Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.

Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 7ba32b83f9..c45ad0a083 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -957,6 +957,7 @@ bool LLParser::ParseOptionalFuncAttrs(AttrBuilder &B) {
     case lltok::kw_ssp:             B.addAttribute(Attribute::StackProtect); break;
     case lltok::kw_sspreq:          B.addAttribute(Attribute::StackProtectReq); break;
     case lltok::kw_uwtable:         B.addAttribute(Attribute::UWTable); break;
+    case lltok::kw_noduplicate:     B.addAttribute(Attribute::NoDuplicate); break;
 
     // Error handling.
     case lltok::kw_zeroext:
@@ -1042,6 +1043,7 @@ bool LLParser::ParseOptionalReturnAttrs(AttrBuilder &B) {
     case lltok::kw_byval: case lltok::kw_nest:
       HaveError |= Error(Lex.getLoc(), "invalid use of parameter-only attribute");
       break;
+
     case lltok::kw_noreturn:       case lltok::kw_nounwind:
     case lltok::kw_uwtable:        case lltok::kw_returns_twice:
     case lltok::kw_noinline:       case lltok::kw_readnone:
@@ -1052,6 +1054,7 @@ bool LLParser::ParseOptionalReturnAttrs(AttrBuilder &B) {
     case lltok::kw_naked:          case lltok::kw_nonlazybind:
     case lltok::kw_address_safety: case lltok::kw_minsize:
     case lltok::kw_alignstack:     case lltok::kw_align:
+    case lltok::kw_noduplicate:
       HaveError |= Error(Lex.getLoc(), "invalid use of function-only attribute");
       break;
     }