[Openmp-commits] [openmp] [amdgpu][openmp] Treat missing TIMESTAMP_FREQUENCY as non-fatal (PR #70987)

[Jon Chesterfield via Openmp-commits]

https://github.com/JonChesterfield created https://github.com/llvm/llvm-project/pull/70987

If you build with dynamic_hsa, the symbol is known and compilation succeeds. If you then run with a slightly older libhsa, this argument is not recognised and an error returned. I'd rather the program runs with a misleading omp wtime than refuses to run at all.

>From 37b81fc45e7bc9336ca2a612a9f367cd028017d8 Mon Sep 17 00:00:00 2001
From: Jon Chesterfield <jonathanchesterfield at gmail.com>
Date: Wed, 1 Nov 2023 21:23:06 +0000
Subject: [PATCH] [amdgpu][openmp] Treat missing TIMESTAMP_FREQUENCY as
 non-fatal

---
 openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp b/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
index 71207f767fdcc60..378cad8f8ca4f15 100644
--- a/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
+++ b/openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp
@@ -1810,10 +1810,12 @@ struct AMDGPUDeviceTy : public GenericDeviceTy, AMDGenericDeviceTy {
       return Err;
     GridValues.GV_Warp_Size = WavefrontSize;
 
-    // Get the frequency of the steady clock.
-    if (auto Err = getDeviceAttr(HSA_AMD_AGENT_INFO_TIMESTAMP_FREQUENCY,
-                                 ClockFrequency))
-      return Err;
+    // Get the frequency of the steady clock. If the attribute is missing
+    // assume running on an older libhsa and default to 0, omp_get_wtime
+    // will be inaccurate but otherwise programs can still run.
+    if (auto Err = getDeviceAttrRaw(HSA_AMD_AGENT_INFO_TIMESTAMP_FREQUENCY,
+                                    ClockFrequency))
+      ClockFrequency = 0;
 
     // Load the grid values dependending on the wavefront.
     if (WavefrontSize == 32)