diff --git a/.gitmodules b/.gitmodules
index a327aaa8d5a34..8f4d3768c21e8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -37,7 +37,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/10.0-2020-05-05
+	branch = rustc/11.0-2020-08-20
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
 	url = https://github.com/rust-embedded/book.git
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-linux/build-clang.sh b/src/ci/docker/host-x86_64/dist-x86_64-linux/build-clang.sh
index 2c00a628a1d35..d6ce2806e390f 100755
--- a/src/ci/docker/host-x86_64/dist-x86_64-linux/build-clang.sh
+++ b/src/ci/docker/host-x86_64/dist-x86_64-linux/build-clang.sh
@@ -18,17 +18,7 @@ cd clang-build
 # For whatever reason the default set of include paths for clang is different
 # than that of gcc. As a result we need to manually include our sysroot's
 # include path, /rustroot/include, to clang's default include path.
-#
-# Alsow there's this weird oddity with gcc where there's an 'include-fixed'
-# directory that it generates. It turns out [1] that Centos 5's headers are so
-# old that they're incompatible with modern C semantics. While gcc automatically
-# fixes that clang doesn't account for this. Tell clang to manually include the
-# fixed headers so we can successfully compile code later on.
-#
-# [1]: https://sourceware.org/ml/crossgcc/2008-11/msg00028.html
-INC="/rustroot/include"
-INC="$INC:/rustroot/lib/gcc/x86_64-unknown-linux-gnu/5.5.0/include-fixed"
-INC="$INC:/usr/include"
+INC="/rustroot/include:/usr/include"
 
 hide_output \
     cmake ../llvm \
diff --git a/src/llvm-project b/src/llvm-project
index 86b120e6f302d..45790d79496be 160000
--- a/src/llvm-project
+++ b/src/llvm-project
@@ -1 +1 @@
-Subproject commit 86b120e6f302d39cd6973b6391fb299d7bc22122
+Subproject commit 45790d79496be37fbce6ec57abad5af8fa7a34d7
diff --git a/src/rustllvm/CoverageMappingWrapper.cpp b/src/rustllvm/CoverageMappingWrapper.cpp
index 4d15e31df15a3..81aba0cbf7d42 100644
--- a/src/rustllvm/CoverageMappingWrapper.cpp
+++ b/src/rustllvm/CoverageMappingWrapper.cpp
@@ -3,6 +3,7 @@
 #include "llvm/ProfileData/Coverage/CoverageMappingWriter.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/LEB128.h"
 
 #include <iostream>
 
@@ -12,14 +13,15 @@ extern "C" void LLVMRustCoverageWriteFilenamesSectionToBuffer(
     const char* const Filenames[],
     size_t FilenamesLen,
     RustStringRef BufferOut) {
-  SmallVector<StringRef,32> FilenameRefs;
+  // LLVM 11's CoverageFilenamesSectionWriter uses its new `Version4` format,
+  // so we're manually writing the `Version3` format ourselves.
+  RawRustStringOstream OS(BufferOut);
+  encodeULEB128(FilenamesLen, OS);
   for (size_t i = 0; i < FilenamesLen; i++) {
-    FilenameRefs.push_back(StringRef(Filenames[i]));
+    StringRef Filename(Filenames[i]);
+    encodeULEB128(Filename.size(), OS);
+    OS << Filename;
   }
-  auto FilenamesWriter = coverage::CoverageFilenamesSectionWriter(
-    makeArrayRef(FilenameRefs));
-  RawRustStringOstream OS(BufferOut);
-  FilenamesWriter.write(OS);
 }
 
 extern "C" void LLVMRustCoverageWriteMappingToBuffer(
@@ -64,5 +66,5 @@ extern "C" void LLVMRustCoverageWriteMappingVarNameToString(RustStringRef Str) {
 }
 
 extern "C" uint32_t LLVMRustCoverageMappingVersion() {
-  return coverage::CovMapVersion::CurrentVersion;
+  return coverage::CovMapVersion::Version3;
 }
diff --git a/src/test/assembly/asm/riscv-types.rs b/src/test/assembly/asm/riscv-types.rs
index 6b6e582442cbc..67dda1024fc24 100644
--- a/src/test/assembly/asm/riscv-types.rs
+++ b/src/test/assembly/asm/riscv-types.rs
@@ -55,7 +55,8 @@ pub unsafe fn sym_fn() {
 
 // CHECK-LABEL: sym_static:
 // CHECK: #APP
-// CHECK: lb t0, extern_static
+// CHECK: auipc t0, %pcrel_hi(extern_static)
+// CHECK: lb t0, %pcrel_lo(.Lpcrel_hi0)(t0)
 // CHECK: #NO_APP
 #[no_mangle]
 pub unsafe fn sym_static() {
@@ -98,45 +99,45 @@ macro_rules! check_reg {
 
 // CHECK-LABEL: reg_i8:
 // CHECK: #APP
-// CHECK: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// CHECK: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // CHECK: #NO_APP
 check!(reg_i8 i8 reg "mv");
 
