diff --git a/LLVM-C.dll b/LLVM-C.dll
index e240855b6..e44f39998 100644
Binary files a/LLVM-C.dll and b/LLVM-C.dll differ
diff --git a/bin/llvm/windows/LLVM-C.lib b/bin/llvm/windows/LLVM-C.lib
index f3bad9a52..6e3fb888d 100644
Binary files a/bin/llvm/windows/LLVM-C.lib and b/bin/llvm/windows/LLVM-C.lib differ
diff --git a/src/llvm-c/Config/llvm-config.h b/src/llvm-c/Config/llvm-config.h
index 4ea68e371..434014a84 100644
--- a/src/llvm-c/Config/llvm-config.h
+++ b/src/llvm-c/Config/llvm-config.h
@@ -66,16 +66,16 @@
 #define LLVM_USE_PERF 0
 
 /* Major version of the LLVM API */
-#define LLVM_VERSION_MAJOR 12
+#define LLVM_VERSION_MAJOR 11
 
 /* Minor version of the LLVM API */
-#define LLVM_VERSION_MINOR 0
+#define LLVM_VERSION_MINOR 1
 
 /* Patch version of the LLVM API */
-#define LLVM_VERSION_PATCH 1
+#define LLVM_VERSION_PATCH 0
 
 /* LLVM version string */
-#define LLVM_VERSION_STRING "12.0.1"
+#define LLVM_VERSION_STRING "11.1.0"
 
 /* Whether LLVM records statistics for use with GetStatistics(),
  * PrintStatistics() or PrintStatisticsJSON()
diff --git a/src/llvm-c/Core.h b/src/llvm-c/Core.h
index 2901ab715..c8a6f9704 100644
--- a/src/llvm-c/Core.h
+++ b/src/llvm-c/Core.h
@@ -162,8 +162,7 @@ typedef enum {
   LLVMX86_MMXTypeKind,   /**< X86 MMX */
   LLVMTokenTypeKind,     /**< Tokens */
   LLVMScalableVectorTypeKind, /**< Scalable SIMD vector type */
-  LLVMBFloatTypeKind,    /**< 16 bit brain floating point type */
-  LLVMX86_AMXTypeKind    /**< X86 AMX */
+  LLVMBFloatTypeKind     /**< 16 bit brain floating point type */
 } LLVMTypeKind;
 
 typedef enum {
@@ -282,7 +281,6 @@ typedef enum {
   LLVMInlineAsmValueKind,
 
   LLVMInstructionValueKind,
-  LLVMPoisonValueValueKind
 } LLVMValueKind;
 
 typedef enum {
@@ -604,17 +602,6 @@ unsigned LLVMGetEnumAttributeKind(LLVMAttributeRef A);
  */
 uint64_t LLVMGetEnumAttributeValue(LLVMAttributeRef A);
 
-/**
- * Create a type attribute
- */
-LLVMAttributeRef LLVMCreateTypeAttribute(LLVMContextRef C, unsigned KindID,
-                                         LLVMTypeRef type_ref);
-
-/**
- * Get the type attribute's value.
- */
-LLVMTypeRef LLVMGetTypeAttributeValue(LLVMAttributeRef A);
-
 /**
  * Create a string attribute.
  */
@@ -637,12 +624,6 @@ const char *LLVMGetStringAttributeValue(LLVMAttributeRef A, unsigned *Length);
  */
 LLVMBool LLVMIsEnumAttribute(LLVMAttributeRef A);
 LLVMBool LLVMIsStringAttribute(LLVMAttributeRef A);
-LLVMBool LLVMIsTypeAttribute(LLVMAttributeRef A);
-
-/**
- * Obtain a Type from a context by its registered name.
- */
-LLVMTypeRef LLVMGetTypeByName2(LLVMContextRef C, const char *Name);
 
 /**
  * @}
@@ -885,7 +866,9 @@ LLVMValueRef LLVMGetInlineAsm(LLVMTypeRef Ty,
  */
 LLVMContextRef LLVMGetModuleContext(LLVMModuleRef M);
 
-/** Deprecated: Use LLVMGetTypeByName2 instead. */
+/**
+ * Obtain a Type from a module by its registered name.
+ */
 LLVMTypeRef LLVMGetTypeByName(LLVMModuleRef M, const char *Name);
 
