[DAGCombine][X86][AArch64] Masked merge unfolding: vector edition.

Summary:
This **appears** to be the last missing piece for the masked merge pattern handling in the backend.

This is [[ https://bugs.llvm.org/show_bug.cgi?id=37104 | PR37104 ]].

[[ https://bugs.llvm.org/show_bug.cgi?id=6773 | PR6773 ]] will introduce an IR canonicalization that is likely bad for the end assembly.
Previously, `andps`+`andnps` / `bsl` would be generated. (see `@out`)
Now, they would no longer be generated  (see `@in`), and we need to make sure that they are generated.

Differential Revision: https://reviews.llvm.org/D46528

llvm-svn: 332904
diff --git a/llvm/test/CodeGen/AArch64/unfold-masked-merge-vector-variablemask.ll b/llvm/test/CodeGen/AArch64/unfold-masked-merge-vector-variablemask.ll
index c3199cc..df86540 100644
--- a/llvm/test/CodeGen/AArch64/unfold-masked-merge-vector-variablemask.ll
+++ b/llvm/test/CodeGen/AArch64/unfold-masked-merge-vector-variablemask.ll
@@ -270,9 +270,8 @@
 define <1 x i8> @in_v1i8(<1 x i8> %x, <1 x i8> %y, <1 x i8> %mask) nounwind {
 ; CHECK-LABEL: in_v1i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <1 x i8> %x, %y
   %n1 = and <1 x i8> %n0, %mask
@@ -287,9 +286,8 @@
 define <2 x i8> @in_v2i8(<2 x i8> %x, <2 x i8> %y, <2 x i8> %mask) nounwind {
 ; CHECK-LABEL: in_v2i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <2 x i8> %x, %y
   %n1 = and <2 x i8> %n0, %mask
@@ -300,9 +298,8 @@
 define <1 x i16> @in_v1i16(<1 x i16> %x, <1 x i16> %y, <1 x i16> %mask) nounwind {
 ; CHECK-LABEL: in_v1i16:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <1 x i16> %x, %y
   %n1 = and <1 x i16> %n0, %mask
@@ -317,9 +314,8 @@
 define <4 x i8> @in_v4i8(<4 x i8> %x, <4 x i8> %y, <4 x i8> %mask) nounwind {
 ; CHECK-LABEL: in_v4i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <4 x i8> %x, %y
   %n1 = and <4 x i8> %n0, %mask
@@ -330,9 +326,8 @@
 define <2 x i16> @in_v2i16(<2 x i16> %x, <2 x i16> %y, <2 x i16> %mask) nounwind {
 ; CHECK-LABEL: in_v2i16:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <2 x i16> %x, %y
   %n1 = and <2 x i16> %n0, %mask
@@ -343,9 +338,8 @@
 define <1 x i32> @in_v1i32(<1 x i32> %x, <1 x i32> %y, <1 x i32> %mask) nounwind {
 ; CHECK-LABEL: in_v1i32:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <1 x i32> %x, %y
   %n1 = and <1 x i32> %n0, %mask
@@ -360,9 +354,8 @@
 define <8 x i8> @in_v8i8(<8 x i8> %x, <8 x i8> %y, <8 x i8> %mask) nounwind {
 ; CHECK-LABEL: in_v8i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <8 x i8> %x, %y
   %n1 = and <8 x i8> %n0, %mask
@@ -373,9 +366,8 @@
 define <4 x i16> @in_v4i16(<4 x i16> %x, <4 x i16> %y, <4 x i16> %mask) nounwind {
 ; CHECK-LABEL: in_v4i16:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <4 x i16> %x, %y
   %n1 = and <4 x i16> %n0, %mask
@@ -386,9 +378,8 @@
 define <2 x i32> @in_v2i32(<2 x i32> %x, <2 x i32> %y, <2 x i32> %mask) nounwind {
 ; CHECK-LABEL: in_v2i32:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <2 x i32> %x, %y
   %n1 = and <2 x i32> %n0, %mask
@@ -399,9 +390,8 @@
 define <1 x i64> @in_v1i64(<1 x i64> %x, <1 x i64> %y, <1 x i64> %mask) nounwind {
 ; CHECK-LABEL: in_v1i64:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
-; CHECK-NEXT:    and v0.8b, v0.8b, v2.8b
-; CHECK-NEXT:    eor v0.8b, v0.8b, v1.8b
+; CHECK-NEXT:    bsl v2.8b, v0.8b, v1.8b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <1 x i64> %x, %y
   %n1 = and <1 x i64> %n0, %mask
@@ -416,9 +406,8 @@
 define <16 x i8> @in_v16i8(<16 x i8> %x, <16 x i8> %y, <16 x i8> %mask) nounwind {
 ; CHECK-LABEL: in_v16i8:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    and v0.16b, v0.16b, v2.16b
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
+; CHECK-NEXT:    bsl v2.16b, v0.16b, v1.16b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <16 x i8> %x, %y
   %n1 = and <16 x i8> %n0, %mask
@@ -429,9 +418,8 @@
 define <8 x i16> @in_v8i16(<8 x i16> %x, <8 x i16> %y, <8 x i16> %mask) nounwind {
 ; CHECK-LABEL: in_v8i16:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    and v0.16b, v0.16b, v2.16b
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
+; CHECK-NEXT:    bsl v2.16b, v0.16b, v1.16b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <8 x i16> %x, %y
   %n1 = and <8 x i16> %n0, %mask
@@ -442,9 +430,8 @@
 define <4 x i32> @in_v4i32(<4 x i32> %x, <4 x i32> %y, <4 x i32> %mask) nounwind {
 ; CHECK-LABEL: in_v4i32:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    and v0.16b, v0.16b, v2.16b
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
+; CHECK-NEXT:    bsl v2.16b, v0.16b, v1.16b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <4 x i32> %x, %y
   %n1 = and <4 x i32> %n0, %mask
@@ -455,9 +442,8 @@
 define <2 x i64> @in_v2i64(<2 x i64> %x, <2 x i64> %y, <2 x i64> %mask) nounwind {
 ; CHECK-LABEL: in_v2i64:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
-; CHECK-NEXT:    and v0.16b, v0.16b, v2.16b
-; CHECK-NEXT:    eor v0.16b, v0.16b, v1.16b
+; CHECK-NEXT:    bsl v2.16b, v0.16b, v1.16b
+; CHECK-NEXT:    mov v0.16b, v2.16b
 ; CHECK-NEXT:    ret
   %n0 = xor <2 x i64> %x, %y
   %n1 = and <2 x i64> %n0, %mask