[AArch64] PR target/68696 FAIL: gcc.target/aarch64/vbslq_u64_1.c scan-assembler-times bif\tv 1

        PR target/68696
        * config/aarch64/aarch64-simd.md (*aarch64_simd_bsl<mode>_alt):
        New pattern.
        (aarch64_simd_bsl<mode>_internal): Update comment to reflect
        the above.

From-SVN: r231696

gcc/ChangeLog

+2015-12-16  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR target/68696
+	* config/aarch64/aarch64-simd.md (*aarch64_simd_bsl<mode>_alt):
+	New pattern.
+	(aarch64_simd_bsl<mode>_internal): Update comment to reflect
+	the above.
+
 2015-12-16  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/68870

gcc/config/aarch64/aarch64-simd.md

@@ -2153,6 +2153,10 @@
 ;;     bit op0, op2, mask
 ;;   if (op0 = op2) (so 0-bits in mask choose bits from op1, else op0)
 ;;     bif op0, op1, mask
+;;
+;; This pattern is expanded to by the aarch64_simd_bsl<mode> expander.
+;; Some forms of straight-line code may generate the equivalent form
+;; in *aarch64_simd_bsl<mode>_alt.
 
 (define_insn "aarch64_simd_bsl<mode>_internal"
   [(set (match_operand:VSDQ_I_DI 0 "register_operand" "=w,w,w")
@@ -2172,6 +2176,29 @@
   [(set_attr "type" "neon_bsl<q>")]
 )
 
+;; We need this form in addition to the above pattern to match the case
+;; when combine tries merging three insns such that the second operand of
+;; the outer XOR matches the second operand of the inner XOR rather than
+;; the first.  The two are equivalent but since recog doesn't try all
+;; permutations of commutative operations, we have to have a separate pattern.
+
+(define_insn "*aarch64_simd_bsl<mode>_alt"
+  [(set (match_operand:VSDQ_I_DI 0 "register_operand" "=w,w,w")
+	(xor:VSDQ_I_DI
+	   (and:VSDQ_I_DI
+	     (xor:VSDQ_I_DI
+	       (match_operand:VSDQ_I_DI 3 "register_operand" "w,w,0")
+	       (match_operand:VSDQ_I_DI 2 "register_operand" "w,0,w"))
+	      (match_operand:VSDQ_I_DI 1 "register_operand" "0,w,w"))
+	  (match_dup:VSDQ_I_DI 2)))]
+  "TARGET_SIMD"
+  "@
+  bsl\\t%0.<Vbtype>, %3.<Vbtype>, %2.<Vbtype>
+  bit\\t%0.<Vbtype>, %3.<Vbtype>, %1.<Vbtype>
+  bif\\t%0.<Vbtype>, %2.<Vbtype>, %1.<Vbtype>"
+  [(set_attr "type" "neon_bsl<q>")]
+)
+
 (define_expand "aarch64_simd_bsl<mode>"
   [(match_operand:VALLDIF 0 "register_operand")
    (match_operand:<V_cmp_result> 1 "register_operand")