This patch generalises the SVE BIC pattern so that it doesn't rely on REG_EQUAL notes. The danger with relying on the notes is that an optimisation could for example replace the original (not ...) note with an (unspec ... UNSPEC_MERGE_PTRUE) in which the predicate is a constant. That's a legitimate change and could even be useful in some situations.
The patch also makes the operand order match the SVE operand order in both the vector and predicate BIC patterns, which makes things easier for the ACLE. Tested on aarch64-linux-gnu (with and without SVE) and aarch64_be-elf. Applied as r274416. Richard 2019-08-14 Richard Sandiford <richard.sandif...@arm.com> Kugan Vivekanandarajah <kugan.vivekanandara...@linaro.org> gcc/ * config/aarch64/aarch64-sve.md (bic<mode>3): Rename to... (*bic<SVE_I:mode>3): ...this. Match the form that an SVE inverse actually has, rather than relying on REG_EQUAL notes. Make the insn operand order match the SVE operand order. (*<nlogical><PRED_ALL:mode>3): Make the insn operand order match the SVE operand order. Index: gcc/config/aarch64/aarch64-sve.md =================================================================== --- gcc/config/aarch64/aarch64-sve.md 2019-08-14 09:03:20.515438326 +0100 +++ gcc/config/aarch64/aarch64-sve.md 2019-08-14 09:05:41.902390293 +0100 @@ -1779,15 +1779,20 @@ (define_insn "<optab><mode>3" ;; - BIC ;; ------------------------------------------------------------------------- -;; REG_EQUAL notes on "not<mode>3" should ensure that we can generate -;; this pattern even though the NOT instruction itself is predicated. -(define_insn "bic<mode>3" +(define_insn_and_rewrite "*bic<mode>3" [(set (match_operand:SVE_I 0 "register_operand" "=w") (and:SVE_I - (not:SVE_I (match_operand:SVE_I 1 "register_operand" "w")) - (match_operand:SVE_I 2 "register_operand" "w")))] + (unspec:SVE_I + [(match_operand 3) + (not:SVE_I (match_operand:SVE_I 2 "register_operand" "w"))] + UNSPEC_MERGE_PTRUE) + (match_operand:SVE_I 1 "register_operand" "w")))] "TARGET_SVE" - "bic\t%0.d, %2.d, %1.d" + "bic\t%0.d, %1.d, %2.d" + "&& !CONSTANT_P (operands[3])" + { + operands[3] = CONSTM1_RTX (<VPRED>mode); + } ) ;; ------------------------------------------------------------------------- @@ -2451,11 +2456,11 @@ (define_insn "*<nlogical><mode>3" [(set (match_operand:PRED_ALL 0 "register_operand" "=Upa") (and:PRED_ALL (NLOGICAL:PRED_ALL - (not:PRED_ALL (match_operand:PRED_ALL 2 "register_operand" "Upa")) - (match_operand:PRED_ALL 3 "register_operand" "Upa")) + (not:PRED_ALL (match_operand:PRED_ALL 3 "register_operand" "Upa")) + (match_operand:PRED_ALL 2 "register_operand" "Upa")) (match_operand:PRED_ALL 1 "register_operand" "Upa")))] "TARGET_SVE" - "<nlogical>\t%0.b, %1/z, %3.b, %2.b" + "<nlogical>\t%0.b, %1/z, %2.b, %3.b" ) ;; -------------------------------------------------------------------------