[C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
detail
2) Change it to actually be a *Use* iterator rather than a *User*
iterator.
3) Add an adaptor which is a User iterator that always looks through the
Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
they wanted a use_iterator (and to explicitly dig out the User when
needed), or a user_iterator which makes the Use itself totally
opaque.
Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.
The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.
However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]
llvm-svn: 203364
diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
index 9be27c6..6ae431b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -133,7 +133,7 @@
!(I->getOpcode() == Instruction::BitCast ||
I->getOpcode() == Instruction::PtrToInt ||
I->getOpcode() == Instruction::IntToPtr) &&
- cast<Instruction>(*I->use_begin())->getParent() == I->getParent();
+ cast<Instruction>(*I->user_begin())->getParent() == I->getParent();
}
unsigned FastISel::getRegForValue(const Value *V) {
@@ -1523,7 +1523,7 @@
// this by scanning the single-use users of the load until we get to FoldInst.
unsigned MaxUsers = 6; // Don't scan down huge single-use chains of instrs.
- const Instruction *TheUser = LI->use_back();
+ const Instruction *TheUser = LI->user_back();
while (TheUser != FoldInst && // Scan up until we find FoldInst.
// Stay in the right block.
TheUser->getParent() == FoldInst->getParent() &&
@@ -1532,7 +1532,7 @@
if (!TheUser->hasOneUse())
return false;
- TheUser = TheUser->use_back();
+ TheUser = TheUser->user_back();
}
// If we didn't find the fold instruction, then we failed to collapse the
diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 8898684..5f0006e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -47,12 +47,10 @@
if (I->use_empty()) return false;
if (isa<PHINode>(I)) return true;
const BasicBlock *BB = I->getParent();
- for (Value::const_use_iterator UI = I->use_begin(), E = I->use_end();
- UI != E; ++UI) {
- const User *U = *UI;
+ for (const User *U : I->users())
if (cast<Instruction>(U)->getParent() != BB || isa<PHINode>(U))
return true;
- }
+
return false;
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 1d82d3e..13daba08 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5580,9 +5580,8 @@
/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
/// value is equal or not-equal to zero.
static bool IsOnlyUsedInZeroEqualityComparison(const Value *V) {
- for (Value::const_use_iterator UI = V->use_begin(), E = V->use_end();
- UI != E; ++UI) {
- if (const ICmpInst *IC = dyn_cast<ICmpInst>(*UI))
+ for (const User *U : V->users()) {
+ if (const ICmpInst *IC = dyn_cast<ICmpInst>(U))
if (IC->isEquality())
if (const Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
if (C->isNullValue())
@@ -7326,12 +7325,10 @@
return A->use_empty();
const BasicBlock *Entry = A->getParent()->begin();
- for (Value::const_use_iterator UI = A->use_begin(), E = A->use_end();
- UI != E; ++UI) {
- const User *U = *UI;
+ for (const User *U : A->users())
if (cast<Instruction>(U)->getParent() != Entry || isa<SwitchInst>(U))
return false; // Use not in entry block.
- }
+
return true;
}