[OPENMP50]Codegen for scan directives in parallel for simd regions.

Summary:
Added codegen for scan directives in parallel for simd regions.

Emits the code for the directive with inscan reductions.
Original code:
```
 #pragma omp parallel for simd reduction(inscan, op : ...)
for() {
  <input phase>;
  #pragma omp scan (in)exclusive(...)
  <scan phase>
}
```
is transformed to something:
```
 #pragma omp parallel
{
size num_iters = <num_iters>;
<type> buffer[num_iters];
 #pragma omp for simd
for (i: 0..<num_iters>) {
  <input phase>;
  buffer[i] = red;
}
 #pragma omp barrier
for (int k = 0; k != ceil(log2(num_iters)); ++k)
for (size cnt = last_iter; cnt >= pow(2, k); --k)
  buffer[i] op= buffer[i-pow(2,k)];
 #pragma omp for simd
for (0..<num_iters>) {
  red = InclusiveScan ? buffer[i] : buffer[i-1];
  <scan phase>;
}
}
```

Reviewers: jdoerfert

Subscribers: yaxunl, guansong, sstefan1, cfe-commits, caomhin

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82115

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index a3677bf..b380143 100644 (file)
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -3627,13 +3627,12 @@ void CodeGenFunction::EmitOMPParallelForSimdDirective(
   // directives: 'parallel' with 'for' directive.
   auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
     Action.Enter(CGF);
-    CGF.EmitOMPWorksharingLoop(S, S.getEnsureUpperBound(), emitForLoopBounds,
-                               emitDispatchForLoopBounds);
+    (void)emitWorksharingDirective(CGF, S, /*HasCancel=*/false);
   };
   {
     auto LPCRegion =
         CGOpenMPRuntime::LastprivateConditionalRAII::disable(*this, S);
-    emitCommonOMPParallelDirective(*this, S, OMPD_simd, CodeGen,
+    emitCommonOMPParallelDirective(*this, S, OMPD_for_simd, CodeGen,
                                    emitEmptyBoundParameters);
   }
   // Check for outer lastprivate conditional update.

diff --git a/clang/test/OpenMP/parallel_for_simd_scan_codegen.cpp b/clang/test/OpenMP/parallel_for_simd_scan_codegen.cpp
new file mode 100644 (file)
index 0000000..42fb9de
--- /dev/null
+++ b/clang/test/OpenMP/parallel_for_simd_scan_codegen.cpp
@@ -0,0 +1,315 @@
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -std=c++11 -triple x86_64-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s
+
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -emit-llvm %s -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -std=c++11 -triple x86_64-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// SIMD-ONLY0-NOT: {{__kmpc|__tgt}}
+// expected-no-diagnostics
+#ifndef HEADER
+#define HEADER
+
+void foo();
+void bar();
+
+// CHECK: define void @{{.*}}baz{{.*}}(i32 %n)
+void baz(int n) {
+  static float a[10];
+  static double b;
+
+  // CHECK: call void (%struct.ident_t*, i32, void (i32*, i32*, ...)*, ...) @__kmpc_fork_call(
+  // CHECK: call void (%struct.ident_t*, i32, void (i32*, i32*, ...)*, ...) @__kmpc_fork_call(
+
