clang/test/CodeGen/X86/x86_64-PR42672.c

   1 // RUN: %clang_cc1 -triple=x86_64-unknown-linux-gnu -DSTRUCT -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-STRUCT
   2 // RUN: %clang_cc1 -triple=x86_64-unknown-linux-gnu -USTRUCT -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-NOSTRUCT
   3 // RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_ODD -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_ODD
   4 // RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_BIG -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_BIG
   5 // RUN: %clang_cc1 -triple=x86_64-unknown-linux-gnu -DPOSSIBLE_X -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-X
   6 // RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_X -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_X
   7 // RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_9BYTES -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_9BYTES
   8 // RUN: not %clang_cc1 -triple=x86_64-unknown-linux-gnu -DIMPOSSIBLE_9BYTES_V2 -emit-llvm %s -o - 2>&1 | FileCheck %s --check-prefix=CHECK-IMPOSSIBLE_9BYTES_V2
   9
  10 // Make sure Clang doesn't treat |lockval| as asm input.
  11 void _raw_spin_lock(void) {
  12 #ifdef STRUCT
  13   struct {
  14     unsigned short owner, next;
  15   } lockval;
  16   lockval.owner = 1;
  17   lockval.next = 2;
  18 #else
  19   int lockval;
  20   lockval = 3;
  21 #endif
  22   asm("nop"
  23       : "=r"(lockval));
  24 }
  25 // CHECK-LABEL: _raw_spin_lock
  26 // CHECK-LABEL: entry:
  27
  28 // CHECK-STRUCT:  %lockval = alloca %struct.anon, align 2
  29 // CHECK-STRUCT:  store i16 1
  30 // CHECK-STRUCT:  store i16 2
  31 // CHECK-STRUCT: [[RES:%[0-9]+]] = call i32 asm "nop", "=r,~{dirflag},~{fpsr},~{flags}"()
  32 // CHECK-STRUCT: store i32 [[RES]], ptr %lockval, align 2
  33
  34 // CHECK-NOSTRUCT: %lockval = alloca i32, align 4
  35 // CHECK-NOSTRUCT: store i32 3
  36 // CHECK-NOSTRUCT:  [[RES:%[0-9]+]] = call i32 asm "nop", "=r,~{dirflag},~{fpsr},~{flags}"()
  37 // CHECK-NOSTRUCT: store i32 [[RES]], ptr %lockval, align 4
  38
  39 // Check Clang correctly handles a structure with padding.
  40 void unusual_struct(void) {
  41   struct {
  42     unsigned short first;
  43     unsigned char second;
  44   } str;
  45   asm("nop"
  46       : "=r"(str));
  47 }
  48
  49 // Check Clang reports an error if attempting to return a structure for which
  50 // no direct conversion to a register is possible.
  51 void odd_struct(void) {
  52 #ifdef IMPOSSIBLE_ODD
  53   struct __attribute__((__packed__)) {
  54     unsigned short first;
  55     unsigned char second;
  56   } str;
  57   asm("nop"
  58       : "=r"(str));
  59 #endif
  60 }
  61 // CHECK-IMPOSSIBLE_ODD: impossible constraint in asm: cannot store value into a register
  62
  63 // Check Clang reports an error if attempting to return a big structure via a register.
  64 void big_struct(void) {
  65 #ifdef IMPOSSIBLE_BIG
  66   struct {
  67     long long int v1, v2, v3, v4;
  68   } str;
  69   asm("nop"
  70       : "=r"(str));
  71 #endif
  72 }
  73 // CHECK-IMPOSSIBLE_BIG: impossible constraint in asm: cannot store value into a register
  74
  75 // Clang is able to emit LLVM IR for an 16-byte structure.
  76 void x_constraint_fit(void) {
  77 #ifdef POSSIBLE_X
  78   struct S {
  79     unsigned x[4];
  80   } z;
  81   asm volatile("nop"
  82                : "=x"(z));
  83 #endif
  84 }
  85 // CHECK-LABEL: x_constraint_fit
  86 // CHECK-X: %z = alloca %struct.S, align 4
  87 // CHECK-X: [[RES:%[0-9]+]] = call i128 asm sideeffect "nop", "=x,~{dirflag},~{fpsr},~{flags}"()
  88 // CHECK-X: store i128 [[RES]], ptr %z, align 4
  89 // CHECK-X: ret
  90
  91 // Clang is unable to emit LLVM IR for a 32-byte structure.
  92 void x_constraint_nofit(void) {
  93 #ifdef IMPOSSIBLE_X
  94   struct S {
  95     unsigned x[8];
  96   } z;
  97   asm volatile("nop"
  98                : "=x"(z));
  99 #endif
 100 }
 101
 102 // CHECK-IMPOSSIBLE_X: invalid output size for constraint
 103
 104 // http://crbug.com/999160
 105 // Clang used to report the following message:
 106 //   "impossible constraint in asm: cannot store struct into a register"
 107 // for the assembly directive below, although there's no struct.
 108 void crbug_999160_regtest(void) {
 109 #ifdef IMPOSSIBLE_9BYTES
 110   char buf[9];
 111   asm(""
 112       : "=r"(buf));
 113 #endif
 114 }
 115
 116 // CHECK-IMPOSSIBLE_9BYTES: impossible constraint in asm: cannot store value into a register
 117
 118 void crbug_999160_regtest_v2(void) {
 119 #ifdef IMPOSSIBLE_9BYTES_V2
 120   char buf[9];
 121   asm("" : "=r"(buf) : "0"(buf));
 122 #endif
 123 }
 124 // CHECK-IMPOSSIBLE_9BYTES_V2: impossible constraint in asm: cannot store value into a register