loop-unroll.c (unroll_loop_runtime_iterations): Condition initial loop peel to loops with exit test at the beginning.
* loop-unroll.c (unroll_loop_runtime_iterations): Condition initial loop peel to loops with exit test at the beginning. From-SVN: r241173
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@ -1,3 +1,8 @@
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2016-10-14 Pat Haugen <pthaugen@us.ibm.com>
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* loop-unroll.c (unroll_loop_runtime_iterations): Condition initial
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loop peel to loops with exit test at the beginning.
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2016-10-14 Pat Haugen <pthaugen@us.ibm.com>
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PR rtl-optimization/68212
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@ -858,7 +858,7 @@ unroll_loop_runtime_iterations (struct loop *loop)
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rtx old_niter, niter, tmp;
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rtx_insn *init_code, *branch_code;
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unsigned i, j, p;
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basic_block preheader, *body, swtch, ezc_swtch;
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basic_block preheader, *body, swtch, ezc_swtch = NULL;
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int may_exit_copy, iter_freq, new_freq;
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gcov_type iter_count, new_count;
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unsigned n_peel;
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@ -918,6 +918,16 @@ unroll_loop_runtime_iterations (struct loop *loop)
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if (tmp != niter)
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emit_move_insn (niter, tmp);
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/* For loops that exit at end, add one to niter to account for first pass
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through loop body before reaching exit test. */
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if (exit_at_end)
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{
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niter = expand_simple_binop (desc->mode, PLUS,
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niter, const1_rtx,
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NULL_RTX, 0, OPTAB_LIB_WIDEN);
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old_niter = niter;
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}
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/* Count modulo by ANDing it with max_unroll; we use the fact that
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the number of unrollings is a power of two, and thus this is correct
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even if there is overflow in the computation. */
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@ -936,20 +946,21 @@ unroll_loop_runtime_iterations (struct loop *loop)
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auto_sbitmap wont_exit (max_unroll + 2);
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/* Peel the first copy of loop body (almost always we must leave exit test
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here; the only exception is when we have extra zero check and the number
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of iterations is reliable. Also record the place of (possible) extra
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zero check. */
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bitmap_clear (wont_exit);
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if (extra_zero_check
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&& !desc->noloop_assumptions)
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bitmap_set_bit (wont_exit, 1);
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ezc_swtch = loop_preheader_edge (loop)->src;
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ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
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1, wont_exit, desc->out_edge,
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&remove_edges,
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DLTHE_FLAG_UPDATE_FREQ);
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gcc_assert (ok);
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if (extra_zero_check)
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{
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/* Peel the first copy of loop body. Leave the exit test if the number
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of iterations is not reliable. Also record the place of the extra zero
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check. */
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bitmap_clear (wont_exit);
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if (!desc->noloop_assumptions)
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bitmap_set_bit (wont_exit, 1);
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ezc_swtch = loop_preheader_edge (loop)->src;
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ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
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1, wont_exit, desc->out_edge,
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&remove_edges,
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DLTHE_FLAG_UPDATE_FREQ);
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gcc_assert (ok);
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}
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/* Record the place where switch will be built for preconditioning. */
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swtch = split_edge (loop_preheader_edge (loop));
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