 /**
@@ -1461,21 +1444,9 @@ unsigned LLVMGetPointerAddressSpace(LLVMTypeRef PointerTy);
 LLVMTypeRef LLVMVectorType(LLVMTypeRef ElementType, unsigned ElementCount);
 
 /**
- * Create a vector type that contains a defined type and has a scalable
- * number of elements.
+ * Obtain the number of elements in a vector type.
  *
- * The created type will exist in the context thats its element type
- * exists in.
- *
- * @see llvm::ScalableVectorType::get()
- */
-LLVMTypeRef LLVMScalableVectorType(LLVMTypeRef ElementType,
-                                   unsigned ElementCount);
-
-/**
- * Obtain the (possibly scalable) number of elements in a vector type.
- *
- * This only works on types that represent vectors (fixed or scalable).
+ * This only works on types that represent vectors.
  *
  * @see llvm::VectorType::getNumElements()
  */
@@ -1506,11 +1477,6 @@ LLVMTypeRef LLVMLabelTypeInContext(LLVMContextRef C);
  */
 LLVMTypeRef LLVMX86MMXTypeInContext(LLVMContextRef C);
 
-/**
- * Create a X86 AMX type in a context.
- */
-LLVMTypeRef LLVMX86AMXTypeInContext(LLVMContextRef C);
-
 /**
  * Create a token type in a context.
  */
@@ -1528,7 +1494,6 @@ LLVMTypeRef LLVMMetadataTypeInContext(LLVMContextRef C);
 LLVMTypeRef LLVMVoidType(void);
 LLVMTypeRef LLVMLabelType(void);
 LLVMTypeRef LLVMX86MMXType(void);
-LLVMTypeRef LLVMX86AMXType(void);
 
 /**
  * @}
@@ -1585,7 +1550,6 @@ LLVMTypeRef LLVMX86AMXType(void);
           macro(Function)                   \
           macro(GlobalVariable)             \
       macro(UndefValue)                     \
-      macro(PoisonValue)                    \
     macro(Instruction)                      \
       macro(UnaryOperator)                  \
       macro(BinaryOperator)                 \
@@ -1719,11 +1683,6 @@ LLVMBool LLVMIsConstant(LLVMValueRef Val);
  */
 LLVMBool LLVMIsUndef(LLVMValueRef Val);
 
-/**
- * Determine whether a value instance is poisonous.
- */
-LLVMBool LLVMIsPoison(LLVMValueRef Val);
-
 /**
  * Convert value instances between types.
  *
@@ -1882,13 +1841,6 @@ LLVMValueRef LLVMConstAllOnes(LLVMTypeRef Ty);
  */
 LLVMValueRef LLVMGetUndef(LLVMTypeRef Ty);
 
-/**
- * Obtain a constant value referring to a poison value of a type.
- *
- * @see llvm::PoisonValue::get()
- */
-LLVMValueRef LLVMGetPoison(LLVMTypeRef Ty);
-
 /**
  * Determine whether a value instance is null.
  *
diff --git a/src/llvm-c/DataTypes.h b/src/llvm-c/DataTypes.h
index 4eb0ac97d..0f27ba818 100644
--- a/src/llvm-c/DataTypes.h
+++ b/src/llvm-c/DataTypes.h
@@ -77,4 +77,8 @@ typedef signed int ssize_t;
 # define UINT64_MAX 0xffffffffffffffffULL
 #endif
 
+#ifndef HUGE_VALF
+#define HUGE_VALF (float)HUGE_VAL
+#endif
+
 #endif /* LLVM_C_DATATYPES_H */
diff --git a/src/llvm-c/DebugInfo.h b/src/llvm-c/DebugInfo.h
index 5a9cd8e2e..cdf5f5a0c 100644
--- a/src/llvm-c/DebugInfo.h
+++ b/src/llvm-c/DebugInfo.h
@@ -159,9 +159,7 @@ enum {
   LLVMDIImportedEntityMetadataKind,
   LLVMDIMacroMetadataKind,
   LLVMDIMacroFileMetadataKind,
-  LLVMDICommonBlockMetadataKind,
-  LLVMDIStringTypeMetadataKind,
-  LLVMDIGenericSubrangeMetadataKind
+  LLVMDICommonBlockMetadataKind
 };
 typedef unsigned LLVMMetadataKind;
 
diff --git a/src/llvm-c/Error.h b/src/llvm-c/Error.h
index bc702ac7a..92f81bf38 100644
--- a/src/llvm-c/Error.h
+++ b/src/llvm-c/Error.h
@@ -62,11 +62,6 @@ void LLVMDisposeErrorMessage(char *ErrMsg);
  */
 LLVMErrorTypeId LLVMGetStringErrorTypeId(void);
 
