From 41fb119e8cce45a9458d72962cc3c07cb503586e Mon Sep 17 00:00:00 2001
From: David Sherwood <david.sherwood@arm.com>
Date: Thu, 4 Jun 2020 15:53:06 +0100
Subject: [PATCH] [CodeGen] Fix nullptr crash in tryConvertSVEWideCompare

When the input to a wide compare instruction is a DUP or SPLAT_VECTOR
node we should deal with cases where the DUP/SPLAT_VECTOR input
operand is not an immediate value. I've fixed the code to return
SDValue() in such cases and added a couple of tests - one each to
represent the signed and unsigned cases.

Differential Revision: https://reviews.llvm.org/D81167
---
 .../Target/AArch64/AArch64ISelLowering.cpp    |  3 +++
 .../AArch64/sve-intrinsics-int-compares.ll    | 26 +++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 5488d3cb12f5..e7f1c59eea4e 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -11452,6 +11452,9 @@ static SDValue tryConvertSVEWideCompare(SDNode *N, ISD::CondCode CC,
     }
     }
 
+    if (!Imm)
+      return SDValue();
+
     SDValue Splat = DAG.getNode(ISD::SPLAT_VECTOR, DL, CmpVT, Imm);
     return DAG.getNode(AArch64ISD::SETCC_PRED, DL, VT, Pred, N->getOperand(2),
                        Splat, DAG.getCondCode(CC));
diff --git a/llvm/test/CodeGen/AArch64/sve-intrinsics-int-compares.ll b/llvm/test/CodeGen/AArch64/sve-intrinsics-int-compares.ll
index 824ce5a1ef60..eb885035307e 100644
--- a/llvm/test/CodeGen/AArch64/sve-intrinsics-int-compares.ll
+++ b/llvm/test/CodeGen/AArch64/sve-intrinsics-int-compares.ll
@@ -940,6 +940,30 @@ define <vscale x 2 x i1> @cmpne_ir_d(<vscale x 2 x i64> %a, <vscale x 2 x i64> %
   ret <vscale x 2 x i1> %out
 }
 
+
+define <vscale x 16 x i1> @cmpgt_wide_splat_b(<vscale x 16 x i1> %pg, <vscale x 16 x i8> %a, i64 %b) {
+; CHECK-LABEL: cmpgt_wide_splat_b:
+; CHECK: cmpgt p0.b, p0/z, z0.b, z1.d
+; CHECK-NEXT: ret
+  %splat = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 %b)
+  %out = call <vscale x 16 x i1> @llvm.aarch64.sve.cmpgt.wide.nxv16i8(<vscale x 16 x i1> %pg,
+                                                                      <vscale x 16 x i8> %a,
+                                                                      <vscale x 2 x i64> %splat)
+  ret <vscale x 16 x i1> %out
+}
+
+define <vscale x 4 x i1> @cmpls_wide_splat_s(<vscale x 4 x i1> %pg, <vscale x 4 x i32> %a, i64 %b) {
+; CHECK-LABEL: cmpls_wide_splat_s:
+; CHECK: cmpls p0.s, p0/z, z0.s, z1.d
+; CHECK-NEXT: ret
+  %splat = call <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64 %b)
+  %out = call <vscale x 4 x i1> @llvm.aarch64.sve.cmpls.wide.nxv4i32(<vscale x 4 x i1> %pg,
+                                                                     <vscale x 4 x i32> %a,
+                                                                     <vscale x 2 x i64> %splat)
+  ret <vscale x 4 x i1> %out
+}
+
+
 declare <vscale x 16 x i1> @llvm.aarch64.sve.cmpeq.nxv16i8(<vscale x 16 x i1>, <vscale x 16 x i8>, <vscale x 16 x i8>)
 declare <vscale x 8 x i1> @llvm.aarch64.sve.cmpeq.nxv8i16(<vscale x 8 x i1>, <vscale x 8 x i16>, <vscale x 8 x i16>)
 declare <vscale x 4 x i1> @llvm.aarch64.sve.cmpeq.nxv4i32(<vscale x 4 x i1>, <vscale x 4 x i32>, <vscale x 4 x i32>)
@@ -1003,3 +1027,5 @@ declare <vscale x 2 x i1> @llvm.aarch64.sve.cmpne.nxv2i64(<vscale x 2 x i1>, <vs
 declare <vscale x 16 x i1> @llvm.aarch64.sve.cmpne.wide.nxv16i8(<vscale x 16 x i1>, <vscale x 16 x i8>, <vscale x 2 x i64>)
 declare <vscale x 8 x i1> @llvm.aarch64.sve.cmpne.wide.nxv8i16(<vscale x 8 x i1>, <vscale x 8 x i16>, <vscale x 2 x i64>)
 declare <vscale x 4 x i1> @llvm.aarch64.sve.cmpne.wide.nxv4i32(<vscale x 4 x i1>, <vscale x 4 x i32>, <vscale x 2 x i64>)
+
+declare <vscale x 2 x i64> @llvm.aarch64.sve.dup.x.nxv2i64(i64)