[Hexagon] Allow use of gather intrinsics even with no-packets

Vgather requires must be in a packet with a store, which contradicts
the no-packets feature. As a consequence, gather/scatter could not be
used with no-packets. Relax this, and allow gather packets as exceptions
to the no-packets requirements.

llvm-svn: 339177

3 files changed, 26 insertions, 14 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp b/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
index 0ac83ea7c5f..f44fb16e2d8 100644
--- a/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
@@ -755,7 +755,6 @@ void HexagonAsmPrinter::EmitInstruction(const MachineInstr *MI) {
   const MCInstrInfo &MCII = *Subtarget->getInstrInfo();
 
   if (MI->isBundle()) {
-    assert(Subtarget->usePackets() && "Support for packets is disabled");
     const MachineBasicBlock* MBB = MI->getParent();
     MachineBasicBlock::const_instr_iterator MII = MI->getIterator();
 
diff --git a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAGHVX.cpp b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAGHVX.cpp
index 8aef9b4560d..530f0622e8d 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAGHVX.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAGHVX.cpp
@@ -2048,10 +2048,6 @@ void HexagonDAGToDAGISel::SelectHvxVAlign(SDNode *N) {
 }
 
 void HexagonDAGToDAGISel::SelectV65GatherPred(SDNode *N) {
-  if (!HST->usePackets()) {
-    report_fatal_error("Support for gather requires packets, "
-                       "which are disabled");
-  }
   const SDLoc &dl(N);
   SDValue Chain = N->getOperand(0);
   SDValue Address = N->getOperand(2);
@@ -2091,10 +2087,6 @@ void HexagonDAGToDAGISel::SelectV65GatherPred(SDNode *N) {
 }
 
 void HexagonDAGToDAGISel::SelectV65Gather(SDNode *N) {
-  if (!HST->usePackets()) {
-    report_fatal_error("Support for gather requires packets, "
-                       "which are disabled");
-  }
   const SDLoc &dl(N);
   SDValue Chain = N->getOperand(0);
   SDValue Address = N->getOperand(2);
diff --git a/llvm/test/CodeGen/Hexagon/no-packets-gather.ll b/llvm/test/CodeGen/Hexagon/no-packets-gather.ll
index 516419b7372..06054b6b2f4 100644
--- a/llvm/test/CodeGen/Hexagon/no-packets-gather.ll
+++ b/llvm/test/CodeGen/Hexagon/no-packets-gather.ll
@@ -1,11 +1,32 @@
-; RUN: llc -march=hexagon -mattr=+hvxv60,hvx-length64b < %s | FileCheck %s --check-prefix=CHECK-GATHER
-; RUN: not llc -march=hexagon -mattr=+hvxv60,hvx-length64b,-packets %s -o /dev/null 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR
+; RUN: llc -march=hexagon -mattr=+hvxv60,hvx-length64b,-packets < %s | FileCheck %s
 
 target triple = "hexagon"
 
-; CHECK-GATHER-LABEL: fred:
-; CHECK-GATHER: vgather
-; CHECK-ERROR: LLVM ERROR: Support for gather requires packets, which are disabled
+; Check that the only (multi-instruction) packet is the one with vgather.
+
+; CHECK-LABEL: fred:
+; CHECK:      {
+; CHECK-NEXT:   allocframe(r29,#64):raw
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   m0 = r2
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   vtmp.w = vgather(r1,m0,v0.w).w
+; CHECK-NEXT:   vmem(r0+#0) = vtmp.new
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   r29 = and(r29,#-64)
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   r0 = add(r29,#0)
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   call foo
+; CHECK-NEXT: }
+; CHECK-NEXT: {
+; CHECK-NEXT:   r31:30 = dealloc_return(r30):raw
+; CHECK-NEXT: }
 
 define void @fred(i8* %p, i32 %x, i32 %y) local_unnamed_addr #0 {
 entry: