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| author | Jim Wilson <wilson@gcc.gnu.org> | 1996-10-21 15:43:33 -0700 |
|---|---|---|
| committer | Jim Wilson <wilson@gcc.gnu.org> | 1996-10-21 15:43:33 -0700 |
| commit | 1dcfa896bdee3c95c22401a88ded22171d5caa81 (patch) | |
| tree | 657889c46e171e69c89c1a6b7ca896c6549bbdce /gcc/unroll.c | |
| parent | d00d338cdc2917a5d7da4ab6b129e0ec99615db4 (diff) | |
| download | gcc-1dcfa896bdee3c95c22401a88ded22171d5caa81.zip gcc-1dcfa896bdee3c95c22401a88ded22171d5caa81.tar.gz gcc-1dcfa896bdee3c95c22401a88ded22171d5caa81.tar.bz2 | |
(loop_comparison_code): New static variable.
(unroll_loop): Add check for loop_comparison_code
(loop_iterations): Set loop_comparison_code.
From-SVN: r12991
Diffstat (limited to 'gcc/unroll.c')
| -rw-r--r-- | gcc/unroll.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/gcc/unroll.c b/gcc/unroll.c index a282be3..b720074 100644 --- a/gcc/unroll.c +++ b/gcc/unroll.c @@ -191,6 +191,7 @@ static rtx loop_iteration_var; static rtx loop_initial_value; static rtx loop_increment; static rtx loop_final_value; +static enum rtx_code loop_comparison_code; /* Forward declarations. */ @@ -878,18 +879,23 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before, for (i = 0; i < unroll_number; i++) labels[i] = gen_label_rtx (); - /* Check for the case where the initial value is greater than or equal - to the final value. In that case, we want to execute exactly - one loop iteration. The code below will fail for this case. */ + /* Check for the case where the initial value is greater than or + equal to the final value. In that case, we want to execute + exactly one loop iteration. The code below will fail for this + case. This check does not apply if the loop has a NE + comparison at the end. */ - emit_cmp_insn (initial_value, final_value, neg_inc ? LE : GE, - NULL_RTX, mode, 0, 0); - if (neg_inc) - emit_jump_insn (gen_ble (labels[1])); - else - emit_jump_insn (gen_bge (labels[1])); - JUMP_LABEL (get_last_insn ()) = labels[1]; - LABEL_NUSES (labels[1])++; + if (loop_comparison_code != NE) + { + emit_cmp_insn (initial_value, final_value, neg_inc ? LE : GE, + NULL_RTX, mode, 0, 0); + if (neg_inc) + emit_jump_insn (gen_ble (labels[1])); + else + emit_jump_insn (gen_bge (labels[1])); + JUMP_LABEL (get_last_insn ()) = labels[1]; + LABEL_NUSES (labels[1])++; + } /* Assuming the unroll_number is 4, and the increment is 2, then for a negative increment: for a positive increment: @@ -3355,6 +3361,7 @@ loop_iterations (loop_start, loop_end) loop_initial_value = initial_value; loop_increment = increment; loop_final_value = final_value; + loop_comparison_code = comparison_code; if (increment == 0) { |