+  // CHECK: call i8* @llvm.stacksave()
+  // CHECK: [[A_BUF_SIZE:%.+]] = mul nuw i64 10, [[NUM_ELEMS:%[^,]+]]
+
+  // float a_buffer[10][n];
+  // CHECK: [[A_BUF:%.+]] = alloca float, i64 [[A_BUF_SIZE]],
+
+  // double b_buffer[10];
+  // CHECK: [[B_BUF:%.+]] = alloca double, i64 10,
+#pragma omp parallel for simd reduction(inscan, +:a[:n], b)
+  for (int i = 0; i < 10; ++i) {
+    // CHECK: call void @__kmpc_for_static_init_4(
+    // CHECK: call i8* @llvm.stacksave()
+    // CHECK: store float 0.000000e+00, float* %
+    // CHECK: store double 0.000000e+00, double* [[B_PRIV_ADDR:%.+]],
+    // CHECK: br label %[[DISPATCH:[^,]+]]
+    // CHECK: [[INPUT_PHASE:.+]]:
+    // CHECK: call void @{{.+}}foo{{.+}}()
+
+    // a_buffer[i][0..n] = a_priv[[0..n];
+    // CHECK: [[BASE_IDX_I:%.+]] = load i32, i32* [[IV_ADDR:%.+]],
+    // CHECK: [[BASE_IDX:%.+]] = zext i32 [[BASE_IDX_I]] to i64
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[BASE_IDX]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[A_PRIV:%.+]] = getelementptr inbounds [10 x float], [10 x float]* [[A_PRIV_ADDR:%.+]], i64 0, i64 0
+    // CHECK: [[BYTES:%.+]] = mul nuw i64 [[NUM_ELEMS:%.+]], 4
+    // CHECK: [[DEST:%.+]] = bitcast float* [[A_BUF_IDX]] to i8*
+    // CHECK: [[SRC:%.+]] = bitcast float* [[A_PRIV]] to i8*
+    // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}[[DEST]], i8* {{.*}}[[SRC]], i64 [[BYTES]], i1 false)
+
+    // b_buffer[i] = b_priv;
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[BASE_IDX]]
+    // CHECK: [[B_PRIV:%.+]] = load double, double* [[B_PRIV_ADDR]],
+    // CHECK: store double [[B_PRIV]], double* [[B_BUF_IDX]],
+    // CHECK: br label %[[LOOP_CONTINUE:.+]]
+
+    // CHECK: [[DISPATCH]]:
+    // CHECK: br label %[[INPUT_PHASE]]
+    // CHECK: [[LOOP_CONTINUE]]:
+    // CHECK: call void @llvm.stackrestore(i8* %
+    // CHECK: call void @__kmpc_for_static_fini(
+    // CHECK: call void @__kmpc_barrier(
+    foo();
+#pragma omp scan inclusive(a[:n], b)
+    // CHECK: [[LOG2_10:%.+]] = call double @llvm.log2.f64(double 1.000000e+01)
+    // CHECK: [[CEIL_LOG2_10:%.+]] = call double @llvm.ceil.f64(double [[LOG2_10]])
+    // CHECK: [[CEIL_LOG2_10_INT:%.+]] = fptoui double [[CEIL_LOG2_10]] to i32
+    // CHECK: br label %[[OUTER_BODY:[^,]+]]
+    // CHECK: [[OUTER_BODY]]:
+    // CHECK: [[K:%.+]] = phi i32 [ 0, %{{.+}} ], [ [[K_NEXT:%.+]], %{{.+}} ]
+    // CHECK: [[K2POW:%.+]] = phi i64 [ 1, %{{.+}} ], [ [[K2POW_NEXT:%.+]], %{{.+}} ]
+    // CHECK: [[CMP:%.+]] = icmp uge i64 9, [[K2POW]]
+    // CHECK: br i1 [[CMP]], label %[[INNER_BODY:[^,]+]], label %[[INNER_EXIT:[^,]+]]
+    // CHECK: [[INNER_BODY]]:
+    // CHECK: [[I:%.+]] = phi i64 [ 9, %[[OUTER_BODY]] ], [ [[I_PREV:%.+]], %{{.+}} ]
+
+    // a_buffer[i] += a_buffer[i-pow(2, k)];
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[I]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[IDX_SUB_K2POW:%.+]] = sub nuw i64 [[I]], [[K2POW]]
