[memprof] Avoid repeated hash lookups (NFC)

[kazutakahirata]

Note that we don't have to worry about CallstackProfileData[Id]
default-constructing the value side of a new map entry. If that
happens, AccessHistogramSize > 0 wouldn't be true, and the new map
entry gets deleted right away.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Kazu Hirata (kazutakahirata)

Changes

Note that we don't have to worry about CallstackProfileData[Id]
default-constructing the value side of a new map entry. If that
happens, AccessHistogramSize > 0 wouldn't be true, and the new map
entry gets deleted right away.

---

Full diff: https://github.com/llvm/llvm-project/pull/136268.diff

1 Files Affected:

• (modified) llvm/lib/ProfileData/MemProfReader.cpp (+6-3)

diff --git a/llvm/lib/ProfileData/MemProfReader.cpp b/llvm/lib/ProfileData/MemProfReader.cpp
index c57f9b22273d4..e0f280b9eb2f6 100644
--- a/llvm/lib/ProfileData/MemProfReader.cpp
+++ b/llvm/lib/ProfileData/MemProfReader.cpp
@@ -600,9 +600,12 @@ Error RawMemProfReader::symbolizeAndFilterStackFrames(
   // Drop the entries where the callstack is empty.
   for (const uint64_t Id : EntriesToErase) {
     StackMap.erase(Id);
-    if (CallstackProfileData[Id].AccessHistogramSize > 0)
-      free((void *)CallstackProfileData[Id].AccessHistogram);
-    CallstackProfileData.erase(Id);
+    if (auto It = CallstackProfileData.find(Id);
+        It != CallstackProfileData.end()) {
+      if (It->second.AccessHistogramSize > 0)
+        free((void *)It->second.AccessHistogram);
+      CallstackProfileData.erase(It);
+    }
   }
 
   if (StackMap.empty())

[llvm-ci]

LLVM Buildbot has detected a new failure on builder openmp-s390x-linux running on systemz-1 while building llvm at step 6 "test-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/88/builds/10618

Here is the relevant piece of the build log for the reference

Step 6 (test-openmp) failure: 1200 seconds without output running [b'ninja', b'-j 4', b'check-openmp'], attempting to kill
...
PASS: ompd-test :: openmp_examples/example_2.c (442 of 452)
PASS: ompd-test :: openmp_examples/example_4.c (443 of 452)
PASS: ompd-test :: openmp_examples/example_5.c (444 of 452)
PASS: ompd-test :: openmp_examples/example_task.c (445 of 452)
UNSUPPORTED: ompd-test :: openmp_examples/ompd_bt.c (446 of 452)
PASS: ompd-test :: openmp_examples/fibonacci.c (447 of 452)
UNSUPPORTED: ompd-test :: openmp_examples/ompd_parallel.c (448 of 452)
PASS: ompd-test :: openmp_examples/parallel.c (449 of 452)
PASS: ompd-test :: openmp_examples/nested.c (450 of 452)
PASS: ompd-test :: openmp_examples/ompd_icvs.c (451 of 452)
command timed out: 1200 seconds without output running [b'ninja', b'-j 4', b'check-openmp'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1382.351288