[IR] Redesign the case iterator in SwitchInst to actually be an iterator
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.
All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.
Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.
Differential Revision: https://reviews.llvm.org/D31548
llvm-svn: 300032
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 0448913..18b2922 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -126,20 +126,20 @@
// If the default is unreachable, ignore it when searching for TheOnlyDest.
if (isa<UnreachableInst>(DefaultDest->getFirstNonPHIOrDbg()) &&
SI->getNumCases() > 0) {
- TheOnlyDest = SI->case_begin().getCaseSuccessor();
+ TheOnlyDest = SI->case_begin()->getCaseSuccessor();
}
// Figure out which case it goes to.
for (auto i = SI->case_begin(), e = SI->case_end(); i != e;) {
// Found case matching a constant operand?
- if (i.getCaseValue() == CI) {
- TheOnlyDest = i.getCaseSuccessor();
+ if (i->getCaseValue() == CI) {
+ TheOnlyDest = i->getCaseSuccessor();
break;
}
// Check to see if this branch is going to the same place as the default
// dest. If so, eliminate it as an explicit compare.
- if (i.getCaseSuccessor() == DefaultDest) {
+ if (i->getCaseSuccessor() == DefaultDest) {
MDNode *MD = SI->getMetadata(LLVMContext::MD_prof);
unsigned NCases = SI->getNumCases();
// Fold the case metadata into the default if there will be any branches
@@ -153,7 +153,7 @@
Weights.push_back(CI->getValue().getZExtValue());
}
// Merge weight of this case to the default weight.
- unsigned idx = i.getCaseIndex();
+ unsigned idx = i->getCaseIndex();
Weights[0] += Weights[idx+1];
// Remove weight for this case.
std::swap(Weights[idx+1], Weights.back());
@@ -172,7 +172,8 @@
// Otherwise, check to see if the switch only branches to one destination.
// We do this by reseting "TheOnlyDest" to null when we find two non-equal
// destinations.
- if (i.getCaseSuccessor() != TheOnlyDest) TheOnlyDest = nullptr;
+ if (i->getCaseSuccessor() != TheOnlyDest)
+ TheOnlyDest = nullptr;
// Increment this iterator as we haven't removed the case.
++i;
@@ -211,7 +212,7 @@
if (SI->getNumCases() == 1) {
// Otherwise, we can fold this switch into a conditional branch
// instruction if it has only one non-default destination.
- SwitchInst::CaseIt FirstCase = SI->case_begin();
+ auto FirstCase = *SI->case_begin();
Value *Cond = Builder.CreateICmpEQ(SI->getCondition(),
FirstCase.getCaseValue(), "cond");