[llvm] r256110 - Nonnull elements in OperandBundleCallSites are not all Instructions

[Sanjoy Das via llvm-commits]

Author: sanjoy
Date: Sat Dec 19 16:40:28 2015
New Revision: 256110

URL: http://llvm.org/viewvc/llvm-project?rev=256110&view=rev
Log:
Nonnull elements in OperandBundleCallSites are not all Instructions

`CloneAndPruneIntoFromInst` sometimes RAUW's dead instructions with
`undef` before erasing them (to avoid deleting instructions that still
have uses).  This changes the `WeakVH` in `OperandBundleCallSites` to
hold an `undef`, and we need to guard for this situation in eventuality
in `llvm::InlineFunction`.

Modified:
    llvm/trunk/include/llvm/Transforms/Utils/Cloning.h
    llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
    llvm/trunk/test/Transforms/Inline/deopt-bundles.ll

Modified: llvm/trunk/include/llvm/Transforms/Utils/Cloning.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Cloning.h?rev=256110&r1=256109&r2=256110&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Cloning.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Cloning.h Sat Dec 19 16:40:28 2015
@@ -75,8 +75,8 @@ struct ClonedCodeInfo {
   bool ContainsDynamicAllocas;
 
   /// All cloned call sites that have operand bundles attached are appended to
-  /// this vector.  This vector may contain nulls if some of the originally
-  /// inserted callsites were DCE'ed after they were cloned.
+  /// this vector.  This vector may contain nulls or undefs if some of the
+  /// originally inserted callsites were DCE'ed after they were cloned.
   std::vector<WeakVH> OperandBundleCallSites;
 
   ClonedCodeInfo() : ContainsCalls(false), ContainsDynamicAllocas(false) {}

Modified: llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp?rev=256110&r1=256109&r2=256110&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp Sat Dec 19 16:40:28 2015
@@ -1196,9 +1196,8 @@ bool llvm::InlineFunction(CallSite CS, I
       SmallVector<OperandBundleDef, 2> OpDefs;
 
       for (auto &VH : InlinedFunctionInfo.OperandBundleCallSites) {
-        if (!VH) continue;  // instruction was DCE'd after being cloned
-
-        Instruction *I = cast<Instruction>(VH);
+        Instruction *I = dyn_cast_or_null<Instruction>(VH);
+        if (!I) continue;  // instruction was DCE'd or RAUW'ed to undef
 
         OpDefs.clear();
 

Modified: llvm/trunk/test/Transforms/Inline/deopt-bundles.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/deopt-bundles.ll?rev=256110&r1=256109&r2=256110&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Inline/deopt-bundles.ll (original)
+++ llvm/trunk/test/Transforms/Inline/deopt-bundles.ll Sat Dec 19 16:40:28 2015
@@ -162,6 +162,42 @@ define i32 @caller_7() {
   ret i32 %x
 }
 
+define i32 @callee_8(i1 %val) alwaysinline personality i8 3 {
+; We want something that PruningFunctionCloner is not smart enough to
+; recognize, but can be recognized by recursivelySimplifyInstruction.
+
+ entry:
+  br i1 %val, label %check, label %precheck
+
+ precheck:
+  br label %check
+
+ check:
+  %p = phi i1 [ %val, %entry ], [ true, %precheck ]
+  br i1 %p, label %do.not, label %do
+
+ do.not:
+  ret i32 0
+
+ do:
+  %phi = phi i32 [ 0, %check ], [ %v, %do ]
+  %v = call fastcc i32 @g.fastcc() [ "deopt"(i32 0, i32 1), "foo"(double 0.0) ]
+  %ic = icmp eq i32 %v, 42
+  br i1 %ic, label %do, label %done
+
+ done:
+  ret i32 %phi
+}
+
+define i32 @caller_8() {
+; CHECK-LABEL: @caller_8(
+ entry:
+; CHECK-NOT: call fastcc i32 @g.fastcc()
+; CHECK: ret i32 0
+  %x = call i32 @callee_8(i1 true) [ "deopt"(i32 7) ]
+  ret i32 %x
+}
+
 attributes #0 = { "foo"="bar" }
 
 ; CHECK: attributes #[[FOO_BAR_ATTR_IDX]] = { "foo"="bar" }