-fcatch-undefined-behavior: add the -ftrapv checks to the set of things caught
by this mode, and also check for signed left shift overflow. The rules for the
latter are a little subtle:
* neither C89 nor C++98 specify the behavior of a signed left shift at all
* in C99 and C11, shifting a 1 bit into the sign bit has undefined behavior
* in C++11, with core issue 1457, shifting a 1 bit *out* of the sign bit has
undefined behavior
As of this change, we use the C99 rules for all C language variants, and the
C++11 rules for all C++ language variants. Once we have individual
-fcatch-undefined-behavior= flags, this should be revisited.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162634 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/catch-undef-behavior.c b/test/CodeGen/catch-undef-behavior.c
index 8c45fa5..5832b6c 100644
--- a/test/CodeGen/catch-undef-behavior.c
+++ b/test/CodeGen/catch-undef-behavior.c
@@ -19,3 +19,28 @@
// CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
return *a;
}
+
+// CHECK: @lsh_overflow
+int lsh_overflow(int a, int b) {
+ // CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31
+ // CHECK-NEXT: br i1 %[[INBOUNDS]]
+
+ // CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]]
+ // CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]]
+ // CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT]], 0
+ // CHECK-NEXT: br i1 %[[NO_OVERFLOW]]
+
+ // CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]]
+ // CHECK-NEXT: ret i32 %[[RET]]
+ return a << b;
+}
+
+// CHECK: @rsh_inbounds
+int rsh_inbounds(int a, int b) {
+ // CHECK: %[[INBOUNDS:.*]] = icmp ult i32 %[[RHS:.*]], 32
+ // CHECK: br i1 %[[INBOUNDS]]
+
+ // CHECK: %[[RET:.*]] = ashr i32 %[[LHS]], %[[RHS]]
+ // CHECK-NEXT: ret i32 %[[RET]]
+ return a >> b;
+}
diff --git a/test/CodeGen/integer-overflow.c b/test/CodeGen/integer-overflow.c
index d7fff4e..176ee65 100644
--- a/test/CodeGen/integer-overflow.c
+++ b/test/CodeGen/integer-overflow.c
@@ -1,6 +1,7 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - | FileCheck %s --check-prefix=DEFAULT
// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - -fwrapv | FileCheck %s --check-prefix=WRAPV
// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - -ftrapv | FileCheck %s --check-prefix=TRAPV
+// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - -fcatch-undefined-behavior | FileCheck %s --check-prefix=CATCH_UB
// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - -ftrapv -ftrapv-handler foo | FileCheck %s --check-prefix=TRAPV_HANDLER
@@ -15,24 +16,28 @@
// DEFAULT: add nsw i32
// WRAPV: add i32
// TRAPV: llvm.sadd.with.overflow.i32
+ // CATCH_UB: llvm.sadd.with.overflow.i32
// TRAPV_HANDLER: foo(
f11G = a + b;
// DEFAULT: sub nsw i32
// WRAPV: sub i32
// TRAPV: llvm.ssub.with.overflow.i32
+ // CATCH_UB: llvm.ssub.with.overflow.i32
// TRAPV_HANDLER: foo(
f11G = a - b;
// DEFAULT: mul nsw i32
// WRAPV: mul i32
// TRAPV: llvm.smul.with.overflow.i32
+ // CATCH_UB: llvm.smul.with.overflow.i32
// TRAPV_HANDLER: foo(
f11G = a * b;
// DEFAULT: sub nsw i32 0,
// WRAPV: sub i32 0,
// TRAPV: llvm.ssub.with.overflow.i32(i32 0
+ // CATCH_UB: llvm.ssub.with.overflow.i32(i32 0
// TRAPV_HANDLER: foo(
f11G = -a;
@@ -41,12 +46,14 @@
// DEFAULT: add nsw i32 {{.*}}, 1
// WRAPV: add i32 {{.*}}, 1
// TRAPV: llvm.sadd.with.overflow.i32({{.*}}, i32 1)
+ // CATCH_UB: llvm.sadd.with.overflow.i32({{.*}}, i32 1)
// TRAPV_HANDLER: foo(
++a;
// DEFAULT: add nsw i32 {{.*}}, -1
// WRAPV: add i32 {{.*}}, -1
// TRAPV: llvm.sadd.with.overflow.i32({{.*}}, i32 -1)
+ // CATCH_UB: llvm.sadd.with.overflow.i32({{.*}}, i32 -1)
// TRAPV_HANDLER: foo(
--a;
@@ -56,11 +63,13 @@
// DEFAULT: getelementptr inbounds i32*
// WRAPV: getelementptr i32*
// TRAPV: getelementptr inbounds i32*
+ // CATCH_UB: getelementptr inbounds i32*
// PR9350: char increment never overflows.
extern volatile signed char PR9350;
// DEFAULT: add i8 {{.*}}, 1
// WRAPV: add i8 {{.*}}, 1
// TRAPV: add i8 {{.*}}, 1
+ // CATCH_UB: add i8 {{.*}}, 1
++PR9350;
}
diff --git a/test/CodeGen/trapv.c b/test/CodeGen/trapv.c
index f52dad5..abad585 100644
--- a/test/CodeGen/trapv.c
+++ b/test/CodeGen/trapv.c
@@ -1,4 +1,5 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -ftrapv %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fcatch-undefined-behavior %s -emit-llvm -o - | FileCheck %s
unsigned int ui, uj, uk;
int i, j, k;
diff --git a/test/CodeGenCXX/catch-undef-behavior.cpp b/test/CodeGenCXX/catch-undef-behavior.cpp
index ed0a776..0ec1cc1 100644
--- a/test/CodeGenCXX/catch-undef-behavior.cpp
+++ b/test/CodeGenCXX/catch-undef-behavior.cpp
@@ -66,3 +66,23 @@
// CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
k = p->f();
}
+
+// CHECK: @_Z12lsh_overflow
+int lsh_overflow(int a, int b) {
+ // CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31
+ // CHECK-NEXT: br i1 %[[INBOUNDS]]
+
+ // CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]]
+ // CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]]
+
+ // This is present for C++11 but not for C: C++ core issue 1457 allows a '1'
+ // to be shifted into the sign bit, but not out of it.
+ // CHECK-NEXT: %[[SHIFTED_OUT_NOT_SIGN:.*]] = lshr i32 %[[SHIFTED_OUT]], 1
+
+ // CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT_NOT_SIGN]], 0
+ // CHECK-NEXT: br i1 %[[NO_OVERFLOW]]
+
+ // CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]]
+ // CHECK-NEXT: ret i32 %[[RET]]
+ return a << b;
+}