[clang] Replace asm with __asm__ in cuda header

[JonChesterfield]

Summary

Asm is a gnu extension for C, so at present -fopenmp -std=c99
and similar fail to compile on nvptx, bug 51344

Changing to __asm__ or __asm works for openmp, all three appear to work
for cuda. Suggesting __asm__ here as __asm is used by MSVC with different
syntax, so this should make for better error diagnostics if the header is
passed to a compiler other than clang.

[JonChesterfield]

Implemented by
F=__clang_cuda_device_functions.h ; sed -i 's$asm$__asm__$g' $F && clang-format -i $F

[tra]

LGTM in general.

clang/lib/Headers/__clang_cuda_device_functions.h

37

Should we also change volatile -> __volatile__ here in other places in the file?

[emankov]

clang/lib/Headers/__clang_cuda_device_functions.h

1043

Unneeded formatting.

1057

Tabs are not allowed, please use whitespaces instead.

[JonChesterfield]

Re: __volatile__. I've done some background reading on it but can't find the original motivation. __asm__ exists because the asm word is in the application namespace and asm is an extension. Volatile has been with us since C89 though, and is also accepted under -ansi. I haven't been able to find a set of compiler flags that reject it.

Cuda however uses volatile to mean a different thing to C as it is part of the atomic model. From poking at -x cuda in godbolt it looks like clang lowers cuda volatile to IR volatile, and not to relaxed atomic. I'm not confident that's correct, in particular i++ on a volatile variable turns into a load and a store, not an atomicrmw. That's orthogonal to this particular change but does make me reluctant to touch the word 'volatile' in anything that is compiled as cuda.

Therefore I'd like to leave it as __asm__ volatile.

clang/lib/Headers/__clang_cuda_device_functions.h

37

Replying at the end

1043

Correct formatting though. This is what clang-format did to the whole file. I'll revert the space in favour of git-clang-format if you prefer

1057

I've been there! It's not a tab, that's the symbol phabricator unhelpfully uses to indicate whitespace change. In this case, four extra spaces to keep the : lined up with the brace

[JonChesterfield]

• whitespace change

[JonChesterfield]

clang/lib/Headers/__clang_cuda_device_functions.h

1043

git-clang-format also wanted to insert the space here and I then had to use -nolint. However hopefully that removes an async round trip in the review chain. Some of the previous lines were 81 characters. I suppose we could apply a whitespace-only clang-format patch first but it doesn't seem worth the time.

[emankov]

clang/lib/Headers/__clang_cuda_device_functions.h

1043

The point is that this formatting is not related to the change.

[tra]

In D107492#2926871, @JonChesterfield wrote:

Therefore I'd like to leave it as __asm__ volatile.

Being the one who introduced inconsistent use of __volatile__ and volatile in this header, I'm pretty sure that PTX's notion of volatile is not involved for inline asm of trap and brkpt. It should be fine changing them to __volatile__ for the sake of uniformity.
Up to you.

[JonChesterfield]

In D107492#2926910, @tra wrote:

In D107492#2926871, @JonChesterfield wrote:

Therefore I'd like to leave it as __asm__ volatile.

Being the one who introduced inconsistent use of __volatile__ and volatile in this header, I'm pretty sure that PTX's notion of volatile is not involved for inline asm of trap and brkpt. It should be fine changing them to __volatile__ for the sake of uniformity.
Up to you.

Ah, I had missed that we already had an instance of __volatile__. We have one __volatile__ and three volatile. I like consistency and it seems you would prefer '__' to '', will patch that at the same time.

