[flang-commits] [flang] [flang][cuda] Set correct bind(c) name for __popc (PR #152795)
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Fri Aug 8 14:06:55 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir
Author: Valentin Clement (バレンタイン クレメン) (clementval)
<details>
<summary>Changes</summary>
The `__popc` interface is used to call lib device functions `__nv_popc` and `__nv_popcll`. Update the module with the correct bind(c) name
---
Full diff: https://github.com/llvm/llvm-project/pull/152795.diff
2 Files Affected:
- (modified) flang/module/cudadevice.f90 (+2-2)
- (modified) flang/test/Lower/CUDA/cuda-device-proc.cuf (+7)
``````````diff
diff --git a/flang/module/cudadevice.f90 b/flang/module/cudadevice.f90
index d0c312c09353f..dc72fc52c7345 100644
--- a/flang/module/cudadevice.f90
+++ b/flang/module/cudadevice.f90
@@ -754,11 +754,11 @@ attributes(device) real(8) function sinpi(x) bind(c,name='__nv_sinpi')
end interface
interface __popc
- attributes(device) integer function __popc(i) bind(c)
+ attributes(device) integer function __popc(i) bind(c, name='__nv_popc')
!dir$ ignore_tkr (d) i
integer, value :: i
end function
- attributes(device) integer function __popcll(i) bind(c)
+ attributes(device) integer function __popcll(i) bind(c, name='__nv_popcll')
!dir$ ignore_tkr (d) i
integer(8), value :: i
end function
diff --git a/flang/test/Lower/CUDA/cuda-device-proc.cuf b/flang/test/Lower/CUDA/cuda-device-proc.cuf
index d5e614a83b354..a8cc5034a9348 100644
--- a/flang/test/Lower/CUDA/cuda-device-proc.cuf
+++ b/flang/test/Lower/CUDA/cuda-device-proc.cuf
@@ -11,6 +11,7 @@ attributes(global) subroutine devsub()
integer(8) :: al
integer(8) :: time
integer :: smalltime
+ integer(4) :: res
call syncthreads()
call syncwarp(1)
@@ -49,6 +50,9 @@ attributes(global) subroutine devsub()
smalltime = clock()
time = clock64()
time = globalTimer()
+
+ res = __popc(ai)
+ res = __popc(al)
end
! CHECK-LABEL: func.func @_QPdevsub() attributes {cuf.proc_attr = #cuf.cuda_proc<global>}
@@ -89,6 +93,9 @@ end
! CHECK: %{{.*}} = nvvm.read.ptx.sreg.clock64 : i64
! CHECK: %{{.*}} = nvvm.read.ptx.sreg.globaltimer : i64
+! CHECK: %{{.*}} = fir.call @__nv_popc(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i32) -> i32
+! CHECK: %{{.*}} = fir.call @__nv_popcll(%{{.*}}) proc_attrs<bind_c> fastmath<contract> : (i64) -> i32
+
subroutine host1()
integer, device :: a(32)
integer, device :: ret
``````````
</details>
https://github.com/llvm/llvm-project/pull/152795
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