0" "-O2" } } */ > +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */ > + > +#if __BITINT_MAXWIDTH__ >= 384 > +__attribute__((noipa)) _BitInt(384) > +foo (int s) > +{ > + _BitInt(384) z = (-(unsigned _BitInt(384)) 4) >> s; > + return z; > +} > +#endif > + > +int > +main () > +{ > +#if __BITINT_MAXWIDTH__ >= 384 > + if (foo (59) != > 0x1fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffwb) > + __builtin_abort (); > + if (foo (0) != -4wb) > + __builtin_abort (); > + if (foo (1) != > 0x7ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffewb) > + __builtin_abort (); > + if (foo (11) != > 0x001fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffwb) > + __builtin_abort (); > + if (foo (123) != > 0x1fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffwb) > + __builtin_abort (); > +#endif > + return 0; > +} > > Jakub > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)