Remove setting of inlinehint and cold attributes based on profile data

[eraman]

Summary

NFC. These hints are only used for inlining and the inliner now uses the same criteria to identify hot and cold callees and set appropriate thresholds without relying on these hints. Hence this removed code is superfluous.

[davidxl]

This looks like a straightforward cleanup (the test cases have been in a previous patch).

[davidxl]

lgtm

lib/CodeGen/CodeGenPGO.cpp

 }
 
 void
 CodeGenPGO::applyFunctionAttributes(llvm::IndexedInstrProfReader *PGOReader,
                                     llvm::Function *Fn) {
   if (!haveRegionCounts())
     return;
 
-  uint64_t MaxFunctionCount = PGOReader->getMaximumFunctionCount();
   uint64_t FunctionCount = getRegionCount(nullptr);
-  if (FunctionCount >= (uint64_t)(0.3 * (double)MaxFunctionCount))
-    // Turn on InlineHint attribute for hot functions.
-    // FIXME: 30% is from preliminary tuning on SPEC, it may not be optimal.
-    Fn->addFnAttr(llvm::Attribute::InlineHint);
-  else if (FunctionCount <= (uint64_t)(0.01 * (double)MaxFunctionCount))
-    // Turn on Cold attribute for cold functions.
-    // FIXME: 1% is from preliminary tuning on SPEC, it may not be optimal.
-    Fn->addFnAttr(llvm::Attribute::Cold);
-
   Fn->setEntryCount(FunctionCount);
 }
 
 void CodeGenPGO::emitCounterIncrement(CGBuilderTy &Builder, const Stmt *S) {
   if (!CGM.getCodeGenOpts().ProfileInstrGenerate || !RegionCounterMap)
     return;
   if (!Builder.GetInsertBlock())
     return;

test/Profile/c-attributes.c

-// Test that instrumentation based profiling sets function attributes correctly.
-
-// RUN: llvm-profdata merge %S/Inputs/c-attributes.proftext -o %t.profdata
-// RUN: %clang %s -o - -mllvm -disable-llvm-optzns -emit-llvm -S -fprofile-instr-use=%t.profdata | FileCheck %s
-
-extern int atoi(const char *);
-
-// CHECK: hot_100_percent(i32{{.*}}%i) [[HOT:#[0-9]+]]
-void hot_100_percent(int i) {
-  while (i > 0)
-    i--;
-}
-
-// CHECK: hot_40_percent(i32{{.*}}%i) [[HOT]]
-void hot_40_percent(int i) {
-  while (i > 0)
-    i--;
-}
-
-// CHECK: normal_func(i32{{.*}}%i) [[NORMAL:#[0-9]+]]
-void normal_func(int i) {
-  while (i > 0)
-    i--;
-}
-
-// CHECK: cold_func(i32{{.*}}%i) [[COLD:#[0-9]+]]
-void cold_func(int i) {
-  while (i > 0)
-    i--;
-}
-
-// CHECK: attributes [[HOT]] = { inlinehint nounwind {{.*}} }
-// CHECK: attributes [[NORMAL]] = { nounwind {{.*}} }
-// CHECK: attributes [[COLD]] = { cold nounwind {{.*}} }
-
-int main(int argc, const char *argv[]) {
-  int max = atoi(argv[1]);
-  int i;
-  for (i = 0; i < max; i++)
-    hot_100_percent(i);
-  for (i = 0; i < max * 4 / 10; i++)
-    hot_40_percent(i);
-  for (i = 0; i < max * 2 / 10; i++)
-    normal_func(i);
-  for (i = 0; i < max / 200; i++)
-    cold_func(i);
-  return 0;
-}

test/Profile/func-entry.c

 // Test that function entry counts are set correctly.
 
 // RUN: llvm-profdata merge %S/Inputs/func-entry.proftext -o %t.profdata
 // RUN: %clang %s -o - -mllvm -disable-llvm-optzns -emit-llvm -S -fprofile-instr-use=%t.profdata | FileCheck %s
 
 void foo(void);
 
-// CHECK: @foo() #0 !prof [[FOO:![0-9]+]]
+// CHECK: @foo() #{{[0-9]}} !prof [[FOO:![0-9]+]]
 void foo() { return; }
 
-// CHECK: @main() #1 !prof [[MAIN:![0-9]+]]
+// CHECK: @main() #{{[0-9]}} !prof [[MAIN:![0-9]+]]
 int main() {
   int i;
   for (i = 0; i < 10000; i++) foo();
   return 0;
 }
 
 // CHECK: [[FOO]] = !{!"function_entry_count", i64 1000}
 // CHECK: [[MAIN]] = !{!"function_entry_count", i64 1}