-/**
- * Create a StringError.
- */
-LLVMErrorRef LLVMCreateStringError(const char *ErrMsg);
-
 LLVM_C_EXTERN_C_END
 
 #endif
diff --git a/src/llvm-c/LinkTimeOptimizer.h b/src/llvm-c/LinkTimeOptimizer.h
index 104ac55c1..9ae65b8fe 100644
--- a/src/llvm-c/LinkTimeOptimizer.h
+++ b/src/llvm-c/LinkTimeOptimizer.h
@@ -15,7 +15,7 @@
 #ifndef LLVM_C_LINKTIMEOPTIMIZER_H
 #define LLVM_C_LINKTIMEOPTIMIZER_H
 
-#include "ExternC.h"
+#include "llvm-c/ExternC.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
diff --git a/src/llvm-c/OrcBindings.h b/src/llvm-c/OrcBindings.h
index 107305145..11cdade7c 100644
--- a/src/llvm-c/OrcBindings.h
+++ b/src/llvm-c/OrcBindings.h
@@ -22,10 +22,10 @@
 #ifndef LLVM_C_ORCBINDINGS_H
 #define LLVM_C_ORCBINDINGS_H
 
-#include "Error.h"
-#include "ExternC.h"
-#include "Object.h"
-#include "TargetMachine.h"
+#include "llvm-c/Error.h"
+#include "llvm-c/ExternC.h"
+#include "llvm-c/Object.h"
+#include "llvm-c/TargetMachine.h"
 
 LLVM_C_EXTERN_C_BEGIN
 
diff --git a/src/llvm-c/Transforms/IPO.h b/src/llvm-c/Transforms/IPO.h
index 3f2cadf32..cde3d2460 100644
--- a/src/llvm-c/Transforms/IPO.h
+++ b/src/llvm-c/Transforms/IPO.h
@@ -57,6 +57,9 @@ void LLVMAddGlobalDCEPass(LLVMPassManagerRef PM);
 /** See llvm::createGlobalOptimizerPass function. */
 void LLVMAddGlobalOptimizerPass(LLVMPassManagerRef PM);
 
+/** See llvm::createIPConstantPropagationPass function. */
+void LLVMAddIPConstantPropagationPass(LLVMPassManagerRef PM);
+
 /** See llvm::createPruneEHPass function. */
 void LLVMAddPruneEHPass(LLVMPassManagerRef PM);
 
diff --git a/src/llvm-c/Transforms/Scalar.h b/src/llvm-c/Transforms/Scalar.h
index ba142508b..93d79a205 100644
--- a/src/llvm-c/Transforms/Scalar.h
+++ b/src/llvm-c/Transforms/Scalar.h
@@ -67,9 +67,6 @@ void LLVMAddIndVarSimplifyPass(LLVMPassManagerRef PM);
 /** See llvm::createInstructionCombiningPass function. */
 void LLVMAddInstructionCombiningPass(LLVMPassManagerRef PM);
 
-/** See llvm::createInstSimplifyLegacyPass function. */
-void LLVMAddInstructionSimplifyPass(LLVMPassManagerRef PM);
-
 /** See llvm::createJumpThreadingPass function. */
 void LLVMAddJumpThreadingPass(LLVMPassManagerRef PM);
 
@@ -128,6 +125,9 @@ void LLVMAddSimplifyLibCallsPass(LLVMPassManagerRef PM);
 /** See llvm::createTailCallEliminationPass function. */
 void LLVMAddTailCallEliminationPass(LLVMPassManagerRef PM);
 
+/** See llvm::createConstantPropagationPass function. */
+void LLVMAddConstantPropagationPass(LLVMPassManagerRef PM);
+
 /** See llvm::demotePromoteMemoryToRegisterPass function. */
 void LLVMAddDemoteMemoryToRegisterPass(LLVMPassManagerRef PM);