Add function entry count metadata.

Summary:
This adds three Function methods to handle function entry counts:
setEntryCount() and getEntryCount().

Entry counts are stored under the MD_prof metadata node with the name
"function_entry_count". They are unsigned 64 bit values set by profilers
(instrumentation and sample profiler changes coming up).

Added documentation for new profile metadata and tests.

Reviewers: dexonsmith, bogner

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9628

llvm-svn: 237260

2 files changed, 43 insertions, 0 deletions

diff --git a/llvm/test/Verifier/function-metadata-bad.ll b/llvm/test/Verifier/function-metadata-bad.ll
new file mode 100644
index 00000000000..9e7ba225408
--- /dev/null
+++ b/llvm/test/Verifier/function-metadata-bad.ll
@@ -0,0 +1,35 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+
+define i32 @bad1() !prof !0 {
+  ret i32 0
+}
+
+!0 = !{i32 123, i32 3}
+; CHECK: assembly parsed, but does not verify as correct!
+; CHECK-NEXT: expected string with name of the !prof annotation
+; CHECK-NEXT: !0 = !{i32 123, i32 3}
+
+define i32 @bad2() !prof !1 {
+  ret i32 0
+}
+
+!1 = !{!"function_entry_count"}
+; CHECK-NEXT: !prof annotations should have exactly 2 operands
+; CHECK-NEXT: !1 = !{!"function_entry_count"}
+
+
+define i32 @bad3() !prof !2 {
+  ret i32 0
+}
+
+!2 = !{!"some_other_count", i64 200}
+; CHECK-NEXT: first operand should be 'function_entry_count'
+; CHECK-NEXT: !2 = !{!"some_other_count", i64 200}
+
+define i32 @bad4() !prof !3 {
+  ret i32 0
+}
+
+!3 = !{!"function_entry_count", !"string"}
+; CHECK-NEXT: expected integer argument to function_entry_count
+; CHECK-NEXT: !3 = !{!"function_entry_count", !"string"}
diff --git a/llvm/test/Verifier/function-metadata-good.ll b/llvm/test/Verifier/function-metadata-good.ll
new file mode 100644
index 00000000000..3d73a1c0694
--- /dev/null
+++ b/llvm/test/Verifier/function-metadata-good.ll
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s -o /dev/null 2>&1
+
+; Function foo() is called 2,304 times at runtime.
+define i32 @foo() !prof !0 {
+  ret i32 0
+}
+
+!0 = !{!"function_entry_count", i32 2304}