[IR] Value: add replaceUsesWithIf() utility

Summary:
While there is always a `Value::replaceAllUsesWith()`,
sometimes the replacement needs to be conditional.

I have only cleaned a few cases where `replaceUsesWithIf()`
could be used, to both add test coverage,
and show that it is actually useful.

Reviewers: jdoerfert, spatel, RKSimon, craig.topper

Reviewed By: jdoerfert

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, aheejin, george.burgess.iv, asbirlea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65528

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367548 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/IR/Value.h b/include/llvm/IR/Value.h
index b2d8e7ac474149aafd8c7aee092c09c003c5f3b8..62db353ba53dcde6d8adb2333538512a88f60d44 100644 (file)
--- a/include/llvm/IR/Value.h
+++ b/include/llvm/IR/Value.h
@@ -14,6 +14,7 @@
 #define LLVM_IR_VALUE_H
 
 #include "llvm-c/Types.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/IR/Use.h"
 #include "llvm/Support/CBindingWrapping.h"
@@ -292,10 +293,29 @@ public:
   /// "V" instead of "this". This function skips metadata entries in the list.
   void replaceNonMetadataUsesWith(Value *V);
 
+  /// Go through the uses list for this definition and make each use point
+  /// to "V" if the callback ShouldReplace returns true for the given Use.
+  /// Unlike replaceAllUsesWith() this function does not support basic block
+  /// values or constant users.
+  void replaceUsesWithIf(Value *New,
+                         llvm::function_ref<bool(Use &U)> ShouldReplace) {
+    assert(New && "Value::replaceUsesWithIf(<null>) is invalid!");
+    assert(New->getType() == getType() &&
+           "replaceUses of value with new value of different type!");
+
+    for (use_iterator UI = use_begin(), E = use_end(); UI != E;) {
+      Use &U = *UI;
+      ++UI;
+      if (!ShouldReplace(U))
+        continue;
+      U.set(New);
+    }
+  }
+
   /// replaceUsesOutsideBlock - Go through the uses list for this definition and
   /// make each use point to "V" instead of "this" when the use is outside the
   /// block. 'This's use list is expected to have at least one element.
-  /// Unlike replaceAllUsesWith this function does not support basic block
+  /// Unlike replaceAllUsesWith() this function does not support basic block
   /// values or constant users.
   void replaceUsesOutsideBlock(Value *V, BasicBlock *BB);
 

diff --git a/lib/Analysis/MemorySSAUpdater.cpp b/lib/Analysis/MemorySSAUpdater.cpp
index 7fea41a8a534f3537c9628d983abfd2516580ffc..39882dab04ca4d7fbecfb99effa2609f2d2fc1d9 100644 (file)
--- a/lib/Analysis/MemorySSAUpdater.cpp
+++ b/lib/Analysis/MemorySSAUpdater.cpp
@@ -267,17 +267,14 @@ void MemorySSAUpdater::insertDef(MemoryDef *MD, bool RenameUses) {
   // before.
   // We now define that def's memorydefs and memoryphis
   if (DefBeforeSameBlock) {
-    for (auto UI = DefBefore->use_begin(), UE = DefBefore->use_end();
-         UI != UE;) {
-      Use &U = *UI++;
+    DefBefore->replaceUsesWithIf(MD, [MD](Use &U) {
       // Leave the MemoryUses alone.
       // Also make sure we skip ourselves to avoid self references.
-      if (isa<MemoryUse>(U.getUser()) || U.getUser() == MD)
-        continue;
+      User *Usr = U.getUser();
+      return !isa<MemoryUse>(Usr) && Usr != MD;
       // Defs are automatically unoptimized when the user is set to MD below,
       // because the isOptimized() call will fail to find the same ID.
-      U.set(MD);
-    }
+    });
   }
 
   // and that def is now our defining access.

diff --git a/lib/IR/Value.cpp b/lib/IR/Value.cpp
index c0efab4a35d6aa80b406f583da7bcc5549470553..763bc2099ef3e7b4071d65835421dacfa9231ca5 100644 (file)
--- a/lib/IR/Value.cpp
+++ b/lib/IR/Value.cpp
@@ -444,15 +444,11 @@ void Value::replaceUsesOutsideBlock(Value *New, BasicBlock *BB) {
          "replaceUses of value with new value of different type!");
   assert(BB && "Basic block that may contain a use of 'New' must be defined\n");
 
