[llvm] r289973 - Fix CodeGenPrepare::stripInvariantGroupMetadata

[Sanjoy Das via llvm-commits]

Author: sanjoy
Date: Fri Dec 16 12:52:33 2016
New Revision: 289973

URL: http://llvm.org/viewvc/llvm-project?rev=289973&view=rev
Log:
Fix CodeGenPrepare::stripInvariantGroupMetadata

`dropUnknownNonDebugMetadata` takes a list of "known" metadata IDs.  The
only reason it worked at all is that `getMetadataID` returns something
unrelated -- it returns the subclass ID of the receiver (which is used
in `dyn_cast` etc.).  That does not numerically match
`LLVMContext::MD_invariant_group` and ends up dropping `invariant_group`
along with every other metadata that does not numerically match
`LLVMContext::MD_invariant_group`.

Modified:
    llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
    llvm/trunk/test/Transforms/CodeGenPrepare/invariant.group.ll

Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=289973&r1=289972&r2=289973&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Fri Dec 16 12:52:33 2016
@@ -5735,6 +5735,5 @@ bool CodeGenPrepare::splitBranchConditio
 }
 
 void CodeGenPrepare::stripInvariantGroupMetadata(Instruction &I) {
-  if (auto *InvariantMD = I.getMetadata(LLVMContext::MD_invariant_group))
-    I.dropUnknownNonDebugMetadata(InvariantMD->getMetadataID());
+  I.setMetadata(LLVMContext::MD_invariant_group, nullptr);
 }

Modified: llvm/trunk/test/Transforms/CodeGenPrepare/invariant.group.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CodeGenPrepare/invariant.group.ll?rev=289973&r1=289972&r2=289973&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/CodeGenPrepare/invariant.group.ll (original)
+++ llvm/trunk/test/Transforms/CodeGenPrepare/invariant.group.ll Fri Dec 16 12:52:33 2016
@@ -7,8 +7,8 @@ define void @foo() {
 enter:
   ; CHECK-NOT: !invariant.group
   ; CHECK-NOT: @llvm.invariant.group.barrier(
-  ; CHECK: %val = load i8, i8* @tmp
-  %val = load i8, i8* @tmp, !invariant.group !0
+  ; CHECK: %val = load i8, i8* @tmp, !tbaa
+  %val = load i8, i8* @tmp, !invariant.group !0, !tbaa !{!1, !1, i64 0}
   %ptr = call i8* @llvm.invariant.group.barrier(i8* @tmp)
   
   ; CHECK: store i8 42, i8* @tmp
@@ -20,4 +20,5 @@ enter:
 
 declare i8* @llvm.invariant.group.barrier(i8*)
 
-!0 = !{!"something"}
\ No newline at end of file
+!0 = !{!"something"}
+!1 = !{!"x", !0}