Fix a major bug with -ftrapv and ++/--. Patch by David Keaton!

llvm-svn: 110347

2 files changed, 67 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index fb277c6f0e2..8d28b2485f2 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1193,7 +1193,8 @@ EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
         BinOp.Ty = E->getType();
         BinOp.Opcode = BinaryOperator::Add;
         BinOp.E = E;
-        return EmitOverflowCheckedBinOp(BinOp);
+        NextVal = EmitOverflowCheckedBinOp(BinOp);
+        break;
       }
     }
   } else {
diff --git a/clang/test/CodeGen/trapv.c b/clang/test/CodeGen/trapv.c
index d10d6176bf9..46b1c8b14f8 100644
--- a/clang/test/CodeGen/trapv.c
+++ b/clang/test/CodeGen/trapv.c
@@ -1,10 +1,72 @@
-// RUN: %clang_cc1 -ftrapv %s -emit-llvm -o %t
-// RUN: grep "__overflow_handler" %t | count 2
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -ftrapv %s -emit-llvm -o - | FileCheck %s
+
+// CHECK: [[I32O:%.*]] = type { i32, i1 }
 
 unsigned int ui, uj, uk;
 int i, j, k;
 
-void foo() {
+// CHECK: define void @test0()
+void test0() {
+  // -ftrapv doesn't affect unsigned arithmetic.
+  // CHECK:      [[T1:%.*]] = load i32* @uj
+  // CHECK-NEXT: [[T2:%.*]] = load i32* @uk
+  // CHECK-NEXT: [[T3:%.*]] = add i32 [[T1]], [[T2]]
+  // CHECK-NEXT: store i32 [[T3]], i32* @ui
   ui = uj + uk;
+
+  // CHECK:      [[T1:%.*]] = load i32* @j
+  // CHECK-NEXT: [[T2:%.*]] = load i32* @k
+  // CHECK-NEXT: [[T3:%.*]] = call [[I32O]] @llvm.sadd.with.overflow.i32(i32 [[T1]], i32 [[T2]])
+  // CHECK-NEXT: [[T4:%.*]] = extractvalue [[I32O]] [[T3]], 0
+  // CHECK-NEXT: [[T5:%.*]] = extractvalue [[I32O]] [[T3]], 1
+  // CHECK-NEXT: br i1 [[T5]]
+  // CHECK:      [[F:%.*]] = load i64 (i64, i64, i8, i8)** @__overflow_handler
+  // CHECK-NEXT: [[T6:%.*]] = sext i32 [[T1]] to i64
+  // CHECK-NEXT: [[T7:%.*]] = sext i32 [[T2]] to i64
+  // CHECK-NEXT: [[T8:%.*]] = call i64 [[F]](i64 [[T6]], i64 [[T7]], i8 3, i8 32)
+  // CHECK-NEXT: [[T9:%.*]] = trunc i64 [[T8]] to i32
+  // CHECK-NEXT: br label
+  // CHECK:      [[T10:%.*]] = phi i32 [ [[T4]], {{.*}} ], [ [[T9]], {{.*}} ]
+  // CHECK-NEXT: store i32 [[T10]], i32* @i
   i = j + k;
 }
+
+// CHECK: define void @test1()
+void test1() {
+  extern void opaque(int);
+  opaque(i++);
+
+  // CHECK:      [[T1:%.*]] = load i32* @i
+  // CHECK-NEXT: [[T2:%.*]] = call [[I32O]] @llvm.sadd.with.overflow.i32(i32 [[T1]], i32 1)
+  // CHECK-NEXT: [[T3:%.*]] = extractvalue [[I32O]] [[T2]], 0
+  // CHECK-NEXT: [[T4:%.*]] = extractvalue [[I32O]] [[T2]], 1
+  // CHECK-NEXT: br i1 [[T4]]
+  // CHECK:      [[F:%.*]] = load i64 (i64, i64, i8, i8)** @__overflow_handler
+  // CHECK-NEXT: [[T5:%.*]] = sext i32 [[T1]] to i64
+  // CHECK-NEXT: [[T6:%.*]] = call i64 [[F]](i64 [[T5]], i64 1, i8 3, i8 32)
+  // CHECK-NEXT: [[T7:%.*]] = trunc i64 [[T6]] to i32
+  // CHECK-NEXT: br label
+  // CHECK:      [[T8:%.*]] = phi i32 [ [[T3]], {{.*}} ], [ [[T7]], {{.*}} ]
+  // CHECK-NEXT: store i32 [[T8]], i32* @i
+  // CHECK-NEXT: call void @opaque(i32 [[T1]])
+}
+
+// CHECK: define void @test2()
+void test2() {
+  extern void opaque(int);
+  opaque(++i);
+
+  // CHECK:      [[T1:%.*]] = load i32* @i
+  // CHECK-NEXT: [[T2:%.*]] = call [[I32O]] @llvm.sadd.with.overflow.i32(i32 [[T1]], i32 1)
+  // CHECK-NEXT: [[T3:%.*]] = extractvalue [[I32O]] [[T2]], 0
+  // CHECK-NEXT: [[T4:%.*]] = extractvalue [[I32O]] [[T2]], 1
+  // CHECK-NEXT: br i1 [[T4]]
+  // CHECK:      [[F:%.*]] = load i64 (i64, i64, i8, i8)** @__overflow_handler
+  // CHECK-NEXT: [[T5:%.*]] = sext i32 [[T1]] to i64
+  // CHECK-NEXT: [[T6:%.*]] = call i64 [[F]](i64 [[T5]], i64 1, i8 3, i8 32)
+  // CHECK-NEXT: [[T7:%.*]] = trunc i64 [[T6]] to i32
+  // CHECK-NEXT: br label
+  // CHECK:      [[T8:%.*]] = phi i32 [ [[T3]], {{.*}} ], [ [[T7]], {{.*}} ]
+  // CHECK-NEXT: store i32 [[T8]], i32* @i
+  // CHECK-NEXT: call void @opaque(i32 [[T8]])
+}