Index: include/llvm/IR/DiagnosticInfo.h
===================================================================
--- include/llvm/IR/DiagnosticInfo.h
+++ include/llvm/IR/DiagnosticInfo.h
@@ -34,7 +34,7 @@
 class SMDiagnostic;
 
 /// \brief Defines the different supported severity of a diagnostic.
-enum DiagnosticSeverity {
+enum DiagnosticSeverity : char {
   DS_Error,
   DS_Warning,
   DS_Remark,
Index: include/llvm/IR/LLVMContext.h
===================================================================
--- include/llvm/IR/LLVMContext.h
+++ include/llvm/IR/LLVMContext.h
@@ -29,6 +29,7 @@
 class DICompositeType;
 class SMDiagnostic;
 class DiagnosticInfo;
+enum DiagnosticSeverity : char;
 template <typename T> class SmallVectorImpl;
 class Function;
 class DebugLoc;
@@ -172,6 +173,10 @@
   /// setDiagnosticContext.
   void *getDiagnosticContext() const;
 
+  /// \brief Get the prefix that should be printed in front of a diagnostic of
+  ///        the given \p Severity
+  static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity);
+
   /// \brief Report a message to the currently installed diagnostic handler.
   ///
   /// This function returns, in particular in the case of error reporting
Index: lib/IR/LLVMContext.cpp
===================================================================
--- lib/IR/LLVMContext.cpp
+++ lib/IR/LLVMContext.cpp
@@ -231,7 +231,8 @@
   return true;
 }
 
-static const char *getDiagnosticMessagePrefix(DiagnosticSeverity Severity) {
+const char *
+LLVMContext::getDiagnosticMessagePrefix(DiagnosticSeverity Severity) {
   switch (Severity) {
   case DS_Error:
     return "error";
Index: test/CodeGen/AArch64/arm64-inline-asm-error-I.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-I.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-I.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AArch64/arm64-inline-asm-error-J.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-J.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-J.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AArch64/arm64-inline-asm-error-K.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-K.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-K.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AArch64/arm64-inline-asm-error-L.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-L.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-L.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AArch64/arm64-inline-asm-error-M.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-M.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-M.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AArch64/arm64-inline-asm-error-N.ll
===================================================================
--- test/CodeGen/AArch64/arm64-inline-asm-error-N.ll
+++ test/CodeGen/AArch64/arm64-inline-asm-error-N.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=arm64 < %s  2> %t
+; RUN: not llc -march=arm64 -exit-on-error < %s  2> %t
 ; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
 
 ; Check for at least one invalid constant.
Index: test/CodeGen/AMDGPU/call.ll
===================================================================
--- test/CodeGen/AMDGPU/call.ll
+++ test/CodeGen/AMDGPU/call.ll
@@ -1,6 +1,6 @@
-; RUN: not llc -march=amdgcn -mcpu=SI -verify-machineinstrs< %s 2>&1 | FileCheck %s
-; RUN: not llc -march=amdgcn -mcpu=tonga -verify-machineinstrs< %s 2>&1 | FileCheck %s
-; RUN: not llc -march=r600 -mcpu=cypress < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=SI -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=r600 -mcpu=cypress -exit-on-error < %s 2>&1 | FileCheck %s
 
 ; CHECK: in function test_call_external{{.*}}: unsupported call to function external_function
 
Index: test/CodeGen/AMDGPU/dynamic_stackalloc.ll
===================================================================
--- test/CodeGen/AMDGPU/dynamic_stackalloc.ll
+++ test/CodeGen/AMDGPU/dynamic_stackalloc.ll
@@ -1,6 +1,6 @@
-; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=+promote-alloca -verify-machineinstrs < %s 2>&1 | FileCheck %s
-; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=-promote-alloca -verify-machineinstrs < %s 2>&1 | FileCheck %s
-; RUN: not llc -march=r600 -mcpu=cypress < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=+promote-alloca -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=-promote-alloca -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=r600 -mcpu=cypress -exit-on-error < %s 2>&1 | FileCheck %s
 
 ; CHECK: in function test_dynamic_stackalloc{{.*}}: unsupported dynamic alloca
 
Index: test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll
===================================================================
--- test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll
+++ test/CodeGen/AMDGPU/no-hsa-graphics-shaders.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=amdgcn -mtriple=amdgcn-unknown-amdhsa < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mtriple=amdgcn-unknown-amdhsa -exit-on-error < %s 2>&1 | FileCheck %s
 
