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:    [[INTPTR:%.*]] = ptrtoint ptr [[ARRAYIDX]] to i64
  12 // CHECK-NEXT:    [[ALIGNED_INTPTR:%.*]] = and i64 [[INTPTR]], -16
  13 // CHECK-NEXT:    [[DIFF:%.*]] = sub i64 [[ALIGNED_INTPTR]], [[INTPTR]]
  14 // CHECK-NEXT:    [[ALIGNED_RESULT:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX]], i64 [[DIFF]]
  15 // CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[ALIGNED_RESULT]], i64 16) ]
  16 // CHECK-NEXT:    [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
  17 // CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 22
  18 // CHECK-NEXT:    [[INTPTR2:%.*]] = ptrtoint ptr [[ARRAYIDX1]] to i64
  19 // CHECK-NEXT:    [[OVER_BOUNDARY:%.*]] = add i64 [[INTPTR2]], 31
  20 // CHECK-NEXT:    [[ALIGNED_INTPTR4:%.*]] = and i64 [[OVER_BOUNDARY]], -32
  21 // CHECK-NEXT:    [[DIFF5:%.*]] = sub i64 [[ALIGNED_INTPTR4]], [[INTPTR2]]
  22 // CHECK-NEXT:    [[ALIGNED_RESULT6:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 [[DIFF5]]
  23 // CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[ALIGNED_RESULT6]], i64 32) ]
  24 // CHECK-NEXT:    [[CALL7:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT6]])
  25 // CHECK-NEXT:    [[ARRAYIDX8:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 16
  26 // CHECK-NEXT:    [[SRC_ADDR:%.*]] = ptrtoint ptr [[ARRAYIDX8]] to i64
  27 // CHECK-NEXT:    [[SET_BITS:%.*]] = and i64 [[SRC_ADDR]], 63
  28 // CHECK-NEXT:    [[IS_ALIGNED:%.*]] = icmp eq i64 [[SET_BITS]], 0
  29 // CHECK-NEXT:    [[CONV:%.*]] = zext i1 [[IS_ALIGNED]] to i32
  30 // CHECK-NEXT:    ret i32 [[CONV]]
  31 //
  32 int test_array(void) {
  33   char buf[1024];
  34   func(__builtin_align_down(&buf[44], 16));
  35   func(__builtin_align_up(&buf[22], 32));
  36   return __builtin_is_aligned(&buf[16], 64);
  37 }
  38
  39 // CHECK-LABEL: @test_array_should_not_mask(
  40 // CHECK-NEXT:  entry:
  41 // CHECK-NEXT:    [[BUF:%.*]] = alloca [1024 x i8], align 32
  42 // CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 64
  43 // CHECK-NEXT:    [[INTPTR:%.*]] = ptrtoint ptr [[ARRAYIDX]] to i64
  44 // CHECK-NEXT:    [[ALIGNED_INTPTR:%.*]] = and i64 [[INTPTR]], -16
  45 // CHECK-NEXT:    [[DIFF:%.*]] = sub i64 [[ALIGNED_INTPTR]], [[INTPTR]]
  46 // CHECK-NEXT:    [[ALIGNED_RESULT:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX]], i64 [[DIFF]]
  47 // CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[ALIGNED_RESULT]], i64 16) ]
  48 // CHECK-NEXT:    [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
  49 // CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 32
  50 // CHECK-NEXT:    [[INTPTR2:%.*]] = ptrtoint ptr [[ARRAYIDX1]] to i64
  51 // CHECK-NEXT:    [[OVER_BOUNDARY:%.*]] = add i64 [[INTPTR2]], 31
  52 // CHECK-NEXT:    [[ALIGNED_INTPTR4:%.*]] = and i64 [[OVER_BOUNDARY]], -32
  53 // CHECK-NEXT:    [[DIFF5:%.*]] = sub i64 [[ALIGNED_INTPTR4]], [[INTPTR2]]
  54 // CHECK-NEXT:    [[ALIGNED_RESULT6:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 [[DIFF5]]
  55 // CHECK-NEXT:    call void @llvm.assume(i1 true) [ "align"(ptr [[ALIGNED_RESULT6]], i64 32) ]
  56 // CHECK-NEXT:    [[CALL7:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT6]])
  57 // CHECK-NEXT:    ret i32 1
  58 //
  59 int test_array_should_not_mask(void) {
  60   _Alignas(32) char buf[1024];
  61   // TODO: The align_up and align_down calls should be folded to no-ops
  62   func(__builtin_align_down(&buf[64], 16));
  63   func(__builtin_align_up(&buf[32], 32));
  64   // This expression can be constant-evaluated:
  65   return __builtin_is_aligned(&buf[64], 32);
  66 }