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author | Tamar Christina <tamar.christina@arm.com> | 2024-01-09 11:16:16 +0000 |
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committer | Tamar Christina <tamar.christina@arm.com> | 2024-01-09 11:16:16 +0000 |
commit | cbf569486b2decbde0308f9f4d0f0837e4cfefd9 (patch) | |
tree | 5839d555eb053f0538adcb626c66a73f8ba358db | |
parent | 468cec536322f98f2d473adbd6a8e88c625cfcdb (diff) | |
download | gcc-cbf569486b2decbde0308f9f4d0f0837e4cfefd9.zip gcc-cbf569486b2decbde0308f9f4d0f0837e4cfefd9.tar.gz gcc-cbf569486b2decbde0308f9f4d0f0837e4cfefd9.tar.bz2 |
middle-end: rejects loops with nonlinear inductions and early breaks [PR113163]
We can't support nonlinear inductions other than neg when vectorizing
early breaks and iteration count is known.
For early break we currently require a peeled epilog but in these cases
we can't compute the remaining values.
gcc/ChangeLog:
PR middle-end/113163
* tree-vect-loop-manip.cc (vect_can_peel_nonlinear_iv_p):
Reject non-linear inductions that aren't supported.
gcc/testsuite/ChangeLog:
PR middle-end/113163
* gcc.target/gcn/pr113163.c: New test.
-rw-r--r-- | gcc/testsuite/gcc.target/gcn/pr113163.c | 30 | ||||
-rw-r--r-- | gcc/tree-vect-loop-manip.cc | 19 |
2 files changed, 49 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.target/gcn/pr113163.c b/gcc/testsuite/gcc.target/gcn/pr113163.c new file mode 100644 index 0000000..99b0fdb --- /dev/null +++ b/gcc/testsuite/gcc.target/gcn/pr113163.c @@ -0,0 +1,30 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-O2 -ftree-vectorize" } */ + +struct _reent { union { struct { char _l64a_buf[8]; } _reent; } _new; }; +static const char R64_ARRAY[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; +char * +_l64a_r (struct _reent *rptr, + long value) +{ + char *ptr; + char *result; + int i, index; + unsigned long tmp = (unsigned long)value & 0xffffffff; + result = + (( + rptr + )->_new._reent._l64a_buf) + ; + ptr = result; + for (i = 0; i < 6; ++i) + { + if (tmp == 0) + { + *ptr = '\0'; + break; + } + *ptr++ = R64_ARRAY[index]; + tmp >>= 6; + } +} diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc index 927f76a..2313d26 100644 --- a/gcc/tree-vect-loop-manip.cc +++ b/gcc/tree-vect-loop-manip.cc @@ -2063,6 +2063,25 @@ vect_can_peel_nonlinear_iv_p (loop_vec_info loop_vinfo, return false; } + /* We can't support partial vectors and early breaks with an induction + type other than add or neg since we require the epilog and can't + perform the peeling. The below condition mirrors that of + vect_gen_vector_loop_niters where niters_vector_mult_vf_var then sets + step_vector to VF rather than 1. This is what creates the nonlinear + IV. PR113163. */ + if (LOOP_VINFO_EARLY_BREAKS (loop_vinfo) + && LOOP_VINFO_VECT_FACTOR (loop_vinfo).is_constant () + && LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) + && induction_type != vect_step_op_neg) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "Peeling for epilogue is not supported" + " for nonlinear induction except neg" + " when VF is known and early breaks.\n"); + return false; + } + return true; } |