[adding cc gcc-patches ] On 12/04/16 09:25, Tom de Vries wrote:
Hi,when compiling the test-case in the patch, we run into an ICE in sese_build_liveouts_use when evaluating 'TREE_CODE (use)' because use is NULL_TREE: ... static void sese_build_liveouts_use (sese_info_p region, bitmap liveouts, basic_block bb, tree use) { gcc_assert (!bb_in_sese_p (bb, region->region)); if (TREE_CODE (use) != SSA_NAME) return; ... I've tracked down the origin of the NULL_TREE use to copy_cond_phi_args, to this snippet: ... if (postpone) { /* If the phi-arg is scev-analyzeable but only in the first stage. */ if (is_gimple_reg (old_name) && scev_analyzable_p (old_name, region->region)) { gimple_seq stmts; tree new_expr = get_rename_from_scev (old_name, &stmts, loop, new_bb, old_bb, iv_map); if (codegen_error_p ()) return false; gcc_assert (new_expr); if (dump_file) { fprintf (dump_file, "[codegen] scev analyzeable, new_expr: "); print_generic_expr (dump_file, new_expr, 0); fprintf (dump_file, "\n"); } gsi_insert_earliest (stmts); new_phi_args[i] = new_name; continue; } /* Postpone code gen for later for back-edges. */ region->incomplete_phis.safe_push (std::make_pair (phi, new_phi)); ... My observations are: - new_name is guaranteed to be NULL_TREE at this point. - the 'new_phi_args[i] = new_name' assignment should set to something non-NULL, given that we're not postponing code generation for later - the whole point of the snippet seems to be to set up an expression new_expr, so probably that's the expression we want to assign to new_phi_args[i]. Bootstrapped and reg-tested on x86_64. Ok for stage4 trunk? Thanks, - Tom 0001-Fix-typo-in-copy_cond_phi_args.patch Fix typo in copy_cond_phi_args 2016-04-12 Tom de Vries <t...@codesourcery.com> PR tree-optimization/68756 * graphite-isl-ast-to-gimple.c (copy_cond_phi_args): Use new_expr instead of new_name. * gcc.dg/graphite/pr68756.c: New test. --- gcc/graphite-isl-ast-to-gimple.c | 2 +- gcc/testsuite/gcc.dg/graphite/pr68756.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/gcc/graphite-isl-ast-to-gimple.c b/gcc/graphite-isl-ast-to-gimple.c index 8dd5dc8..88609c0 100644 --- a/gcc/graphite-isl-ast-to-gimple.c +++ b/gcc/graphite-isl-ast-to-gimple.c @@ -2439,7 +2439,7 @@ copy_cond_phi_args (gphi *phi, gphi *new_phi, vec<tree> iv_map, bool postpone) fprintf (dump_file, "\n"); } gsi_insert_earliest (stmts); - new_phi_args [i] = new_name; + new_phi_args[i] = new_expr; continue; } diff --git a/gcc/testsuite/gcc.dg/graphite/pr68756.c b/gcc/testsuite/gcc.dg/graphite/pr68756.c new file mode 100644 index 0000000..ddb9789 --- /dev/null +++ b/gcc/testsuite/gcc.dg/graphite/pr68756.c @@ -0,0 +1,26 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -floop-nest-optimize" } */ + +unsigned int z4, pz; +int nn[2]; + +static unsigned int +xq (unsigned int dj) +{ + return dj > 1 ? z4 : z4 + dj; +} + +void +la (void) +{ + int hd, dl; + unsigned int hn = 0; + + for (hd = 0; hd < 2; ++hd) + { + for (dl = 0; dl < 2; ++dl) + nn[dl] = 0; + --hn; + pz = xq (hn); + } +}
