[PATCH] D93410: [SimplifyCFG] Preserve !annotation in FoldBranchToCommonDest.

[Florian Hahn via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG75c04bfc61d6: [SimplifyCFG] Preserve !annotation in FoldBranchToCommonDest. (authored by fhahn).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93410/new/

https://reviews.llvm.org/D93410

Files:
  llvm/lib/Transforms/Utils/SimplifyCFG.cpp
  llvm/test/Transforms/SimplifyCFG/annotations.ll


Index: llvm/test/Transforms/SimplifyCFG/annotations.ll
===================================================================
--- llvm/test/Transforms/SimplifyCFG/annotations.ll
+++ llvm/test/Transforms/SimplifyCFG/annotations.ll
@@ -6,8 +6,8 @@
 ; CHECK-LABEL: define {{.*}} @test_preserve_and({{.*}}
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C_1:%.*]] = icmp ult i8* [[A:%.*]], [[B:%.*]], !annotation !0
-; CHECK-NEXT:    [[C_2:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]]
-; CHECK-NEXT:    [[OR_COND:%.*]] = and i1 [[C_1]], [[C_2]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]], !annotation !0
+; CHECK-NEXT:    [[OR_COND:%.*]] = and i1 [[C_1]], [[C_2]], !annotation !0
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[CONT1:%.*]], label [[TRAP:%.*]], !annotation !0
 ; CHECK:       trap: ; preds = %entry
 ; CHECK-NEXT:    call void @fn1()
@@ -39,8 +39,8 @@
 ; CHECK-LABEL: define {{.*}} @test_preserve_or({{.*}}
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C_1:%.*]] = icmp uge i8* [[A:%.*]], [[B:%.*]], !annotation !0
-; CHECK-NEXT:    [[C_2:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]]
-; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_1]], [[C_2]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]], !annotation !0
+; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_1]], [[C_2]], !annotation !0
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[TRAP:%.*]], label [[CONT1:%.*]], !annotation !0
 ; CHECK:       trap: ; preds = %entry
 ; CHECK-NEXT:    call void @fn1()
@@ -73,9 +73,9 @@
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C_1:%.*]] = icmp ult i8* [[A:%.*]], [[B:%.*]], !annotation !0
 ; CHECK-NEXT:    [[C_2:%.*]] = xor i1 [[C_1]], true
-; CHECK-NEXT:    [[C_2_NOT:%.*]] = xor i1 [[C_2]], true
-; CHECK-NEXT:    [[C_3:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]]
-; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_2_NOT]], [[C_3]]
+; CHECK-NEXT:    [[C_2_NOT:%.*]] = xor i1 [[C_2]], true, !annotation !0
+; CHECK-NEXT:    [[C_3:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]], !annotation !0
+; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_2_NOT]], [[C_3]], !annotation !0
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[TRAP:%.*]], label [[CONT1:%.*]], !annotation !0
 ; CHECK:       trap: ; preds = %entry
 ; CHECK-NEXT:    call void @fn1()
@@ -111,7 +111,7 @@
 ; CHECK-NEXT:    [[C_1:%.*]] = icmp ult i8* [[A:%.*]], [[B:%.*]], !annotation !0
 ; CHECK-NEXT:    [[C_2:%.*]] = xor i1 [[C_1]], true
 ; CHECK-NEXT:    [[C_2_NOT:%.*]] = xor i1 [[C_2]], true
-; CHECK-NEXT:    [[C_3:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]]
+; CHECK-NEXT:    [[C_3:%.*]] = icmp uge i8* [[C:%.*]], [[D:%.*]], !annotation !0
 ; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_2_NOT]], [[C_3]]
 ; CHECK-NEXT:    br i1 [[OR_COND]], label [[TRAP:%.*]], label [[CONT1:%.*]], !annotation !0
 ; CHECK:       trap: ; preds = %entry
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2886,11 +2886,15 @@
     Changed = true;
 
     IRBuilder<> Builder(PBI);
+    // The builder is used to create instructions to eliminate the branch in BB.
+    // If BB's terminator has !annotation metadata, add it to the new
+    // instructions.
+    Builder.CollectMetadataToCopy(BB->getTerminator(),
+                                  {LLVMContext::MD_annotation});
 
     // If we need to invert the condition in the pred block to match, do so now.
     if (InvertPredCond) {
       Value *NewCond = PBI->getCondition();
-
       if (NewCond->hasOneUse() && isa<CmpInst>(NewCond)) {
         CmpInst *CI = cast<CmpInst>(NewCond);
         CI->setPredicate(CI->getInversePredicate());
@@ -2941,8 +2945,9 @@
       // its potential value. The previous information might have been valid
       // only given the branch precondition.
       // For an analogous reason, we must also drop all the metadata whose
-      // semantics we don't understand.
-      NewBonusInst->dropUnknownNonDebugMetadata();
+      // semantics we don't understand. We *can* preserve !annotation, because
+      // it is tied to the instruction itself, not the value or position.
+      NewBonusInst->dropUnknownNonDebugMetadata(LLVMContext::MD_annotation);
 
       PredBlock->getInstList().insert(PBI->getIterator(), NewBonusInst);
       NewBonusInst->takeName(&BonusInst);


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D93410.312477.patch
Type: text/x-patch
Size: 4370 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201217/73ae6eeb/attachment.bin>