Hi! While fixing a -O3 -g vectorizer ICE that only reproduced on GCC-4.4-RH branch, I've noticed couple of similar issues on the trunk. The first hunk is just a cleanup, there is no point to set use_stmt again to the same thing as it has been set before.
The second and third hunks are to ignore debug stmts, other places in tree-vect-loop.c that similarly look for the exit phi look similarly. The last hunk fixes GOMP_SIMD_LANE handling, and the testcase is from the FAIL in redhat/gcc-4_4-branch. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2014-02-13 Jakub Jelinek <ja...@redhat.com> * tree-vect-loop.c (vect_is_slp_reduction): Don't set use_stmt twice. (get_initial_def_for_induction, vectorizable_induction): Ignore debug stmts when looking for exit_phi. (vectorizable_live_operation): Fix up condition. * gcc.c-torture/compile/20140213.c: New test. --- gcc/tree-vect-loop.c.jj 2014-02-05 15:28:10.000000000 +0100 +++ gcc/tree-vect-loop.c 2014-02-13 15:36:38.117741038 +0100 @@ -1968,10 +1968,8 @@ vect_is_slp_reduction (loop_vec_info loo FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) { gimple use_stmt = USE_STMT (use_p); - if (is_gimple_debug (use_stmt)) - continue; - - use_stmt = USE_STMT (use_p); + if (is_gimple_debug (use_stmt)) + continue; /* Check if we got back to the reduction phi. */ if (use_stmt == phi) @@ -3507,9 +3505,13 @@ get_initial_def_for_induction (gimple iv exit_phi = NULL; FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg) { - if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (USE_STMT (use_p)))) + gimple use_stmt = USE_STMT (use_p); + if (is_gimple_debug (use_stmt)) + continue; + + if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (use_stmt))) { - exit_phi = USE_STMT (use_p); + exit_phi = use_stmt; break; } } @@ -5413,10 +5415,13 @@ vectorizable_induction (gimple phi, gimp loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e); FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg) { - if (!flow_bb_inside_loop_p (loop->inner, - gimple_bb (USE_STMT (use_p)))) + gimple use_stmt = USE_STMT (use_p); + if (is_gimple_debug (use_stmt)) + continue; + + if (!flow_bb_inside_loop_p (loop->inner, gimple_bb (use_stmt))) { - exit_phi = USE_STMT (use_p); + exit_phi = use_stmt; break; } } @@ -5514,7 +5519,7 @@ vectorizable_live_operation (gimple stmt { gimple use_stmt = USE_STMT (use_p); if (gimple_code (use_stmt) == GIMPLE_PHI - || gimple_bb (use_stmt) == merge_bb) + && gimple_bb (use_stmt) == merge_bb) { if (vec_stmt) { --- gcc/testsuite/gcc.c-torture/compile/20140213.c.jj 2013-08-25 18:20:55.717911035 +0200 +++ gcc/testsuite/gcc.c-torture/compile/20140213.c 2014-02-13 16:23:45.631401820 +0100 @@ -0,0 +1,21 @@ +static unsigned short +foo (unsigned char *x, int y) +{ + unsigned short r = 0; + int i; + for (i = 0; i < y; i++) + r += x[i]; + return r; +} + +int baz (int, unsigned short); + +void +bar (unsigned char *x, unsigned char *y) +{ + int i; + unsigned short key = foo (x, 0x10000); + baz (0, 0); + for (i = 0; i < 0x80000; i++) + y[i] = x[baz (i, key)]; +} Jakub