clang/test/CodeGen/bitfield.c

   1 // RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - -O3 -no-struct-path-tbaa | FileCheck %s
   2 // RUN: %clang_cc1 -triple i386-unknown-unknown %s -emit-llvm -o - -O3 | FileCheck %s --check-prefix=PATH
   3
   4 static int f0(int n) {
   5   struct s0 {
   6     int a : 30;
   7     int b : 2;
   8     long long c : 31;
   9   } x = { 0xdeadbeef, 0xdeadbeef, 0xdeadbeef };
  10
  11   x.a += n;
  12   x.b += n;
  13   x.c += n;
  14
  15   return x.a + x.b + x.c;
  16 }
  17
  18 int g0(void) {
  19 // CHECK-LABEL: @g0()
  20 // CHECK: ret i32 1
  21 // PATH-LABEL: @g0()
  22 // PATH: ret i32 1
  23   return f0(-1) + 44335655;
  24 }
  25
  26 static int f1(void) {
  27   struct s1 {
  28     int a:13;
  29     char b;
  30     unsigned short c:7;
  31   } x;
  32
  33   x.a = -40;
  34   x.b = 10;
  35   x.c = 15;
  36
  37   return x.a + x.b + x.c;
  38 }
  39
  40 int g1(void) {
  41 // CHECK-LABEL: @g1()
  42 // CHECK: ret i32 1
  43 // PATH-LABEL: @g1()
  44 // PATH: ret i32 1
  45   return f1() + 16;
  46 }
  47
  48 static int f2(void) {
  49   struct s2 {
  50     short a[3];
  51     int b : 15;
  52   } x;
  53
  54   x.a[0] = x.a[1] = x.a[2] = -40;
  55   x.b = 10;
  56
  57   return x.b;
  58 }
  59
  60 int g2(void) {
  61 // CHECK-LABEL: @g2()
  62 // CHECK: ret i32 1
  63 // PATH-LABEL: @g2()
  64 // PATH: ret i32 1
  65   return f2() - 9;
  66 }
  67
  68 static int f3(int n) {
  69   struct s3 {
  70     unsigned a:16;
  71     unsigned b:28 __attribute__ ((packed));
  72   } x = { 0xdeadbeef, 0xdeadbeef };
  73   struct s4 {
  74     signed a:16;
  75     signed b:28 __attribute__ ((packed));
  76   } y;
  77   y.a = -0x56789abcL;
  78   y.b = -0x56789abcL;
  79   return ((y.a += x.a += n) +
  80           (y.b += x.b += n));
  81 }
  82
  83 int g3(void) {
  84 // CHECK-LABEL: @g3()
  85 // CHECK: ret i32 1
  86 // PATH-LABEL: @g3()
  87 // PATH: ret i32 1
  88   return f3(20) + 130725747;
  89 }
  90
  91 static int f4(void) {
  92   struct s5 {
  93     int b:1;
  94   } x;
  95   x.b = 1;
  96   return x.b;
  97 }
  98
  99 int g4(void) {
 100 // CHECK-LABEL: @g4()
 101 // CHECK: ret i32 1
 102 // PATH-LABEL: @g4()
 103 // PATH: ret i32 1
 104   return f4() + 2;
 105 }