[Lint] Add check for intrinsic get.active.lane.mask

[SjoerdMeijer]

Summary

As @efriedma pointed out in D86301, this not equal to 0 check of get.active.lane.mask's second operand needs to live here in Lint and not the Verifier.

[SjoerdMeijer]

Updated test

[SjoerdMeijer]

Little non-urgent ping, but would be nice to get this little guy out of the way.

[efriedma]

LGTM

llvm/lib/Analysis/Lint.cpp

if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I))
 
     case Intrinsic::stackrestore:
       // Stackrestore doesn't read or write memory, but it sets the
       // stack pointer, which the compiler may read from or write to
       // at any time, so check it for both readability and writeability.
       visitMemoryReference(I, I.getArgOperand(0), MemoryLocation::UnknownSize,
                            None, nullptr, MemRef::Read | MemRef::Write);
       break;
+    case Intrinsic::get_active_lane_mask:
+      if (auto *TripCount = dyn_cast<ConstantInt>(I.getArgOperand(1)))
+        Assert(!TripCount->isZero(), "get_active_lane_mask: operand #2 "
+               "must be greater than 0", &I);
+      break;
     }
 }
 
 void Lint::visitReturnInst(ReturnInst &I) {
   Function *F = I.getParent()->getParent();
   Assert(!F->doesNotReturn(),
          "Unusual: Return statement in function with noreturn attribute", &I);
 

llvm/test/Analysis/Lint/get-active-lane-mask.ll

+; RUN: opt -lint -disable-output < %s 2>&1 | FileCheck %s
+
+define <4 x i1> @t3(i32 %IV) {
+;
+; CHECK:      get_active_lane_mask: operand #2 must be greater than 0
+; CHECK-NEXT: %res = call <4 x i1> @llvm.get.active.lane.mask.v4i1.i32(i32 %IV, i32 0)
+;
+  %res = call <4 x i1> @llvm.get.active.lane.mask.v4i1.i32(i32 %IV, i32 0)
+  ret <4 x i1> %res
+}
+
+define <4 x i1> @t4(i32 %IV) {
+;
+; CHECK-NOT: get_active_lane_mask
+; CHECK-NOT: call <4 x i1> @llvm.get.active.lane.mask
+;
+  %res = call <4 x i1> @llvm.get.active.lane.mask.v4i1.i32(i32 %IV, i32 1)
+  ret <4 x i1> %res
+}
+
+define <4 x i1> @t5(i32 %IV) {
+;
+; CHECK-NOT: get_active_lane_mask
+; CHECK-NOT: call <4 x i1> @llvm.get.active.lane.mask
+;
+  %res = call <4 x i1> @llvm.get.active.lane.mask.v4i1.i32(i32 %IV, i32 -1)
+  ret <4 x i1> %res
+}
+
+declare <4 x i1> @llvm.get.active.lane.mask.v4i1.i32(i32, i32)