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[IDX_SUB_K2POW]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX_SUB_K2POW:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[I]]
+    // CHECK: [[IDX_SUB_K2POW:%.+]] = sub nuw i64 [[I]], [[K2POW]]
+    // CHECK: [[B_BUF_IDX_SUB_K2POW:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[IDX_SUB_K2POW]]
+    // CHECK: [[A_BUF_END:%.+]] = getelementptr float, float* [[A_BUF_IDX]], i64 [[NUM_ELEMS]]
+    // CHECK: [[ISEMPTY:%.+]] = icmp eq float* [[A_BUF_IDX]], [[A_BUF_END]]
+    // CHECK: br i1 [[ISEMPTY]], label %[[RED_DONE:[^,]+]], label %[[RED_BODY:[^,]+]]
+    // CHECK: [[RED_BODY]]:
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_ELEM:%.+]] = phi float* [ [[A_BUF_IDX_SUB_K2POW]], %[[INNER_BODY]] ], [ [[A_BUF_IDX_SUB_K2POW_NEXT:%.+]], %[[RED_BODY]] ]
+    // CHECK: [[A_BUF_IDX_ELEM:%.+]] = phi float* [ [[A_BUF_IDX]], %[[INNER_BODY]] ], [ [[A_BUF_IDX_NEXT:%.+]], %[[RED_BODY]] ]
+    // CHECK: [[A_BUF_IDX_VAL:%.+]] = load float, float* [[A_BUF_IDX_ELEM]],
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_VAL:%.+]] = load float, float* [[A_BUF_IDX_SUB_K2POW_ELEM]],
+    // CHECK: [[RED:%.+]] = fadd float [[A_BUF_IDX_VAL]], [[A_BUF_IDX_SUB_K2POW_VAL]]
+    // CHECK: store float [[RED]], float* [[A_BUF_IDX_ELEM]],
+    // CHECK: [[A_BUF_IDX_NEXT]] = getelementptr float, float* [[A_BUF_IDX_ELEM]], i32 1
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_NEXT]] = getelementptr float, float* [[A_BUF_IDX_SUB_K2POW_ELEM]], i32 1
+    // CHECK: [[DONE:%.+]] = icmp eq float* [[A_BUF_IDX_NEXT]], [[A_BUF_END]]
+    // CHECK: br i1 [[DONE]], label %[[RED_DONE]], label %[[RED_BODY]]
+    // CHECK: [[RED_DONE]]:
+
+    // b_buffer[i] += b_buffer[i-pow(2, k)];
+    // CHECK: [[B_BUF_IDX_VAL:%.+]] = load double, double* [[B_BUF_IDX]],
+    // CHECK: [[B_BUF_IDX_SUB_K2POW_VAL:%.+]] = load double, double* [[B_BUF_IDX_SUB_K2POW]],
+    // CHECK: [[RED:%.+]] = fadd double [[B_BUF_IDX_VAL]], [[B_BUF_IDX_SUB_K2POW_VAL]]
+    // CHECK: store double [[RED]], double* [[B_BUF_IDX]],
+
+    // --i;
+    // CHECK: [[I_PREV:%.+]] = sub nuw i64 [[I]], 1
+    // CHECK: [[CMP:%.+]] = icmp uge i64 [[I_PREV]], [[K2POW]]
+    // CHECK: br i1 [[CMP]], label %[[INNER_BODY]], label %[[INNER_EXIT]]
+    // CHECK: [[INNER_EXIT]]:
+
+    // ++k;
+    // CHECK: [[K_NEXT]] = add nuw i32 [[K]], 1
+    // k2pow <<= 1;
+    // CHECK: [[K2POW_NEXT]] = shl nuw i64 [[K2POW]], 1
+    // CHECK: [[CMP:%.+]] = icmp ne i32 [[K_NEXT]], [[CEIL_LOG2_10_INT]]
+    // CHECK: br i1 [[CMP]], label %[[OUTER_BODY]], label %[[OUTER_EXIT:[^,]+]]
+    // CHECK: [[OUTER_EXIT]]:
+    bar();
+    // CHECK: call void @__kmpc_for_static_init_4(
+    // CHECK: call i8* @llvm.stacksave()
+    // CHECK: store float 0.000000e+00, float* %
+    // CHECK: store double 0.000000e+00, double* [[B_PRIV_ADDR:%.+]],
+    // CHECK: br label %[[DISPATCH:[^,]+]]
+
+    // Skip the before scan body.
