Introduce f[no-]max-unknown-pointer-align=[number] option

to instruct the code generator to not enforce a higher alignment 
than the given number (of bytes) when accessing memory via an opaque 
pointer or reference. Patch reviewed by John McCall (with post-commit
review pending). rdar://16254558


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@214911 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 57 insertions, 0 deletions

diff --git a/test/CodeGenCXX/align-avx-complete-objects.cpp b/test/CodeGenCXX/align-avx-complete-objects.cpp
new file mode 100644
index 0000000000..25f4ef1099
--- /dev/null
+++ b/test/CodeGenCXX/align-avx-complete-objects.cpp
@@ -0,0 +1,57 @@
+// RUN: %clang_cc1 -x c++ %s -O0 -triple=x86_64-apple-darwin -target-feature +avx2 -fmax-type-align=16 -emit-llvm -o - -Werror | FileCheck %s
+// rdar://16254558
+
+typedef float AVX2Float __attribute__((__vector_size__(32)));
+
+
+volatile float TestAlign(void)
+{
+       volatile AVX2Float *p = new AVX2Float;
+        *p = *p;
+        AVX2Float r = *p;
+        return r[0];
+}
+
+// CHECK: [[R:%.*]] = alloca <8 x float>, align 32
+// CHECK-NEXT:  [[CALL:%.*]] = call noalias i8* @_Znwm(i64 32)
+// CHECK-NEXT:  [[ZERO:%.*]] = bitcast i8* [[CALL]] to <8 x float>*
+// CHECK-NEXT:  store <8 x float>* [[ZERO]], <8 x float>** [[P:%.*]], align 8
+// CHECK-NEXT:  [[ONE:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  [[TWO:%.*]] = load volatile <8 x float>* [[ONE]], align 16
+// CHECK-NEXT:  [[THREE:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  store volatile <8 x float> [[TWO]], <8 x float>* [[THREE]], align 16
+// CHECK-NEXT:  [[FOUR:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  [[FIVE:%.*]] = load volatile <8 x float>* [[FOUR]], align 16
+// CHECK-NEXT:  store <8 x float> [[FIVE]], <8 x float>* [[R]], align 32
+// CHECK-NEXT:  [[SIX:%.*]] = load <8 x float>* [[R]], align 32
+// CHECK-NEXT:  [[VECEXT:%.*]] = extractelement <8 x float> [[SIX]], i32 0
+// CHECK-NEXT:  ret float [[VECEXT]]
+
+typedef float AVX2Float_Explicitly_aligned __attribute__((__vector_size__(32))) __attribute__((aligned (32)));
+
+typedef AVX2Float_Explicitly_aligned AVX2Float_indirect;
+
+typedef AVX2Float_indirect AVX2Float_use_existing_align;
+
+volatile float TestAlign2(void)
+{
+       volatile AVX2Float_use_existing_align *p = new AVX2Float_use_existing_align;
+        *p = *p;
+        AVX2Float_use_existing_align r = *p;
+        return r[0];
+}
+
+// CHECK: [[R:%.*]] = alloca <8 x float>, align 32
+// CHECK-NEXT:  [[CALL:%.*]] = call noalias i8* @_Znwm(i64 32)
+// CHECK-NEXT:  [[ZERO:%.*]] = bitcast i8* [[CALL]] to <8 x float>*
+// CHECK-NEXT:  store <8 x float>* [[ZERO]], <8 x float>** [[P:%.*]], align 8
+// CHECK-NEXT:  [[ONE:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  [[TWO:%.*]] = load volatile <8 x float>* [[ONE]], align 32
+// CHECK-NEXT:  [[THREE:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  store volatile <8 x float> [[TWO]], <8 x float>* [[THREE]], align 32
+// CHECK-NEXT:  [[FOUR:%.*]] = load <8 x float>** [[P]], align 8
+// CHECK-NEXT:  [[FIVE:%.*]] = load volatile <8 x float>* [[FOUR]], align 32
+// CHECK-NEXT:  store <8 x float> [[FIVE]], <8 x float>* [[R]], align 32
+// CHECK-NEXT:  [[SIX:%.*]] = load <8 x float>* [[R]], align 32
+// CHECK-NEXT:  [[VECEXT:%.*]] = extractelement <8 x float> [[SIX]], i32 0
+// CHECK-NEXT:  ret float [[VECEXT]]