 ; CHECK: in function pixel_s{{.*}}: unsupported non-compute shaders with HSA
 define amdgpu_ps void @pixel_shader() #0 {
Index: test/CodeGen/AMDGPU/private-memory-broken.ll
===================================================================
--- test/CodeGen/AMDGPU/private-memory-broken.ll
+++ test/CodeGen/AMDGPU/private-memory-broken.ll
@@ -1,5 +1,5 @@
-; RUN: not llc -verify-machineinstrs -march=amdgcn -mcpu=SI %s -o /dev/null 2>&1 | FileCheck %s
-; RUN: not llc -verify-machineinstrs -march=amdgcn -mcpu=tonga %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: not llc -verify-machineinstrs -march=amdgcn -mcpu=SI -exit-on-error %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: not llc -verify-machineinstrs -march=amdgcn -mcpu=tonga -exit-on-error %s -o /dev/null 2>&1 | FileCheck %s
 
 ; Make sure promote alloca pass doesn't crash
 
Index: test/CodeGen/AMDGPU/promote-alloca-bitcast-function.ll
===================================================================
--- test/CodeGen/AMDGPU/promote-alloca-bitcast-function.ll
+++ test/CodeGen/AMDGPU/promote-alloca-bitcast-function.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=amdgcn < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -exit-on-error < %s 2>&1 | FileCheck %s
 
 ; Make sure that AMDGPUPromoteAlloca doesn't crash if the called
 ; function is a constantexpr cast of a function.
Index: test/CodeGen/ARM/2012-09-25-InlineAsmScalarToVectorConv2.ll
===================================================================
--- test/CodeGen/ARM/2012-09-25-InlineAsmScalarToVectorConv2.ll
+++ test/CodeGen/ARM/2012-09-25-InlineAsmScalarToVectorConv2.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -mtriple=arm-eabi -mcpu=cortex-a8 %s -o - 2>&1 | FileCheck %s
+; RUN: not llc -mtriple=arm-eabi -mcpu=cortex-a8 -exit-on-error %s -o - 2>&1 | FileCheck %s
 
 ; Check for error message:
 ; CHECK: scalar-to-vector conversion failed, possible invalid constraint for vector type
Index: test/CodeGen/BPF/many_args1.ll
===================================================================
--- test/CodeGen/BPF/many_args1.ll
+++ test/CodeGen/BPF/many_args1.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=bpf < %s 2> %t1
+; RUN: not llc -march=bpf -exit-on-error < %s 2> %t1
 ; RUN: FileCheck %s < %t1
 ; CHECK: too many args
 
Index: test/CodeGen/BPF/many_args2.ll
===================================================================
--- test/CodeGen/BPF/many_args2.ll
+++ test/CodeGen/BPF/many_args2.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=bpf < %s 2> %t1
+; RUN: not llc -march=bpf -exit-on-error < %s 2> %t1
 ; RUN: FileCheck %s < %t1
 ; CHECK: too many args
 
Index: test/CodeGen/BPF/struct_ret1.ll
===================================================================
--- test/CodeGen/BPF/struct_ret1.ll
+++ test/CodeGen/BPF/struct_ret1.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=bpf < %s 2> %t1
+; RUN: not llc -march=bpf -exit-on-error < %s 2> %t1
 ; RUN: FileCheck %s < %t1
 ; CHECK: only integer returns
 
Index: test/CodeGen/BPF/struct_ret2.ll
===================================================================
--- test/CodeGen/BPF/struct_ret2.ll
+++ test/CodeGen/BPF/struct_ret2.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=bpf < %s 2> %t1
+; RUN: not llc -march=bpf -exit-on-error < %s 2> %t1
 ; RUN: FileCheck %s < %t1
 ; CHECK: only small returns
 
Index: test/CodeGen/MIR/Generic/invalid-jump-table-kind.mir
===================================================================
--- test/CodeGen/MIR/Generic/invalid-jump-table-kind.mir
+++ test/CodeGen/MIR/Generic/invalid-jump-table-kind.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 
 --- |
 
Index: test/CodeGen/MIR/Generic/llvm-ir-error-reported.mir
===================================================================
--- test/CodeGen/MIR/Generic/llvm-ir-error-reported.mir
+++ test/CodeGen/MIR/Generic/llvm-ir-error-reported.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 # This test ensures an error is reported if the embedded LLVM IR contains an
 # error.
 
Index: test/CodeGen/MIR/Generic/machine-function-missing-function.mir
===================================================================
--- test/CodeGen/MIR/Generic/machine-function-missing-function.mir
+++ test/CodeGen/MIR/Generic/machine-function-missing-function.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 # This test ensures that an error is reported when the mir file has LLVM IR and
 # one of the machine functions has a name that doesn't match any function in
 # the LLVM IR.
Index: test/CodeGen/MIR/Generic/machine-function-missing-name.mir
===================================================================
--- test/CodeGen/MIR/Generic/machine-function-missing-name.mir
+++ test/CodeGen/MIR/Generic/machine-function-missing-name.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 # This test ensures that an error is reported when a machine function doesn't
 # have a name attribute.
 
