clang/test/CodeGen/builtin-align-array.c

   1 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
   2 /// Check that the alignment builtins handle array-to-pointer decay
   3 // RUN: %clang_cc1 -triple=x86_64-unknown-unknown -o - -emit-llvm %s | FileCheck %s
   4
   5 extern int func(char *c);
   6
   7 // CHECK-LABEL: @test_array(
   8 // CHECK-NEXT:  entry:
   9 // CHECK-NEXT:    [[BUF:%.*]] = alloca [1024 x i8], align 16
  10 // CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 44
  11 // CHECK-NEXT:    [[ALIGNED_RESULT:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[ARRAYIDX]], i64 -16)
  12 // CHECK-NEXT:    [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
  13 // CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 22
  14 // CHECK-NEXT:    [[OVER_BOUNDARY:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 31
  15 // CHECK-NEXT:    [[ALIGNED_RESULT2:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[OVER_BOUNDARY]], i64 -32)
  16 // CHECK-NEXT:    [[CALL3:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT2]])
  17 // CHECK-NEXT:    [[ARRAYIDX4:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 16
  18 // CHECK-NEXT:    [[SRC_ADDR:%.*]] = ptrtoint ptr [[ARRAYIDX4]] to i64
  19 // CHECK-NEXT:    [[SET_BITS:%.*]] = and i64 [[SRC_ADDR]], 63
  20 // CHECK-NEXT:    [[IS_ALIGNED:%.*]] = icmp eq i64 [[SET_BITS]], 0
  21 // CHECK-NEXT:    [[CONV:%.*]] = zext i1 [[IS_ALIGNED]] to i32
  22 // CHECK-NEXT:    ret i32 [[CONV]]
  23 //
  24 int test_array(void) {
  25   char buf[1024];
  26   func(__builtin_align_down(&buf[44], 16));
  27   func(__builtin_align_up(&buf[22], 32));
  28   return __builtin_is_aligned(&buf[16], 64);
  29 }
  30
  31 // CHECK-LABEL: @test_array_should_not_mask(
  32 // CHECK-NEXT:  entry:
  33 // CHECK-NEXT:    [[BUF:%.*]] = alloca [1024 x i8], align 32
  34 // CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 64
  35 // CHECK-NEXT:    [[ALIGNED_RESULT:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[ARRAYIDX]], i64 -16)
  36 // CHECK-NEXT:    [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
  37 // CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 32
  38 // CHECK-NEXT:    [[OVER_BOUNDARY:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 31
  39 // CHECK-NEXT:    [[ALIGNED_RESULT2:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[OVER_BOUNDARY]], i64 -32)
  40 // CHECK-NEXT:    [[CALL3:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT2]])
  41 // CHECK-NEXT:    ret i32 1
  42 //
  43 int test_array_should_not_mask(void) {
  44   _Alignas(32) char buf[1024];
  45   // TODO: The align_up and align_down calls should be folded to no-ops
  46   func(__builtin_align_down(&buf[64], 16));
  47   func(__builtin_align_up(&buf[32], 32));
  48   // This expression can be constant-evaluated:
  49   return __builtin_is_aligned(&buf[64], 32);
  50 }