+    // CHECK: call void @{{.+}}foo{{.+}}()
+
+    // CHECK: [[EXIT_INSCAN:[^,]+]]:
+    // CHECK: br label %[[LOOP_CONTINUE:[^,]+]]
+
+    // CHECK: [[DISPATCH]]:
+    // a_priv[[0..n] = a_buffer[i][0..n];
+    // CHECK: [[BASE_IDX_I:%.+]] = load i32, i32* [[IV_ADDR:%.+]],
+    // CHECK: [[BASE_IDX:%.+]] = zext i32 [[BASE_IDX_I]] to i64
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[BASE_IDX]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[A_PRIV:%.+]] = getelementptr inbounds [10 x float], [10 x float]* [[A_PRIV_ADDR:%.+]], i64 0, i64 0
+    // CHECK: [[BYTES:%.+]] = mul nuw i64 [[NUM_ELEMS:%.+]], 4
+    // CHECK: [[DEST:%.+]] = bitcast float* [[A_PRIV]] to i8*
+    // CHECK: [[SRC:%.+]] = bitcast float* [[A_BUF_IDX]] to i8*
+    // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}[[DEST]], i8* {{.*}}[[SRC]], i64 [[BYTES]], i1 false)
+
+    // b_priv = b_buffer[i];
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[BASE_IDX]]
+    // CHECK: [[B_BUF_IDX_VAL:%.+]] = load double, double* [[B_BUF_IDX]],
+    // CHECK: store double [[B_BUF_IDX_VAL]], double* [[B_PRIV_ADDR]],
+    // CHECK: br label %[[SCAN_PHASE:[^,]+]]
+
+    // CHECK: [[SCAN_PHASE]]:
+    // CHECK: call void @{{.+}}bar{{.+}}()
+    // CHECK: br label %[[EXIT_INSCAN]]
+
+    // CHECK: [[LOOP_CONTINUE]]:
+    // CHECK: call void @llvm.stackrestore(i8* %
+    // CHECK: call void @__kmpc_for_static_fini(
+    // CHECK: call void @llvm.stackrestore(i8*
+  }
+
+  // CHECK: call i8* @llvm.stacksave()
+  // CHECK: [[A_BUF_SIZE:%.+]] = mul nuw i64 10, [[NUM_ELEMS:%[^,]+]]
+
+  // float a_buffer[10][n];
+  // CHECK: [[A_BUF:%.+]] = alloca float, i64 [[A_BUF_SIZE]],
+
+  // double b_buffer[10];
+  // CHECK: [[B_BUF:%.+]] = alloca double, i64 10,
+#pragma omp parallel for simd reduction(inscan, +:a[:n], b)
+  for (int i = 0; i < 10; ++i) {
+    // CHECK: call void @__kmpc_for_static_init_4(
+    // CHECK: call i8* @llvm.stacksave()
+    // CHECK: store float 0.000000e+00, float* %
+    // CHECK: store double 0.000000e+00, double* [[B_PRIV_ADDR:%.+]],
+    // CHECK: br label %[[DISPATCH:[^,]+]]
+
+    // Skip the before scan body.
+    // CHECK: call void @{{.+}}foo{{.+}}()
+
+    // CHECK: [[EXIT_INSCAN:[^,]+]]:
+
+    // a_buffer[i][0..n] = a_priv[[0..n];
+    // CHECK: [[BASE_IDX_I:%.+]] = load i32, i32* [[IV_ADDR:%.+]],
+    // CHECK: [[BASE_IDX:%.+]] = zext i32 [[BASE_IDX_I]] to i64
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[BASE_IDX]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[A_PRIV:%.+]] = getelementptr inbounds [10 x float], [10 x float]* [[A_PRIV_ADDR:%.+]], i64 0, i64 0
+    // CHECK: [[BYTES:%.+]] = mul nuw i64 [[NUM_ELEMS:%.+]], 4
+    // CHECK: [[DEST:%.+]] = bitcast float* [[A_BUF_IDX]] to i8*
+    // CHECK: [[SRC:%.+]] = bitcast float* [[A_PRIV]] to i8*
+    // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}[[DEST]], i8* {{.*}}[[SRC]], i64 [[BYTES]], i1 false)
+
+    // b_buffer[i] = b_priv;
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[BASE_IDX]]
+    // CHECK: [[B_PRIV:%.+]] = load double, double* [[B_PRIV_ADDR]],