Index: test/CodeGen/MIR/Generic/machine-function-redefinition-error.mir
===================================================================
--- test/CodeGen/MIR/Generic/machine-function-redefinition-error.mir
+++ test/CodeGen/MIR/Generic/machine-function-redefinition-error.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 # This test ensures that the machine function errors are reported correctly.
 
 ---
Index: test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-aliased.mir
===================================================================
--- test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-aliased.mir
+++ test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-aliased.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 
 --- |
 
Index: test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-immutable.mir
===================================================================
--- test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-immutable.mir
+++ test/CodeGen/MIR/X86/spill-slot-fixed-stack-object-immutable.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 
 --- |
 
Index: test/CodeGen/MIR/X86/variable-sized-stack-object-size-error.mir
===================================================================
--- test/CodeGen/MIR/X86/variable-sized-stack-object-size-error.mir
+++ test/CodeGen/MIR/X86/variable-sized-stack-object-size-error.mir
@@ -1,4 +1,4 @@
-# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -o /dev/null %s 2>&1 | FileCheck %s
+# RUN: not llc -march=x86-64 -start-after branch-folder -stop-after branch-folder -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 --- |
 
   define i32 @test(i32 %a) {
Index: test/CodeGen/PowerPC/crbit-asm-disabled.ll
===================================================================
--- test/CodeGen/PowerPC/crbit-asm-disabled.ll
+++ test/CodeGen/PowerPC/crbit-asm-disabled.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -mcpu=pwr7 -o /dev/null %s 2>&1 | FileCheck %s
+; RUN: not llc -mcpu=pwr7 -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 target datalayout = "E-m:e-i64:64-n32:64"
 target triple = "powerpc64-unknown-linux-gnu"
 
Index: test/CodeGen/PowerPC/vec-asm-disabled.ll
===================================================================
--- test/CodeGen/PowerPC/vec-asm-disabled.ll
+++ test/CodeGen/PowerPC/vec-asm-disabled.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -mcpu=pwr7 -o /dev/null %s 2>&1 | FileCheck %s
+; RUN: not llc -mcpu=pwr7 -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 target datalayout = "E-m:e-i64:64-n32:64"
 target triple = "powerpc64-unknown-linux-gnu"
 
Index: test/CodeGen/X86/asm-reject-reg-type-mismatch.ll
===================================================================
--- test/CodeGen/X86/asm-reject-reg-type-mismatch.ll
+++ test/CodeGen/X86/asm-reject-reg-type-mismatch.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -o /dev/null %s 2>&1 | FileCheck %s
+; RUN: not llc -exit-on-error -o /dev/null %s 2>&1 | FileCheck %s
 target triple = "x86_64--"
 
 ; CHECK: error: couldn't allocate output register for constraint '{ax}'
Index: tools/llc/llc.cpp
===================================================================
--- tools/llc/llc.cpp
+++ tools/llc/llc.cpp
@@ -25,6 +25,8 @@
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LegacyPassManager.h"
@@ -111,6 +113,11 @@
     cl::desc("Discard names from Value (other than GlobalValue)."),
     cl::init(false), cl::Hidden);
 
+static cl::opt<bool> ExitOnError(
+    "exit-on-error",
+    cl::desc("Exit as soon as an error is encountered."),
+    cl::init(false), cl::Hidden);
+
 static int compileModule(char **, LLVMContext &);
 
 static std::unique_ptr<tool_output_file>
@@ -181,6 +188,17 @@
   return FDOut;
 }
 
+static void DiagnosticHandler(const DiagnosticInfo &DI, void *Context) {
+  bool *HasError = static_cast<bool *>(Context);
+  if (DI.getSeverity() == DS_Error)
+    *HasError = true;
+
+  DiagnosticPrinterRawOStream DP(errs());
+  errs() << LLVMContext::getDiagnosticMessagePrefix(DI.getSeverity()) << ": ";
+  DI.print(DP);
+  errs() << "\n";
+}
+
 // main - Entry point for the llc compiler.
 //
 int main(int argc, char **argv) {
@@ -215,6 +233,12 @@
 
   Context.setDiscardValueNames(DiscardValueNames);
 
+  // Set a diagnostic handler that doesn't exit on the first error
+  if (!ExitOnError) {
+    bool HasError = false;
+    Context.setDiagnosticHandler(DiagnosticHandler, &HasError);
+  }
+
   // Compile the module TimeCompilations times to give better compile time
   // metrics.
   for (unsigned I = TimeCompilations; I; --I)
@@ -441,6 +465,12 @@
 
     PM.run(*M);
 
+    if (!ExitOnError) {
+      auto HasError = *static_cast<bool *>(Context.getDiagnosticContext());
+      if (HasError)
+        return 1;
+    }
+
     // Compare the two outputs and make sure they're the same
     if (CompileTwice) {
       if (Buffer.size() != CompileTwiceBuffer.size() ||