Mark @llvm.trap cold

A call to @llvm.trap can be expected to be cold (i.e. unlikely to be
reached in a normal program execution).

Outlining paths which unconditionally trap is an important memory
saving. As the hot/cold splitting pass (imho) should not treat all
noreturn calls as cold, explicitly mark @llvm.trap cold so that it can
be outlined.

Split out of https://reviews.llvm.org/D54244.

Differential Revision: https://reviews.llvm.org/D54329

llvm-svn: 346885

1 files changed, 10 insertions, 1 deletions

diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
index 06e44e3b57c..049282e5ebf 100644
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -489,6 +489,9 @@ struct AttributeComparator {
     if (L->isNoReturn != R->isNoReturn)
       return R->isNoReturn;
 
+    if (L->isCold != R->isCold)
+      return R->isCold;
+
     if (L->isConvergent != R->isConvergent)
       return R->isConvergent;
 
@@ -622,7 +625,7 @@ void IntrinsicEmitter::EmitAttributes(const CodeGenIntrinsicTable &Ints,
 
     if (!intrinsic.canThrow ||
         intrinsic.ModRef != CodeGenIntrinsic::ReadWriteMem ||
-        intrinsic.isNoReturn || intrinsic.isNoDuplicate ||
+        intrinsic.isNoReturn || intrinsic.isCold || intrinsic.isNoDuplicate ||
         intrinsic.isConvergent || intrinsic.isSpeculatable) {
       OS << "      const Attribute::AttrKind Atts[] = {";
       bool addComma = false;
@@ -636,6 +639,12 @@ void IntrinsicEmitter::EmitAttributes(const CodeGenIntrinsicTable &Ints,
         OS << "Attribute::NoReturn";
         addComma = true;
       }
+      if (intrinsic.isCold) {
+        if (addComma)
+          OS << ",";
+        OS << "Attribute::Cold";
+        addComma = true;
+      }
       if (intrinsic.isNoDuplicate) {
         if (addComma)
           OS << ",";