[AArch64] Rework SVE integer comparisons
The remaining uses of UNSPEC_MERGE_PTRUE were in integer comparison
patterns. These aren't actually merging operations but zeroing ones,
although there's no practical difference when the predicate is a PTRUE.
All comparisons produced by expand are predicated on a PTRUE,
although we try to pattern-match a compare-and-AND as a predicated
comparison during combine.
Like previous patches, this one rearranges things in a way that works
better with the ACLE, where the initial predicate might or might not
be a PTRUE. The new patterns use UNSPEC_PRED_Z to represent zeroing
predication, with a aarch64_sve_ptrue_flag to record whether the
predicate is all-true (as for UNSPEC_PTEST).
See the block comment in the patch for more details.
2019-08-14 Richard Sandiford <richard.sandiford@arm.com>
gcc/
* config/aarch64/aarch64-protos.h (aarch64_sve_same_pred_for_ptest_p):
Declare.
* config/aarch64/aarch64.c (aarch64_sve_same_pred_for_ptest_p)
(aarch64_sve_emit_int_cmp): New functions.
(aarch64_convert_sve_data_to_pred): Use aarch64_sve_emit_int_cmp.
(aarch64_sve_cmp_operand_p, aarch64_emit_sve_ptrue_op_cc): Delete.
(aarch64_expand_sve_vec_cmp_int): Use aarch64_sve_emit_int_cmp.
* config/aarch64/aarch64.md (UNSPEC_MERGE_PTRUE): Delete.
(UNSPEC_PRED_Z): New unspec.
(set_clobber_cc_nzc): Delete.
* config/aarch64/aarch64-sve.md: Add a block comment about
UNSPEC_PRED_Z.
(*cmp<SVE_INT_CMP:cmp_op><mode>): Rename to...
(@aarch64_pred_cmp<SVE_INT_CMP:cmp_op><mode>): ...this, replacing
the old pattern with that name. Use UNSPEC_PRED_Z instead of
UNSPEC_MERGE_PTRUE.
(*cmp<SVE_INT_CMP:cmp_op><mode>_cc): Use UNSPEC_PRED_Z instead of
UNSPEC_MERGE_PTRUE. Use aarch64_sve_same_pred_for_ptest_p to
check for compatible predicates.
(*cmp<cmp_op><SVE_INT_CMP:mode>_ptest): Likewise.
(*cmp<cmp_op><mode>_and): Match a known-ptrue UNSPEC_PRED_Z instead
of UNSPEC_MERGE_PTRUE. Split into the new form of predicated
comparisons above.
From-SVN: r274429
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