commit 2fcf60e78efde7b9766bb58dd2fcf0b5773d75ee
author Duncan P. N. Exon Smith <dexonsmith@apple.com> Mon Jan 12 22:30:34 2015 +0000
committer Duncan P. N. Exon Smith <dexonsmith@apple.com> Mon Jan 12 22:30:34 2015 +0000
tree cb985c1de12e0e8392046c335bbbe32746e5b8fd
parent 0b31dd1d67c0bb68db6f868a2330b61c7a162c71

Bitcode: Simplify emission of METADATA_BLOCK

Refactor logic so that we know up-front whether to open a block and
whether we need an MDString abbreviation.

This is almost NFC, but will start emitting `MDString` abbreviations
when the first record is not an `MDString`.

llvm-svn: 225712

llvm/lib/Bitcode/Writer/ValueEnumerator.cpp

diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
index 2c0fdc0..b117d7b 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -282,7 +282,7 @@
   return V.first->getType()->isIntOrIntVectorTy();
 }
 
-ValueEnumerator::ValueEnumerator(const Module &M) {
+ValueEnumerator::ValueEnumerator(const Module &M) : HasMDString(false) {
   if (shouldPreserveBitcodeUseListOrder())
     UseListOrders = predictUseListOrder(M);
 
@@ -546,6 +546,8 @@
   else if (auto *C = dyn_cast<ConstantAsMetadata>(MD))
     EnumerateValue(C->getValue());
 
+  HasMDString |= isa<MDString>(MD);
+
   // Replace the dummy ID inserted above with the correct one.  MDValueMap may
   // have changed by inserting operands, so we need a fresh lookup here.
   MDs.push_back(MD);