Change the IR-generation of VLAs so that we capture bounds,

not sizes;  so that we use well-typed allocas;  and so that we
properly recurse through the full set of variably-modified types.

llvm-svn: 133827

1 files changed, 43 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/vla.cpp b/clang/test/CodeGenCXX/vla.cpp
new file mode 100644
index 00000000000..cee00f27713
--- /dev/null
+++ b/clang/test/CodeGenCXX/vla.cpp
@@ -0,0 +1,43 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin %s -emit-llvm -o - | FileCheck %s
+
+// rdar://problem/9506377
+void test0(void *array, int n) {
+  // CHECK: define void @_Z5test0Pvi(
+  // CHECK:      [[ARRAY:%.*]] = alloca i8*, align 8
+  // CHECK-NEXT: [[N:%.*]] = alloca i32, align 4
+  // CHECK-NEXT: [[REF:%.*]] = alloca i16*, align 8
+  // CHECK-NEXT: [[S:%.*]] = alloca i16, align 2
+  // CHECK-NEXT: store i8* 
+  // CHECK-NEXT: store i32
+
+  // Capture the bounds.
+  // CHECK-NEXT: [[T0:%.*]] = load i32* [[N]], align 4
+  // CHECK-NEXT: [[DIM0:%.*]] = zext i32 [[T0]] to i64
+  // CHECK-NEXT: [[T0:%.*]] = load i32* [[N]], align 4
+  // CHECK-NEXT: [[T1:%.*]] = add nsw i32 [[T0]], 1
+  // CHECK-NEXT: [[DIM1:%.*]] = zext i32 [[T1]] to i64
+  typedef short array_t[n][n+1];
+
+  // CHECK-NEXT: [[T0:%.*]] = load i8** [[ARRAY]], align 8
+  // CHECK-NEXT: [[T1:%.*]] = bitcast i8* [[T0]] to i16*
+  // CHECK-NEXT: store i16* [[T1]], i16** [[REF]], align 8
+  array_t &ref = *(array_t*) array;
+
+  // CHECK-NEXT: [[T0:%.*]] = load i16** [[REF]]
+  // CHECK-NEXT: [[T1:%.*]] = mul i64 1, [[DIM1]]
+  // CHECK-NEXT: [[T2:%.*]] = getelementptr inbounds i16* [[T0]], i64 [[T1]]
+  // CHECK-NEXT: [[T3:%.*]] = getelementptr inbounds i16* [[T2]], i64 2
+  // CHECK-NEXT: store i16 3, i16* [[T3]]
+  ref[1][2] = 3;
+
+  // CHECK-NEXT: [[T0:%.*]] = load i16** [[REF]]
+  // CHECK-NEXT: [[T1:%.*]] = mul i64 4, [[DIM1]]
+  // CHECK-NEXT: [[T2:%.*]] = getelementptr inbounds i16* [[T0]], i64 [[T1]]
+  // CHECK-NEXT: [[T3:%.*]] = getelementptr inbounds i16* [[T2]], i64 5
+  // CHECK-NEXT: [[T4:%.*]] = load i16* [[T3]]
+  // CHECK-NEXT: store i16 [[T4]], i16* [[S]], align 2
+  short s = ref[4][5];
+
+  // CHECK-NEXT: ret void
+}
+