https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80906
Bug ID: 80906 Summary: [7/8 Regression] ICE in copy_loop_close_phi_args, at graphite-isl-ast-to-gimple.c:2094 Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: asolokha at gmx dot com Target Milestone: --- gcc-8.0.0-alpha20170521 snapshot, as well as gcc 7.1, ICEs when compiling the following snippet w/ -O2 (-O3, -Ofast) -floop-nest-optimize: int qc; int ec (int lh[][2]) { const int jv = 3; int zf, hp, c5 = 0, m3 = 1; for (zf = 0; zf < jv; ++zf) for (hp = 0; hp < jv; ++hp) { short int bm = 0; for (qc = 0; qc < jv; ++qc) --bm; if (bm != 0) --c5; lh[0][0] = 0; m3 *= jv; } return c5 + m3; } % x86_64-unknown-linux-gnu-gcc-8.0.0-alpha20170521 -O2 -floop-nest-optimize -c bnjajc7i.c bnjajc7i.c: In function 'ec': bnjajc7i.c:4:1: internal compiler error: in copy_loop_close_phi_args, at graphite-isl-ast-to-gimple.c:2094 ec (int lh[][2]) ^~ Earlier I posted another testcase which I believe reproduces the same issue in PR70390 comment 10. So, the current PR may well be a duplicate of PR70390, though the testcase filed above compiles well by gcc 6.3.