[IR] Add Freeze instruction

Summary:
- Define Instruction::Freeze, let it be UnaryOperator
- Add support for freeze to LLLexer/LLParser/BitcodeReader/BitcodeWriter
  The format is `%x = freeze <ty> %v`
- Add support for freeze instruction to llvm-c interface.
- Add m_Freeze in PatternMatch.
- Erase freeze when lowering IR to SelDag.

Reviewers: deadalnix, hfinkel, efriedma, lebedev.ri, nlopes, jdoerfert, regehr, filcab, delcypher, whitequark

Reviewed By: lebedev.ri, jdoerfert

Subscribers: jfb, kristof.beyls, hiraditya, lebedev.ri, steven_wu, dexonsmith, xbolva00, delcypher, spatel, regehr, trentxintong, vsk, filcab, nlopes, mehdi_amini, deadalnix, llvm-commits

Differential Revision: https://reviews.llvm.org/D29011

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index b8497095666..23e855148bb 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -69,6 +69,7 @@ typedef enum {
 
   /* Standard Unary Operators */
   LLVMFNeg           = 66,
+  LLVMFreeze         = 68,
 
   /* Standard Binary Operators */
   LLVMAdd            = 8,
@@ -3747,6 +3748,7 @@ LLVMValueRef LLVMBuildNUWNeg(LLVMBuilderRef B, LLVMValueRef V,
                              const char *Name);
 LLVMValueRef LLVMBuildFNeg(LLVMBuilderRef, LLVMValueRef V, const char *Name);
 LLVMValueRef LLVMBuildNot(LLVMBuilderRef, LLVMValueRef V, const char *Name);
+LLVMValueRef LLVMBuildFreeze(LLVMBuilderRef, LLVMValueRef V, const char *Name);
 
 /* Memory */
 LLVMValueRef LLVMBuildMalloc(LLVMBuilderRef, LLVMTypeRef Ty, const char *Name);