From 4844826c1519858143f658b4caf958f0d2cd3ead Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Tue, 4 Nov 2014 20:10:06 +0000
Subject: [PATCH] AArch64: Pattern match integer vector abs like we do on ARM.

This kind of pattern is emitted by the loop vectorizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221289 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/AArch64/AArch64InstrInfo.td | 22 ++++++++
 test/CodeGen/AArch64/arm64-vabs.ll     | 70 ++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)

diff --git a/lib/Target/AArch64/AArch64InstrInfo.td b/lib/Target/AArch64/AArch64InstrInfo.td
index 831defa3987..252ed40cf67 100644
--- a/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2426,6 +2426,28 @@ defm FMOV : FPMoveImmediate<"fmov">;
 //===----------------------------------------------------------------------===//
 
 defm ABS    : SIMDTwoVectorBHSD<0, 0b01011, "abs", int_aarch64_neon_abs>;
+def : Pat<(xor (v8i8 (AArch64vashr V64:$src, (i32 7))),
+               (v8i8 (add V64:$src, (AArch64vashr V64:$src, (i32 7))))),
+          (ABSv8i8 V64:$src)>;
+def : Pat<(xor (v4i16 (AArch64vashr V64:$src, (i32 15))),
+               (v4i16 (add V64:$src, (AArch64vashr V64:$src, (i32 15))))),
+          (ABSv4i16 V64:$src)>;
+def : Pat<(xor (v2i32 (AArch64vashr V64:$src, (i32 31))),
+               (v2i32 (add V64:$src, (AArch64vashr V64:$src, (i32 31))))),
+          (ABSv2i32 V64:$src)>;
+def : Pat<(xor (v16i8 (AArch64vashr V128:$src, (i32 7))),
+               (v16i8 (add V128:$src, (AArch64vashr V128:$src, (i32 7))))),
+          (ABSv16i8 V128:$src)>;
+def : Pat<(xor (v8i16 (AArch64vashr V128:$src, (i32 15))),
+               (v8i16 (add V128:$src, (AArch64vashr V128:$src, (i32 15))))),
+          (ABSv8i16 V128:$src)>;
+def : Pat<(xor (v4i32 (AArch64vashr V128:$src, (i32 31))),
+               (v4i32 (add V128:$src, (AArch64vashr V128:$src, (i32 31))))),
+          (ABSv4i32 V128:$src)>;
+def : Pat<(xor (v2i64 (AArch64vashr V128:$src, (i32 63))),
+               (v2i64 (add V128:$src, (AArch64vashr V128:$src, (i32 63))))),
+          (ABSv2i64 V128:$src)>;
+
 defm CLS    : SIMDTwoVectorBHS<0, 0b00100, "cls", int_aarch64_neon_cls>;
 defm CLZ    : SIMDTwoVectorBHS<1, 0b00100, "clz", ctlz>;
 defm CMEQ   : SIMDCmpTwoVector<0, 0b01001, "cmeq", AArch64cmeqz>;
diff --git a/test/CodeGen/AArch64/arm64-vabs.ll b/test/CodeGen/AArch64/arm64-vabs.ll
index 5afc8d9f3f4..fae2b90e5ba 100644
--- a/test/CodeGen/AArch64/arm64-vabs.ll
+++ b/test/CodeGen/AArch64/arm64-vabs.ll
@@ -802,3 +802,73 @@ define <2 x i64> @sabdl_from_extract_dup(<4 x i32> %lhs, i32 %rhs) {
   %res1 = zext <2 x i32> %res to <2 x i64>
   ret <2 x i64> %res1
 }
+
+define <2 x i32> @abspattern1(<2 x i32> %a) nounwind {
+; CHECK-LABEL: abspattern1:
+; CHECK: abs.2s
+; CHECK-NEXT: ret
+        %tmp1neg = sub <2 x i32> zeroinitializer, %a
+        %b = icmp sge <2 x i32> %a, zeroinitializer
+        %abs = select <2 x i1> %b, <2 x i32> %a, <2 x i32> %tmp1neg
+        ret <2 x i32> %abs
+}
+
+define <4 x i16> @abspattern2(<4 x i16> %a) nounwind {
+; CHECK-LABEL: abspattern2:
+; CHECK: abs.4h
+; CHECK-NEXT: ret
+        %tmp1neg = sub <4 x i16> zeroinitializer, %a
+        %b = icmp sgt <4 x i16> %a, zeroinitializer
+        %abs = select <4 x i1> %b, <4 x i16> %a, <4 x i16> %tmp1neg
+        ret <4 x i16> %abs
+}
+
+define <8 x i8> @abspattern3(<8 x i8> %a) nounwind {
+; CHECK-LABEL: abspattern3:
+; CHECK: abs.8b
+; CHECK-NEXT: ret
+        %tmp1neg = sub <8 x i8> zeroinitializer, %a
+        %b = icmp slt <8 x i8> %a, zeroinitializer
+        %abs = select <8 x i1> %b, <8 x i8> %tmp1neg, <8 x i8> %a
+        ret <8 x i8> %abs
+}
+
+define <4 x i32> @abspattern4(<4 x i32> %a) nounwind {
+; CHECK-LABEL: abspattern4:
+; CHECK: abs.4s
+; CHECK-NEXT: ret
+        %tmp1neg = sub <4 x i32> zeroinitializer, %a
+        %b = icmp sge <4 x i32> %a, zeroinitializer
+        %abs = select <4 x i1> %b, <4 x i32> %a, <4 x i32> %tmp1neg
+        ret <4 x i32> %abs
+}
+
+define <8 x i16> @abspattern5(<8 x i16> %a) nounwind {
+; CHECK-LABEL: abspattern5:
+; CHECK: abs.8h
+; CHECK-NEXT: ret
+        %tmp1neg = sub <8 x i16> zeroinitializer, %a
+        %b = icmp sgt <8 x i16> %a, zeroinitializer
+        %abs = select <8 x i1> %b, <8 x i16> %a, <8 x i16> %tmp1neg
+        ret <8 x i16> %abs
+}
+
+define <16 x i8> @abspattern6(<16 x i8> %a) nounwind {
+; CHECK-LABEL: abspattern6:
+; CHECK: abs.16b
+; CHECK-NEXT: ret
+        %tmp1neg = sub <16 x i8> zeroinitializer, %a
+        %b = icmp slt <16 x i8> %a, zeroinitializer
+        %abs = select <16 x i1> %b, <16 x i8> %tmp1neg, <16 x i8> %a
+        ret <16 x i8> %abs
+}
+
+define <2 x i64> @abspattern7(<2 x i64> %a) nounwind {
+; CHECK-LABEL: abspattern7:
+; CHECK: abs.2d
+; CHECK-NEXT: ret
+        %tmp1neg = sub <2 x i64> zeroinitializer, %a
+        %b = icmp sle <2 x i64> %a, zeroinitializer
+        %abs = select <2 x i1> %b, <2 x i64> %tmp1neg, <2 x i64> %a
+        ret <2 x i64> %abs
+}