[GlobalIsel] Add llvm.invariant.start and llvm.invariant.end

Jessica Paquette · Jessica Paquette · commit b328d95333e0 · 2018-10-05T21:02:46.000Z
Port over the implementation in SelectionDAGBuilder.cpp into the IRTranslator and update the arm64-irtranslator test. These were causing fallbacks in CTMark/Bullet (-Rpass-missed=gisel-select), and this patch fixes that. https://reviews.llvm.org/D52945 llvm-svn: 343885
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -955,6 +955,14 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
         .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
     return true;
   }
+  case Intrinsic::invariant_start: {
+    LLT PtrTy = getLLTForType(*CI.getArgOperand(0)->getType(), *DL);
+    unsigned Undef = MRI->createGenericVirtualRegister(PtrTy);
+    MIRBuilder.buildUndef(Undef);
+    return true;
+  }
+  case Intrinsic::invariant_end:
+    return true;
   }
   return false;
 }
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll b/llvm/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -2207,3 +2207,17 @@ define void @test_blockaddress() {
 block:
   ret void
 }
+
+%t = type { i32 }
+declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) readonly nounwind
+declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture) nounwind
+define void @test_invariant_intrin() {
+; CHECK-LABEL: name: test_invariant_intrin
+; CHECK: %{{[0-9]+}}:_(s64) = G_IMPLICIT_DEF
+; CHECK-NEXT: RET_ReallyLR
+  %x = alloca %t
+  %y = bitcast %t* %x to i8*
+  %inv = call {}* @llvm.invariant.start.p0i8(i64 8, i8* %y)
+  call void @llvm.invariant.end.p0i8({}* %inv, i64 8, i8* %y)
+  ret void
+}

Original file line number	Diff line number	Diff line change
`@@ -955,6 +955,14 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,`
`955`	`955`	`.addUse(getOrCreateVReg(*CI.getArgOperand(0)));`
`956`	`956`	`return true;`
`957`	`957`	`}`
	`958`	`+ case Intrinsic::invariant_start: {`
	`959`	`+ LLT PtrTy = getLLTForType(CI.getArgOperand(0)->getType(), DL);`
	`960`	`+ unsigned Undef = MRI->createGenericVirtualRegister(PtrTy);`
	`961`	`+ MIRBuilder.buildUndef(Undef);`
	`962`	`+ return true;`
	`963`	`+ }`
	`964`	`+ case Intrinsic::invariant_end:`
	`965`	`+ return true;`
`958`	`966`	`}`
`959`	`967`	`return false;`
`960`	`968`	`}`