[JonChesterfield]

• consistent volatile

clang/lib/Headers/__clang_cuda_device_functions.h

 __DEVICE__ int __all(int __a) { return __nvvm_vote_all(__a); }
 __DEVICE__ int __any(int __a) { return __nvvm_vote_any(__a); }
 __DEVICE__ unsigned int __ballot(int __a) { return __nvvm_vote_ballot(__a); }
 __DEVICE__ unsigned int __brev(unsigned int __a) { return __nv_brev(__a); }
 __DEVICE__ unsigned long long __brevll(unsigned long long __a) {
   return __nv_brevll(__a);
 }
 #if defined(__cplusplus)
-__DEVICE__ void __brkpt() { asm volatile("brkpt;"); }
+__DEVICE__ void __brkpt() { __asm__ __volatile__("brkpt;"); }
 __DEVICE__ void __brkpt(int __a) { __brkpt(); }
 #else
-__DEVICE__ void __attribute__((overloadable)) __brkpt(void) { asm volatile("brkpt;"); }
+__DEVICE__ void __attribute__((overloadable)) __brkpt(void) {
+  __asm__ __volatile__("brkpt;");
+}
 __DEVICE__ void __attribute__((overloadable)) __brkpt(int __a) { __brkpt(); }
 #endif
 __DEVICE__ unsigned int __byte_perm(unsigned int __a, unsigned int __b,
                                     unsigned int __c) {
   return __nv_byte_perm(__a, __b, __c);
 }
 __DEVICE__ int __clz(int __a) { return __nv_clz(__a); }
 __DEVICE__ int __clzll(long long __a) { return __nv_clzll(__a); }

 __DEVICE__ unsigned int __pm3(void) { return __nvvm_read_ptx_sreg_pm3(); }
 __DEVICE__ int __popc(int __a) { return __nv_popc(__a); }
 __DEVICE__ int __popcll(long long __a) { return __nv_popcll(__a); }
 __DEVICE__ float __powf(float __a, float __b) {
   return __nv_fast_powf(__a, __b);
 }
 
 // Parameter must have a known integer value.
-#define __prof_trigger(__a) asm __volatile__("pmevent \t%0;" ::"i"(__a))
+#define __prof_trigger(__a) __asm__ __volatile__("pmevent \t%0;" ::"i"(__a))
 __DEVICE__ int __rhadd(int __a, int __b) { return __nv_rhadd(__a, __b); }
 __DEVICE__ unsigned int __sad(int __a, int __b, unsigned int __c) {
   return __nv_sad(__a, __b, __c);
 }
 __DEVICE__ float __saturatef(float __a) { return __nv_saturatef(__a); }
 __DEVICE__ int __signbitd(double __a) { return __nv_signbitd(__a); }
 __DEVICE__ int __signbitf(float __a) { return __nv_signbitf(__a); }
 __DEVICE__ void __sincosf(float __a, float *__s, float *__c) {
   return __nv_fast_sincosf(__a, __s, __c);
 }
 __DEVICE__ float __sinf(float __a) { return __nv_fast_sinf(__a); }
 __DEVICE__ int __syncthreads_and(int __a) { return __nvvm_bar0_and(__a); }
 __DEVICE__ int __syncthreads_count(int __a) { return __nvvm_bar0_popc(__a); }
 __DEVICE__ int __syncthreads_or(int __a) { return __nvvm_bar0_or(__a); }
 __DEVICE__ float __tanf(float __a) { return __nv_fast_tanf(__a); }
 __DEVICE__ void __threadfence(void) { __nvvm_membar_gl(); }
 __DEVICE__ void __threadfence_block(void) { __nvvm_membar_cta(); };
 __DEVICE__ void __threadfence_system(void) { __nvvm_membar_sys(); };
-__DEVICE__ void __trap(void) { asm volatile("trap;"); }
+__DEVICE__ void __trap(void) { __asm__ __volatile__("trap;"); }
 __DEVICE__ unsigned int __uAtomicAdd(unsigned int *__p, unsigned int __v) {
   return __nvvm_atom_add_gen_i((int *)__p, __v);
 }
 __DEVICE__ unsigned int __uAtomicAdd_block(unsigned int *__p,
                                            unsigned int __v) {
   return __nvvm_atom_cta_add_gen_i((int *)__p, __v);
 }
 __DEVICE__ unsigned int __uAtomicAdd_system(unsigned int *__p,
__DEVICE__ unsigned int __vsubss4(unsigned int __a, unsigned int __b) {
   return __nv_vsubss4(__a, __b);
 }
 __DEVICE__ unsigned int __vsubus2(unsigned int __a, unsigned int __b) {
   return __nv_vsubus2(__a, __b);
 }
 __DEVICE__ unsigned int __vsubus4(unsigned int __a, unsigned int __b) {
   return __nv_vsubus4(__a, __b);
 }
 #else // CUDA_VERSION >= 9020
 // CUDA no longer provides inline assembly (or bitcode) implementation of these
 // functions, so we have to reimplment them. The implementation is naive and is
 // not optimized for performance.
 
