https://gcc.gnu.org/g:64401760f220a9c8fc64c03202ac3c312ecbb7fb
commit r13-10367-g64401760f220a9c8fc64c03202ac3c312ecbb7fb Author: Richard Biener <[email protected]> Date: Tue Feb 17 11:05:45 2026 +0100 tree-optimization/124132 - fix type problem in loop splitting The following fixes the computation of the 2nd loop IV bound after loop splitting when only one of the split IV and the loop control variable is a pointer. PR tree-optimization/124132 * tree-ssa-loop-split.cc (compute_new_first_bound): Fix bound difference computation. * gcc.dg/torture/pr124132.c: New testcase. (cherry picked from commit 9a5ee941a2cc525811748f78d42a36d1100c12d7) Diff: --- gcc/testsuite/gcc.dg/torture/pr124132.c | 16 ++++++++++++++++ gcc/tree-ssa-loop-split.cc | 19 ++++++++----------- 2 files changed, 24 insertions(+), 11 deletions(-) diff --git a/gcc/testsuite/gcc.dg/torture/pr124132.c b/gcc/testsuite/gcc.dg/torture/pr124132.c new file mode 100644 index 000000000000..8d14fc0346d2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr124132.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-w" } */ + +char slow_mul1_dst1, code_some_shards___gf_mulc__0, code_some_shards_lim; +long slow_mul1_dst_max; +long long code_some_shards_pos; +void code_some_shards() +{ + char *dst = &slow_mul1_dst1; + for (; dst < &code_some_shards_lim; dst++) + { + if (code_some_shards_pos < slow_mul1_dst_max) + *dst = code_some_shards___gf_mulc__0; + code_some_shards_pos += 1; + } +} diff --git a/gcc/tree-ssa-loop-split.cc b/gcc/tree-ssa-loop-split.cc index fca678113eb8..8c675c089c67 100644 --- a/gcc/tree-ssa-loop-split.cc +++ b/gcc/tree-ssa-loop-split.cc @@ -419,21 +419,15 @@ compute_new_first_bound (gimple_seq *stmts, class tree_niter_desc *niter, tree end = force_gimple_operand (niter->bound, &stmts2, true, NULL_TREE); gimple_seq_add_seq_without_update (stmts, stmts2); - if (POINTER_TYPE_P (TREE_TYPE (enddiff))) - { - tree tem = gimple_convert (stmts, sizetype, enddiff); - tem = gimple_build (stmts, NEGATE_EXPR, sizetype, tem); - enddiff = gimple_build (stmts, POINTER_PLUS_EXPR, - TREE_TYPE (enddiff), - end, tem); - } + if (POINTER_TYPE_P (TREE_TYPE (controlbase))) + enddiff = gimple_build (stmts, POINTER_DIFF_EXPR, + ssizetype, end, enddiff); else enddiff = gimple_build (stmts, MINUS_EXPR, TREE_TYPE (enddiff), end, enddiff); /* Compute guard_init + (end-beg). */ tree newbound; - enddiff = gimple_convert (stmts, TREE_TYPE (guard_init), enddiff); if (POINTER_TYPE_P (TREE_TYPE (guard_init))) { enddiff = gimple_convert (stmts, sizetype, enddiff); @@ -442,8 +436,11 @@ compute_new_first_bound (gimple_seq *stmts, class tree_niter_desc *niter, guard_init, enddiff); } else - newbound = gimple_build (stmts, PLUS_EXPR, TREE_TYPE (guard_init), - guard_init, enddiff); + { + enddiff = gimple_convert (stmts, TREE_TYPE (guard_init), enddiff); + newbound = gimple_build (stmts, PLUS_EXPR, TREE_TYPE (guard_init), + guard_init, enddiff); + } /* Depending on the direction of the IVs the new bound for the first loop is the minimum or maximum of old bound and border.
