[GlobalISel] IRTranslator: Translate the intrinsics ignored by CodeGen

Summary:
Translate `llvm.assume`, `llvm.var.annotation` and `llvm.sideeffect` to nothing
as they have no effect on CodeGen.

Reviewers: qcolombet, aditya_nandakumar, dsanders, paquette, aemerson, arsenm

Reviewed By: arsenm

Subscribers: hiraditya, wdng, rovka, kristof.beyls, javed.absar, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63022

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362834 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -1108,6 +1108,11 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
   }
   case Intrinsic::invariant_end:
     return true;
+  case Intrinsic::assume:
+  case Intrinsic::var_annotation:
+  case Intrinsic::sideeffect:
+    // Discard annotate attributes, assumptions, and artificial side-effects.
+    return true;
   }
   return false;
 }

test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

@@ -2390,3 +2390,30 @@ define float @test_rint_f32(float %x) {
   %y = call float @llvm.rint.f32(float %x)
   ret float %y
 }
+
+declare void @llvm.assume(i1)
+define void @test_assume(i1 %x) {
+  ; CHECK-LABEL: name:            test_assume
+  ; CHECK-NOT: llvm.assume
+  ; CHECK: RET_ReallyLR
+  call void @llvm.assume(i1 %x)
+  ret void
+}
+
+declare void @llvm.sideeffect()
+define void @test_sideeffect() {
+  ; CHECK-LABEL: name:            test_sideeffect
+  ; CHECK-NOT: llvm.sideeffect
+  ; CHECK: RET_ReallyLR
+  call void @llvm.sideeffect()
+  ret void
+}
+
+declare void @llvm.var.annotation(i8*, i8*, i8*, i32)
+define void @test_var_annotation(i8*, i8*, i8*, i32) {
+  ; CHECK-LABEL: name:            test_var_annotation
+  ; CHECK-NOT: llvm.var.annotation
+  ; CHECK: RET_ReallyLR
+  call void @llvm.var.annotation(i8* %0, i8* %1, i8* %2, i32 %3)
+  ret void
+}