+    // CHECK: store double [[B_PRIV]], double* [[B_BUF_IDX]],
+    // CHECK: br label %[[LOOP_CONTINUE:[^,]+]]
+
+    // CHECK: [[DISPATCH]]:
+    // CHECK: br label %[[INPUT_PHASE:[^,]+]]
+
+    // CHECK: [[INPUT_PHASE]]:
+    // CHECK: call void @{{.+}}bar{{.+}}()
+    // CHECK: br label %[[EXIT_INSCAN]]
+
+    // CHECK: [[LOOP_CONTINUE]]:
+    // CHECK: call void @llvm.stackrestore(i8* %
+    // CHECK: call void @__kmpc_for_static_fini(
+    // CHECK: call void @__kmpc_barrier(
+    foo();
+#pragma omp scan exclusive(a[:n], b)
+    // CHECK: [[LOG2_10:%.+]] = call double @llvm.log2.f64(double 1.000000e+01)
+    // CHECK: [[CEIL_LOG2_10:%.+]] = call double @llvm.ceil.f64(double [[LOG2_10]])
+    // CHECK: [[CEIL_LOG2_10_INT:%.+]] = fptoui double [[CEIL_LOG2_10]] to i32
+    // CHECK: br label %[[OUTER_BODY:[^,]+]]
+    // CHECK: [[OUTER_BODY]]:
+    // CHECK: [[K:%.+]] = phi i32 [ 0, %{{.+}} ], [ [[K_NEXT:%.+]], %{{.+}} ]
+    // CHECK: [[K2POW:%.+]] = phi i64 [ 1, %{{.+}} ], [ [[K2POW_NEXT:%.+]], %{{.+}} ]
+    // CHECK: [[CMP:%.+]] = icmp uge i64 9, [[K2POW]]
+    // CHECK: br i1 [[CMP]], label %[[INNER_BODY:[^,]+]], label %[[INNER_EXIT:[^,]+]]
+    // CHECK: [[INNER_BODY]]:
+    // CHECK: [[I:%.+]] = phi i64 [ 9, %[[OUTER_BODY]] ], [ [[I_PREV:%.+]], %{{.+}} ]
+
+    // a_buffer[i] += a_buffer[i-pow(2, k)];
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[I]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[IDX_SUB_K2POW:%.+]] = sub nuw i64 [[I]], [[K2POW]]
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[IDX_SUB_K2POW]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX_SUB_K2POW:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[I]]
+    // CHECK: [[IDX_SUB_K2POW:%.+]] = sub nuw i64 [[I]], [[K2POW]]
+    // CHECK: [[B_BUF_IDX_SUB_K2POW:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[IDX_SUB_K2POW]]
+    // CHECK: [[A_BUF_END:%.+]] = getelementptr float, float* [[A_BUF_IDX]], i64 [[NUM_ELEMS]]
+    // CHECK: [[ISEMPTY:%.+]] = icmp eq float* [[A_BUF_IDX]], [[A_BUF_END]]
+    // CHECK: br i1 [[ISEMPTY]], label %[[RED_DONE:[^,]+]], label %[[RED_BODY:[^,]+]]
+    // CHECK: [[RED_BODY]]:
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_ELEM:%.+]] = phi float* [ [[A_BUF_IDX_SUB_K2POW]], %[[INNER_BODY]] ], [ [[A_BUF_IDX_SUB_K2POW_NEXT:%.+]], %[[RED_BODY]] ]
+    // CHECK: [[A_BUF_IDX_ELEM:%.+]] = phi float* [ [[A_BUF_IDX]], %[[INNER_BODY]] ], [ [[A_BUF_IDX_NEXT:%.+]], %[[RED_BODY]] ]
+    // CHECK: [[A_BUF_IDX_VAL:%.+]] = load float, float* [[A_BUF_IDX_ELEM]],
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_VAL:%.+]] = load float, float* [[A_BUF_IDX_SUB_K2POW_ELEM]],
+    // CHECK: [[RED:%.+]] = fadd float [[A_BUF_IDX_VAL]], [[A_BUF_IDX_SUB_K2POW_VAL]]
+    // CHECK: store float [[RED]], float* [[A_BUF_IDX_ELEM]],
+    // CHECK: [[A_BUF_IDX_NEXT]] = getelementptr float, float* [[A_BUF_IDX_ELEM]], i32 1
+    // CHECK: [[A_BUF_IDX_SUB_K2POW_NEXT]] = getelementptr float, float* [[A_BUF_IDX_SUB_K2POW_ELEM]], i32 1
+    // CHECK: [[DONE:%.+]] = icmp eq float* [[A_BUF_IDX_NEXT]], [[A_BUF_END]]
