[llvm] r343885 - [GlobalIsel] Add llvm.invariant.start and llvm.invariant.end

[Jessica Paquette via llvm-commits]

Author: paquette
Date: Fri Oct  5 14:02:46 2018
New Revision: 343885

URL: http://llvm.org/viewvc/llvm-project?rev=343885&view=rev
Log:
[GlobalIsel] Add llvm.invariant.start and llvm.invariant.end

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

Modified:
    llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
    llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

Modified: llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp?rev=343885&r1=343884&r2=343885&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp (original)
+++ llvm/trunk/lib/CodeGen/GlobalISel/IRTranslator.cpp Fri Oct  5 14:02:46 2018
@@ -955,6 +955,14 @@ bool IRTranslator::translateKnownIntrins
         .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;
 }

Modified: llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll?rev=343885&r1=343884&r2=343885&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll Fri Oct  5 14:02:46 2018
@@ -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
+}