[PGO] Handle and report overflow during profile merge for all types of data

Summary: Surface counter overflow when merging profile data. Merging still occurs on overflow but counts saturate to the maximum representable value. Overflow is reported to the user.

Reviewers: davidxl, dnovillo, silvas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15547

llvm-svn: 255825

1 files changed, 43 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-profdata/overflow-sample.test b/llvm/test/tools/llvm-profdata/overflow-sample.test
new file mode 100644
index 00000000000..cd6268db2ab
--- /dev/null
+++ b/llvm/test/tools/llvm-profdata/overflow-sample.test
@@ -0,0 +1,43 @@
+Tests for overflow when merging sampled profiles.
+
+1- Merge profile having maximum counts with itself and verify overflow detected
+RUN: llvm-profdata merge -sample %p/Inputs/overflow-sample.proftext %p/Inputs/overflow-sample.proftext -o %t.out 2>&1 | FileCheck %s -check-prefix=MERGE_OVERFLOW
+RUN: llvm-profdata show -sample %t.out | FileCheck %s --check-prefix=SHOW_OVERFLOW
+MERGE_OVERFLOW: {{.*}}: main: Counter overflow
+SHOW_OVERFLOW: Function: main: 2000, 0, 2 sampled lines
+SHOW_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_OVERFLOW-NEXT:   1: 1000, calls: _Z3bari:18446744073709551615
+SHOW_OVERFLOW-NEXT:   2: 1000, calls: _Z3fooi:18446744073709551615
+SHOW_OVERFLOW-NEXT: }
+SHOW_OVERFLOW-NEXT: No inlined callsites in this function
+SHOW_OVERFLOW-NEXT: Function: _Z3fooi: 18446744073709551615, 2000, 1 sampled lines
+SHOW_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_OVERFLOW-NEXT:   1: 18446744073709551615
+SHOW_OVERFLOW-NEXT: }
+SHOW_OVERFLOW-NEXT: No inlined callsites in this function
+SHOW_OVERFLOW-NEXT: Function: _Z3bari: 18446744073709551615, 2000, 1 sampled lines
+SHOW_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_OVERFLOW-NEXT:   1: 18446744073709551615
+SHOW_OVERFLOW-NEXT: }
+SHOW_OVERFLOW-NEXT: No inlined callsites in this function
+
+2- Merge profile having maximum counts by itself and verify no overflow
+RUN: llvm-profdata merge -sample %p/Inputs/overflow-sample.proftext -o %t.out 2>&1 | FileCheck %s -allow-empty -check-prefix=MERGE_NO_OVERFLOW
+RUN: llvm-profdata show -sample %t.out | FileCheck %s --check-prefix=SHOW_NO_OVERFLOW
+MERGE_NO_OVERFLOW-NOT: {{.*}}: main: Counter overflow
+SHOW_NO_OVERFLOW: Function: main: 1000, 0, 2 sampled lines
+SHOW_NO_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_NO_OVERFLOW-NEXT:   1: 500, calls: _Z3bari:18446744073709551615
+SHOW_NO_OVERFLOW-NEXT:   2: 500, calls: _Z3fooi:18446744073709551615
+SHOW_NO_OVERFLOW-NEXT: }
+SHOW_NO_OVERFLOW-NEXT: No inlined callsites in this function
+SHOW_NO_OVERFLOW-NEXT: Function: _Z3fooi: 18446744073709551615, 1000, 1 sampled lines
+SHOW_NO_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_NO_OVERFLOW-NEXT:   1: 18446744073709551615
+SHOW_NO_OVERFLOW-NEXT: }
+SHOW_NO_OVERFLOW-NEXT: No inlined callsites in this function
+SHOW_NO_OVERFLOW-NEXT: Function: _Z3bari: 18446744073709551615, 1000, 1 sampled lines
+SHOW_NO_OVERFLOW-NEXT: Samples collected in the function's body {
+SHOW_NO_OVERFLOW-NEXT:   1: 18446744073709551615
+SHOW_NO_OVERFLOW-NEXT: }
+SHOW_NO_OVERFLOW-NEXT: No inlined callsites in this function