Fix a bug in IRBuilder that's been there for who knows how long. It

failed to correctly propagate the NUW and NSW flags to the constant
folder for two instructions. I've added a unittest to cover flag
propagation for the rest of the instructions and constant expressions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198538 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 51 insertions, 0 deletions

diff --git a/unittests/IR/IRBuilderTest.cpp b/unittests/IR/IRBuilderTest.cpp
index fcb5677907..a0a72e82ed 100644
--- a/unittests/IR/IRBuilderTest.cpp
+++ b/unittests/IR/IRBuilderTest.cpp
@@ -16,6 +16,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/Module.h"
+#include "llvm/Support/NoFolder.h"
 #include "gtest/gtest.h"
 
 using namespace llvm;
@@ -190,6 +191,56 @@ TEST_F(IRBuilderTest, FastMathFlags) {
 
 }
 
+TEST_F(IRBuilderTest, WrapFlags) {
+  IRBuilder<true, NoFolder> Builder(BB);
+
+  // Test instructions.
+  GlobalVariable *G = new GlobalVariable(*M, Builder.getInt32Ty(), true,
+                                         GlobalValue::ExternalLinkage, 0);
+  Value *V = Builder.CreateLoad(G);
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNSWAdd(V, V))->hasNoSignedWrap());
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNSWMul(V, V))->hasNoSignedWrap());
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNSWSub(V, V))->hasNoSignedWrap());
+  EXPECT_TRUE(cast<BinaryOperator>(
+                  Builder.CreateShl(V, V, "", /* NUW */ false, /* NSW */ true))
+                  ->hasNoSignedWrap());
+
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNUWAdd(V, V))->hasNoUnsignedWrap());
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNUWMul(V, V))->hasNoUnsignedWrap());
+  EXPECT_TRUE(
+      cast<BinaryOperator>(Builder.CreateNUWSub(V, V))->hasNoUnsignedWrap());
+  EXPECT_TRUE(cast<BinaryOperator>(
+                  Builder.CreateShl(V, V, "", /* NUW */ true, /* NSW */ false))
+                  ->hasNoUnsignedWrap());
+
+  // Test operators created with constants.
+  Constant *C = Builder.getInt32(42);
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNSWAdd(C, C))
+                  ->hasNoSignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNSWSub(C, C))
+                  ->hasNoSignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNSWMul(C, C))
+                  ->hasNoSignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(
+                  Builder.CreateShl(C, C, "", /* NUW */ false, /* NSW */ true))
+                  ->hasNoSignedWrap());
+
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNUWAdd(C, C))
+                  ->hasNoUnsignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNUWSub(C, C))
+                  ->hasNoUnsignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(Builder.CreateNUWMul(C, C))
+                  ->hasNoUnsignedWrap());
+  EXPECT_TRUE(cast<OverflowingBinaryOperator>(
+                  Builder.CreateShl(C, C, "", /* NUW */ true, /* NSW */ false))
+                  ->hasNoUnsignedWrap());
+}
+
 TEST_F(IRBuilderTest, RAIIHelpersTest) {
   IRBuilder<> Builder(BB);
   EXPECT_FALSE(Builder.getFastMathFlags().allowReciprocal());