On Wed, 20 Jun 2018, Tom de Vries wrote:
> Hi,
>
> Consider the test-case from the patch. When compiled with "-O2
> -ftree-parallelize-loops=2 -fno-tree-dce", it ICEs like this:
> ...
> error: mismatching comparison operand types
> signed int
> unsigned int
> if (ivtmp_32 < 3)
> during GIMPLE pass: parloops
> pr86097.c:4:1: internal compiler error: verify_gimple failed
> ...
>
> The comparison with signed int and unsigned int operands is generated during
> the call to canonicalize_loop_ivs in the parloops pass.
>
> Parloops calls canonicalize_loop_ivs with nit (the number of loop iterations)
> set to (unsigned int)3. Then canonicalize_loop_ivs decides to use a canonical
> iv of type signed int. At the end of canonicalize_loop_ivs, the comparison
> between the unsigned nit and the signed iv is constructed.
>
> This patch fixes the ICE by ensuring that nit is casted to the iv type in this
> case.
>
> Bootstrapped and reg-tested on x86_64.
>
> OK for trunk?
OK.
Thanks,
Richard.
> Thanks,
> - Tom
>
> Generate correctly typed compare in canonicalize_loop_ivs
>
> 2018-06-20 Tom de Vries <tdevr...@suse.de>
>
> PR tree-optimization/86097
> * tree-ssa-loop-manip.c (canonicalize_loop_ivs): Also convert *nit to
> iv type if signedness of iv type is not the same as that of *nit.
>
> * gcc.dg/autopar/pr86097.c: New test.
>
> ---
> gcc/testsuite/gcc.dg/autopar/pr86097.c | 31 +++++++++++++++++++++++++++++++
> gcc/tree-ssa-loop-manip.c | 3 ++-
> 2 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/testsuite/gcc.dg/autopar/pr86097.c
> b/gcc/testsuite/gcc.dg/autopar/pr86097.c
> new file mode 100644
> index 00000000000..b48e87b8bf9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/autopar/pr86097.c
> @@ -0,0 +1,31 @@
> +/* { dg-options "-O2 -ftree-parallelize-loops=2 -fno-tree-dce
> -Wno-aggressive-loop-optimizations" } */
> +int rp, vd;
> +
> +void
> +p5 (int cd)
> +{
> + while (cd != 0)
> + {
> + for (rp = 0; rp < 4; ++rp)
> + for (vd = 0; vd < 1; ++vd)
> + {
> + g0:
> + ;
> + }
> +
> + ++rp;
> + }
> +
> + while (rp < 2)
> + {
> + for (cd = 0; cd < 1; ++cd)
> + for (rp = 1; rp != 0; ++rp)
> + {
> + }
> +
> + ++rp;
> + }
> +
> + if (cd != 0)
> + goto g0;
> +}
> diff --git a/gcc/tree-ssa-loop-manip.c b/gcc/tree-ssa-loop-manip.c
> index bf425afd436..5acee6c98f3 100644
> --- a/gcc/tree-ssa-loop-manip.c
> +++ b/gcc/tree-ssa-loop-manip.c
> @@ -1542,7 +1542,8 @@ canonicalize_loop_ivs (struct loop *loop, tree *nit,
> bool bump_in_latch)
> precision = GET_MODE_PRECISION (mode);
> type = build_nonstandard_integer_type (precision, unsigned_p);
>
> - if (original_precision != precision)
> + if (original_precision != precision
> + || TYPE_UNSIGNED (TREE_TYPE (*nit)) != unsigned_p)
> {
> *nit = fold_convert (type, *nit);
> *nit = force_gimple_operand (*nit, &stmts, true, NULL_TREE);
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
