From 42b5e08e7123aefbc6e93b547f44e3ed7604526f Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 23 Nov 2007 08:46:22 +0000
Subject: [PATCH] Fix a bug where we'd try to find a scev value for a bitcast
 operand, even though the bitcast operand did not have integer type.  This
 fixes PR1814.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44286 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/ScalarEvolution.cpp              |  8 ++++++++
 .../2007-11-23-BitcastCrash.ll                | 20 +++++++++++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 test/Transforms/IndVarsSimplify/2007-11-23-BitcastCrash.ll

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index cc6cde2ba21..1508fd0c524 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1470,6 +1470,9 @@ static uint32_t GetMinTrailingZeros(SCEVHandle S) {
 /// Analyze the expression.
 ///
 SCEVHandle ScalarEvolutionsImpl::createSCEV(Value *V) {
+  if (!isa<IntegerType>(V->getType()))
+    return SE.getUnknown(V);
+    
   if (Instruction *I = dyn_cast<Instruction>(V)) {
     switch (I->getOpcode()) {
     case Instruction::Add:
@@ -2076,6 +2079,11 @@ SCEVHandle ScalarEvolutionsImpl::getSCEVAtScope(SCEV *V, const Loop *L) {
           if (Constant *C = dyn_cast<Constant>(Op)) {
             Operands.push_back(C);
           } else {
+            // If any of the operands is non-constant and if they are
+            // non-integer, don't even try to analyze them with scev techniques.
+            if (!isa<IntegerType>(Op->getType()))
+              return V;
+              
             SCEVHandle OpV = getSCEVAtScope(getSCEV(Op), L);
             if (SCEVConstant *SC = dyn_cast<SCEVConstant>(OpV))
               Operands.push_back(ConstantExpr::getIntegerCast(SC->getValue(), 
diff --git a/test/Transforms/IndVarsSimplify/2007-11-23-BitcastCrash.ll b/test/Transforms/IndVarsSimplify/2007-11-23-BitcastCrash.ll
new file mode 100644
index 00000000000..555cadda6de
--- /dev/null
+++ b/test/Transforms/IndVarsSimplify/2007-11-23-BitcastCrash.ll
@@ -0,0 +1,20 @@
+; RUN: llvm-as < %s | opt -indvars -disable-output
+; PR1814
+target datalayout = "e-p:32:32-f64:32:64-i64:32:64-f80:32:32"
+
+define void @FuncAt1938470480(i32, i32, i32, i32, i32, i32, i32, i32, i64, i64, i64, i64, i64, i64, i64, i64, i1, i1, i1, i1, i1, i1) {
+EntryBlock:
+	br label %asmBlockAt738ab7f3
+
+asmBlockAt738ab9b0:		; preds = %asmBlockAt738ab7f3
+	%.lcssa6 = phi i64 [ %23, %asmBlockAt738ab7f3 ]		; <i64> [#uses=0]
+	ret void
+
+asmBlockAt738ab7f3:		; preds = %asmBlockAt738ab7f3, %EntryBlock
+	%ebp95 = phi i32 [ 128, %EntryBlock ], [ %24, %asmBlockAt738ab7f3 ]		; <i32> [#uses=2]
+	sub <4 x i16> zeroinitializer, zeroinitializer		; <<4 x i16>>:22 [#uses=1]
+	bitcast <4 x i16> %22 to i64		; <i64>:23 [#uses=1]
+	add i32 %ebp95, -64		; <i32>:24 [#uses=1]
+	icmp ult i32 %ebp95, 64		; <i1>:25 [#uses=1]
+	br i1 %25, label %asmBlockAt738ab9b0, label %asmBlockAt738ab7f3
+}
-- 
2.34.1