• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // RUN: %clang -target mipsel-unknown-linux -S -o - -emit-llvm %s \
2 // RUN: | FileCheck %s
3 
4 // This checks that the frontend will accept inline asm constraints
5 // c', 'l' and 'x'.
6 
main()7 int main()
8 {
9   // 'c': 16 bit address register for Mips16, GPR for all others
10   // I am using 'c' to constrain both the target and one of the source
11   // registers. We are looking for syntactical correctness.
12   // CHECK: %{{[0-9]+}} = call i32 asm sideeffect "addi $0,$1,$2 \0A\09\09", "=c,c,I"(i32 %{{[0-9]+}}, i32 %{{[0-9]+}}) [[NUW:#[0-9]+]], !srcloc !{{[0-9]+}}
13   int __s, __v = 17;
14   int __t;
15   __asm__ __volatile__(
16       "addi %0,%1,%2 \n\t\t"
17       : "=c" (__t)
18         : "c" (__s), "I" (__v));
19 
20   // 'l': lo register
21   // We are making it clear that destination register is lo with the
22   // use of the 'l' constraint ("=l").
23   // CHECK:   %{{[0-9]+}} = call i32 asm sideeffect "mtlo $1 \0A\09\09", "=l,r,~{lo}"(i32 %{{[0-9]+}}) [[NUW]], !srcloc !{{[0-9]+}}
24   int i_temp = 44;
25   int i_result;
26   __asm__ __volatile__(
27       "mtlo %1 \n\t\t"
28       : "=l" (i_result)
29         : "r" (i_temp)
30           : "lo");
31 
32   // 'x': Combined lo/hi registers
33   // We are specifying that destination registers are the hi/lo pair with the
34   // use of the 'x' constraint ("=x").
35   // CHECK:  %{{[0-9]+}} = call i64 asm sideeffect "mthi $1 \0A\09\09mtlo $2 \0A\09\09", "=x,r,r"(i32 %{{[0-9]+}}, i32 %{{[0-9]+}}) [[NUW]], !srcloc !{{[0-9]+}}
36   int i_hi = 3;
37   int i_lo = 2;
38   long long ll_result = 0;
39   __asm__ __volatile__(
40       "mthi %1 \n\t\t"
41       "mtlo %2 \n\t\t"
42       : "=x" (ll_result)
43         : "r" (i_hi), "r" (i_lo)
44           : );
45 
46   return 0;
47 }
48 
49 // CHECK: attributes [[NUW]] = { nounwind }
50