+    // CHECK: br i1 [[DONE]], label %[[RED_DONE]], label %[[RED_BODY]]
+    // CHECK: [[RED_DONE]]:
+
+    // b_buffer[i] += b_buffer[i-pow(2, k)];
+    // CHECK: [[B_BUF_IDX_VAL:%.+]] = load double, double* [[B_BUF_IDX]],
+    // CHECK: [[B_BUF_IDX_SUB_K2POW_VAL:%.+]] = load double, double* [[B_BUF_IDX_SUB_K2POW]],
+    // CHECK: [[RED:%.+]] = fadd double [[B_BUF_IDX_VAL]], [[B_BUF_IDX_SUB_K2POW_VAL]]
+    // CHECK: store double [[RED]], double* [[B_BUF_IDX]],
+
+    // --i;
+    // CHECK: [[I_PREV:%.+]] = sub nuw i64 [[I]], 1
+    // CHECK: [[CMP:%.+]] = icmp uge i64 [[I_PREV]], [[K2POW]]
+    // CHECK: br i1 [[CMP]], label %[[INNER_BODY]], label %[[INNER_EXIT]]
+    // CHECK: [[INNER_EXIT]]:
+
+    // ++k;
+    // CHECK: [[K_NEXT]] = add nuw i32 [[K]], 1
+    // k2pow <<= 1;
+    // CHECK: [[K2POW_NEXT]] = shl nuw i64 [[K2POW]], 1
+    // CHECK: [[CMP:%.+]] = icmp ne i32 [[K_NEXT]], [[CEIL_LOG2_10_INT]]
+    // CHECK: br i1 [[CMP]], label %[[OUTER_BODY]], label %[[OUTER_EXIT:[^,]+]]
+    // CHECK: [[OUTER_EXIT]]:
+    bar();
+    // CHECK: call void @__kmpc_for_static_init_4(
+    // CHECK: call i8* @llvm.stacksave()
+    // CHECK: store float 0.000000e+00, float* %
+    // CHECK: store double 0.000000e+00, double* [[B_PRIV_ADDR:%.+]],
+    // CHECK: br label %[[DISPATCH:[^,]+]]
+
+    // CHECK: [[SCAN_PHASE:.+]]:
+    // CHECK: call void @{{.+}}foo{{.+}}()
+    // CHECK: br label %[[LOOP_CONTINUE:.+]]
+
+    // CHECK: [[DISPATCH]]:
+    // if (i >0)
+    //   a_priv[[0..n] = a_buffer[i-1][0..n];
+    // CHECK: [[BASE_IDX_I:%.+]] = load i32, i32* [[IV_ADDR:%.+]],
+    // CHECK: [[BASE_IDX:%.+]] = zext i32 [[BASE_IDX_I]] to i64
+    // CHECK: [[CMP:%.+]] = icmp eq i64 [[BASE_IDX]], 0
+    // CHECK: br i1 [[CMP]], label %[[IF_DONE:[^,]+]], label %[[IF_THEN:[^,]+]]
+    // CHECK: [[IF_THEN]]:
+    // CHECK: [[BASE_IDX_SUB_1:%.+]] = sub nuw i64 [[BASE_IDX]], 1
+    // CHECK: [[IDX:%.+]] = mul nsw i64 [[BASE_IDX_SUB_1]], [[NUM_ELEMS]]
+    // CHECK: [[A_BUF_IDX:%.+]] = getelementptr inbounds float, float* [[A_BUF]], i64 [[IDX]]
+    // CHECK: [[A_PRIV:%.+]] = getelementptr inbounds [10 x float], [10 x float]* [[A_PRIV_ADDR:%.+]], i64 0, i64 0
+    // CHECK: [[BYTES:%.+]] = mul nuw i64 [[NUM_ELEMS:%.+]], 4
+    // CHECK: [[DEST:%.+]] = bitcast float* [[A_PRIV]] to i8*
+    // CHECK: [[SRC:%.+]] = bitcast float* [[A_BUF_IDX]] to i8*
+    // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}[[DEST]], i8* {{.*}}[[SRC]], i64 [[BYTES]], i1 false)
+
+    // b_priv = b_buffer[i];
+    // CHECK: [[B_BUF_IDX:%.+]] = getelementptr inbounds double, double* [[B_BUF]], i64 [[BASE_IDX_SUB_1]]
+    // CHECK: [[B_BUF_IDX_VAL:%.+]] = load double, double* [[B_BUF_IDX]],
+    // CHECK: store double [[B_BUF_IDX_VAL]], double* [[B_PRIV_ADDR]],
+    // CHECK: br label %[[SCAN_PHASE]]
+
+    // CHECK: [[LOOP_CONTINUE]]:
+    // CHECK: call void @llvm.stackrestore(i8* %
+    // CHECK: call void @__kmpc_for_static_fini(
+    // CHECK: call void @llvm.stackrestore(i8*
+  }
+}
+
+// CHECK: !{!"llvm.loop.vectorize.enable", i1 true}
+
+#endif
+