UseListOrder: Visit global values
When predicting use-list order, we visit functions in reverse order
followed by `GlobalValue`s and write out use-lists at the first
opportunity. In the reader, this will translate to *after* the last use
has been added.
For this to work, we actually need to descend into `GlobalValue`s.
Added a targeted test in `use-list-order.ll` and `RUN` lines to the
newly passing tests in `test/Bitcode`.
There are two remaining failures in `test/Bitcode`:
- blockaddress.ll: I haven't thought through how to model the way
block addresses change the order of use-lists (or how to work around
it).
- metadata-2.ll: There's an old-style `@llvm.used` global array here
that I suspect the .ll parser isn't upgrading properly. When it
round-trips through bitcode, the .bc reader *does* upgrade it, so
the extra variable (`i8* null`) has an extra use, and the shuffle
vector doesn't match.
I think the fix is to upgrade old-style global arrays (or reject
them?) in the .ll parser.
This is part of PR5680.
llvm-svn: 214321
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
index c05d6ae..fa1c8b3 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -211,9 +211,9 @@
// Recursive descent into constants.
if (const Constant *C = dyn_cast<Constant>(V))
- if (C->getNumOperands() && !isa<GlobalValue>(C))
+ if (C->getNumOperands()) // Visit GlobalValues.
for (const Value *Op : C->operands())
- if (isa<Constant>(Op) && !isa<GlobalValue>(Op))
+ if (isa<Constant>(Op)) // Visit GlobalValues.
predictValueUseListOrder(Op, F, OM, Stack);
}
@@ -241,8 +241,7 @@
for (const BasicBlock &BB : F)
for (const Instruction &I : BB)
for (const Value *Op : I.operands())
- if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
- isa<InlineAsm>(*Op))
+ if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
predictValueUseListOrder(Op, &F, OM, Stack);
for (const BasicBlock &BB : F)
for (const Instruction &I : BB)