-  use_iterator UI = use_begin(), E = use_end();
-  for (; UI != E;) {
-    Use &U = *UI;
-    ++UI;
-    auto *Usr = dyn_cast<Instruction>(U.getUser());
-    if (Usr && Usr->getParent() == BB)
-      continue;
-    U.set(New);
-  }
+  replaceUsesWithIf(New, [BB](Use &U) {
+    auto *I = dyn_cast<Instruction>(U.getUser());
+    // Don't replace if it's an instruction in the BB basic block.
+    return !I || I->getParent() != BB;
+  });
 }
 
 namespace {

diff --git a/lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp b/lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp
index d20352259e07369788a3ae111d185f2c3f714c34..9b60596e42b43ea81fd11e18ebb728893c7a9fc4 100644 (file)
--- a/lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp
+++ b/lib/Target/WebAssembly/WebAssemblyOptimizeReturned.cpp
@@ -64,11 +64,8 @@ void OptimizeReturned::visitCallSite(CallSite CS) {
       if (isa<Constant>(Arg))
         continue;
       // Like replaceDominatedUsesWith but using Instruction/Use dominance.
-      for (auto UI = Arg->use_begin(), UE = Arg->use_end(); UI != UE;) {
-        Use &U = *UI++;
-        if (DT->dominates(Inst, U))
-          U.set(Inst);
-      }
+      Arg->replaceUsesWithIf(Inst,
+                             [&](Use &U) { return DT->dominates(Inst, U); });
     }
 }
 

diff --git a/lib/Transforms/IPO/LowerTypeTests.cpp b/lib/Transforms/IPO/LowerTypeTests.cpp
index 716d4e8ede75d0a2373f1ea7de4c456aa1823b81..769dc484b9e07ae55379196bffa0dfca8153099e 100644 (file)
--- a/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -1685,16 +1685,7 @@ void LowerTypeTestsModule::replaceCfiUses(Function *Old, Value *New, bool IsDefi
 }
 
 void LowerTypeTestsModule::replaceDirectCalls(Value *Old, Value *New) {
-  auto UI = Old->use_begin(), E = Old->use_end();
-  for (; UI != E;) {
-    Use &U = *UI;
-    ++UI;
-
-    if (!isDirectCall(U))
-      continue;
-
-    U.set(New);
-  }
+  Old->replaceUsesWithIf(New, [](Use &U) { return isDirectCall(U); });
 }
 
 bool LowerTypeTestsModule::lower() {

diff --git a/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index f190a319d139dedab4bd3381b16c6cad83e2a8a5..0b586e34c2707e11daa3b7d19692e17a53b51d22 100644 (file)
--- a/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -1002,11 +1002,8 @@ bool HWAddressSanitizer::instrumentStack(
         AI->hasName() ? AI->getName().str() : "alloca." + itostr(N);
     Replacement->setName(Name + ".hwasan");
 
-    for (auto UI = AI->use_begin(), UE = AI->use_end(); UI != UE;) {
-      Use &U = *UI++;
-      if (U.getUser() != AILong)
-        U.set(Replacement);
-    }
+    AI->replaceUsesWithIf(Replacement,
+                          [AILong](Use &U) { return U.getUser() != AILong; });
 
     for (auto *DDI : AllocaDeclareMap.lookup(AI)) {
       DIExpression *OldExpr = DDI->getExpression();

diff --git a/lib/Transforms/Scalar/LoopSink.cpp b/lib/Transforms/Scalar/LoopSink.cpp
index 975452e13f099bb545d54a549887971a487b3c5d..65e0dee0225ae0adff5d7dce9a71f92c9c78da91 100644 (file)
--- a/lib/Transforms/Scalar/LoopSink.cpp
+++ b/lib/Transforms/Scalar/LoopSink.cpp
@@ -230,12 +230,9 @@ static bool sinkInstruction(Loop &L, Instruction &I,
     IC->setName(I.getName());
     IC->insertBefore(&*N->getFirstInsertionPt());
     // Replaces uses of I with IC in N
-    for (Value::use_iterator UI = I.use_begin(), UE = I.use_end(); UI != UE;) {
-      Use &U = *UI++;
-      auto *I = cast<Instruction>(U.getUser());
-      if (I->getParent() == N)
-        U.set(IC);
-    }
+    I.replaceUsesWithIf(IC, [N](Use &U) {
+      return cast<Instruction>(U.getUser())->getParent() == N;
+    });
     // Replaces uses of I with IC in blocks dominated by N
     replaceDominatedUsesWith(&I, IC, DT, N);
     LLVM_DEBUG(dbgs() << "Sinking a clone of " << I << " To: " << N->getName()