On 01/14/2016 05:33 PM, Andreas Krebbel wrote:
When processing substitutions the operands are renumbered. To find a
free operand number the array used_operands_numbers is used to record
the operand numbers already in use. Currently this array is used to
assign new numbers *before* all the RTXes in the vector have been
processed.
* gensupport.c (process_substs_on_one_elem): Split loop to
complete mark_operands_used_in_match_dup on all expressions in the
vector first.
(adjust_operands_numbers): Inline into process_substs_on_one_elem
and remove function.
Mostly ok, I think. As an aside, all the define_subst stuff in
gensupport looks rather suspiciously clunky and the comments are in
broken English. We should fix this stuff at some point.
@@ -1976,6 +1986,14 @@ find_first_unused_number_of_operand ()
It visits all expressions in PATTERN and assigns not-occupied
operand indexes to MATCH_OPERANDs and MATCH_OPERATORs of this
PATTERN. */
+/* If output pattern of define_subst contains MATCH_DUP, then this
+ expression would be replaced with the pattern, matched with
+ MATCH_OPERAND from input pattern. This pattern could contain any
+ number of MATCH_OPERANDs, MATCH_OPERATORs etc., so it's possible
+ that a MATCH_OPERAND from output_pattern (if any) would have the
+ same number, as MATCH_OPERAND from copied pattern. To avoid such
+ indexes overlapping, we assign new indexes to MATCH_OPERANDs,
+ laying in the output pattern outside of MATCH_DUPs. */
static void
renumerate_operands_in_pattern (rtx pattern)
{
If you want to keep this comment, you might want to move it inside the
function (or into the caller). Ok with or without any such change - this
looks a bit weird but I don't know what's best.
Bernd
