From a73a654bb42b2117eb8b52b1401862373ace4760 Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Tue, 3 Oct 2006 15:19:11 +0000
Subject: [PATCH] Simplify, now that predsimplify depends on break-crit-edges.
 Fix SwitchInst where dest-block is the same as one of the cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30700 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/PredicateSimplifier.cpp | 34 +++++--------------
 1 file changed, 8 insertions(+), 26 deletions(-)

diff --git a/lib/Transforms/Scalar/PredicateSimplifier.cpp b/lib/Transforms/Scalar/PredicateSimplifier.cpp
index b6de61bacd1..99832907998 100644
--- a/lib/Transforms/Scalar/PredicateSimplifier.cpp
+++ b/lib/Transforms/Scalar/PredicateSimplifier.cpp
@@ -413,8 +413,6 @@ namespace {
     // Used by terminator instructions to proceed from the current basic
     // block to the next. Verifies that "current" dominates "next",
     // then calls visitBasicBlock.
-    void proceedToSuccessor(TerminatorInst *TI, unsigned edge,
-                            PropertySet &CurrentPS, PropertySet &NextPS);
     void proceedToSuccessors(PropertySet &CurrentPS, BasicBlock *Current);
 
     // Visits each instruction in the basic block.
@@ -616,17 +614,6 @@ void PredicateSimplifier::visitInstruction(Instruction *I,
     visit(BO, KnownProperties);
 }
 
-// The basic block on the target of the specified edge must be known
-// to be immediately dominated by the parent of the TerminatorInst.
-void PredicateSimplifier::proceedToSuccessor(TerminatorInst *TI,
-                                             unsigned edge,
-                                             PropertySet &CurrentPS,
-                                             PropertySet &NextPS) {
-  assert(edge < TI->getNumSuccessors() && "Invalid index for edge.");
-
-  visitBasicBlock(TI->getSuccessor(edge), NextPS);
-}
-
 void PredicateSimplifier::proceedToSuccessors(PropertySet &KP,
                                               BasicBlock *BBCurrent) {
   DTNodeType *Current = DT->getNode(BBCurrent);
@@ -676,14 +663,14 @@ void PredicateSimplifier::visit(BranchInst *BI, PropertySet &KP) {
     if ((*I)->getBlock() == TrueDest) {
       PropertySet TrueProperties(KP);
       TrueProperties.addEqual(ConstantBool::getTrue(), Condition);
-      proceedToSuccessor(BI, 0, KP, TrueProperties);
+      visitBasicBlock(TrueDest, TrueProperties);
       continue;
     }
 
     if ((*I)->getBlock() == FalseDest) {
       PropertySet FalseProperties(KP);
       FalseProperties.addEqual(ConstantBool::getFalse(), Condition);
-      proceedToSuccessor(BI, 1, KP, FalseProperties);
+      visitBasicBlock(FalseDest, FalseProperties);
       continue;
     }
 
@@ -702,20 +689,15 @@ void PredicateSimplifier::visit(SwitchInst *SI, PropertySet KP) {
   for (DTNodeType::iterator I = Node->begin(), E = Node->end(); I != E; ++I) {
     BasicBlock *BB = (*I)->getBlock();
 
-    PropertySet Copy(KP);
-
+    PropertySet BBProperties(KP);
     if (BB == SI->getDefaultDest()) {
-      PropertySet NewProperties(KP);
       for (unsigned i = 1, e = SI->getNumCases(); i < e; ++i)
-        NewProperties.addNotEqual(Condition, SI->getCaseValue(i));
-
-      proceedToSuccessor(SI, 0, Copy, NewProperties);
+        if (SI->getSuccessor(i) != BB)
+          BBProperties.addNotEqual(Condition, SI->getCaseValue(i));
     } else if (ConstantInt *CI = SI->findCaseDest(BB)) {
-      PropertySet NewProperties(KP);
-      NewProperties.addEqual(Condition, CI);
-      proceedToSuccessor(SI, SI->findCaseValue(CI), Copy, NewProperties);
-    } else 
-      visitBasicBlock(BB, Copy);
+      BBProperties.addEqual(Condition, CI);
+    }
+    visitBasicBlock(BB, BBProperties);
   }
 }
 
-- 
2.34.1