 // Helper function to convert N-bit boolean subfields into all-0 or all-1.
 // E.g. __bool2mask(0x01000100,8) -> 0xff00ff00
 //      __bool2mask(0x00010000,16) -> 0xffff0000
 __DEVICE__ unsigned int __bool2mask(unsigned int __a, int shift) {
   return (__a << shift) - __a;
 }
 __DEVICE__ unsigned int __vabs2(unsigned int __a) {
   unsigned int r;
-  asm("vabsdiff2.s32.s32.s32 %0,%1,%2,%3;"
+  __asm__("vabsdiff2.s32.s32.s32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(0), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabs4(unsigned int __a) {
   unsigned int r;
-  asm("vabsdiff4.s32.s32.s32 %0,%1,%2,%3;"
+  __asm__("vabsdiff4.s32.s32.s32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(0), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabsdiffs2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff2.s32.s32.s32 %0,%1,%2,%3;"
+  __asm__("vabsdiff2.s32.s32.s32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 
 __DEVICE__ unsigned int __vabsdiffs4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff4.s32.s32.s32 %0,%1,%2,%3;"
+  __asm__("vabsdiff4.s32.s32.s32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabsdiffu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff2.u32.u32.u32 %0,%1,%2,%3;"
+  __asm__("vabsdiff2.u32.u32.u32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabsdiffu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff4.u32.u32.u32 %0,%1,%2,%3;"
+  __asm__("vabsdiff4.u32.u32.u32 %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabsss2(unsigned int __a) {
   unsigned int r;
-  asm("vabsdiff2.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vabsdiff2.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(0), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vabsss4(unsigned int __a) {
   unsigned int r;
-  asm("vabsdiff4.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vabsdiff4.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(0), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vadd2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd2.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vadd2.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vadd4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd4.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vadd4.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vaddss2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd2.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vadd2.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vaddss4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd4.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vadd4.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vaddus2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd2.u32.u32.u32.sat %0,%1,%2,%3;"
+  __asm__("vadd2.u32.u32.u32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vaddus4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vadd4.u32.u32.u32.sat %0,%1,%2,%3;"
+  __asm__("vadd4.u32.u32.u32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vavgs2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vavrg2.s32.s32.s32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vavrg2.s32.s32.s32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vavgs4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vavrg4.s32.s32.s32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vavrg4.s32.s32.s32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vavgu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vavrg2.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vavrg2.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vavgu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vavrg4.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vavrg4.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vseteq2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.eq %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.eq %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpeq2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vseteq2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vseteq4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.eq %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.eq %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpeq4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vseteq4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetges2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.s32.s32.ge %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.s32.s32.ge %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpges2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetges2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetges4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.s32.s32.ge %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.s32.s32.ge %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpges4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetges4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetgeu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.ge %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.ge %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgeu2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgeu2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetgeu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.ge %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.ge %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgeu4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgeu4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetgts2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.s32.s32.gt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.s32.s32.gt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgts2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgts2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetgts4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.s32.s32.gt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.s32.s32.gt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgts4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgts4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetgtu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.gt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.gt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgtu2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgtu2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetgtu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.gt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.gt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpgtu4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetgtu4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetles2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.s32.s32.le %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.s32.s32.le %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmples2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetles2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetles4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.s32.s32.le %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.s32.s32.le %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmples4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetles4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetleu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.le %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.le %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpleu2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetleu2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetleu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.le %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.le %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpleu4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetleu4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetlts2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.s32.s32.lt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.s32.s32.lt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmplts2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetlts2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetlts4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.s32.s32.lt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.s32.s32.lt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmplts4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetlts4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetltu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.lt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.lt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpltu2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetltu2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetltu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.lt %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.lt %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpltu4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetltu4(__a, __b), 8);
 }
 __DEVICE__ unsigned int __vsetne2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset2.u32.u32.ne %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset2.u32.u32.ne %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpne2(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetne2(__a, __b), 16);
 }
 __DEVICE__ unsigned int __vsetne4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vset4.u32.u32.ne %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vset4.u32.u32.ne %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vcmpne4(unsigned int __a, unsigned int __b) {
   return __bool2mask(__vsetne4(__a, __b), 8);
 }
 