 // CHECK-LABEL: reg_i16:
 // CHECK: #APP
-// CHECK: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// CHECK: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // CHECK: #NO_APP
 check!(reg_i16 i16 reg "mv");
 
 // CHECK-LABEL: reg_i32:
 // CHECK: #APP
-// CHECK: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// CHECK: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // CHECK: #NO_APP
 check!(reg_i32 i32 reg "mv");
 
 // CHECK-LABEL: reg_f32:
 // CHECK: #APP
-// CHECK: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// CHECK: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // CHECK: #NO_APP
 check!(reg_f32 f32 reg "mv");
 
 // riscv64-LABEL: reg_i64:
 // riscv64: #APP
-// riscv64: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// riscv64: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // riscv64: #NO_APP
 #[cfg(riscv64)]
 check!(reg_i64 i64 reg "mv");
 
 // riscv64-LABEL: reg_f64:
 // riscv64: #APP
-// riscv64: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// riscv64: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // riscv64: #NO_APP
 #[cfg(riscv64)]
 check!(reg_f64 f64 reg "mv");
 
 // CHECK-LABEL: reg_ptr:
 // CHECK: #APP
-// CHECK: mv {{[a-z0-9]+}}, {{[a-z0-9]+}}
+// CHECK: add {{[a-z0-9]+}}, zero, {{[a-z0-9]+}}
 // CHECK: #NO_APP
 check!(reg_ptr ptr reg "mv");
 
@@ -154,45 +155,45 @@ check!(freg_f64 f64 freg "fmv.d");
 
 // CHECK-LABEL: a0_i8:
 // CHECK: #APP
-// CHECK: mv a0, a0
+// CHECK: add a0, zero, a0
 // CHECK: #NO_APP
 check_reg!(a0_i8 i8 "a0" "mv");
 
 // CHECK-LABEL: a0_i16:
 // CHECK: #APP
-// CHECK: mv a0, a0
+// CHECK: add a0, zero, a0
 // CHECK: #NO_APP
 check_reg!(a0_i16 i16 "a0" "mv");
 
 // CHECK-LABEL: a0_i32:
 // CHECK: #APP
-// CHECK: mv a0, a0
+// CHECK: add a0, zero, a0
 // CHECK: #NO_APP
 check_reg!(a0_i32 i32 "a0" "mv");
 
 // CHECK-LABEL: a0_f32:
 // CHECK: #APP
-// CHECK: mv a0, a0
+// CHECK: add a0, zero, a0
 // CHECK: #NO_APP
 check_reg!(a0_f32 f32 "a0" "mv");
 
 // riscv64-LABEL: a0_i64:
 // riscv64: #APP
-// riscv64: mv a0, a0
+// riscv64: add a0, zero, a0
 // riscv64: #NO_APP
 #[cfg(riscv64)]
 check_reg!(a0_i64 i64 "a0" "mv");
 
 // riscv64-LABEL: a0_f64:
 // riscv64: #APP
-// riscv64: mv a0, a0
+// riscv64: add a0, zero, a0
 // riscv64: #NO_APP
 #[cfg(riscv64)]
 check_reg!(a0_f64 f64 "a0" "mv");
 
 // CHECK-LABEL: a0_ptr:
 // CHECK: #APP
-// CHECK: mv a0, a0
+// CHECK: add a0, zero, a0
 // CHECK: #NO_APP
 check_reg!(a0_ptr ptr "a0" "mv");
 
diff --git a/src/test/codegen/scalar-pair-bool.rs b/src/test/codegen/scalar-pair-bool.rs
index d91ee7f816ded..4704c8ad797d8 100644
--- a/src/test/codegen/scalar-pair-bool.rs
+++ b/src/test/codegen/scalar-pair-bool.rs
@@ -24,8 +24,9 @@ pub fn pair_i32_bool(pair: (i32, bool)) -> (i32, bool) {
 #[no_mangle]
 pub fn pair_and_or((a, b): (bool, bool)) -> (bool, bool) {
     // Make sure it can operate directly on the unpacked args
-    // CHECK: and i1 %_1.0, %_1.1
-    // CHECK: or i1 %_1.0, %_1.1
+    // (but it might not be using simple and/or instructions)
+    // CHECK-DAG: %_1.0
+    // CHECK-DAG: %_1.1
     (a && b, a || b)
 }
 
diff --git a/src/test/run-make-fulldeps/instrument-coverage/expected_export_coverage.json b/src/test/run-make-fulldeps/instrument-coverage/expected_export_coverage.json
index 5881cf4b7dbbc..75bec80bdf886 100644
--- a/src/test/run-make-fulldeps/instrument-coverage/expected_export_coverage.json
+++ b/src/test/run-make-fulldeps/instrument-coverage/expected_export_coverage.json
@@ -55,5 +55,5 @@
     }
   ],
   "type": "llvm.coverage.json.export",
-  "version": "2.0.0"
+  "version": "2.0.1"
 }