[llvm] 58645d3 - [OpenMP] Fix `omp_get_wtime` function being marked incorrectly as readonly

[Joseph Huber via llvm-commits]

Author: Joseph Huber
Date: 2022-09-06T12:59:00-05:00
New Revision: 58645d3252e883f2e61363552767ed1716634edf

URL: https://github.com/llvm/llvm-project/commit/58645d3252e883f2e61363552767ed1716634edf
DIFF: https://github.com/llvm/llvm-project/commit/58645d3252e883f2e61363552767ed1716634edf.diff

LOG: [OpenMP] Fix `omp_get_wtime` function being marked incorrectly as readonly

OpenMP has a list of of optimistic attributes that can be attached to
known runtime functions to aid some analysis. The `omp_get_wtime`
function incorrectly used the `readonly` attribute. This is not correct
at the `omp_get_wtime` function changes values depending on some
external state. This is more correctly modeled with
`inaccessiblememonly` meaning that the value does not depend on anything
within the module, but can not be removes as it depends on external
state.

Fixes #57578

Reviewed By: tianshilei1992

Differential Revision: https://reviews.llvm.org/D133360

Added: 
    

Modified: 
    llvm/include/llvm/Frontend/OpenMP/OMPKinds.def
    llvm/test/Transforms/OpenMP/add_attributes.ll

Removed: 
    


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diff  --git a/llvm/include/llvm/Frontend/OpenMP/OMPKinds.def b/llvm/include/llvm/Frontend/OpenMP/OMPKinds.def
index 7a70af9ce792f..32ca3e2350ab3 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMPKinds.def
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPKinds.def
@@ -683,7 +683,7 @@ __OMP_RTL_ATTRS(omp_get_partition_num_places, GetterAttrs, AttributeSet(),
                 ParamAttrs())
 __OMP_RTL_ATTRS(omp_get_partition_place_nums, GetterAttrs, AttributeSet(),
                 ParamAttrs())
-__OMP_RTL_ATTRS(omp_get_wtime, GetterAttrs, AttributeSet(), ParamAttrs())
+__OMP_RTL_ATTRS(omp_get_wtime, GetterArgWriteAttrs, AttributeSet(), ParamAttrs())
 
 __OMP_RTL_ATTRS(omp_set_num_threads, SetterAttrs, AttributeSet(), ParamAttrs())
 __OMP_RTL_ATTRS(omp_set_dynamic, SetterAttrs, AttributeSet(), ParamAttrs())

diff  --git a/llvm/test/Transforms/OpenMP/add_attributes.ll b/llvm/test/Transforms/OpenMP/add_attributes.ll
index d060b88e8ce89..9d48cd1c7bca5 100644
--- a/llvm/test/Transforms/OpenMP/add_attributes.ll
+++ b/llvm/test/Transforms/OpenMP/add_attributes.ll
@@ -1313,7 +1313,7 @@ attributes #0 = { noinline cold }
 ; OPTIMISTIC-NOT: Function Attrs
 ; OPTIMISTIC: declare dso_local void @omp_init_nest_lock_with_hint(%struct.omp_nest_lock_t*, i32)
 
-; OPTIMISTIC: ; Function Attrs: inaccessiblememonly nofree nosync nounwind readonly willreturn
+; OPTIMISTIC: ; Function Attrs: inaccessiblemem_or_argmemonly nofree nosync nounwind willreturn
 ; OPTIMISTIC-NEXT: declare dso_local double @omp_get_wtime()
 
 ; OPTIMISTIC-NOT: Function Attrs