 // Based on ITEM 23 in AIM-239: http://dspace.mit.edu/handle/1721.1/6086
 // (a & b) + (a | b) = a + b = (a ^ b) + 2 * (a & b) =>

 __DEVICE__ unsigned int __vmaxs2(unsigned int __a, unsigned int __b) {
   unsigned int r;
   if ((__a & 0x8000) && (__b & 0x8000)) {
     // Work around a bug in ptxas which produces invalid result if low element
     // is negative.
     unsigned mask = __vcmpgts2(__a, __b);
     r = (__a & mask) | (__b & ~mask);
   } else {
-    asm("vmax2.s32.s32.s32 %0,%1,%2,%3;"
+    __asm__("vmax2.s32.s32.s32 %0,%1,%2,%3;"
             : "=r"(r)
             : "r"(__a), "r"(__b), "r"(0));
   }
   return r;
 }
 __DEVICE__ unsigned int __vmaxs4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmax4.s32.s32.s32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmax4.s32.s32.s32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vmaxu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmax2.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmax2.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vmaxu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmax4.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmax4.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vmins2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmin2.s32.s32.s32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmin2.s32.s32.s32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vmins4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmin4.s32.s32.s32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmin4.s32.s32.s32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vminu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmin2.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmin2.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vminu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vmin4.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vmin4.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vsads2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff2.s32.s32.s32.add %0,%1,%2,%3;"
+  __asm__("vabsdiff2.s32.s32.s32.add %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vsads4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff4.s32.s32.s32.add %0,%1,%2,%3;"
+  __asm__("vabsdiff4.s32.s32.s32.add %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vsadu2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff2.u32.u32.u32.add %0,%1,%2,%3;"
+  __asm__("vabsdiff2.u32.u32.u32.add %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vsadu4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vabsdiff4.u32.u32.u32.add %0,%1,%2,%3;"
+  __asm__("vabsdiff4.u32.u32.u32.add %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 
 __DEVICE__ unsigned int __vsub2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub2.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vsub2.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vneg2(unsigned int __a) { return __vsub2(0, __a); }
 
 __DEVICE__ unsigned int __vsub4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub4.u32.u32.u32 %0,%1,%2,%3;" : "=r"(r) : "r"(__a), "r"(__b), "r"(0));
+  __asm__("vsub4.u32.u32.u32 %0,%1,%2,%3;"
+          : "=r"(r)
+          : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vneg4(unsigned int __a) { return __vsub4(0, __a); }
 __DEVICE__ unsigned int __vsubss2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub2.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vsub2.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vnegss2(unsigned int __a) {
   return __vsubss2(0, __a);
 }
 __DEVICE__ unsigned int __vsubss4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub4.s32.s32.s32.sat %0,%1,%2,%3;"
+  __asm__("vsub4.s32.s32.s32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vnegss4(unsigned int __a) {
   return __vsubss4(0, __a);
 }
 __DEVICE__ unsigned int __vsubus2(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub2.u32.u32.u32.sat %0,%1,%2,%3;"
+  __asm__("vsub2.u32.u32.u32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 __DEVICE__ unsigned int __vsubus4(unsigned int __a, unsigned int __b) {
   unsigned int r;
-  asm("vsub4.u32.u32.u32.sat %0,%1,%2,%3;"
+  __asm__("vsub4.u32.u32.u32.sat %0,%1,%2,%3;"
           : "=r"(r)
           : "r"(__a), "r"(__b), "r"(0));
   return r;
 }
 #endif // CUDA_VERSION >= 9020
 
 // For OpenMP we require the user to include <time.h> as we need to know what
 // clock_t is on the system.
 #ifndef __OPENMP_NVPTX__
 __DEVICE__ /* clock_t= */ int clock() { return __nvvm_read_ptx_sreg_clock(); }