commit e6f87ca812809543444d7d5961aea2509b8a3227
author James Molloy <james.molloy@arm.com> Fri Nov 06 10:32:53 2015 +0000
committer James Molloy <james.molloy@arm.com> Fri Nov 06 10:32:53 2015 +0000
tree 0484ecea76aab7032b2b590638de7650912e9e14
parent a805030ae821fa03fb76d89b9bb81ee66f676105

Add a new attribute: norecurse

This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.

llvm-svn: 252282

llvm/lib/AsmParser/LLLexer.cpp

diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 2eb5f0b..82d6eb7 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -616,6 +616,7 @@
   KEYWORD(noduplicate);
   KEYWORD(noimplicitfloat);
   KEYWORD(noinline);
+  KEYWORD(norecurse);
   KEYWORD(nonlazybind);
   KEYWORD(nonnull);
   KEYWORD(noredzone);

llvm/lib/AsmParser/LLParser.cpp

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 1c219ad..7feb99d 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -998,6 +998,7 @@
     case lltok::kw_nonlazybind: B.addAttribute(Attribute::NonLazyBind); break;
     case lltok::kw_noredzone: B.addAttribute(Attribute::NoRedZone); break;
     case lltok::kw_noreturn: B.addAttribute(Attribute::NoReturn); break;
+    case lltok::kw_norecurse: B.addAttribute(Attribute::NoRecurse); break;
     case lltok::kw_nounwind: B.addAttribute(Attribute::NoUnwind); break;
     case lltok::kw_optnone: B.addAttribute(Attribute::OptimizeNone); break;
     case lltok::kw_optsize: B.addAttribute(Attribute::OptimizeForSize); break;

llvm/lib/AsmParser/LLToken.h

diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 06b5f9b..ecd6481 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -123,6 +123,7 @@
     kw_noduplicate,
     kw_noimplicitfloat,
     kw_noinline,
+    kw_norecurse,
     kw_nonlazybind,
     kw_nonnull,
     kw_noredzone,

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 7c1b208..bc84619 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1305,6 +1305,8 @@
     return Attribute::NoImplicitFloat;
   case bitc::ATTR_KIND_NO_INLINE:
     return Attribute::NoInline;
+  case bitc::ATTR_KIND_NO_RECURSE:
+    return Attribute::NoRecurse;
   case bitc::ATTR_KIND_NON_LAZY_BIND:
     return Attribute::NonLazyBind;
   case bitc::ATTR_KIND_NON_NULL:

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index c73b099..941e547 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -202,6 +202,8 @@
     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
   case Attribute::NoInline:
     return bitc::ATTR_KIND_NO_INLINE;
+  case Attribute::NoRecurse:
+    return bitc::ATTR_KIND_NO_RECURSE;
   case Attribute::NonLazyBind:
     return bitc::ATTR_KIND_NON_LAZY_BIND;
   case Attribute::NonNull:

llvm/lib/IR/Attributes.cpp

diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index 2586cb5..bdefe59 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -232,6 +232,8 @@
     return "noredzone";
   if (hasAttribute(Attribute::NoReturn))
     return "noreturn";
+  if (hasAttribute(Attribute::NoRecurse))
+    return "norecurse";
   if (hasAttribute(Attribute::NoUnwind))
     return "nounwind";
   if (hasAttribute(Attribute::OptimizeNone))
@@ -442,6 +444,7 @@
   case Attribute::JumpTable:       return 1ULL << 45;
   case Attribute::Convergent:      return 1ULL << 46;
   case Attribute::SafeStack:       return 1ULL << 47;
+  case Attribute::NoRecurse:       return 1ULL << 48;
   case Attribute::Dereferenceable:
     llvm_unreachable("dereferenceable attribute not supported in raw format");
     break;

llvm/lib/IR/Verifier.cpp

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 813f9ca..0fce50e 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1233,7 +1233,8 @@
         I->getKindAsEnum() == Attribute::OptimizeNone ||
         I->getKindAsEnum() == Attribute::JumpTable ||
         I->getKindAsEnum() == Attribute::Convergent ||
-        I->getKindAsEnum() == Attribute::ArgMemOnly) {
+        I->getKindAsEnum() == Attribute::ArgMemOnly ||
+        I->getKindAsEnum() == Attribute::NoRecurse) {
       if (!isFunction) {
         CheckFailed("Attribute '" + I->getAsString() +
                     "' only applies to functions!", V);